TY - JOUR

T1 - Dynamics of sex-biased gene expression during development in the stick insect Timema californicum

AU - Djordjevic, Jelisaveta

AU - Dumas, Zoe

AU - Robinson-Rechavi, Marc

AU - Schwander, Tanja

AU - Parker, Darren James

PY - 2022/8

Y1 - 2022/8

N2 - Sexually dimorphic phenotypes are thought to arise primarily from sex-biased gene expression during development. Major changes in developmental strategies, such as the shift from hemimetabolous to holometabolous development, are therefore expected to have profound consequences for the dynamics of sex-biased gene expression. However, no studies have previously examined sex-biased gene expression during development in hemimetabolous insects, precluding comparisons between developmental strategies. Here we characterized sex-biased gene expression at three developmental stages in a hemimetabolous stick insect (Timema californicum): hatchlings, juveniles, and adults. As expected, the proportion of sex-biased genes gradually increased during development, mirroring the gradual increase of phenotypic sexual dimorphism. Sex-biased genes identified at early developmental stages were generally consistently male- or female-biased at later stages, suggesting their importance in sexual differentiation. Additionally, we compared the dynamics of sex-biased gene expression during development in T. californicum to those of the holometabolous fly Drosophila melanogaster by reanalyzing publicly available RNA-seq data from third instar larval, pupal and adult stages. In D. melanogaster, 84% of genes were sex-biased at the adult stage (compared to only 20% in T. californicum), and sex-biased gene expression increased abruptly at the adult stage when morphological sexual dimorphism is manifested. Our findings are consistent with the prediction that the dynamics of sex-biased gene expression during development differ extensively between holometabolous and hemimetabolous insect species.

AB - Sexually dimorphic phenotypes are thought to arise primarily from sex-biased gene expression during development. Major changes in developmental strategies, such as the shift from hemimetabolous to holometabolous development, are therefore expected to have profound consequences for the dynamics of sex-biased gene expression. However, no studies have previously examined sex-biased gene expression during development in hemimetabolous insects, precluding comparisons between developmental strategies. Here we characterized sex-biased gene expression at three developmental stages in a hemimetabolous stick insect (Timema californicum): hatchlings, juveniles, and adults. As expected, the proportion of sex-biased genes gradually increased during development, mirroring the gradual increase of phenotypic sexual dimorphism. Sex-biased genes identified at early developmental stages were generally consistently male- or female-biased at later stages, suggesting their importance in sexual differentiation. Additionally, we compared the dynamics of sex-biased gene expression during development in T. californicum to those of the holometabolous fly Drosophila melanogaster by reanalyzing publicly available RNA-seq data from third instar larval, pupal and adult stages. In D. melanogaster, 84% of genes were sex-biased at the adult stage (compared to only 20% in T. californicum), and sex-biased gene expression increased abruptly at the adult stage when morphological sexual dimorphism is manifested. Our findings are consistent with the prediction that the dynamics of sex-biased gene expression during development differ extensively between holometabolous and hemimetabolous insect species.

U2 - 10.1038/s41437-022-00536-y

DO - 10.1038/s41437-022-00536-y

M3 - Article

C2 - 35581477

VL - 129

SP - 113

EP - 122

JO - Heredity

JF - Heredity

SN - 0018-067X

IS - 2

ER -