Chromosomes in two bug species of Hebrus (Hebridae, Heteroptera). The occurrence of neo-XY sex chromosome system in Heteroptera

Authors
Nokkala, S Nokkala, C
Citation
S. Nokkala et C. Nokkala, Chromosomes in two bug species of Hebrus (Hebridae, Heteroptera). The occurrence of neo-XY sex chromosome system in Heteroptera, CARYOLOGIA, 52(1-2), 1999, pp. 27-30
Citations number
12
Categorie Soggetti
Biology
Journal title
CARYOLOGIA
ISSN journal
00087114 → ACNP
Volume
52
Issue
1-2
Year of publication
1999
Pages
27 - 30
Database
ISI
SICI code
0008-7114(199901/06)52:1-2<27:CITBSO>2.0.ZU;2-B
Abstract
Chromosomes in two species in the genus Hebrus (Hebridae, Heteroptera) mere studied. The species H. ruficeps (Th.) showed the chromosome number 2n = 2 2A + XY with achiasmate sex chromosomes, which divided in the first meiotic division and separated from one another at the second division. H. pusillu s (Fn.) displayed 2n = 22A + neo-XY. The chromosomes of the neo-XY bivalent separated prereductionalIy in the first division. Both species lacked m-ch romosomes. It was suggested that although the XY sex chromosome system prev ails in Heteroptera, the formation of the neo-XY system has taken place in an XO ancestor after the loss of the Y chromosome.