Evolution of mouse major histocompatibility complex genes borne by t chromosomes.
AUTOR(ES)
Figueroa, F
RESUMO
Virtually all wild mouse populations carry t haplotypes that cause embryonic lethality or semilethality, distortion of segregation ratios, suppression of crossing-over, and male sterility. The t complex of genes is located on chromosome 17, closely linked to the H-2, the major histocompatibility complex of the mouse. The t haplotypes differ from each other not only in lethal genes they carry but also in their linked H-2 haplotypes. In this study, we compared the class II H-2 genes present on 31 t chromosomes extracted from wild populations in different parts of the world. The comparison was based on the analysis of DNA fragments obtained after digestion with restriction endonucleases. The results reveal the existence of three major groups of class II alleles representing main branches on the evolutionary tree of the t chromosomes. Alleles within each group are similar if not identical, although they are borne by chromosomes that have been separated in time and space. The presence of similar alleles in Mus musculus and Mus domesticus suggests that some of them may have been separated for more than 1 million years. This must also be the minimal age of the t chromosomes but, because at least two of the three main branches appear to be related in their origin, the actual age of t chromosomes could be much greater. The observations support the proposal that H-2 genes evolve slowly.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=397657Documentos Relacionados
- Structure, function, and evolution of mouse TL genes, nonclassical class I genes of the major histocompatibility complex.
- Assignment of genes to regions of mouse chromosomes.
- Concerted evolution of class I genes in the major histocompatibility complex of murine rodents.
- Transmembrane domain length variation in the evolution of major histocompatibility complex class I genes.
- Evolution of the major histocompatibility complex: molecular cloning of major histocompatibility complex class I from the amphibian Xenopus.