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Biomedical subjects

I R Franklin

Publications and source records attributed to I R Franklin.

8 recordsLinked to original sources
PubMed2004

Gene expression in sheep skin and wool (hair).

We sequenced 2939 ESTs from fetal and adult sheep skin. Stages of gestation were picked to coincide with the major events in skin appendage (wool follicle) formation. Clustering analysis generated a nonredundant set of ESTs 2435 strong (83% nonredundant). Approximately 24% of these gave no hit to NCBI build 29 of the human genome, while 35% were tentatively classified by putative function based on BLASTX hits with a p(N) of <10(-4). In addition to bioinformatics analysis of our ESTs and gene mapping, we have generated a large EST spatial expression data set using in situ hybridization. One thousand one hundred forty-two ESTs have been used for in situ localization; about 31% are from adult sheep skin, 39% from late gestation fetal sheep skin, and 30% from midgestation fetal sheep skin. These probes have been used in over 3000 hybridization experiments. In this report, we summarize the results of in situs on adult sheep skin.

Animals↗
PubMed2003

Systematic screening of sheep skin cDNA libraries for microsatellite sequences.

65,000 sheep skin cDNA clones were gridded in high density on to nylon membranes and screened for (CA)n and (GA)n repeat containing clones. 296 dinucleotide repeat-containing clones were identified with approximately 85% non-redundancy. Clones were single-pass 5' sequenced and we compared the Expressed Sequence Tag (EST) sequences to the Swiss-Prot database to ascertain their identity and/or putative function. We then aligned the ESTs against the human genomic sequence to determine the locations of human orthologous sequences. Finally, we developed a subset of polymorphic microsatellite markers and positioned them on the ovine linkage map.

Animals↗
PubMed1995

Effects of cis-trans viability selection on some two-locus models.

Most analyses of two-locus viability models have assumed that the fitness of double heterozygotes are the same whether in the cis or trans configuration. This assumption is unlikely to hold for polymorphic sites within the same locus. We examine the quantitative and qualitative effects of incorporating cis-trans viability differences into a number of deterministic two-locus models. A new result is the finding that two asymmetric equilibria with similar levels of linkage disequilibrium, but different gene frequencies, may arise in quite realistic biological models. The general, and most important, conclusion is that high levels of linkage disequilibrium may be generated by very small selective differences in cis and trans. Polymorphic sites that interact selectively are expected to show high levels of linkage disequilibrium. Conversely, if two polymorphic sites within a gene are found to be in linkage equilibrium, it is likely that one or both are selectively neutral.

Animals↗
PubMed1994

Decline in heterozygosity under full-sib and double first-cousin inbreeding in Drosophila melanogaster.

The effects of inbreeding on heterozygosities and reproductive fitness were determined by carrying out full-sib and double first-cousin inbreeding in Drosophila melanogaster populations for up to 18 generations. Parents were scored each generation for five or six polymorphic enzyme loci, and progeny numbers per pair were recorded. Inbreeding depression, in the form of significant reductions in progeny numbers and significant extinction of lines, was observed. Heterozygosity decreased at a significantly slower rate than predicted, being about 80% of expected. The full-sib and double first-cousin treatments showed similar disagreement with expectations over comparable ranges of inbreeding. Natural selection was shown to favor heterozygotes in the inbred lines. Associative overdominance was the most probable explanation for the slower than expected decline in heterozygosity.

Alleles↗