Figure 5

Diploidization mechanism: origin of C. androgenes. The proposed fast diploidization mechanism through an "intermediate triploid female" with altered meiosis and trivalent segregation. Scheme A: cn = 35 androgen might have appeared or by direct hybridization of species/forms, or by incorrect X segregation during the meiosis I of the triploid female. Both ways might give rise to a male with cn = 35, with a numerically and structurally diploid karyotype, but with a suppressed meiosis, an indication of a possible hybrid origin. Scheme B: cn = 53 androgen would derive directly from a C. gallica-like strain: the accidental loss on an X chromosome produced a male individual with suppressed meiosis, which started the cn = 53 androgenetic clone, with numerically triploid karyotype, but with diploid structure.