Sex Chromosome Evolution: Moths and Butterflies Break the Rules - Beatriz Viçoso (IST, Austria)

4:00pm - 5:00pm / Tuesday 13th February 2018 / Venue: Lecture Theatre 1 Life Sciences Building
Type: Seminar / Category: Research / Series: BEEM Seminar
  • Suitable for: Staff and students with an interest in Behaviour, Evolution, Ecology and Microbiology
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Lepidoptera (moths and butterflies) have one of the best-studied ZW sex chromosome systems, but two important aspects of their evolution have remained unresolved:

Whether or not Lepidoptera as a whole have a global mechanism to regulate expression of the Z to compensate for the single copy of Z-linked genes in ZW females (i.e. a global mechanism of dosage compensation)

Whether the W is derived from an autosome (the canonical model for the origin of sex chromosomes), or from a non-canonical mechanism, such as the recruitment of a B-chromosome.

We have used comparative genomics and transcriptomics to obtain a better understanding of sex chromosome evolution in this group. We found that unlike other ZW clades (e.g. birds and snakes), all Lepidoptera studied so far have a chromosome-wide mechanism of dosage compensation. Further, while the Z appears to be ancient and well conserved, the W likely arose later through a non-canonical mechanism. These results emphasize the need to look at patterns of evolution in a broad range of organisms, and the potential of Lepidoptera as a model for ZW chromosome evolution.