Neuropeptide hormones arose early in evolution. Multigene families in vertebrates are proposed to have arisen initially in early vertebrates by genome duplication events. In its simplest form, the theory suggests that the copy of a duplicated, ancestral single gene diverged in sequence, and possibly function, from its original match. My goal was to understand the structural and functional evolution of two neuropeptides, gonadotropinreleasing hormone (GnRH), a member of a single gene family, and pituitary adenylate cyclase-activating polypeptide (PACAP), a member of a multigene superfamily of hormones. GnRH is the primary regulator of reproduction in vertebrates, but the evolutionary origin of GnRH is not clear. In the protochordate tunicate Ciona intestinalis, I found there are two genes that encode GnRH peptides, however each gene encodes different GnRH peptides. Furthermore, these peptides are novel structures for GnRH and quickly induce spawning in Ciona, suggesting a novel and direct action for GnRH in the control of reproduction. In studies of the novel form of GnRH in lake whitefish, wfGnRH, I provide proof wfGnRH is a gonadotropin-releasing form in whitefish by showing it to be an activator of pituitary gonadotropin and growth hormone gene expression, and is colocalized in the forebrain region. PACAP is a hormone structurally related to glucagon and has been tightly conserved in structure during evolution. PACAP is produced as either a 27 or a 38 amino acid form in vertebrates, whereas in one tunicate studied to date, PACAP is produced from each of two genes as a 27 amino acid form. PACAP regulates several endocrine systems and has direct and indirect actions on metabolism, growth, and reproduction, and is well-known for its ability to potently secrete insulin in laboratory testing. I studied a number of species to increase our understanding of PACAP gene diversity in evolution. I was unable to identify a PACAP-like gene in the tunicate species, C. intestinalis. However, I identified a number of novel PACAP peptide structures in nine fish species by molecular biological and bioinformatic approaches. I was able to identify a second copy of a PACAP gene in five of the nine species. Using these data, I constructed a phylogenetic relationship for prohormones for PACAP in chordates and propose a updated explanation for the evolution of the PACAPfglucagon superfamily of genes in vertebrates. Using morpholino-based knockdown of the PACAP peptides in zebrafish early development, I showed that each copy of these two genes is functional and important in normal development in zebrafish, suggesting that divergence in function of the two different PACAP genes coincided with divergence in sequence. I also studied mice to determine the proposed role for PACAP in themogulation. Recently, the pups born to a new model of mouse with a targeted disruption of the PACAP gene (PACAP-null) have been found to have disruption of normal lipid and carbohydrate metabolism and die early in the second postnatal week. Furthermore it has been determined this phenotype is temperature sensitive. I hypothesized that there is a disruption of the thyroid axis in these mice that contributes to their problems with thermogenesis, and because these mice have a compromised adrenergic response, they are more sensitive to obesity. I showed that there is twice as much of the active form of thyroid hormone (TH), 3,5,3'-triiodothyronine (T3), in PACAP-null mice compared to their wildtype littermates. Mice reared at different temperatures (21, 24 and 28 °C) had increased survival with increasing temperature from 14% surviving at 21°C to 79 % at 28°C, and mice held at 28°C had lower levels of THs compared to 21°C. Treatment of PACAP-null mice with methimizole decreased their level of T3 and increases their survival suggesting the levels of T3 in mice at 21°C are toxic. Mice raised at 28°C on one of two diets, regular chow (low fat) and high fat were studied for difference in appetite and in tolerance to obesity. There were no differences in either appetite or many obesity-related parameters such as mass, fed and fasted glucose levels, fat distribution or plasma levels of leptin in PACAP-null mice compared to their sex- and diet-matched wildtype comparison groups. However, there was an increase in insulin sensitivity in PACAP-null mice fed a high fat diet.

Tunicata umfasst 3000 marine Arten, mit sehr unterschiedlichen Lebensstrategien. Als eines der drei großen Taxa innerhalb der Chordata, stellt die Evolution der Tunikaten eine Schlüsselkomponente bei der Aufklärung der Evolution der Chordaten und Cranioten dar. Dafür ist ein Verständnis der Merkmalstransformationen innerhalb der Tunikaten notwendig. Leider sind die internen Verwandtschaftsverhältnisse der fünf großen Tunikatentaxa in verschiedenen molekularphylogenetischen Studien widersprüchlich. Bisher gibt es nur wenige morphologische phylogenetische Analysen. Ein Schwerpunkt dieser Arbeit liegt auf der Untersuchung neuroanatomischer Merkmale, da das Nervensystem wahrscheinlich phylogenetische Informationen enthält. Durch das Anwenden moderner morphologischer Methoden, wie hochauflösende konfokale Laserscan- und Elektronenmikroskopie (REM und TEM), und 3d Rekonstruktionen basierend auf lichtmikroskopischen Schnitten, wurde die Verfügbarkeit neuroanatomischer Daten wesentlich verbessert. Die Ergebnisse zeigen, dass die Variation neuroanatomischer Merkmale größer ist als bisher angenommen und dass sich die Gehirnanatomie und die Verteilung von Neurotransmittern in den zwei Stadien der Thaliaceen unterscheidet. Neue unabhängige Merkmale des Nervensystems wurden in einer Matrix kodiert. Ergänzt mit traditionellen in der Tunikatentaxonomie verwendeten Merkmalen, entstand die bisher umfangreichste morphologische Datenmatrix, die 116 Merkmale für insgesamt 54 Arten umfasst. Die kladistische Analyse ergab monophyletische Tunicata, in denen die Appendicularia die Schwestergruppe der übrigen Tunikaten bildet. Ascidiacea ist monophyletisch, während „Thaliacea“ paraphyletisch ist. Zusätzlich wurde eine kombinierte phylogenetische Analyse basierend auf den morphologischen Daten und 18S rDNA-Sequenzen durchgeführt. Eine stufenweise stärkere Gewichtung phänotypischer Merkmale zeigt, dass die morphologischen Daten das Ergebnis der kladistischen Analyse stark beeinflussen. / Tunicata comprises 3000 marine species with diverse life-history strategies. As one of the three major chordate taxa, the evolution of tunicates plays a key role to elucidate chordate and craniate evolution. Therefore, a broader understanding of character transformations within tunicates is essential, but the interrelationships of the five main tunicate subtaxa in previous molecular phylogenetic analyses were contradictory. Morphological phylogenetic analyses are rare. In this comparative study emphasis was given to neuroanatomical characters, as the nervous system probably contains phylogenetic information. Applying modern morphological techniques like high-resolution confocal laser scanning microscopy and electron microscopy (SEM and TEM), serial sectioning for light microscopy, and digital 3d reconstruction, the number of available tunicate neuroanatomical data was considerably increased. It was revealed that the variation of neuroanatomical characters is higher than previously assumed, a specific pattern of serotonin-like immunoreactive cells in ascidians is present, and that brain anatomy and distribution of neurotransmitters in the two thaliacean life-cycle stages differs. Novel independent characters of the central nervous system were coded in a matrix for a cladistic analysis. Including traditional morphological from tunicate literature this effort resulted in the largest morphological data matrix to date, containing 116 phenotypic characters and 54 species. The cladistic analysis resulted in monophyletic Tunicata, with Appendicularia the sister taxon to the remaining tunicates. Furthermore, the monophyly of Ascidiacea is supported, whereas “Thaliacea” are paraphyletic. An additional phylogenetic analysis combining morphological and 18S rDNA-sequence data was performed. A reevaluation of this dataset with a successively increased weighting of the phenotypic data showed that morphological data strongly influence the outcome of the cladistic analysis.

No description available.

Neural control of reproduction in vertebrates and invertebrates has generated considerable interest due to the presence of common neuropeptides. Gonadotropin-releasing hormone (GnRH), a neuropeptide, is the final integrator of neural regulation governing reproduction in vertebrates by controlling the release of gonadotropins. Little is known about GnRH before the origin of vertebrates or about the biological significance of multiple GnRH forms in a single species. To understand the role of GnRH in invertebrates, I selected a tunicate, Ciona intestinalis, the sister group to vertebrates and amphioxus, Branchiostoina floridae, a group more basal than tunicates. Neural control of reproduction in these chordates was compared with that in the zebrafish, Danio rerio. From the zebrafish, I isolated four GnRH receptor cDNAs that each map to a distinct chromosome and are expressed in a variety of tissues. Each receptor was functional, as shown by its response to physiological doses of native GnRH peptides. Also, two receptors showed selectivity between GnRH1 and GnRH2. Protein localization of each zebrafish GnRH receptor with specific antisera showed that all four receptors are present in the pituitary. However, the most striking localization revealed the presence of GnRH networks in a major motor control centre and fibre tract system in the hindbrain and spinal cord. Both structures are major components in the control of motor movements, such as swimming. Phylogenetic and synteny analysis segregates the four zebrafish GnRH receptors into two distinct phylogenetic groups that are separate gene lineages conserved throughout vertebrate evolution. In Ciona intestinalis, we found two GnRH genes that each encode three GnRH decapeptides in tandem, for six unique GnRH forms from this species. These genes are expressed throughout development. With an immunocytochemical approach, at least one peptide was found in the dorsal strand nerve plexus adjacent to the gonads in adults. Injection near the gonads of gravid Ciona quickly induced spawning, suggesting a novel action for control of reproduction by GnRH. My further studies identified four novel GnRH receptors encoded within the genome of this protochordate, and showed that three receptors responded to Ciona GnRHs by stimulating intracellular accumulation of cAMP. In contrast, only one receptor activated inositol phosphate turnover in response to one of the Ciona GnRHs. My final study involved identifying the GnRH signalling components in amphioxus. I found four novel GnRH receptors, with three displaying sensitivity to the highly conserved vertebrate GnRH2 and one of these showing selectivity for GnRH1. My pharmacological testing showed that the capacity to respond to GnRH1 and GnRH2 is evolutionarily conserved between amphioxus and vertebrates, and that key motifs found to be important in GnRH binding, signalling and activation are present in the amphioxus receptors. Phylogenetic analysis showed that two receptors cluster with the recently identified octopus GnRHR-like sequence; the other two receptors group at the base of the vertebrate GnRHR clade and may represent the proto-vertebrate condition, after which gene duplication and sequence divergence resulted in the four contemporary vertebrate GnRHRs. This work reveals novel and important features of the GnRH signalling axis throughout chordate evolution.

No / The excavation at Cnip, Isle of Lewis, Scotland of the largest, and only known family cemetery from the early Norse period in the Hehrides, provided a unique opportunity to use Sr isotope analysis to examine the origins of people who may have been Norwegian Vikings. Sr isotope analysis permits direct investigation of a person's place of origin rather than indirectly through acquired cultural and artefactual affiliations. Sr isotope data suggest that the Norse group at Cnip was of mixed origins. The majority were consistent with indigenous origins but two individuals, of middle-age and different sex. were immigrants. They were, however, not from Norway but were raised separately, most probably on Tertiary volcanic rocks (e.g. the Inner Hebrides or NE Ireland) or, for the female, on marine carbonate rocks.

Pour bien comprendre comment les espèces actuelles ont évolué, il est important d’étudier certains groupes clés. Ces groupes clés sont parfois bien négligés au profit d’autres groupes apparentés. L’embranchement Hemichordata forme, avec Echinodermata, le clade Ambulacraria. Ce dernier, avec l’embranchement Chordata, forme le super-embranchement Deuterostomia. Parmi les deutérostomes, la classe d’hémichordé Enteropneusta est souvent considérée comme étant la plus ressemblante au dernier ancêtre commun des deutérostomes. Les entéropneustes partagent en effet plusieurs caractéristiques avec Chordata et Ambulacraria et en étudiant celles-ci on peut reconstruire et comprendre leurs états ancestraux. Dans le chapitre d’introduction, j’aborde la morphologie générale des hémichordés et leurs relations évolutives avec les deux autres embranchement deutérostomes. Je présente aussi les caractéristiques qu’ils partagent avec les échinodermes et les cordés. J’aborde ensuite les formes que prennent les parties dures chez les animaux et en particulier chez les deutérostomes. Dans le chapitre deux, j’examine et décris la forme et la composition chimique des osselets chez huit espèces d’hémichordé. Cette étude représente un énorme bond dans nos connaissances sur la biominéralisation chez les hémichordés, car jusqu’à présent les osselets n’avaient été décrits que chez deux espèces, et la composition chimique déterminée chez une seule d’entre elle. J’interprète également ces données dans un contexte évolutif, car les osselets d’hémichordé sont probablement homologues au squelette des échinodermes. Ce chapitre est important, car il nous donne une hypothèse sur l’origine des osselets chez le dernier ancêtre commun des ambulacraires. Dans le chapitre trois, je quantifie l’asymétrie dans les fentes pharyngiennes de populations de deux espèces d’entéropneustes et d’une espèce de cordé non-vertébré. En mettant ces différents nivaux de symétrie en parallèle avec leur comportement alimentaire, les résultats supportent l’hypothèse de l’alimentation par filtration comme rôle initial des fentes pharyngiennes chez les deutérostomes et que la perte de cette fonction induit du bruit développemental, une vestigialisation ou une perte des fentes branchiales. Dans le chapitre quatre, J’utilise la micro-tomographie aux rayons-X pour décrire une espèce d’hémichordé qui était jusqu’à présent un numen nudum. Cette nouvelle technique est comparée avec l’histologie traditionnelle afin de prouver qu’elle pourrait être utilisée dans les futures études taxonomiques sur les hémichordés. Dans le chapitre cinq, je présente quelques expériences qui ont dû être exclues des chapitres précédents car elles ont donné des résultats négatifs non-publiables. Je discute des raisons pour lesquelles ces expériences ont échoué ainsi que quelques pistes de solutions possibles pour qui voudrait tenter de les refaire. Ensuite je récapitule les résultats des chapitres précédents pour montrer comment étudier les hémichordés peut encore nous apprendre beaucoup sur d’autres groupes pourtant déjà très étudiés. / The phylum Hemichordata forms, with Echinodermata, the group Ambulacraria that in turns forms with Chordata, the Deuterostomia. Among deuterostomes, the hemichordate class Enteropneusta is often viewed as the group that most closely resembles the last common ancestor of deuterostomes. Enteropneusts indeed share many traits with the other two deuterostome phyla and by studying them, we can infer the ancestral states of those traits. In the first chapter, I present the general morphology of hemichordates and their relationships with the other two deuterostome phyla. I also discuss the shared traits between the hemichordates, the echinoderms and the chordates. Last, I present the varied shapes that hard parts can take in animals, with a focus on deuterostomes. In chapter two, I describe the shape and mineral composition of ossicles in eight enteropneust species. This study is a major leap in our understanding of biomineralization in Hemichordata since up to this point ossicles were only described in two species and the mineral composition determined for only one. I discuss these results in an evolutionary context since hemichordate ossicles are probably homologous with echinoderm skeletal ossicles. This chapter is significant because it provides a hypothesis on the origin of ossicles in the last common ancestor of ambulacrarians. In chapter three, I quantify the level of asymmetry of the pharyngeal slits in populations of two species of enteropneusts and the invertebrate cephalochordate Branchiostoma floridae. We found that adults of these species display fluctuating asymmetry in the gills and that this asymmetry is lower in filter feeding. This is significant because it supports the hypothesis that filter feeding is an ancestral feature of deuterostomes and that the loss of this function increases developmental noise, vestigiality, or loss of the gills. In chapter four, I use X-ray microtomography to describe the enteropneust Balanoglossus occidentalis that was heretofore a nomen nudum. This new technique is compared with traditional histology to show that it is a viable tool in hemichordate taxonomical studies. In chapter five, I present a few experiments that had to be excluded from the other chapters because they gave negative, unpublishable results. I discuss the probable causes of their failures and potential ways to solve these issues for those who would want to pursue them further. Finally, I summarise the results of the previous chapters to show how studying hemichordates can still teach us a lot about the origin and evolution of the better studied deuterostome phyla.

No / Traditional methods of dietary reconstruction do not allow the investigation of dietary variability within the lifetimes of individual hominins. However, laser ablation stable isotope analysis reveals that the ¿13C values of Paranthropus robustus individuals often changed seasonally and interannually. These data suggest that Paranthropus was not a dietary specialist and that by about 1.8 million years ago, savanna-based foods such as grasses or sedges or animals eating these foods made up an important but highly variable part of its diet.

Ling, Ka Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 124-157). / Abstracts in English and Chinese. / Acknowledgement --- p.ii / Abstract --- p.iv / 摘要 --- p.vii / Table of content --- p.ix / List of figures --- p.xiii / List of tables --- p.xv / Abbreviations --- p.xvi / Chapter 1 --- Food authentication --- p.1 / Chapter 1.1 --- Introduction and definition --- p.1 / Chapter 1.2 --- Importance of species identification in food authentication --- p.3 / Chapter 1.3 --- Methods for species identification in food authentication --- p.8 / Chapter 1.4 --- Legislation --- p.17 / Chapter 1.5 --- Objectives --- p.19 / Chapter 2 --- Molecular authentication and antitussive bioassay of Stemona root (Baibu) and root of Asparagus filicinus (Xiao-baibu) --- p.20 / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Materials and methods --- p.22 / Chapter 2.3 --- Results --- p.34 / Chapter 2.4 --- Discussion --- p.40 / Chapter 2.5 --- Conclusions --- p.44 / Chapter 3 --- Rapid detection of oilfish and escolar in fish steaks: a tool to prevent keriorrhea episodes --- p.45 / Chapter 3.1 --- Introduction --- p.45 / Chapter 3.2 --- Materials and methods --- p.49 / Chapter 3.3 --- Results --- p.59 / Chapter 3.4 --- Discussion --- p.69 / Chapter 3.5 --- Conclusions --- p.75 / Chapter 4 --- Widespread adulteration of crocodile meat with python and water monitor meats --- p.76 / Chapter 4.1 --- Introduction --- p.76 / Chapter 4.2 --- Materials and methods --- p.78 / Chapter 4.3 --- Results --- p.89 / Chapter 4.4 --- Discussion --- p.96 / Chapter 4.5 --- Conclusions --- p.100 / Chapter 5 --- Authentication of dried and ready-to-eat hashima products --- p.101 / Chapter 5.1 --- Introduction --- p.101 / Chapter 5.2 --- Source species of hashima --- p.103 / Chapter 5.3 --- Materials and methods --- p.106 / Chapter 5.4 --- Results --- p.116 / Chapter 5.5 --- Discussion --- p.119 / Chapter 5.6 --- Conclusions --- p.121 / Chapter 6 --- General conclusions --- p.122 / Chapter 6.1 --- Key findings --- p.122 / Chapter 6.2 --- Applications and implications --- p.123 / Chapter 7 --- References --- p.124

Lake Tanganyika is a complex, tropical ecosystem in East Africa, harboring an estimated 2,100 species. Extensive watershed deforestation threatens the biodiversity and ecological integrity of the lake. In this dissertation, ecological and paleoecological methods were employed to study the distribution of invertebrate biodiversity through space and time, with particular emphasis on linkages between biodiversity and land –use patterns. Ecological surveys of fish, mollusc, and ostracod crustacean diversity at sites in northern Lake Tanganyika representing different levels of watershed disturbance revealed a negative correlation between biodiversity and intensity of watershed disturbance. To elucidate the long -term relationship between disturbance and biodiversity, paleoecological records of invertebrates offshore from watersheds experiencing different degrees of anthropogenic disturbance were examined. Life, death, and fossil assemblages of ostracod valves were compared to assess the reliability and natural variability inherent to the paleoecological record. These comparisons indicated that paleoecological (i.e. death and fossil) assemblages reliably preserve information on species richness, abundance, and occurrence frequency at comparable -to- annual resolution. Unlike life assemblages, species composition of paleoecological assemblages reflects input of species from multiple habitat types. Ostracod paleoecological assemblages are characterized by spatiotemporal averaging that renders them representative of larger areas and longer time spans than life assemblages. Thus, paleoecological assemblages provide an efficient means of characterizing longer -term, site -average conditions. Natural variability in ostracod fossil assemblages from a sediment core representing the Late Glacial to the present indicates that abundance of individual ostracod species is highly variable. Ostracod assemblages were preserved in only the most recent 2,500 years of sediment. Species composition of ostracod assemblages reflects lake water depth. Core geochemical data indicate that the coring site may have been below the oxycline for ~2,000 years, inhibiting ostracod survival and preservation. Paleoecological, sedimentological, and stable isotope data revealed differences in biodiversity and watershed disturbance through time offshore from a pair of sites. The protected site is offshore from Gombe Stream National Park (Tanzania), the other offshore from a deforested watershed outside the park. Offshore from the deforested watershed, sedimentation rates increased, and turnover in ostracod species composition occurred during the past 50 years. Comparable changes were not observed offshore from the park.

Two taxa of amphibians, five taxa of reptiles, and eighteen taxa of mammals were collected by screen-washing sediments from the upper Bidahochi Formation at White Cone peak, northeastern Arizona. Five new species of mammals were recovered. They include Perognathoides bidahochiensis (Heteromyidae), Bensonomys yazhi (Cricetidae), Bensonomys bradyi (Cricetidae), Paronychomys alticuspis (Cricetidae), and Martes (Plionictis) repenningi (Mustelidae). Bensonomys yazhi and Bensonomys bradyi are close to the stem of Central and South Americal hesperomyine radiation. The radiation began in the southwest United States and Mexico during the Hemphillian. The middle member of the Bidahochi Formation is dated at 6.7 m. y. by a basalt from Roberts Mesa. The paleomagnetic data and the White Cone local fauna support this middle Hemphillian date.