Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri--Columbia, 1998. / Includes bibliographical references.

Call number: LD2668 .T4 1953 R62 / Master of Science

Call number: LD2668 .T4 1979 O26 / Master of Science

Thesis (MSc)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: This study describes: 1. The isolation of total RNA and mRNA from Angora goat adrenals. 2. Synthesis and nucleotide sequence alignment of Angora goat CYPI7 cDNA. Two DNA sequences were produced, identifying two CVP 17 alleles in an Angora goat from the Swartland district. 3. The development of a CYPI7 genotype test for Angora goats. 4. Genotyping of Angora goats and Boer goats with the developed genotype test. S. Mapping of the substituted amino acids in the amino terminal of CVP 17 to a specific CYPI7 genotype. 6. Partial synthesis and alignment of Angora goat genomic nucleotide CYPI7 sequences. / AFRIKAANSE OPSOMMING: Hierdie studie beskryf: 1. Die isolering van totale RNA en mRNA van Angorabok byniere. 2. Sintese en nukleotied volgorde oplyning van Angorabok CYP17 eDNA. Twee DNA volgordes is geproduseer, en so is twee CYP17 allele in 'n Angorabok van die Swartland omgewing geïdentifiseer. 3. Die ontwikkeling van 'n CYP17 genotipe toets vir Angorabokke. 4. Genotipering van Angorabokke en Boerbokke met die ontwikkelde genotipe toets. 5. Korrelering van die omgeruilde aminosure in die aminoterminaal van CYPl7 met 'n spesifieke genotipe. 6. Gedeeltelike sintese en oplyning van Angorabok genomiese CYPl7 nukleotied volgordes.

Thesis (MSc)--University of Stellenbosch, 2004. / ENGLISH ABSTRACT: Geographic variation in the presence/absence of generation glands in females of the cordylus-niger-oelofseni complex was described and correlated with climatic variables. Preserved and live specimens from 96 localities in the area south of 32°30' S and west of 19°45' E in the Western Cape, South Africa, were examined for the presence or absence of generation glands. Females from western coastal localities and from the Cape Fold Mountains generally lack generation glands, while females from inland lowland localities generally possess glands. A GIS analysis was performed to determine mean annual minimum temperature, mean annual maximum temperature, potential evaporation, mean annual precipitation, mean annual fog and mean annual cloud cover measured at 14:00 for each locality. Discriminant function and canonical analyses showed a highly significant correlation between the presence and absence of generation glands and five of the six climatic variables. It is suggested that the high incidence of fog and lower temperatures experienced along the west coast as a result of the cold Benguela Current, and the high incidence of orographic fog and cloud cover in the Cape Fold Mountains may affect energy allocation in females. In order to maintain their reproductive output, females may be forced to invest less energy in secondary sexual characters such as generation glands. Interspecific variation in the location, occurrence, number, and age of gland differentiation was investigated for cordylid lizards. For several species, data were obtained from the literature and for others data were obtained from material housed in the Ellerman Collection of the University of Stellenbosch. Cordylus cordylus and C. cataphractus were used for an evaluation of inter- and intrapopulation variation. Data for C. cordylus were obtained from five populations on the coastal lowlands of the Western Cape, while data on C. cataphractus come from the literature. The sex, snout-vent length, and number of generation glands were recorded for a representative sample of lizards at each locality. While in all species generation glands were located in the femoral region, Cordylus giganteus and C. microlepidotus had additional generation glands elsewhere on the body. It is suggested that additional generation glands in these species may be related to an increased need for chemical communication in a low-visibility environment in the case of C. giganteus, and in low population densities in the case of C. microlepidotus. Generation glands are present in all cordylid males, but females of some species may lack these glands. All cordylids display sexual dimorphism with regards to the presence and number of generation glands, with males having significantly more glands than females, indicating that these glands may play a more important role in males than in females. Low sexual dimorphism in at least two species suggests that generation glands may be equally important in both sexes of these species. In females, the presence of generation glands is closely regulated by climate. There is no indication of differences in generation gland profile between ground-dwelling and rock-dwelling species, except that in at least three ground-dwelling species, generation glands are already present at birth. In other species these glands differentiate only later in life. In the males of most species, generation glands start to differentiate prior to or at sexual maturity with a drastic increase in number when asymptotic body size is reached. The considerable inter- and intrapopulation variation in gland number in females, but not in males, underscores the hypothesis that the presence of generation glands in females is energy-linked and closely regulated by climate. An opposite geographic pattern of generation gland number in C. cataphractus, suggests that other factors than climate must be responsible for a difference in gland number and a difference in population density is suggested as explanation. To test for differences in aggression levels, females with and those without generation glands were staged in two experiments. In one experiment, females from different localities were staged against each other, while females from the same locality were paired in another experiment. No significant difference in aggression levels between females with and those without generation glands were observed in both experiments. It is suggested that generation glands do not exclusively function in territorial marking, but rather as a scent enhancer for femoral gland secretions. Inorder to elucidate the functional significance of generation glands, male response to female gland stimuli was investigated for 12 male C. cordylus. Males were presented with different female gland secretions (femoral, generation, and femoral and generation gland secretion combined) and water was used as a control. Total number of tongue-flicks and number of tongue-flicks directed at the secretion were counted. No significant difference was observed in the number of tongue-flicks between the different treatment groups. Males did, however, display leg-waving and head-rubbing behaviour. At present, the behaviour displayed by male C. cordylus in the presence of female gland stimuli, is unclear. The general absence of tongue-flicking of sandpaper labelled by female gland stimuli may be because of a flaw in the experimental design or because the experiment was conducted outside the breeding season. The display ofleg-waving and head-rubbing behaviour, however, suggests that cordylids do not exclusively rely on tongue-flicking for detection of conspecifics. The real function of generation glands thus still remains unresolved and further studies are needed to clarify this. / AFRIKAANSE OPSOMMING: Geografiese variasie in die aan-/afwesigheid van generasiekliere in wyfies van die cordylus-niger-oelofseni kompleks is beskryf en met klimaatsveranderlikes gekorreleer. Gepreserveerde en lewende materiaal, afkomstig van 96 lokaliteite in die area suid van 32°30' S en wes van 19°45'0 in die Wes-Kaap, Suid-Afrika, is vir die aan- ofafwesigheid van generasiekliere ondersoek. Generasiekliere is oor die algemeen afwesig in wyfies van westelike kuslokaliteite en die Kaapse Plooiberge, terwyl dit aanwesig is in wyfies van die binnelandse laagland lokaliteite. 'n GIS-analise is gedoen om die gemiddelde jaarlikse minimum temperatuur, gemiddelde jaarlikse maksimum temperatuur, potensiële verdamping, gemiddelde jaarlikse neerslag, gemiddelde jaarlikse mis en gemiddelde jaarlikse wolkbedekking, gemeet teen 14:00, vir elke lokaliteit te bepaal. Diskriminantefunksie en kanonieke analises toon 'n hoogs beduidende korrelasie tussen die aan- en afwesigheid van kliere en vyf van die ses klimaatsveranderlikes. Daar word voorgestel dat die hoë voorkoms van mis en lae temperature wat langs die weskus ervaar word as gevolg van die koue Benguela Seestroom, en die hoë voorkoms van orografiese mis en wolkbedekking in die Kaapse Plooiberge, die energie-toekenning in wyfies beïnvloed. Om hulle voortplantingsuitset te handhaaf, word wyfies moontlik gedwing om minder energie in sekondêre geslagskenmerke, soos generasiekliere, te belê. Interspesifieke variasie in die posisie, voorkoms, aantal en tyd van klierontwikkeling is vir verskeie gordelakkedisspesies ondersoek. Data vir verskeie spesies is vanuit die literatuur verkry, terwyl data vir ander spesies vanafmaterial in die Ellerman-versameling van die Universiteit van Stellenbosch verkry is. Cordylus cordylus en C. cataphractus is vir 'n evaluering van inter- en intrapopulasie variasie gebruik. Data vir C. cordylus is vanafvyfpopulasie wat op die kuslaaglande van die Wes-Kaap voorkom, ingesamel, terwyl data oor C. cataphractus vanuit die literatuur verkry is. Geslag, snoet-kloaak-lengte en die aantal generasiekliere is aangeteken vir 'n verteenwoordigende aantal individue van elke populasie. Terwyl generasiekliere in die femorale wyk van alle spesies aangetref word, het Cordylus giganteus en C. microlepidotus ook addisionele generasiekliere in ander dele van die liggaam. Daar is tot die gevolgtrekking gekom dat addisionele generasiekliere in hierdie spesies moontlik verwant is aan 'n groter behoefte aan chemiese kommunikasie in 'n lae sigbaarheidsomgewing in die geval van C. giganteus, en in 'n lae populasiedigtheid in die geval van C. microlepidotus. Generasiekliere word in alle gordelakkedis mannetjies aangetref, maar kan afwesig wees in wyfies van sommige spesies. Alle gordelakkedisse toon geslagsdimorfisme met betrekking tot die aanwesigheid en aantal generasiekliere, en mannetjies het beduidend meer kliere as wyfies, wat daarop dui dat hierdie kliere moontlik 'n meer belangrike rol by mannetjies as by wyfies speel. Lae geslagsdimorfisme inten minste twee spesies stel voor dat generasiekliere moontlik ewe belangrik in beide geslagte van hierdie spesies kan wees. In wyfies word die aanwesigheid van generasiekliere sterk deur klimaat gereguleer. Daar is geen aanduiding van verskille in generasieklierprofiel tussen grondbewonende en rotsbewonende spesies nie, behalwe dat generasiekliere reeds by geboorte teenwoordig is in ten minste drie grondbewonende spesies. In ander spesies ontwikkel hierdie kliere eers later. In mannetjies van die meeste spesies, begin generasiekliere voor oftydens geslagsrypheid ontwikkel, met 'n drastiese toename in aantal kliere wanneer asimptotiese liggaamsgrootte bereik word. Die aansienlike inter- en intrapopulasie variasie in aantal kliere in wyfies, maar nie in mannetjies nie, ondersteun die hipotese dat die teenwoordigheid van generasiekliere in wyfies aan energie gekoppel is en deur klimaat gereguleer word. 'n Teenoorgestelde geografiese patroon in die aantal generasiekliere in C. cataphractus, stel voor dat ander faktore as klimaat vir die verskil in aantal kliere verantwoordelik is en 'n verskil in populasiedigtheid word as verklaring voorgestel. Om vir verskille in aggressievlakke te toets, is wyfies met en wyfies sonder generasiekliere is teenoor mekaar getoets in twee eksperimente. In een eksperiment is wyfies van verskillende lokaliteite teenoor mekaar getoets, en in 'n ander eksperiment is wyfies van dieselfde lokaliteit teenoor mekaar getoets. Inbeide eksperimente is geen beduidende verskille is in die aggressievlakke van wyfies nie waargeneem nie. Daar word voorgestel dat generasiekliere nie uitsluitlik in gebiedsafbakening funksioneer nie, maar dat dit eerder as reukversterker vir die femorale kliere dien. Om die funksie van generasiekliere vas te stel, is die reaksie van 12 mannetjie C. cordylus op klierstimuli van wyfies getoets. Verskillende kliersekresies (femoraal, generasie, en femoraal en generasie gekombineerd) van wyfies is mannetjies voorgelê, en water is as 'n kontrole gebruik. Totale aantal tongskiete en aantal tongskiete wat na die sekresie gerig is, is getel. Geen beduidende verskil in die aantal tongskiete is tussen die verskillende groepe waargeneem nie. Mannetjies het egter beenwaai- en kopvryfgedrag getoon. Die rede vir die gedrag wat deur C. cordylus mannetjies in die teenwoordigheid van klierstimuli van wyfies vertoon word, is egter tans onduidelik. Die algemene afwesigheid van tongskiete na skuurpapier wat met klierstimuli van wyfies gemerk is, mag moontlik wees as gevolg van 'n fout in die eksperimentele ontwerp of omdat die eksperiment buite die paarseisoen uitgevoer is. Die vertoning van beenwaai- en kopvryfgedrag stel egter voor dat gordelakkedisse nie uitsluitlik op tongskiete staatmaak om lede van dieselfde spesie waar te neem nie. Die ware funksie van generasiekliere is dus steeds onopgelos en verdere studies word benodig om dit duidelikheid hieroor te kry.

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Radiotherapy is the primary treatment for patients with head and neck cancer, which account for roughly 60,000 annual diagnoses in the U.S. and approximately 500,000 worldwide. About 90% of these individuals receive radiation therapy, and salivary hypofunction and xerostomia occur in 60-85% of these patients due to irreversible damage to the salivary glands. Current preventative and palliative care fail to improve quality of life, accentuating the need for regenerative therapies. Stem/progenitor-cell based therapies have been proposed to regenerate the irradiated glands; however, the identity of stem and progenitor cells in the adult salivary glands has remained somewhat elusive. Moreover, it is unclear how salivary progenitors respond to radiation and whether they can be stimulated to effectively reinstate salivary function. The second chapter of the present study describes the development of a label-retaining assay in salivary glands using EdU. The label-retaining cells (LRCs) identified in murine salivary glands have proliferative potential in vitro and expressed markers of putative salivary progenitors, such as Keratin 5, Keratin 14, and c-Kit. Interestingly, LRCs were still present 30 days following radiation, when chronic loss of saliva is evident. The significance of these findings lies in the potential of this model to study the mechanisms that prevent salivary progenitors from maintaining salivary gland homeostasis upon exposure to radiation, which will in turn facilitate the development of regenerative therapies for salivary gland dysfunction. In the following chapter, we show that a unique population of murine salivary gland LRCs undergo compensatory proliferation in response to radiation. The initiation of compensatory proliferation is tightly associated with inactivation of the kinase aPKCζ and increased nuclear localization of YAP. This part of the study provides novel insights into the regulation of function of salivary gland progenitors, which can be utilized for the development of therapeutic agents to treat salivary hypofunction. Finally, the last chapter describes how the mechanisms found to initiate compensatory proliferation in acinar LRCs as a response to radiation are involved in the regeneration of salivary glands with IGF-1. Administration of IGF-1 post-radiation restores salivary function in mice, but the mechanisms of regeneration are still unknown. Here, we show that IGF-1 requires aPKCζ to restore saliva production. Further, IGF-1 inhibits nuclear translocation of Yap in an aPKCζ-dependent fashion. We propose that a tightly regulated balance in the levels of aPKCζ and Yap in acinar LRCs has to be maintained in order to restore function following radiation. In conclusion, the findings from this study provide new knowledge in regards to the regulation of function of salivary progenitors during a state of injury (by radiation) and during regeneration (with IGF), and offer potential targets of study for the development of new therapeutics for salivary gland dysfunction. Future studies will determine whether aPKCζ and Yap can be effectively targeted in salivary progenitors to restore salivary function in head and neck cancer patients who receive radiation therapy.