Another interesting gene is apolipoprotein Bwhich has accumulated three nonsense mutations on the Y-chromosome. Email alerts Article activity alert. Background Natural selection alters the local genomic environment around newly evolved sex-determination loci in two ways. All expected phenotypic classes of exceptional females were also recovered.
Excluded from our analyses are multiple exchanges and exchange events without phenotypic consequence, such as exchanges between homologous rDNA loci of sister chromatids. Microsatellite distribution on sex chromosomes at different stages of heteromorphism and heterochromatinization in two lizard species Squamata: Eublepharidae: Coleonyx elegans and Lacertidae: Eremias velox BMC Genet.
Read article at publisher's site DOI : Hum Mol Genet. These chromosomes had the expected genetic properties and cytological structures. This is a preview of subscription content, log in to check access. Lee, N.
Snake Sex Determination Dogma Overturned. Life Sci. Ferns and lycophytes have bisexual gametophytes and so there is no evidence for sex chromosomes. Male chromosome or Y chromosome contains many genes determining various characteristics. Environmental Sex Determination.
Analyses of additional species are needed to understand ancestral states and the patterns of evolutionary transition between sex-determination systems, as well as providing a framework for understanding why African cichlids have such rapid turnover in sex chromosome systems.
The phylogenetic relationship of the species studied is shown in Figure 1 Meyer Matthew A Conte. Cytology of recombinant chromosomes.