L'ordre des rongeurs (Rodentia) est le groupe de mammifères le plus riche en espèces, les muroïdes étant la superfamille la plus diversifiée. Comme ils occupent des niches écologiques arboricoles, semi-aquatiques, souterraines et terrestres, les rongeurs peuvent présenter des traits morphologiques reflétant leurs adaptations à des environnements aussi divers. Cette thèse porte sur la morphologie de l'endocrâne, de la bulle auditive et de la cochlée dans trois tribus (Otomyini, Taterillini et Gerbillini) représentant 10 espèces de rongeurs africains, en se concentrant sur la variabilité de ces traits, leur fonction et leur adaptabilité, à l'aide d'imagerie par micro-scanner et de méthodes de comparaison de formes tridimensionnelles. De plus, les variations de la taille du crâne ont également été étudiées en fonction du réchauffement climatique et des variables climatiques. Les changements / variations morphologiques sont liées à des différences environnementales. Par conséquent, chaque chapitre de cette étude détaille l'effet des changements environnementaux (dans l'espace et dans le temps) sur différents traits morphologiques, c'est-à-dire la taille générale du crâne (chapitre 2), la cochlée et les bulles auditives (chapitre 3), et la taille et la forme endocrânienne (chapitre 4). Le chapitre 2 traite spécifiquement du changement climatique au sens strict et les deux autres chapitres traitent de différents gradients environnementaux. Le chapitre 2 teste l'applicabilité de la "troisième réponse universelle au réchauffement" (c'est-à-dire de la diminution de la taille corporelle) et de la "règle des ressource" dans deux sous-familles de muridés, Murinae et Gerbillinae. L'étude montre que la troisième réponse n'est pas universelle puisqu'une seule espèce s'est conformée à ce type de réponse. De plus, il a été démontré que la disponibilité de nourriture (règle des ressources) était un facteur plus important que la règle de Bergmann pour expliquer les corrélations entre variations de l'environnement et celles de la taille des espèces de rongeurs.[...] / The order Rodentia is the most speciose group of mammals with muroids being the most diverse superfamily. Since they are represented in arboreal, semiaquatic, subterranean and terrestrial niches, rodents may exhibit morphological traits reflecting their adaptations to such diverse environments. This thesis focuses on the morphology of the endocranium, auditory bulla and cochlea in three tribes (Otomyini, Taterillini and Gerbillini) representing 10 species of African rodents, concentrating on their variability, function and adaptability, using micro-CT imaging and 3D shape comparative methods. Additionally, variations in cranial size were also studied in respective of global warming and climatic variables. Morphological changes/variations are a result of environmental change, therefore each chapter in this study details the effect of environmental change (in space and time) on different morphological traits i.e. general cranial size (chapter 2), cochlea and auditory bulla (chapter 3) and endocranial size and shape (chapter 4). With chapter 2 dealing specifically with climate change in its straict sense and the remaining two chapters looking at different environmental gradients. Chapter 2 tests the applicability of the "third universal response to warming" (i.e. declining body size) and the Resource Rule in two murid subfamilies, Murinae and Gerbillinae. The study shows that the third response is not as universal as only one species conformed to this response. Further, food availability (Resource Rule) was shown to be the more important factor correlated with body size variations in rodent species than Bergmann's Rule. [...]

Microtubules are tubular polymers that are involved in a variety of cellular processes such as cell movement, mitosis and intracellular transport. The dynamic behavior of microtubules makes this possible because all of these processes require quick responses. Embryonic stem (ES) cells were first isolated from mouse embryos and they have two unique characteristics; they can be kept undifferentiated for many passages with a stable karyotype and they can be differentiated into any type of cells under appropriate conditions. The pluripotency of ES cells, their ease of manipulation in culture, and their ability to contribute to the mouse germ-line provides us a model of differentiation both in vitro and in vivo. In my thesis I focused on the cell division and neuronal differentiation of ES cells and developed two methods to understand the effects of microtubule dynamics in spindle assembly and chromosome segregation and to reveal the roles of different Microtubule Associated Proteins (MAPs) in the neuronal morphology formation. In the first part, we developed a live-cell imaging method for ES cells to visualize, track and analyze the single cell behavior in a cell population over a time period. So far many techniques have been adapted and combined for imaging of cell lines, mainly for the cancer or immortalized ones. However, because ES cells are very prone to apoptosis, tend to form spheres and hard to stably label, it is quite tricky to image them in culture conditions. In our system, we combined the BAC-based gene expression with wide-field deconvolution microscopy for ES cells that are plated onto the laminin-511 coated surface and kept in CO2 independent culture conditions. This combined technique does not interfere with the growth of cells and keeps them healthy up to 24 hours on the microscope stage. In the second part, we analyzed the effects of MAPs chTOG, EB1, Kif18A and MCAK in the overall spindle morphology and mitotic progression in mES cells. For this purpose, we utilized our stable TUBB-GFP and H2A-GFP cell lines along with our live-cell imaging set-up to reveal the effects of the above-mentioned proteins and the interplay among each other. By using RNAi method we either single or co-depleted the genes by siRNAs and measured the spindle length and width in RNAi conditions. We further analyzed the mitotic progression in H2A-GFP cell line in terms of the metaphase timing and the percentage of chromosome segregation errors. Our results showed that, EB1 depletion did not cause any significant changes in the overall spindle morphology or in the metaphase timing. However, the co-depletion of EB1 with chTOG partially rescued the sichTOG specific mini-spindle phenotype. siKif18A produced longer spindles without any change in the spindle width. Surprisingly, the co-depletion of antagonistic chTOG and Kif18A proteins had additive effects on the spindle dynamics and on mitotic progression in a way that spindle assembly was severely disrupted by the absence of these two proteins and as a result of this, both metaphase timing and chromosome missegregation levels increased significantly. These results overall indicate that MAPs have important roles in the regulation of dynamic instability and these proteins have an interplay among each other to be able to control the morphology of the spindle as well as the correct segregation of chromosomes into daughter cells. In the last part, I will introduce you a new ES cell based differentiation and morphology model, which brings the advantages of high resolution imaging capacity, control over development and easy genetic manipulation and culturing. We have generated Tet-induced shRNA cell lines against chTOG, Kif18A and MCAK, which are also stably expressing TUBB-GFP. These labeled cells were mixed with unlabeled wild-type mES cells before differentiation at 1:1000 ratio and then they were differentiated into mouse cortical cells and spinal motor neurons. Our results showed that, all of the three genes could be successfully knocked-down by shRNA after 48 hours of Tet induction. After mixing the labeled and unlabeled cells, single neurons could be imaged at high resolution and their skeletons could be generated afterwards. The RNAi studies in shchTOG cell line showed that, the knock-down of this gene in early differentiation interferes with the neuronal differentiation.

Die vorliegende Arbeit wurde als kumulative Dissertation auf der Grundlage von in international anerkannten Zeitschriften mit Fachgutachtersystem (Peer-review-Verfahren) veröffentlichten Publikationen verfasst. Mit Hilfe eines neuen integrativen Ansatzes aus Morphologie und Molekulargenetik wurden Studien zur intraspezifischen Variabilität einzelner Vertreter der Familie Lymnaeidae (Schlammschnecken) durchgeführt, die Schlussfolgerungen darüber zulassen, welche Wertigkeit den in dieser Gruppe bisher für Taxonomie und Systematik verwendeten morphologischen und anatomischen Merkmalen überhaupt zugemessen werden sollte. Ein weiteres Ziel der Analysen war herauszufinden, inwiefern eigene Rekonstruktionen phylogenetischer Bäume, basierend auf Kern- und Mitochondrienmarkern, bisher bestehende Hypothesen zur Taxonomie und Systematik der Lymnaeidae bestätigen oder widerlegen. Erste eigene molekulargenetisch überprüfte morphologische Analysen bei paläarktischen Vertretern der Gattung Radix zeigen, dass die zur Artdifferenzierung etablierten Merkmale Gehäuseform, Mantelpigmentierung, Längenverhältnis der beiden Abschnitte des männlichen Kopulationsapparates (Praeputium und Phallotheca), Länge des Bursaductes und Form der Bursa copulatrix eine höhere innerartliche Variabilität aufweisen als eigentlich für die einzelnen Arten angenommen wurde. Sie sind, entgegen bisheriger Annahmen, zu einem großen Teil nicht artspezifisch. Molekulargenetisch deutlich unterscheidbare Arten können die gleiche Gehäuseform und Mantelpigmentierung aufweisen und sind oft auch mittels anatomischer Merkmale nicht eindeutig unterscheidbar. Es kann, auch anhand erster eigener Studien an anderen Vertretern der Familie Lymnaeidae, geschlussfolgert werden, dass von den meisten Malakologen bisher in diese Merkmale innerhalb der Schlammschnecken eine Bedeutung für Taxonomie und Systematik hineininterpretiert wurde, die sie offensichtlich auf Grund ihrer hohen Plastizität nicht besitzen. Die molekulargenetischen Methoden eröffnen hier neue Perspektiven für ihre Beurteilung sowie für die objektivere Abgrenzung von Arten und Gattungen. Auf der Basis der neuen Erkenntnisse über die Variabilität morphologischer Merkmale wurde für die mitteleuropäischen Vertreter der Gattung Radix ein neuer Bestimmungsschlüssel erarbeitet, der mehr Radix-Formen als bisher berücksichtigt. Bei molekulargenetischen Untersuchungen an Vertretern der Gattung Stagnicola konnte ein relativ hoher Prozentsatz an Hybridisierung festgestellt werden, was in der Praxis Konsequenzen für die Anwendung des Barcoding mit mitochondrialen Markern (COI und Cytochrom b) hat. / This work was written as cumulative doctoral thesis based on publications in peer reviewed international journals. Aim of the studies was to analyse the range of the intraspecific variability of some representatives of the family Lymnaeidae as well as to find out which value should be given to the morphological and anatomical characters used for taxonomy and systematics at all. For this a new integrative approach of morphology and molecular genetics was sought. It was also important to find out how own reconstructions of phylogenetic trees based on nuclear and mitochondrial markers confirm or refute existing views on taxonomy and systematics of the Lymnaeidae. First own morphological analyses of Palaearctic representatives of the genus Radix checked by molecular genetics reveal that shell morphology, mantle pigmentation, length ratio of Praeputium to penial sheath, length of the duct of the bursa copulatrix and shape of the bursa show more variability in this characteristics as recognised for these species in literature. They are, contrary to previous assumptions, to a large extent not specific for single species. With molecular genetic methods clearly distinguishable species may have the same shell morphology and mantle pigmentation and could be not clearly differentiated by anatomical characters in many cases. It can be concluded, also on the basis of own studies of other representatives of the family Lymnaeidae, that to these characters was given an importance for taxonomy and systematics by most of the malacologists that they obviously do not have because of their high plasticity. Molecular genetic methods allow a new interpretation of the importance of morphological and anatomical characters and a more objective definition of species and genera. Based on the new findings on variability of morphological characters a new determination key for the representatives of the genus Radix in central Europe was elaborated. It enables the determination of more Radix forms than it was previously possible with determination tools. Molecular genetic analyses of representatives of the genus Stagnicola revealed a high percentage of hybridisation. In practise, this has consequences for the application of barcoding on the base of mitochondrial markers (COI and cyt-b).

Borophosphates are intermediate compounds of systems MxOy–B2O3–P2O5–(H2O) (M = main group or transition metal) which contain complex anionic structures built of interconnected trigonal–planar BO3 and / or BO4 and PO4 groups and their partially protonated species. The main objective of the present work was to synthesize, characterize and to study the properties of new selected 3d transition metal borophosphates. The selected four elements are scandium (Sc), iron (Fe), cobalt (Co) and nickel (Ni) due to their interesting contributions to borophosphate structural chemistry. The mild hydrothermal method was employed for the syntheses. During the investigation of borophosphates containing alkali–metals and scandium, the following three compounds were prepared and structurally characterized: MISc[BP2O8(OH)] (MI = K, Rb), CsSc[B2P3O11(OH)3] The anionic partial structure of MISc[BP2O8(OH)] (MI = K, Rb) consists of the well known open–branched four–membered rings of alternating borate and phosphate tetrahedra (a loop–branched hexamer with B : P = 1 : 2). The anionic partial structure of CsSc[B2P3O11(OH)3] represents the new type of oligomer containing boron in three– and four– fold coordination (B : P = 2 : 3). This is also the first time that a BO3 group is not only linked to borate species but also to a phosphate tetrahedron. This kind of oligomer was already predicted for borates but was never observed. By this, CsSc[B2P3O11(OH)3] is a special compound with regard to the structural building principles of borates and borophosphates. The significant differences in the crystal structures of MISc[BP2O8(OH)] (MI = K, Rb) and CsSc[B2P3O11(OH)3] may be due to the higher coordination number of cesium. Thermal treatment (up to 1000 ºC) of these compounds resulted in white crystalline products containing new phases with unknown crystal structures. Besides the discovery of alkali–metal scandium borophosphates, five new alkali metal scandium hydrogenphosphates were synthesized and structurally characterized: Li2Sc[(PO4)(HPO4)], MISc(HPO4)2 (MI = K, Rb, Cs, NH4) It was already predicted that open framework scandium phosphates should be isotypes of the respective indium phosphates. It was also stated that there should be a whole family of scandium hydrogenphosphates as we were able to confirm with the five novel compounds. Our systematic study reveals the structural changes of the anionic partial frameworks with increasing ionic radii of the alkali–metal ion. With respect to the M―T connections (M = six coordinated central metal atom, T = four coordinated phosphorous atom) the channel size increases from 8–membered rings in Li2Sc[(PO4)(HPO4)] to 12–membered rings in MISc(HPO4)2 (MI = K, Rb, Cs, NH4). KSc(HPO4)2 exhibits a new structure type in the family of monohydrogenphosphates with the general formula MIMIII(HPO4)2. This provides further evidence that scandium is a suitable element for the synthesis of framework structures with different channel sizes. The observation that in analogy to MISc(HPO4)2 (MI = Rb, Cs, NH4) a compound exists where the MI site is replaced by H3O+ gives rise to the hope that ion exchange properties could be of interest in this class of compounds. In addition, the possible existence of further modifications (as reported for the element–combinations RbV, NH4V, RbFe, and CsIn) shoud be investigated by thermoanalytical and X–ray methods. The extensive studies on borophosphate containing the transition metals Fe, Co, Ni together with alkaline earth–metals (Mg, Ca, Sr, Ba) led to the preparation of 13 compounds containing the combination of two different divalent M1IIM2II ions: CaM2II[BP2O7(OH)3] (M2II = Fe, Ni), BaM2II[BP2O8(OH)] (M2II = Fe, Co), SrFe[BP2O8(OH)2], CaCo(H2O)[BP2O8(OH)]•H2O, M1II0.5M2II(H2O)2[BP2O8]•H2O (M1II0.5 = Ca, Sr, Ba; M2II = Fe, Co, Ni) The anionic partial structure of CaM2II[BP2O7(OH)3] (M2II = Fe, Ni) consists of a tetrahedral triple [BP2O7(OH)3]4-, built from a central (HO)2BO2 tetrahedron sharing common vertices with two (H0.5)OPO3 tetrahedra. The complex anions in the crystal structure of BaM2II[BP2O8(OH)] (M2II = Fe, Co) comprises open–branched four–membered rings, [B2P4O16(OH)2]8-, which are formed by alternating (HO)BO3 and PO4 tetrahedra sharing common corners with two additional PO4 branches. The interconnection of these complex anions with M2II coordination octahedra (M2II = Fe, Co, Ni) by sharing common corners results in overall three–dimensional frameworks which contain channels filled with the M1II ions (M1II = Ca, Ba). The anionic partial structure of SrFe[BP2O8(OH)2] is built from a central (HO)2BO2 tetrahedron sharing common vertices with two PO4 tetrahedra. Surprisingly, SrFe[BP2O8(OH)2] represents the first example in the structural chemistry of borophosphates where the charge of the anionic partial structure is balanced by a divalent and a trivalent species (MIIMIII). Although being a member of the M1IIM2II[BP2O8(OH)] family the crystal structure of CaCo(H2O)[BP2O8(OH)]•H2O is different. Interestingly, this is the first case in the borophosphate structural chemistry where dimers of cobalt coordination octahedra together with borophosphate oligomers form a (two–dimensional) layered structure. The helical borophosphates M1II0.5M2II(H2O)2[BP2O8]•H2O (M1II0.5 = Ca, Sr, Ba; M2II = Fe, Co, Ni) contain one–dimensional infinite loop–branched borophosphate helices built of alternatively distorted borate and phosphate tetrahedra. Up to now, the group of compounds with 1[BP2O8]3– helical chain anions has been synthesized only in combination with different cations MIMII and MIII (MI = Li, Na, K; MII = Mg, Mn, Fe, Co, Ni, Zn; MIII = Sc, In, Fe). The systematic investigation on helical borophosphates of transition metals (Fe, Co, Ni) and alkaline–earth metals showed that it is also possible to accommodate divalent metal cations within the structure without disturbing the anionic partial structure. It was not possible to find the completely ordered structural model for the compounds M1II0.5M2II(H2O)2[BP2O8]•H2O (M1II0.5 = Ca, Sr, Ba; M2II = Co) but the substructure presented shows good agreement with the ordered known helical borophosphate compounds. Interestingly, it was also possible to judge the “kind of superstructure” against the crystal morphology. Syntheses of one of the few examples of borophosphates containing layered anionic partial structures (63 net topology) containing transition metal cations (Fe, Co, Ni) was realized with 6 isotypic compounds: MII(H2O)2[B2P2O8(OH)2]•H2O (MII = Fe, Co, Ni, Ni0.5Co0.5, Ni0.8Zn0.2, Ni0.5Mg0.5) The compounds MII(H2O)2[B2P2O8(OH)2]•H2O (MII = Fe, Co, Ni) adopt the structure type of Mg(H2O)2[B2P2O8(OH)2]•H2O characterized by a two–dimensional borophosphate anion. Substitution on the transition metal sites was shown to be possible (Ni0.5Co0.5) realized for this structure type. With the synthesis of Ni0.8Zn0.2(H2O)2[B2P2O8(OH)2]•H2O and Ni0.5Mg0.5(H2O)2[B2P2O8(OH)2]•H2O it was also proved that magnetically diluted samples can be prepared in analogy to Mg1–x Cox(H2O)2[B2P2O8(OH)2]•H2O (x = 0.25). The thermal stability of these compounds is very similar with a slight shift to higher decomposition temperatures for the Ni0.5Mg0.5(H2O)2[B2P2O8(OH)2]•H2O. In contrast to other borophosphates such as MIMII(H2O)2[BP2O8]∙H2O and MIII(H2O)2[BP2O8]∙H2O, it is not possible to rehydrate partially dehydrated samples even though the crystal structure may suggest this property. This shows that the aqua–ligands significantly contribute to the stability of the structure. The magnetic behavior of MII(H2O)2[B2P2O8(OH)2]•H2O (MII = Fe, Ni) corresponds well with separated 3d ions without strong magnetic interactions down to 1.8 K. Quite surprising was the remarkable change in the crystal habit that was observed during the synthesis upon addition of alkali–metal cations. Syntheses with the absence of alkali–metals lead to a change in the crystal habit by reducing of the number of faces in direction of the more simple prismatic morphology. Our research on borophosphates containing mixed transition metals led to the preparation of a borophosphate and a phosphate: FeCo(H2O)[BP3O9(OH)4], Fe1.3Co0.7[P2O7]∙2H2O The anionic partial structure of FeCo(H2O)[BP3O9(OH)4] is an open–branched tetramer built from (HO)BO3 sharing common O–corners with one (HO)PO3, one (HO)2PO2 and one PO4 group. The crystal structure is an isotype to Mg2(H2O)[BP3O9(OH)4]. Fe1.3Co0.7[P2O7]∙2H2O contains the diphosphate composed of two corner–sharing tetrahedra (isotypic to MII[X2O7]∙2H2O (MII = Mg, Mn, Co, Fe and X = P, As). However, the crystal structure of both, FeCo(H2O)[BP3O9(OH)4] and Fe1.3Co0.7[P2O7]∙2H2O, contains octahedral zigzag chains, which are interconnected by the respective tetrahedral anions. The octahedral chains in these crystal structures are closely related to the octahedral arrangements in MIIH2P2O7 (MII = Co, Ni) which exhibit a field-induced metamagnetic behavior from an antiferromagnetic state to a ferromagnetic state and to MII[BPO4(OH)2] (MII = Mn, Fe, Co) which indicate a low-dimensional antiferromagnetic correlation of the MII ions by dominant exchange interactions within the one–dimensional octahedral chain structure. Therefore, due to the similar structural features, FeCo(H2O)[BP3O9(OH)4] and Fe1.3Co0.7[P2O7]∙2H2O may exhibit interesting magnetic properties. Thermal investigation revealed that both compounds are stable until 300 ºC and transform into pyrophosphates at higher temperatures. Fe1.3Co0.7[P2O7]∙2H2O represents the first hydrated mixed divalent cation diphosphate.

With respect to the principles of biomineralization, it is of interest to study the crystallization of calcium oxalates under various experimental conditions. Calcium oxalates play decisive roles as biominerals in plants and as pathological “urinary/kidney stones” in vertebrates. Calcium oxalate exists in three different hydration states; calcium oxalate monohydrate (COM, monoclinic, a = 6.290(1)Å, b = 14.583(1)Å, c = 10.116(1)Å, β = 109.46°, P21/c), calcium oxalate dihydrate (COD, tetragonal, a = b = 12.371(3)Å, c = 7.357(2)Å, α = β = γ = 90°, I4/m) and calcium oxalate trihydrate (COT, triclinic, a = 6.11(1)Å, b = 7.167(2)Å, c = 8.457(2)Å, α = 76.5(2)°, β = 70.35(2)°, γ = 70.62(2)°, P ). Monoclinic COM and tetragonal COD are the most common phyto-crystals and the main constituents of kidney and urinary stones. The occurrence of calcium oxalates in plants represents a useful biogenesis (protection against herbivores) unlike the devastating occurrence in renal tubules. Therefore, biomineralization can be physiological or pathological. A systematic investigation of the morphological evolution of calcium oxalates in the presence of organic components is essential for understanding the mechanism of “pathological biomineralization”. In order to understand the pathological biomineralization of uroliths, it is necessary grow calcium oxalates comparable in morphology under similar growth conditions. The formation of calcium oxalate stones within a gelatinous state of proteins, polysaccharides, lipids and other biomacromolecules under a flow of supersaturated urine supports the fact that an “organic” gel model can simulate the process of urinary stone formation under in vitro conditions. Furthermore, synthetic polymers with precisely known functions and solution behaviours are better choices to understand the interaction of acidic proteins with calcium oxalates. Therefore, as a first step to unravel the complex pathology of uro/nephro lithiasis, we started to examine the structure and morphology of calcium oxalates crystallized in the presence of organic additives such as the sodium salt of polyacrylic acid (PAA) as well as agar gel. The influence of initial calcium oxalate concentration, pH and concentration of the additives on the formation of hydration states of calcium oxalates have been investigated along with the stated general methods. Apart from the three hydrated forms, calcium oxalate exists also in the anhydrous form (COA). Although three modifications of COA (α, β and γ) are reported in the literatures, the crystal structures and phase transformations were controversially discussed. We have been able to reveal the crystal structure of the β-modification of the anhydrous calcium oxalate by a combination of atomistic simulations and Rietveld refinements on the basis of powder X-ray diffraction pattern. β-COA belongs to the monoclinic system with unit cell parameters, a = 6.1644(3)Å, b = 7.3623(2)Å, c = 9.5371(5)Å, β = 90.24(2)°, P2/m (No. 10). The dehydration of COM was mimicked in silico to receive an initial model of the crystal structure of anhydrous calcium oxalate. This general approach may also be accessible for other decomposition processes ending up with crystalline powders of unknown crystal structure. No evidence for transformations from or to the α- or γ- modifications was found during our investigations. The growth pattern of COD crystals precipitated from aqueous solutions in the presence of PAA is clearly dependent on the concentration of PAA. By increasing the concentration of PAA, the shape of COD has been found to change from tetragonal bi-pyramids with dominant (101) pyramidal faces to tetragonal prisms with dominant (100) prism faces and finally to dumbbells. At still higher PAA concentrations, the morphology is reverted back to rod-like tetragonal prisms. Apart from these experiments, the interaction of PAA with (100) and (101) crystal faces of COD was explored with the aid of atomistic simulations. The simulation confirmed that during the development of the aggregates, strong interactions of PAA with the (100) faces take over control of morphologies. Our investigations show that the inner architecture of all the morphological varieties of COD was found to be dominated by an inner “core” consisting of thin elongated crystallites together with incorporated PAA and an outer “shell” formed as a consequence of secondary nucleation processes. We propose that for all types of COD aggregates, relative proportion of calcium oxalate and PAA dictates the shape and formation of nanometer sized crystallites which then aggregate and align to form the core. Such cores enriched with PAA may act as the sites for secondary nucleation events of calcium oxalate crystallites which then cover the core like a shell. In vitro experimental models for the growth of calcium oxalates can give valuable information on the growth and aggregation of urinary stones. Therefore, the “double diffusion technique” in agar gel matrix has been used for the biomimetic growth of calcium oxalate (COM) stones. A great variety of morphological forms of COM are produced in agar gel matrices (2 wt.-% agar gel of pH 8.5) ranging from platy crystallites to dumbbells and spherulites. The COM dumbbells and spherulites are assumed to be formed by the aggregation of smaller crystallites as a consequence of increased supersaturation inside the gel. Moreover, an increase of the pH value of the agar gel has been found to suppress the growth of COM and favours the growth of COD. The morphology of COD crystals grown in 2 wt.-% agar gel of pH 11.5 includes tetragonal prisms and dumbbells. The system calcium oxalate/ PAA/ H2O is a suitable model system for the investigation of principles of biomineral growth (shape development) in general. Our results demonstrate that the double diffusion technique in agar gel is a convenient route to grow calcium oxalate aggregates showing close resemblance to biogenic calculi and to study their ontogeny.

L'objectif de cette thèse est de préparer des microsphères chargées en une protéine modèle, le lysozyme, en utilisant un nouveau copolymère pentabloc. La libération de protéine à partir des microsphères obtenues doit être continue et complète sur une période d’au moins un mois. Des copolymères pentabloc PLGA-P188-PLGA et une protéine modèle, le lysozyme, ont été utilisés. La présence du bloc central P188 la masse molaire du segment PLGA, le type de solvant, la concentration en polymère, la vitesse d’agitation de l’émulsion et la teneur en tensioactif ont tous un effet sur la porosité des microsphères. La teneur en tensioactif et la vitesse d'agitation ont principalement contribué au contrôle de la taille des particules. En ajustant les caractéristiques du segment PLGA et les paramètres du procédé, la libération de la protéine a été améliorée. Une libération prolongée et complète de protéines sur 8 semaines a été obtenue en suivant le modèle d’Higuchi. La modulation du profil de libération de la protéine a été obtenue par un mélange physique de différentes microsphères. Cette stratégie peut-être appliquée à une seule protéine ou dans le cadre d’une thérapie combinée. / The aim of this thesis is to formulate protein-loaded microspheres with penta-block copolymers for a sustained and completed protein release for at least one month. A new PLGA-P188-PLGA penta-block copolymers were used. The presence of a P188 central block facilitated the control of particle morphology and size. LA/GA ratio, the molecular weight of PLGA segment, solvent type, polymer concentration, emulsifying speed and surfactant content all affected microsphere porosity.The surfactant concentration and agitation speed principally contributed to particle size control. By adjusting the polymer characteristics and the process parameters, the protein release was improved remarkably. An 8-week completed and sustained protein release complying with the Higuchi model was achieved. The physical mixing of different microparticles was then studied for modulating release profile.The achievement of protein delivery with controlled release profile raised its applicability, especially for one protein sustained release or combined therapy.

A fundamental problem in biology is the reconstruction of the relatedness of all (extant) species. Traditionally, systematists employ visually recognizable characters of organisms for classification and evolutionary analysis. Recent developments in molecular and computational biology, however, lead to a whole different perspective on how to address the problem of inferring relatedness. The discovery of molecules, carrying genetic information, and the comparison of their primary structure has, in a rather short period of time, revolutionized our understanding of the phylogenetic relationship of many organisms. These novel approaches, however, turned out to bear similar problems as previous techniques. Moreover, they created new ones. Hence, taxonomists came to realize that even with this new type of data not all problematic relationships could be unambiguously resolved. The search for complementary approaches has led to the utilization of rare genomic changes and other characters which are largely independent from the primary structure of the underlying sequence(s). These “higher order” characters are thought to be evolutionary conserved in certain lineages and largely unaffected by primary sequence data-based problems, allowing for a better resolution of the Tree of Life. The central aim of this thesis is the utilization of molecular characters of higher order in connection with their consistent and comparable extraction from a given data set. Two novel methods are presented that allow such an inference. This is complemented with the search for and analysis of known and novel molecular characteristics to study the relationships among Metazoa, both intra- as well as interspecific. The first method tackles a common problem in phylogenetic analyses: the inference of reliable data set. As part of this thesis a pipeline was created for the automated annotation of metazoan mitochondrial genomes. Data thus obtained constitutes a reliable and standardized starting point for all downstream analyses, e.g. genome rearrangement studies. The second method utilizes a subclass of gaps, namely those which define an approximate split of a given data set. The definition and inference of such split-inducing indels (splids) is based on two basic principles. First, indels at the same position, i.e. sharing the same end points in two sequences, are likely homologous. Second, independent single-residue insertions and deletions tend to occur more frequently than multi-residue indels. It is shown that trees based on splids recover most of the undisputed monophyletic groups while influence of the underlying alignment algorithm is relatively small. Mitochondrial markers are a valuable tool for the understanding of small and large scale population structure. The non-coding control region of mitochondrial DNA (mtDNA) often contains a higher amount of variability compared to genes encoding proteins and non-coding RNAs. A case study on a small scale population structure investigates the control region of the European Fire-bellied Toad in order to find highly variable parts which are of potential importance to develop informative genetic markers. A particular focus is placed on the investigation of the evolutionary dynamics of the repetitive region at an inter- and intraspecific level. This includes understanding mechanisms underlying its evolution, i.e. by exploring the impact of secondary structure on slipped strand mispairing during mtDNA replication. The 7SK RNA is a key player in the regulation of polymerase II (Pol-II) transcription, interacting with at least three known proteins: It mediates the inhibition of the Positive Transcription Elongation Factor b (P-TEFb) by the HEXIM1/2 proteins, thereby repressing transcript elongation by Pol-II. A highly specific interaction with LARP7 (La-Related Protein 7), on the other hand, regulates its stability. 7SK RNA is capped at its 5’ end by a highly specific methyltransferase MePCE (Methylphosphate Capping Enzyme). Employing sequence and structure similarity it is shown that the 7SK RNA as well as its protein binding partners have a much earlier evolutionary origin than previously expected. Furthermore, this study presents a good illustration of the pitfalls of using markers of higher order for phylogenetic inference.

La luxation du coude, seconde luxation en termes de fréquence (luxations à la main exclues), est souvent compliquée d’une fracture de la tête radiale, parfois comminutive et inaccessible à une ostéosynthèse. Dans le contexte de lésions ligamentaires importantes associées, la simple résection de la tête radiale se solde habituellement par une instabilité articulaire grave. Le recours à l’hémi-arthroplastie est dans ces circonstances actuellement systématique.Plusieurs types de prothèses sont disponibles mais aucune d’entre elles ne reproduit exactement l’anatomie. Les prothèses en silicone étant abandonnées, l’engouement actuel est en faveur de prothèses métalliques qui, par leur rigidité, permettent un meilleur transfert des contraintes axiales tout en restaurant la stabilité en valgus. Trois types de prothèses sont disponibles, les prothèses monobloc (un seul composant articulé avec le capitulum), les prothèses modulaires (deux composants, cupule et tige de tailles variables pour s’adapter au mieux à l’anatomie du patient), et les prothèses bi-articulées offrant également une certaine modularité et comportant une articulation entre tige et cupule permettant une meilleure adaptabilité de cette dernière au capitulum et à l’incisure radiale de l’ulna dans les différents mouvements du coude et de l’avant-bras. Appartenant à cette dernière catégorie, la prothèse de Judet présente la particularité de posséder un col angulé de 15° pour s’adapter au mieux à l’anatomie variable des patients. Les résultats à court et moyen terme de ces implants sont généralement bons mais les résultats à long terme sont encore peu documentés.Dans une hémi-arthroplastie, une bonne adaptabilité de la prothèse implique une meilleure congruence articulaire et donc un transfert des forces sur une surface plus grande, avec moins de contraintes. L’arthroplastie la plus congruente est donc celle qui, potentiellement, induit le moins d’usure du capitulum. Les prothèses monopolaires sont décrites comme plus stable mais moins congruentes que les prothèses bipolaires.Les buts de la présente étude sont d’une part d’évaluer les modifications des surfaces de contact radio-capitulaire en fonction de différentes positions de flexion du coude et de rotation de l’avant-bras sur coude intact et de les comparer à celles obtenues avec trois différents types de prothèses de tête radiale (prothèse monopolaire, prothèse bipolaire simple et prothèse bipolaire de Judet). D’autre part, le travail évalue la stabilité du coude au cours de différents mouvements de flexion du coude et de rotation de l’avant-bras avant et après ces trois différents modes d’arthroplastie de la tête radiale.Les hypothèses de départ sont que les surfaces de contact diminuent après toute arthroplastie de tête radiale, la prothèse de Judet offrant de meilleures surfaces de contact pour une stabilité moindre, la prothèse monopolaire offrant une plus grande stabilité latérale pour des surfaces de contact moindres et la prothèse bipolaire droite conférant une stabilité et des surfaces articulaires de contact intermédiaires.Pour tester ces hypothèses, 12 membres supérieurs de cadavres frais ont été utilisés. Les surfaces de contact radio-capitulaire ont été évaluées par la réalisation de moulage de l’articulation avant et après arthroplastie de la tête radiale et la stabilité du coude a été évaluée par le biais d’une analyse du mouvement rendue possible par l’utilisation d’un système optoélectronique. Cinq variables ont ainsi pu être évaluées dans les états intact, après capsulectomie antérieure (nécessaire à la réalisation des moulages), après résection de la tête radiale et après la pose de chacune des trois prothèses de tête radiale.Il a été observé que les surfaces de contact radio-capitulaire chutaient après les arthroplasties de tête radiale sans pour autant qu’il n’y ait de distinction entre ces dernières. La position de supination offrait de meilleures surfaces de contact articulaires notamment par le biais d’un contact radio-conoïdien complémentaire au contact radio-capitulaire. Les prothèses bi-articulées présentaient une subluxation latérale de leur tête radiale en position neutre et cela s’accompagnait d’une diminution des surfaces articulaires de contact. L’analyse cinématique a permis de mettre en évidence que la réalisation d’une capsulectomie antérieure augmentait la laxité du coude en varus tout comme les arthroplasties de tête radiale et que la laxité du coude en valgus était augmentée après résection de la tête radiale.La laxité rotatoire du coude, dépendante de la rotation de l’avant-bras, était également augmentée par la capsulectomie antérieure et cet effet était majoré après les prothèses bi-articulées.Les stabilités latérale et rotatoire du coude en regard de la prothèse monopolaire se rapprochaient de celles observées en regard de la tête radiale native tandis que la stabilité du coude en regard des prothèses bi-articulées était un intermédiaire entre la stabilité observée dans la situation native et celle observée en l’absence de tête radiale.Les résultats de la présente étude plaident en faveur de l’utilisation de prothèses monopolaires qui semblent offrir une meilleure stabilité du coude ainsi qu’un meilleur contact articulaire en position neutre. Les mécanismes qui sous-tendent l’instabilité des prothèses bi-articulées ne sont pas clairs et l’exploitation d’autres paramètres issus de l’analyse cinématique pourrait permettre de mieux définir ces phénomènes d’instabilité. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished

Les polyuréthanes segmentés thermoplastiques (TPUs) sont des matériaux élastomères thermoplastiques qui couvrent une large gamme d’applications. Ces matériaux possèdent intrinsèquement une aptitude à la nano-structuration car ils présentent dans leur structure macromoléculaire une alternance de segments rigides et de segments souples thermodynamiquement immiscibles en dessous d’une certaine température (température de micro-mélange). Ainsi, en refroidissant à partir de l’état fondu, une micro-séparation de phase, dont la cinétique dépend de la température, se produit. De plus, l’application d’une déformation avant cette structuration modifie sa cinétique. Ainsi, en vue d’appréhender l’effet de la mise en oeuvre sur certaines propriétés de ces matériaux, il s’avère intéressant d’étudier l’influence de l’histoire thermomécanique sur la structuration. Cette étude repose sur l’observation du comportement de cristallisation et/ou de séparation de phase de cinq polyuréthanes commerciaux de nature chimique différente, en fonction de différentes conditions thermiques et mécaniques appliquées en milieu modèle ou en conditions de mise en oeuvre réelles. Les techniques utilisées sont principalement rhéologiques, rhéo-optiques et par diffusion de rayons X aux petits angles (SAXS). Ces différentes analyses permettent d’affirmer que les contraintes appliquées dans le fondu des matériaux avant leur solidification modifient de façon drastique la cinétique de structuration mais aussi leur morphologie résultante. En effet, une orientation particulière des entités structurées au sein des matériaux peut être engendrée par des contraintes appliquées en fonction de leur intensité. Cette morphologie résultante particulière joue également un rôle sur les propriétés mécaniques finales des matériaux. / Thermoplastic segmented polyurethanes are an important class of thermoplastic elastomers which cover a wide range of applications. These materials are multi-block copolymers composed of alternating “hard” and “soft” segments which are respectively below and above their glass transition temperature under ambient conditions. TPUs exhibit a twophase microstructure which arises from the thermodynamic incompatibility between the hard and soft segments. This microphase separation is often combined with the crystallization of either or both segments. The mechanical properties of these polymers will depend upon the overall multiblock length and the hard block sequence length and how they affect the material morphology. Our goal is to understand how the polyurethane final properties can be affected by the processing stresses (extrusion, injection…). In this scope, experiments were performed using a rheometer or an optical microscope coupled with a shearing hot stage. A preshear controlled treatment was applied and its effect on the material structuration was followed. These characterizations highlighted the enhancement of phase separation kinetics by the shear. For instance, for presheared samples, phase separation and/or crystallization of the hard segments occur ten times faster than for non-sheared ones. Moreover, SAXS experiments carried out on samples structured from several conditions illustrated perpendicular arrangements of crystalline domains perpendicularly to the flow direction. Finally, this particular morphology induced by shear modifies the materials final mechanical properties

Ce travail concerne l’élaboration, l’étude de la microstructure semicristalline et les propriétés de films de chitosane, envisagés pour le relargage de principes actifs. La microstructure semicristalline des films de chitosane influence fortement leurs propriétés physicochimiques et fonctionnelles. Dans ce contexte, nous avons réalisé une étude systématique par diffraction de rayons X en faisant varier différents paramètres structuraux de chitosane statistiques (DA) et les paramètres d’élaboration des films (l’état de neutralisation, la nature du contre-ion et le pourcentage d’eau dans les films avant neutralisation, et la situation de l’étape de neutralisation dans le procédé). Nous avons obtenus différentes microstructures semicristallines en terme d’allomorphes hydratés ou anhydres, en jouant sur les conditions plus ou moins hydrophobes au moment de la neutralisation. Par ailleurs, une étude de la mobilité moléculaire par spectroscopies diélectrique et mécanique a permis de mettre en évidence différentes relaxations secondaires, toujours en fonctions des paramètres physicochimiques qui conditionnent la balance des interactions hydrophiles/hydrophobes. De plus, la Spectroscopie mécanique a montré une transition réversible de comportement hydrophile / hydrophobe dépendant du traitement thermique appliqué. Cette étude nous a montré que le degré d’acétylation n’influence pas directement la mobilité moléculaire dans les films de chitosane, mais c’est encore la balance des interactions hydrophiles / hydrophobes qui gouverne la réponse viscoélastique et diélectrique. Finalement, nous avons réalisé une étude du gonflement de films de chitosane en relation avec les paramètres de mise en oeuvre. Les résultats sont reliés à la microstructure semicristalline. Le relargage de protéines a été abordé par l’étude d’une protéine modèle (Ovalbumine). La technique de dichroïsme circulaire a permis d’étudier les interactions ovalbumine/chitosane à l’état solide (dans le film) comme à l’état solution (après relargage). Les cinétiques de relargage ont été déterminées et discutées en fonction du gonflement et de la morphologie cristalline / This work concerns the elaboration, semicrystalline microstructure and properties study of chitosan films for application of release of active principle. The semicrystalline microstructure of chitosan films strongly influences their physicochemical and functional properties, so their control becomes very important for the aimed application. In this context, we have performed a systematic study by X-ray diffraction on chitosan films varying different parameters that influence their semicrystalline microstructure, particularly, the degree of acetylation, the elaboration routes, the neutralization state, the counter-ion nature and the water content before neutralization. We have achieved to control the semicrystalline microstructure by the combination of these parameters. Furthermore, the study of the molecular mobility behaviour was carried out showing the different relaxation processes present in the chitosan films. A viscoelastic study by mechanical spectroscopy showed hydrophilic/hydrophobic transitions as a function of he thermal treatment. This study showed that the degree of acetylation does not have a strong influence on the molecular mobility in the chitosane films. Finally, we have conducted a study of swelling of chitosan film in relation to the semicrystalline microstructure. Then, a model protein (Ovalbumin) has been incorporated to study its interaction with chitosan in the solid state (in the film) and in solution (after release) and in order to evaluate its release