Evolution and developmental dynamics of sex-biased gene expression. Rana temporaria

Using multiple developmental series of RNAseq datasets from one Rana temporaria population with proto-Y chromosomes, we aim to understand :i) Do sex chromosomes at an early stage of evolution show signs of differentiation?ii) Has transcriptional sexualization already started, i.e. are proto-sex chromosomes already enriched in sex-biased genes compared to autosomes?iii) Does sex bias in gene expression (whether sex-linked or autosomal) depend on genotypic- or on phenotypic-sex, and do sex-biased genes display faster rates of evolution? iv) How does sex bias change along developmental stages?