Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 5 uppsatser.

Restriction enzyme, molecular cloning and DNA annealing techniques have been used to study mRNA and DNA coding for the embryonic feather keratins of the chicken and the DNA genomes of coliphages 186 and P2. The coliphage DNAs were used to develop the techniques for application to the keratin system which awaited the availability of appropriate bio - hazard containment facilities before being undertaken. The following results were obtained. 1. Restriction endonuclease cleavage of chick DNA with BamHI, BgïII, EcoRI, or HindIII, fractionation on agarose gels, immobilization on nitrocellulose filters and annealing to DNA complementary to purified 12S mRNA isolated from the developing embryonic feather and coding for embryonic feather keratins, yielded a complex pattern of major and minor bands. These patterns consisted of 4 - 6 major bands and many minor bands. No simple repeat length could be deduced from these patterns, suggesting that keratin - coding DNA is heterogeneous in coding sequences, non - coding sequences or both. 2. Keratin gene expression was shown to be independent of DNA rearrangement, as the complex pattern of restriction fragments was identical in DNA isolated from germ - line tissue ( sperm ) the differentiated feather tissue and somatic tissue not synthesizing keratins ( erythrocytes ). Keratin gene expression must therefore involve the activation of pre - existing control regions in the DNA. 3. The purified 12S mRNA coding for feather keratin was transcribed into double - stranded DNA and individual species isolated by molecular cloning in E. coli. Sequence variation between species was confirmed by restriction enzyme analysis. 4. Preliminary analysis of the cloned species revealed the existence of two distinct groups of species comprising 12S mRNA : Group I ( the more abundant group ) and Group II ( the less abundant ). The fact that filter - bound DNA of individual Group I species bound more 12s cDNA than equal amounts of Group II species DNA and that pure Group I species and total 12S mRNA sequences ( coding for keratins in cell - free translation systems ) annealed to exactly the same complex set of EcoRI, HindIII, or BgïII restricted chick DNA fragments, compels the conclusion that Group I species represent true keratin coding sequences. Group II species annealed to restricted chick DNA fragments which were totally different to those annealing, to either Group I species or total 12S mRNA sequences. Different Group II species appeared to anneal to certain common fragments, suggesting that this less abundant group was comprised of a family of sequence related species and were not simply contaminating mRNA species coding for ' housekeeping ' functions. Their exact nature is at present, however, uncertain. 5. Group I species, the presumptive keratin - coding species, are members of a family of homologous species present in the chick genome. This is demonstrated by the fact that the two Group I species which have been examined so far, shown to be non - identical by restriction analysis, and total 12S mRNA sequences from which they were derived, annealed to the same set of between 20 and 30 BglII, HindIII or EcoRI restricted chick DNA fragments under annealing and washing conditions of low stringency, ( high salt ). Under stringent ( low salt ) washing conditions, however, all except between 1 and 3 of the duplexes formed by these fragments and the Group I species were differentially lost from the filter, indicating that the majority of duplexes were mis - matched and therefore that these multiple copies were homologous and not identical. In addition the two non - identical Group I species annealed to EcoRI generated chick DNA fragments of different sizes under the stringent ( low salt ) washing conditions, demonstrating that differences must exist in the sequence of adjacent non - coding and / or intervening sequences ( should they exist ) for these two species. 6. Although the two Group I species discussed above annealed to different EcoRI generated chick DNA fragments under the stringent ( low salt ) washing conditions, they both annealed under these conditions to a HindIII generated chick DNA fragment of size 3.0 kb. Assuming that this is a single fragment and not two fragments co - electrophoresing by chance, sequences identical to or with very close homology to both of these species lie on the same fragment and are therefore linked in the genome. The exact nature of this linkage and of the extent of gene clustering, should it exist, was not determined. 7. Restriction cleavage maps of coliphages 186 and P2 were determined for the enzymes BamHI, BglII, EcoRI, HindIII, PstI, SaïI, XbaI, and XhoI. These maps were used to analyse four insertion or deletion mutants affecting the major control region of 186. 186ins2 and 186ins3 were shown to be insertions of an IS3 element in the cI. gene and int gene respectively. 186dell and 186del2 were shown to carry the same deletion affecting the cI gene, but 186del2 carried a cryptic insert in the repressor binding site ( operator ). / Thesis (Ph.D.)--Department of Biochemistry, 1979.

Bibliography: 31 unnumbered leaves at end of vol

Bibliography: leaves 98-136 / viii, 152 leaves : 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 Paediatrics, 1989

Thesis (M.Sc. (Environmental Biology))--Mahidol University, 1979.

Uma população experimental F2 foi desenvolvida a partir do cruzamento de uma linhagem macho de frangos de corte com uma linhagem de postura, com o objetivo de mapear QTLs (locos controladores de características quantitativas) para características de desempenho e carcaça. Um total de 2.063 animais F2 em 21 famílias de irmãos completos obtidas em 17 incubações. As aves foram criadas como frangos de corte e abatidas a 6 semanas de idade, foram avaliadas 19 características de desempenho e carcaça. A genotipagem foi realizada em 3 fases: 1) Um total de 80 marcadores microssatélites do cromossomo 1 foram testados nos indivíduos parentais e F1 para identificar marcadores informativos. 2) Genotipagem seletiva dos indivíduos F2 que representam os extremos fenotípicos para peso vivo aos 42 dias de idade (P42), para identificar regiões potencialmente associadas (P < 0,10) com esta característica. 3) Sete famílias de irmãos completos (649 F2) foram genotipados para 12 marcadores associados na fase 2 e para 14 marcadores flanqueadores. Mapeamento por intervalo utilizando regressão foi aplicado para dois modelos genéticos (F2 e meio-irmãos) para detectar QTLs Foram encontradas fortes evidências de QTLs afetando peso vivo, consumo de ração, conversão alimentar e peso de asas, coxas e sobrecoxas, peito, gordura abdominal, fígado, pulmão e coração no cromossomo 1. / An F2 chicken population was developed by crossing a broiler sire line and a layer line, with the objective of mapping Quantitative Trait Loci (QTL) for performance and carcass traits. A total of 2,063 F2 chicks in 21 full-sib families from 17 hatches were reared as broilers and slaughtered at 6 weeks of age. Nineteen performance and carcass quality traits were measured. The genotyping was done in three phases: 1) A total of 80 microsatellite markers from chromosome 1 were tested in the parental and F1 individuals to identify informative markers. 2) Selective genotyping of F2 individuals, representing extreme phenotypes for body weight at 42 days of age (BW42), to identify regions potentially associated (P < 0,10) with this trait. 3) Seven full-sib families (649 F2 chicks) were genotyped for 12 markers associated in phase 2 and for additional 14 flanking markers. Interval mapping using regression methods was applied to two different genetic models: 1) Line-cross; 2) Half-sib analyses for mapping QTL. Strong evidences for QTL affecting body weight, feed intake, feed conversion and weights of drums and thighs, breast, abdominal fat, liver, lung and heart were found on chromosome 1.

Since changes in chromosome morphology contribute to the knowledge of evolution as well as to chromosome dynamics, this study looks specifically at one chromosome compared in twelve different species of Perissodactyls: Equus caballus (ECA), E. przewalskii (EPR), Equus africanus somaliensis (EAF), E. asinus (EAS), E. hemionus onager (EHO), E. h. kulan (EHK), E. h. kiang (EKI), E. zebra hartmannae (EZH), E. grevyi (EGR), E. burchelli (EBU), Tapirus indicus (TIN), and Rhinoceros unicornis (RUN). While chromosome morphology studies have been done in some of the extant equids, none have followed the evolution of this chromosome, homologous to Equus caballus chromosome 20 (ECA20), which contains the major histocompatibility complex (MHC). The gene order on the chromosome arm homologous to human chromosome six in most Equidae is reversed with respect to the centromere in comparison to humans. Multicolor fluorescence in situ hybridization was used to show that four probes from ECA20 hybridized to ECA20 (control), SWA5, EAS8, EHO16, EHK14, EKI16, EZH10, EGR11, EBU13, TIN4, and one of RUN12, 14, 15, or 22. The order for the four genes in the horses, zebras, and rhinoceros were as follows: cen-EDN1-MHC-ITPR3-MUT. Hybridization to the ass and tapir chromosomes displayed a possible neocentromere formation. It is apparent the chromosome has gone through several morphological changes while undergoing speciation in the Equidae, yet the overall gene order is conserved.

Includes bibliography / 154, [94] leaves, [12] 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 Biochemistry, 1986

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2002. / Härtill 4 uppsatser.