De novotranscriptome sequencing to identify the sex-determination genes inHyriopsis schlegelii

Abstract

(2015) De novo transcriptome sequencing to identify the sex-determination genes in

Sex Determining Mechanisms in Bivalves

“…In freshwater mussels, an in-depth study of sex-specific genes has recently been conducted on sperm and ovary tissues of the gonochoric species Hyriopsis schlegelii (Shi et al 2015). A total of 45,422 unigenes were found to be differentially expressed between the ovary and sperm and among them, key genes reported to govern sexdetermination pathways in mammals were identified, including Sry, Dmrt1, Dmrt2, Sox9, GATA4 and WT1, which were upregulated in males, and Wnt4, Rspo1, Foxl2, and β -catenin, which were upregulated in females (Shi et al 2015).…”

“…A total of 45,422 unigenes were found to be differentially expressed between the ovary and sperm and among them, key genes reported to govern sexdetermination pathways in mammals were identified, including Sry, Dmrt1, Dmrt2, Sox9, GATA4 and WT1, which were upregulated in males, and Wnt4, Rspo1, Foxl2, and β -catenin, which were upregulated in females (Shi et al 2015). These results suggest that H. schlegelii and mammals use similar gene regulatory mechanisms to control sex determination (Shi et al 2015).…”

“…A total of 45,422 unigenes were found to be differentially expressed between the ovary and sperm and among them, key genes reported to govern sexdetermination pathways in mammals were identified, including Sry, Dmrt1, Dmrt2, Sox9, GATA4 and WT1, which were upregulated in males, and Wnt4, Rspo1, Foxl2, and β -catenin, which were upregulated in females (Shi et al 2015). These results suggest that H. schlegelii and mammals use similar gene regulatory mechanisms to control sex determination (Shi et al 2015). Broadly, male sex determination in mammals is initiated by the expression of Sry (Sex-determining region on Y), which suppresses ovarian promoting genes and activates Sox9 (Sry-box 9), a key element of the testis-determining cascade leading to the activation of Dmrt1 and differentiation of Sertoli cells, whereas female sex determination is initiated by the forkhead box transcription factor FoxL2, β -catenin and Wnt4, which promotes and maintains ovarian development while suppressing Sox9 (Veitia 2010).…”

“…Broadly, male sex determination in mammals is initiated by the expression of Sry (Sex-determining region on Y), which suppresses ovarian promoting genes and activates Sox9 (Sry-box 9), a key element of the testis-determining cascade leading to the activation of Dmrt1 and differentiation of Sertoli cells, whereas female sex determination is initiated by the forkhead box transcription factor FoxL2, β -catenin and Wnt4, which promotes and maintains ovarian development while suppressing Sox9 (Veitia 2010). Because hermaphroditism has already been noted in H. schlegelii, Shi et al (2015) also focused their efforts on searching for key genes known to regulate sex determination in other hermaphroditic model species, such as Caenorhabditis elegans. Interestingly, genes associated with hermaphrodite phenotypes in the roundworm C. elegans, i.e., Tra-1, Tra-2α, Tra-2β, Fem1A, Fem1B, and Fem1C (reviewed in Gamble and Zarkower 2012), and genes associated with dosage compensation mechanisms in the fruit fly Drosophila, such as Msl1, Msl2, and Msl3 (Legube et al 2006), were also identified in H. schlegelii, suggesting that diverse regulatory mechanisms regulate sexual polymorphism in this species (Shi et al 2015).…”

“…Because hermaphroditism has already been noted in H. schlegelii, Shi et al (2015) also focused their efforts on searching for key genes known to regulate sex determination in other hermaphroditic model species, such as Caenorhabditis elegans. Interestingly, genes associated with hermaphrodite phenotypes in the roundworm C. elegans, i.e., Tra-1, Tra-2α, Tra-2β, Fem1A, Fem1B, and Fem1C (reviewed in Gamble and Zarkower 2012), and genes associated with dosage compensation mechanisms in the fruit fly Drosophila, such as Msl1, Msl2, and Msl3 (Legube et al 2006), were also identified in H. schlegelii, suggesting that diverse regulatory mechanisms regulate sexual polymorphism in this species (Shi et al 2015).…”