Data from: Sexually dimorphic gene expression and transcriptome evolution provides mixed evidence for a fast‐Z effect in Heliconius
Data files
Dec 19, 2018 version files 1.79 MB
-
1_1_melpomene_erato_ortho.txt
402.50 KB
-
divergence_autosomes.csv
565.05 KB
-
divergence_Z.csv
26.75 KB
-
polymorphism_autosomes.csv
758.78 KB
-
polymorphism_Z.csv
33.82 KB
-
results_heliconius-1.csv
2.40 KB
-
total_alignement_autosomes_heliconius.SFS_DoFE
311 B
-
total_alignement_autosomes_heliconius.SFS_sum
757 B
-
total_alignement_autosomes_heliconius.sum
1.61 KB
-
total_alignement_Z_heliconius.SFS_DoFE
284 B
-
total_alignement_Z_heliconius.SFS_sum
749 B
-
total_alignement_Z_heliconius.sum
1.59 KB
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.