Cytogenetic Analysis of the Members of the Snake Genera , , , and .

The recent discovery of two independently evolved XX/XY sex determination systems in the snake genera and sparked a new drive to study the evolution of sex chromosomes in poorly studied lineages of snakes, where female heterogamety was previously assumed. Therefore, we examined seven species from the genera , , , and by conventional and molecular cytogenetic methods. Despite the fact that these species have similar karyotypes in terms of chromosome number and morphology, we detected variability in the distribution of heterochromatin, telomeric repeats, and rDNA loci.