A chromosomal investigation of four species of Chinese Panorpidae (Insecta, Mecoptera)

By

Xu, Bo
Li, Yankai
Hua, Baozhen

Type

Article

Date of Publication

2013

Original Publication

Comparative cytogenetics : international journal of plant & animal cytogenetics, karyosystematics and molecular systematics

Volume

7

Series / Issue

Issue: 3

Pages

229-239

Subjects

achiasmatic male meiosis , chromosome , Mecoptera , Panorpidae , XO sex-chromosome system

Contributed by

Pensoft Publishers

Language

English

Published by

St. Petersburg, Russia [Published] with technical support of Zoological Institute RAS [2007]-

Identifiers

DOI: https://doi.org/10.3897/compcytogen.v7i3.5500

 

Abstract

The male adults of four species of the Chinese Panorpidae in Mecoptera were cytogenetically studied using conventional squashing procedures. The results show that their sex-chromosome system belongs to the XO type, with n = 19 + X(O) in Panorpa emarginata Cheng, 1949 and Panorpa dubia Chou & Wang, 1981, n = 23 + X(O) in Panorpa sp., and n = 20 + X(O) in Neopanorpa lui Chou & Ran, 1981. X chromosomes of these species usually appear dot-shaped in late prophase I and are easily differentiated from autosomal bivalents. Meiosis in these Panorpidae lacks typical diplotene and diakinesis. In late prophase I, pairs of homologous chromosomes remain parallel in a line and show no evidence of crossing-over. Some of them even appear as a single unit because of extremely intimate association, all with a tendency of increasing condensation. The evolutionary significance of their chromosomal differences and the achiasmatic meiosis of Panorpidae are briefly discussed.