Honors Project--Smith College, Northampton, Mass., 2010. / Includes bibliographical references (p. 121-131).

Thesis (M.A.) -- Central Connecticut State University, 2006. / Thesis advisor: Thomas King. "... in partial fulfillment of the requirements for the degree of Master of Arts in Biomolecular Sciences." Includes bibliographical references (leaves 39-41). Also available via the World Wide Web.

Thesis (Ph.D.)--University of Alberta, 1997. / Submitted to the Faculty of Graduate Studies and Research in partial fulfilment of the requirements for the degree of Doctor of Philosophy, Department of Psychology. Also available online.

No description available.

No description available.

Rhabdomys pumilio, in the Eastern Cape of South Africa, does not use short day length as an inhibitory cue for reproductive activity, and, despite previous records indicating that these mice are strictly seasonal in their reproduction, litters have been found during the winters of some years,both in the Eastern Cape and in the Western Cape. This led me to believe that the reproductive activity of Rhabdomys pumilio is more opportunistic and that the cue or cues used to control reproduction are less predictable and, or more variable than the photoperiod cue used by many seasonally reproducing rodents. Two experiments were conducted, investigating the influence of low ambient temperature (15⁰C)and reduced food availability on the reproductive activity of both male and female four striped field mice. Mice were maintained in one of four conditions (food restricted at 15⁰C, food restricted at 26⁰C, ad lib. food at 15⁰C, and ad lib. food at 26⁰C) for 4 (males) and 8 weeks (females)(photoperiod 12L:12D, humidity 40%). Results indicated that the males reduced their reproductive activity slightly when exposed to either low temperature or low food availability and that maximum inhibition of reproduction occurred when mice were exposed to both low temperature and low food availability. However, female reproductive activity was inhibited when exposed to low food availability, irrespective of the temperature. Both sexes of mice showed varying abilities to resist fat loss and, in the males, the size of the fat store had a significant effect on reproduction. This varying ability to resist fat loss could be related to levels of activity and in the females (where activity was quantified), high activity scores were significantly associated with reproductive inhibition. These results support the hypothesis that reproduction in Rhabdomys pumilio is opportunistic and controlled by the availability of energy. I propose that the females will be more sensitive to reproductive inhibition due to their far greater post-fertilization responsibilities, where the reproductive activity of the females is rapidly inhibited by a reduction in food availability, while the males are less readily inhibited by low food availability or low temperature, unless the change in the controlling factors is severe enough, or prolonged, at which stage their reproductive activity will cease. The significance of opportunistic reproduction in the seasonal but unpredictable climate of the study area is discussed.

ABSTRACT Environmentally-induced stereotypic behaviour (SB) results from the chronic impact of captivity on brain development and function and, consequently, on behaviour. My study sought to determine group- and individual-level predictors and correlates of SB in the striped mouse, Rhabdomys dilectus, and to identify the mechanisms underlying the stereotypic phenotype. This aim was addressed by collecting cross-sectional and longitudinal behavioural and physiological data from a combination of wild-caught (WC) and captive-born (CB) striped mice born and reared in different social and environmental conditions. First, I examined the group-level effects of rearing conditions. Results confirmed the genetic contribution to SB performance in striped mice, and furthermore indicated that (1) striped mice weaned at or later than their natural weaning age are less likely to develop SB than striped mice weaned prematurely; (2) striped mice reared biparentally showed significantly less SB as adults than striped mice reared by their mothers alone; (3) striped mice raised from weaning in enriched conditions were four times less likely than standard-housed individuals to develop SB, an effect which endured after enriched-housed striped mice were transferred to standard housing; and (4) birth origin predicts the emergence of SB in striped mice, with those WC individuals trapped as adults being relatively protected from the development of SB compared with both WC individuals trapped as juveniles and CB striped mice. I also showed that (1) WC striped mice were more fearful and less active than CB animals, but that these traits did not covary with SB, and (2) WC striped mice were less perseverative and behaviourally more flexible than CB animals, traits that did covary with SB. Second, I characterized the developmental trajectory of SB in a large group of CB, standard-housed striped mice, and then investigated potential individual-level predictors, mediators, and correlates of SB in these animals. Measures of perseveration, activity, and anxiety/fearfulness assessed in juveniles before the development of SB did not predict which animals later developed SB, but stereotypic adults were more active and more perseverative than nonstereotypic individuals. Whilst preweaning developmental maturity did not predict which striped mice later developed SB, striped mice showing accelerated development in the preweaning period were likely to show SB at an earlier age, at a higher frequency, and potentially with reduced variability, effects which persisted into adulthood. In conclusion, my study shows that more naturalistic rearing environments reduce the incidence of SB, an effect mediated by genetic factors and possibly also by experience-dependent alterations in forebrain function. However, further work is necessary to explore whether the association between forebrain function and SB expression in striped mice is causal because, whilst environments which decrease perseverative tendencies also reduce SB, I found no evidence that such tendencies predict which striped mice later develop SB.

Thesis (PhD)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: The geographic genetic population structure and evolutionary history of the African four-striped mouse, Rhabdomys pumilio, was investigated using mitochondrial (mtDNA) cytochrome b gene (1140 bp) and control region (994 bp) sequences and a combination of cytogenetic banding techniques (G- and C-banding), and fluorescence in situ hybridization. Two cytotypes (2n = 46 and 2n = 48) were identified by cytogenetic analysis. No evidence of diploid number variation within populations was found nor were there differences in gross chromosome morphology, or subtle interchromosomal rearrangements at levels detected by ZOO-FISH. The comparative painting data (using the complete suite, N = 20, of Mus musculus chromosome specific painting probes) show that 10 mouse chromosomes have been retained as chromosomal arms, or intact chromosome blocks within the R. pumilio genome, six produced double signals, while the remaining four hybridized to three or more R. pumilio chromosomes. In total, the 20 mouse chromosome paints detected 40 segments of conserved synteny. Their analysis revealed eight R. pumilio specific contiguous segment associations, a further two that were shared by R. pumilio and other rodents for which comparable data are available, the Black (Rattus rattus) and Norwegian (Rattus nONegicus) rats, but not by the Chinese hamster, Cricetulus grise us. The results suggest that mouse chromosomes 1, 10, and 17 have undergone extensive rearrangements during genome evolution in the murids and may be useful markers for enhancing our understanding of the mode and tempo of chromosome evolution in rodents. Following initial studies using control region sequences, the phylogeographic appraisal of R. pumilio was done using cytochrome b gene sequences. Analyses based on a variety of analytical procedures resulted in the detection of two major mtDNA lineages that correspond roughly to the xeric and mesic biotic zones of southern Africa. One clade comprises specimens with 2n = 48, and the other representatives of two cytotypes (2n = 48 and 2n = 46). The mean sequence divergence (12.0%, range 8.3% -15.6%) separating the two mtDNA clades is comparable to among-species variation within murid genera suggesting their recognition as distinct species, the prior names for which would be R. dilecfus and R. pumilio. Low sequence divergences and the diploid number dichotomy within the mesic lineage support the recognition of two subspecies corresponding to R. d. dilecfus (2n = 46) and R. d. chakae (2n = 48). The data do not support subspecific division within the nominate, R. pumilio. Molecular dating places cladogenesis of the two putative species at less than 5 million years, a period characterised by extensive climatic oscillations which are thought to have resulted in habitat fragmentation throughout much of the species' range. / AFRIKAANSE OPSOMMING: Die geografiesebevolkingsstruktuur en evolusionêre verwantskappe binne die Afrika streepmuis, Rhabdoys pumilio, is ondersoek deur middel van mitochondriale ONS volgordebepaling van die geenfragment sitochroom b (1140 basispare) en die reguleerstreek (994 bp) in kombinasie met sitogenetiese tegnieke (G- en Cbandkleuring en f1uoreseerende in situ hibridisasie). Twee sitotipes (2n = 46 en 2n = 48) is geidentifiseer deur sitogenetiese analasie. Geen bewys van variasie in die 2n chromosoomgetal binne bevolkings is gevind nie. Verder is daar ook geen verskil in die morfologies struktuur van chromosome aanwesig binne bevolkings nie. Vergelykende data (verkry met behulp van die N = 20 Mus musculus chromosoomspesifiekepeilers) dui daarop dat 10 muis chromosome behoud gebly het as chromosoomarms of chromosoomblokke binne die R. pumilio genoom. Ses peilers het dubbel seine gelewer terwyl die oorblywende vier peilers gehibridiseer het aan drie of meer R. pumilio chromosome. In totaal het die 20 muischromosoomverwe 40 konserwatiewe segmente geidentifiseer. Die analise dui agt R. pumilio spesifieke aaneenlopende segmentassosiasies aan, met 'n addisionele twee wat deur R. pumilio en ander muisagtiges vir wie vergelykende data beskikbaar is, byvoorbeeld die swart (Rattus rattus) en Noorweegse (R. norvegicus) rot maar nie die Chinese hamster, Cricetulus grise us, gedeel word. Die resultate stel voor dat muischromosoom 1, 10 en 17 ekstensiewe herrangskikkings ondergaan het gedurende die genoom evolusie binne die Muridae en dat hulle waarskynlik waardevolle merkers kan wees om beide die patroon en tempo van chromosome evolusie in muisagtiges verder te kan verstaan. Die filogeografiese verwantskappe binne R. pumilio is ondersoek deur middel van ONS volgordebepalings van die reguleerstreek asook sitochroom b. Die resultate van hierdie studie het twee divergente mitochondriale ONS eenhede ontdek wat gekorreleer kan word met xeriese en mesiese klimaatsones binne suidelike Afrika. Een groep bestaan uit diere met 2n = 48, terwyl die ander genetiese groep twee sitotipes (2n = 46 en 2n= 48) insluit. 'n Gemiddelde genetiese divergensie van 12.0% (varieer tussen 8.3% - 15.5%) verdeel die twee mtDNS-groepe en is vergelykbaar met tussenspesievariasie binne ander muisagtige genera, wat moontlik daarop dui dat twee verskillende spesies teenwoordig is; die voorgestelde name is R. di/ectus en R. pumilio. Lae genetiese divergensie binne die mesiese groep versterk die moontlike teenwoordigheid van twee subspesies, R. d. di/ectus (2n = 46) en R. d. chakae (2n = 48). Die data verleen egter nie steun aan die divisie binne R. pumilio nie. Molekulêre datering van die twee spesies dui daarop dat die divergensie ten minste 5 miljoen jaar gelede plaasgevind het. Die periode was gekarakteriseer deur ekstensiewe klimaatsossilasies, wat gely het tot habitat fragmentasie in die spesie se verspreidingsgebied.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 92-107). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2000. / Typescript. Vita. Includes bibliographical references (leaves 189-242). Also available on the Internet.