The Pacific Giant salamander, Dicamptodon tenebrosus, from the Pacific Northwest of North America has variable numbers of supernumerary chromosomes, from 0 to 10, per individual. B chromosome frequency among populations varies geographically such that salamanders from the most southern and northern regions have lower average numbers of B chromosomes than salamanders in the middle of the range. This variation in B frequency may be correlated with both historical and climatic factors. To assess how the supernumerary chromosomes originated in D. tenebrosus, B chromosome DNA was isolated by microdissection and amplified by degenerate oligonucleotideprimed PCR. The B DNA hybridized similarly to genomic DNA from individuals of D. tenebrosus and the related species D. copei and D. ensatus demonstrating that the supernumerary chromosomes were derived from the normal chromosome complement. Unique hybridization bands in both D. copei and D. tenebrosus suggest that the shared sequences have evolved independently.

Bicaudal-D (Bic-D) is essential in Drosophila for the establishment of oocyte fate and polarity within the developing oocyte. To study these processes we have engineered a chimeric Bic-D::GFP fusion protein which behaves like the endogenous Bic-D polypeptide. We have identified three genes which are required for the normal subcellular distribution of Bic-D::GFP two genes predicted to encode RNA binding proteins (egalitarian and orb) and Dynein heavy chain. In particular, they affect Bic-D::GFP localization during the early germarial stages of oogenesis during which oocyte fate is established, or later when anterior-posterior polarity is initiated. Our results support the model that Bic-D acts in conjunction with mRNA binding proteins and a negative-end directed microtubule motor in localizing mRNAs. Throughout stages 1--6 of oocyte development, Bic-D::GFP accumulates in the oocyte in a strong posterior cortical focus, resembling a spool, that is aligned with a crater-like indentation in the oocyte nucleus. The aligned focus and crater reveal an early oocyte polarity and a previously undescribed asymmetric subcellular structure that may be involved in tethering the oocyte nucleus. Shape, positioning and orientation of the oocyte nucleus change around stage 6--7, concomitantly with a change in position of the Bic-D::GFP focus to the presumptive dorsoanterior corner. This re-orientation appears to anticipate the establishment of a new dorsoventral polarity in the oocyte and egg chamber. Dhc and Bic-D are both involved in the process of re-orientation of the oocyte nucleus and in polarity formation.

The perinuclear theca (PT) is a cytoskeletal structure that covers the nucleus of mammalian spermatozoa and is believed to have a membrane binding role. The objectives of this study were to analyze the protein composition of the mouse PT, to identify its major protein component, and to characterize this protein's transcriptional and translational origins during spermatogenesis. The PT was extracted from demembranated and acrosome-depleted mouse sperm heads by alkaline treatment. The protein profile of the PT extract was composed of several polypeptides of which a 15 kDa subacrosomal protein predominated and was found to be immunocross-reactive with a previously cloned 15 kDa PT protein of the rat (PERF 15) that belongs to a family of lipid binding proteins. A primer pair designed from rat PERF 15 cDNA was then used to screen a mouse testicular cDNA library by polymerase chain reaction (PCR). The deduced amino acid sequence obtained from the PCR product was almost identical to the testicular-specific rat PERF 15. Developmental Northern blots and in situ hybridization studies performed with riboprobes encoding the mouse PERF 15 cDNA revealed that mRNA levels were highest in round and early elongating mouse spermatids. Immunohistochemistry indicated that PERF 15 began to be expressed in the cytoplasm of mid-pachytene spermatocytes and appeared to reach maximum expression in the distal cytoplasm of late elongating mouse spermatids, long after transcriptional arrest. During the development of round and early elongating spermatids, the immunolabel became progressively concentrated over the anterior half of the spermatid nucleus suggesting a subacrosomal deposition of PERF 15 during this phase of mouse spermatogenesis.

Thesis (M.S.)--University of Hawaii at Manoa, 2007. / Includes bibliographical references (leaves 53-57). / viii, 57 leaves, bound col. ill. 29 cm

Errata pasted onto front end-paper. / Includes bibliographical references (p. 261-288) / xiv, 294 p. : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Focuses on the mechanism of action of the creA gene product of A. nidulans, and its ability to control the regulated expression of three genes for which there exists evidence for control by creA at the transcription level. / Thesis (Ph.D.)--University of Adelaide, Dept. of Genetics, 1997?

Thesis (Ph.D.)--Oklahoma State University, 2008. / Vita. Includes bibliographical references.

Thesis (Ph.D.)--George Mason University, 2009. / Vita: p. 123. Thesis director: John J. Grefenstette. Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Bioinformatics and Computational Biology. Title from PDF t.p. (viewed Sept. 8, 2009). Includes bibliographical references (p. 114-122). Also issued in print.

Thesis (Ph.D.)--Oklahoma State University, 2009. / Vita. Includes bibliographical references.

Thesis (M. Phil.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 124-142).

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Microbiology and Molecular Genetics." Includes bibliographical references (p. 102-110).