Sex Determination, Sex Chromosomes, and Karyotype Evolution in Insects

Abstract

Insects harbor a tremendous diversity of sex determining mechanisms both within and between groups. For example, in some orders such as Hymenoptera, all members are haplodiploid, whereas Diptera contain species with homomorphic as well as male and female heterogametic sex chromosome systems or paternal genome elimination. We have established a large database on karyotypes and sex chromosomes in insects, containing information on over 13000 species covering 29 orders of insects. This database constitutes a unique starting point to report phylogenetic patterns on the distribution of sex determination mechanisms, sex chromosomes, and karyotypes among insects and allows us to test general theories on the evolutionary dynamics of karyotypes, sex chromosomes, and sex determination systems in a comparative framework. Phylogenetic analysis reveals that male heterogamety is the ancestral mode of sex determination in insects, and transitions to female heterogamety are extremely rare. Many insect orders harbor species with complex sex chromosomes, and gains and losses of the sex-limited chromosome are frequent in some groups. Haplodiploidy originated several times within insects, and parthenogenesis is rare but evolves frequently. Providing a single source to electronically access data previously distributed among more than 500 articles and books will not only accelerate analyses of the assembled data, but also provide a unique resource to guide research on which taxa are likely to be informative to address specific questions, for example, for genome sequencing projects or large-scale comparative studies.

Telomere structure in insects: A review

“…For the purposes of classification of various groups of Insecta, we generally use the system developed by Misof et al () which is based on phylogenomic data. For some orders, we also follow Beutel et al (), Peters et al (), Mason et al (), Blackmon, Ross, and Bachtrog () and a few other papers.…”

Sex‐specific changes in the aphid DNA methylation landscape

“…In mammals and birds, these sex chromosomes tend to be diverged between the sexes, (i.e., the X and Y, or the W and Z), alleviating some of the sexual antagonistic conflicts (Pennell & Morrow, ). Insects show a vast diversity of sex chromosome systems which range from the classical male heterogametic XY system in Drosophila, to ZW systems in Lepidoptera (Blackmon, Ross, & Bachtrog, ; Kaiser & Bachtrog, ). In some insect clades, such as grasshoppers, crickets and cockroaches, the original Y chromosome has been completely lost.…”

QTL Mapping and Marker Identification for Sex-Determining: Indicating XY Sex Determination System in the Swimming Crab (Portunus trituberculatus)

“…In crustaceans animals, the mechanisms of sex determination are remarkably diverse and are controlled by genetic and/or environmental factor (Ford, 2008). The sex determination system of some crustaceans can be identified by karyotype analysis (Abu-Almaaty, 2017; Blackmon et al, 2017). In crabs, four species ( Eriocheir japonica , Hemigrapsus sanguineus , Hemigrapsus penicillatus , and Plagusia dentipes ) were believed to have an XY sex determination system via karyotype analysis (Niiyama, 1937, 1938, 1959; Lecher and Noel, 1995).…”