published_or_final_version / abstract / Pathology / Doctoral / Doctor of Philosophy

No description available.

published_or_final_version / Pathology / Master / Master of Medical Sciences

Recognising that NPT2 is the major Na/Pi cotransporter in the kidney, that hereditary hypophosphatemic rickets with hypercalciuria (HHRH) is caused by a renal Pi leak and, that Npt2 knockout mice demonstrate a biochemical phenotype similar to that of patients with HHRH, we sought to determine whether NPT2 was a candidate gene for this disorder. Using single-strand conformation polymorphsim (SSCP) analysis and sequencing in six unrelated pedigrees with the disease, we found no disease-causing mutations. Two polymorphisms were identified in the gene and used as markers to examine segregation of NPT2 with the disease. HHRH did not segregate with the gene markers. In addition, the impact of NPT2 on bone mineral density (BMD) was examined by genotyping a population of 104 individuals for which BMD data was available, and determining whether there was an association between NPT2 genotype and bone density. No significant association was found between NPT2 genotype and BMD.

Rationale. Definition of complex behavioral disorders is generally phenomenological in nature and guided by pragmatic, rather than genetic, concerns. Consequently, important aspect of genetic analysis is the search for novel phenotypic definitions from the familial/genetic perspective. SLI study 1. SLI denotes an inability to acquire normal language in the absence of peripheral hearing impairment, neurological disorder, and mental retardation. Sibling resemblance for several theoretically derived specific components of the SLI phenotype was examined in families of SLI children. In 38 sib-pairs from 10 French-speaking pedigrees, Verb Tense Morphology sub-tests (Real and Non-real Words) showed nonparametric correlations of 0.39 and 0.35, respectively (p < 0.05, 2-tailed). In a densely affected Anglophone pedigree, 41 sib-pair showed familial resemblance with respect to Derivational Morphology (r = 0.52, p < 0.01). SLI study 2. Family history study in 27 families examined the relationship between attention deficit/hyperactivity in SLI children and familial risk of speech/language disorders. Higher odds of speech/language disorders were observed in first-degree relatives of 13 SLI children who also had a medical record of attention deficit/hyperactivity (15/27 vs. 4/46, p = 0.001). Alcoholism study 1. Latent class analysis (LCA) including gender and 15 antisocial behaviors (>15yr) was performed in 236 broadly ascertained alcohol-dependent subjects (121 males, 115 females). Evidence for 3 qualitative behavioral classes was obtained: Socially Adjusted Adults, SAA; Antisocial Non-Aggressive Adults, ANAA; and Antisocial Aggressive Adults, AAA. In both, genders, the AAA class had the earliest age of onset for alcohol dependence (p = 0.001), more alcoholic first-degree relatives and more of other psychopathology. In females, the ANAA class was intermediate. In the ANAA males, socially adjusted childhood behavior differentiated the late onset from the intermediate ons

In the present study, DNA sequences associated with an apomixis gene inPennisetum ciliare were isolated from a distantly related grass species, Tripsacum dactyloides. Primers were developed for two bioinformatics-identified candidate genes (Pca2l and Pca24) for apomixis in Pennisetum ciliare. Homologous gene sequences were successfully isolated from both diploid (2n=36) and tetraploid (4n=72) Tripsacum using the primers and polymerase chain reaction (PCR) amplification. Bioinformatics analysis of the purified, cloned and sequenced PCR products revealed that the isolated homolog of the Pca2l gene varies significantly between the diploid and the tetraploid Tripsacum. Comparative genome analyses against Oryza, Zea, Arabidopsis, Pennisetum, Tripsacum and the National Center for Biotechnology Information (NCBI) nucleotide collection (nr) have shown that the PCR-generated sequences are reproductive specific. Analysis of the Trip2lT3c sequence was shown to be a Rab2 homolog with an e-value of 9e-23. Further proteomics analyses of the putative gene products have revealed that the Pca2l and the Tripsacum sequences may be partially conserved, with the Trip2lT3c sequence more highly conserved than the Trip21D3a. / Department of Biology

Bibliography: leaves 126-158. / 158, [77] leaves (some folded), [19] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Microbiology and Immunology, 1991

No description available.

Trypanosoma brucei and T. congolense are protozoan parasites that infect humans, domestic livestock and wildlife in Africa. These parasites undergo complex morphological and biochemical changes, during the various stages of their life cycle. These changes correlate with alterations in the levels of trypanosomal lysosomal cysteine proteases, suggesting a role for transcriptional regulation of the cysteine protease in these parasites. The mechanism of this regulation is not yet understood nor have the promoter regions of the cloned trypanosome cysteine protease genes been investigated. This study involved an attempt to clone the T. brucei and T. congolense DNA fragments containing the promoter regions as the initial step in the investigation of the control elements of the cysteine protease gene. Trypanosomes were isolated from infected rat blood employing a combination of the methods of isopicnic isolation on Percoll gradients and DEAE-cellulose anion exchange resin chromatography. Approximately 5 x 10⁹ viable trypanosome cells were isolated from the infected rat blood and chromosomal DNA (approximately 500 μg) was extracted by alkaline-lysis method. Trypanosome genomic libraries were initially constructed in Eschericia coli HB101 employing the positive selection vector pEcoR251. The Trypanosoma brucei pEcoR251 library contained 6 000 recombinants and the Trypanosoma congolense library contained 15 000 recombinants. Plasmid DNA was then extracted from pools of recombinants, employing the alkaline-lysis method, digested with EcoRl restriction endonuclease and resolved by agarose gel electrophoresis. After Southern hybridisation, the pEcoR251 libraries did not reveal any putative clones containing the fragment of interest when probed with both an oligonucleotide probe and the PCR generated dsDNA probe. Genomic libraries were then constructed in the phagemid pUC119. The T. brucei and T. congolense genomic libraries contained 33 000 and 27 000 recombinants respectively. Recombinants from the T. brucei and T. congolense libraries were pooled in lots of 400 and 300 respectively. Of the 80 T. brucei plasmid pools that were screened 30 pools contained fragments that hybridised with the probe whilst 12 pools from the 90 T. congolense library pools that were screened contained fragments that hybridised with the probe. Putative clones identified appeared to contain inserts, ranging between two and seven kb in size. A partial T. congolense library consisting of approximately 12 pools was screened by colony hybridisation for identification of individual clones and 76 putative clones were identified. After confirmation of these putative clones on a dot blot using a DIG-labelled dsDNA probe, a selection of 30 putative clones were subjected to Southern hybridisation using a DIG-labelled DNA probe. Following Southern hybridisation 23 putative clones were identified to contain DNA inserts of interest in the range of two to seven kb. Five clones, designated pCPC1, pCPC2, pCPC3, pCPC4 and pCPC5 were then selected for further restriction mapping. Clone pCPC4 contains a seven kb fragment of T. congolense genomic DNA. A partial T. brucei library consisting of approximately 30 pools was screened by colony hybridisation for the identification of individual putative clones. Although plasmid pools containing putative clones were identified repeatedly by Southern blotting and DNA/DNA hybridisation, it was not possible to identify individual putative clones following transformation into E. coli MV1184 and colony hybridisation. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1997.

Pervasive developmental disorders are a group of neurodevelopmental-neuropsychiatric disorders that are characterized by variable and severe pervasive impairments in several areas of child development, notably social interaction, communication and imagination. They all share clinical features but differ in the severity and age of onset of the impairments. Except for Rett Syndrome (RTT), the etiology of these disorders is unknown, but there is strong evidence that genetic factors contribute to their pathogenesis. While no major genes have been linked to theses disorders linkages, association and chromosomal studies suggest that many loci may be involved. / One aim of the present study was to search for genetics variants associated with autism and other related disorders. This study represents the first family-based association study looking at the entire X chromosome using a French-Canadian autistic population, a genetically homogenous group. We found association between autism and markers at two loci. Our results support the existence of a putative gene located on the X chromosome and moreover the founder effect, in the French-Canadian population, may provide greater power to fine map disease genes especially in complex traits. / The second aim of the present thesis was to confirm the involvement of the MECP2 gene in our RTT group of patients. While we confirm the presence of mutations in this gene in our cohort of RTT patients we also demonstrated that clinical stringency greatly influences the mutation detection rate for this disorder.