RT Journal
A1 Shao, Changwei
A1 Li, Qiye
A1 Chen, Songlin
A1 Zhang, Pei
A1 Lian, Jinmin
A1 Hu, Qiaomu
A1 Sun, Bing
A1 Jin, Lijun
A1 Liu, Shanshan
A1 Wang, Zongji
A1 Zhao, Hongmei
A1 Jin, Zonghui
A1 Liang, Zhuo
A1 Li, Yangzhen
A1 Zheng, Qiumei
A1 Zhang, Yong
A1 Wang, Jun
A1 Zhang, Guojie
T1 Epigenetic modification and inheritance in sexual reversal of fish
JF Genome Research 
JO Genome Research 
YR 2014 
FD April 01 
VO 24 
IS 4 
SP 604 
OP 615 
DO 10.1101/gr.162172.113 
UL http://genome.cshlp.org/content/24/4/604.abstract 
AB Environmental sex determination (ESD) occurs in divergent, phylogenetically unrelated taxa, and in some species, co-occurs with genetic sex determination (GSD) mechanisms. Although epigenetic regulation in response to environmental effects has long been proposed to be associated with ESD, a systemic analysis on epigenetic regulation of ESD is still lacking. Using half-smooth tongue sole (Cynoglossus semilaevis) as a model—a marine fish that has both ZW chromosomal GSD and temperature-dependent ESD—we investigated the role of DNA methylation in transition from GSD to ESD. Comparative analysis of the gonadal DNA methylomes of pseudomale, female, and normal male fish revealed that genes in the sex determination pathways are the major targets of substantial methylation modification during sexual reversal. Methylation modification in pseudomales is globally inherited in their ZW offspring, which can naturally develop into pseudomales without temperature incubation. Transcriptome analysis revealed that dosage compensation occurs in a restricted, methylated cytosine enriched Z chromosomal region in pseudomale testes, achieving equal expression level in normal male testes. In contrast, female-specific W chromosomal genes are suppressed in pseudomales by methylation regulation. We conclude that epigenetic regulation plays multiple crucial roles in sexual reversal of tongue sole fish. We also offer the first clues on the mechanisms behind gene dosage balancing in an organism that undergoes sexual reversal. Finally, we suggest a causal link between the bias sex chromosome assortment in the offspring of a pseudomale family and the transgenerational epigenetic inheritance of sexual reversal in tongue sole fish.