Sexually dimorphic gene expression and transcriptome evolution provides mixed evidence for a fast-Z effect in Heliconius
Authors
Publication Date
2019-03Journal Title
Journal of Evolutionary Biology
ISSN
1420-9101
Publisher
Wiley-Blackwell
Volume
32
Pages
194-204
Type
Article
This Version
VoR
Metadata
Show full item recordCitation
Jiggins, C. (2019). Sexually dimorphic gene expression and transcriptome evolution provides mixed evidence for a fast-Z effect in Heliconius. Journal of Evolutionary Biology, 32 194-204. https://doi.org/10.1111/jeb.13410
Abstract
Sex chromosomes have different evolutionary properties compared to autosomes due to their hemizygous nature. In particular, recessive mutations are more readily exposed to selection, which can lead to faster rates of molecular evolution. Here, we report patterns of gene expression and molecular evolution for a group of butterflies. First, we improve the completeness of the Heliconius melpomene reference annotation, a neotropical butterfly with a ZW sex determination system. Then, we analyse RNA from male and female whole abdomens and sequence female ovary and gut tissue to identify sex and tissue specific gene expression profiles in H. melpomene. Using these expression profiles we compare: 1) sequence divergence and polymorphism; 2) the strength of positive and negative selection; and 3) rates of adaptive evolution, for Z and autosomal genes between two species of Heliconius butterflies, H. melpomene and H. erato.
We show that the rate of adaptive substitutions is higher for Z than autosomal genes, but contrary to expectation, it is also higher for male biased than female biased genes. Additionally, we find no significant increase in the rate of adaptive evolution or purifying selection on genes expressed in ovary tissue, a heterogametic specific tissue. Our results contribute to a growing body of literature from other ZW systems that also provide mixed evidence for a fast‐Z effect where hemizygosity influences the rate of adaptive substitutions.
Sponsorship
European Research Council (339873)
NERC (1364753)
Embargo Lift Date
2100-01-01
Identifiers
External DOI: https://doi.org/10.1111/jeb.13410
This record's URL: https://www.repository.cam.ac.uk/handle/1810/287452
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