The deep conservation of the Lepidoptera Z chromosome suggests a non canonical origin of the W Journal Article

Author(s): Fraisse, Christelle; Picard, Marion A; Vicoso, Beatriz
Article Title: The deep conservation of the Lepidoptera Z chromosome suggests a non canonical origin of the W
Affiliation IST Austria
Abstract: Moths and butterflies (Lepidoptera) usually have a pair of differentiated WZ sex chromosomes. However, in most lineages outside of the division Ditrysia, as well as in the sister order Trichoptera, females lack a W chromosome. The W is therefore thought to have been acquired secondarily. Here we compare the genomes of three Lepidoptera species (one Dytrisia and two non-Dytrisia) to test three models accounting for the origin of the W: (1) a Z-autosome fusion; (2) a sex chromosome turnover; and (3) a non-canonical mechanism (e.g., through the recruitment of a B chromosome). We show that the gene content of the Z is highly conserved across Lepidoptera (rejecting a sex chromosome turnover) and that very few genes moved onto the Z in the common ancestor of the Ditrysia (arguing against a Z-autosome fusion). Our comparative genomics analysis therefore supports the secondary acquisition of the Lepidoptera W by a non-canonical mechanism, and it confirms the extreme stability of well-differentiated sex chromosomes.
Journal Title: Nature Communications
Volume: 8
Issue 1
ISSN: 2041-1723
Publisher: Nature Publishing Group  
Date Published: 2017-12-01
Start Page: Article number: 1486
Copyright Statement: CC BY
Sponsor: This project was funded by an Austrian Science Foundation FWF grant (Project P 28842) to B.V
DOI: 10.1038/s41467-017-01663-5
Notes: The authors thank Harald Krenn for advice on microlepidoptera, Ariana Macon for DNA extractions and preparation for sequencing, the Vicoso lab, Dominik Schrempf and Chay Graham for taking part in moth collections and James R. Walters, Petr Nguyen, and Anna Voleníková for their comments on the manuscript.
Open access: yes (OA journal)