Anna Maryańska-Nadachowska, Valentina G. Kuznetsova, Dorota Lachowska, Sakis Drosopoulos
Journal of Insect Science 12 (54), 1-17, (17 April 2012) https://doi.org/10.1673/031.012.5401
KEYWORDS: cytogenetics, Karyotype evolution, sex chromosome system
The evolution of karyotypes and sex determination system of Philaenus Stål (Auchenorrhyncha: Aphrophoridae) species is studied here in detail. The most plausible scenario of chromosomal rearrangements accompanying phylogenetic differentiation in Philaenus is advanced. It is postulated that the ancestral karyotype of Philaenus was 2n = 24 X0. Karyotype changes occurred several times independently in the genus. The karyotype of 2n = 22 X0 (P. spumarius and P. tesselatus) originated from 2n = 24 X0 by fusion between two autosomal pairs. The neo—XY system (P. arslani, P. loukasi, P. signatus, P. maghresignus, and P. tarifa) also originated from the 24 X0 karyotype by means of independent fusions between autosomes and the original X chromosome. The neo—X1X2Y system (P. italosignus) evolved from the 2n = 22 neo—XY karyotype by an additional fusion between the Y chromosome and one more autosomal pair. The neo—XnY system of P. italosignus is the first reported case of an evolutionarily fixed multiple sex chromosome system in Auchenorrhyncha.