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PubMed1989

Linkage studies of HLA and insulin gene restriction fragment length polymorphisms in families with IDDM.

Linkage analysis of HLA DR antigen as well as DR and DQ restriction fragment length polymorphism (RFLP) data using the LIPED computer program and various three-allele disease locus models showed very close linkage to an insulin-dependent diabetes mellitus (IDDM)-susceptibility locus. RFLP data alone were equal or superior to conventional HLA antigen typing in the linkage analysis. Insulin gene restriction fragment data were analyzed for evidence of either a susceptibility locus linked to the insulin gene or an effect of alleles at the insulin locus on the HLA-linked susceptibility gene. No evidence was found of any effect of the insulin gene, and it is suggested that alternative explanations of the reported population associations between the insulin gene and IDDM should be considered.

Computer Simulation↗

PubMedDate not supplied

Comparative mapping of genes from human chromosome 12 by genetic linkage mapping in cattle.

Loci from human chromosome 12 were mapped in cattle to compare the gene order between species. Polymorphisms were detected in cattle in six loci that had been mapped with high precision in humans. Four of these loci, LALBA, SLC2A3, SYT1, and TPI1, mapped to bovine chromosome 5, and one, PLA2G1B, mapped to bovine chromosome 17. The sixth locus, SLC2A3L, due to a fragment produced by the SLC2A3 primers, maps to the telomeric region of BTA18. The differences in gene order between human chromosome 12 and cattle chromosome 5, when these loci are added to others already mapped in cattle, show evidence of significant rearrangement in gene order requiring several evolutionary events. There is also evidence in cattle chromosome 5 of the interspersal of material conserved on human chromosome 22 into the material conserved on human chromosome 12, consistent with ZOOFISH analyses. This analysis indicates that the larger block near the centromere is conserved on the long arm of human chromosome 12 and the smaller block near the telomere is conserved as part of the short arm of human chromosome 12. The level of variation detected in the amplified cattle DNA was approximately 1 variant per 464 nucleotides of haploid DNA using single-strand conformation polymorphism analysis. This corresponds to a per individual level of 1 variant per 1, 961 nucleotides of haploid DNA. This confirms lower genetic variability in cattle compared to humans but indicates the potential for millions of single nucleotide polymorphisms in cattle.

Animals↗