Étude de la conversion génique chez les familles multigéniques.
|Title:||Étude de la conversion génique chez les familles multigéniques.|
|Abstract:||Three multigene families have been studied from the point of view of gene conversion. The data sets included a group of plant actin genes from five different angiosperm species (maize, tomato, potato, soybean and tobacco), a group of primate globin genes (the $\delta$ and $\beta$ genes of human and tarsier, the $\gamma\sb1$ and $\gamma\sb2$ genes of human and orangutan) and a group of zinc finger genes (Zfx and Zfy), linked to the sex chromosomes of seven mammalian species (rat, mouse, fox, squirrel monkey, baboon, orangutan, human). The analysis was done by using four simulation methods and one compatibility method. The compatibility method is a variant of Fitch method (Fitch et al. 1990). The simulation methods include Sawyer's method (Sawyer 1989) and the codoubles method (Balding et al. 1992). To take into account the fact that different chromosomes may have different mutation rates, a variant of the codoubles method is introduced (the method of variable rates). All these methods are non specific and a method for specifically detecting areas of gene conversion is also introduced. Two conversion events were detected in the maize family. These results based exclusively on exons are confirmed by a high degree of sequence similarity between corresponding introns. The results obtained for the globin genes are in agreement with previous compatibility analyses and confirm the presence of gene conversion in this multigene family. In the case of the Zfx/Zfy genes, gene conversion was detected at a significant level for the rat and/or squirrel monkey lineages. Site by site analysis indicates that the conversion occurred probably in the primate lineage. soon after the separation of primates and rodents.|
|Collection||Thèses, 1910 - 2010 // Theses, 1910 - 2010|