Full-Length Transcriptome Sequences Provide Insight Into Hermaphroditism of Freshwater Pearl Mussel Hyriopsis schlegelii

Qi Zeng; Beijuan Hu; Andres Hortas Blanco; Wanchang Zhang; Daxian Zhao; Paulino Martínez; Yijiang Hong

doi:10.3389/fgene.2022.868742

Full-Length Transcriptome Sequences Provide Insight Into Hermaphroditism of Freshwater Pearl Mussel Hyriopsis schlegelii

Front Genet. 2022 Mar 24:13:868742. doi: 10.3389/fgene.2022.868742. eCollection 2022.

Authors

Qi Zeng^{1

2}, Beijuan Hu^{1

2

3}, Andres Hortas Blanco⁴, Wanchang Zhang^{1

2}, Daxian Zhao^{1

2}, Paulino Martínez⁴, Yijiang Hong^{1

2

3}

Affiliations

¹ School of Life Sciences, Nanchang University, Nanchang, China.
² Key Lab of Aquatic Resources and Utilization of Jiangxi, Nanchang, China.
³ Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang, China.
⁴ Department of Zoology Genetics and Physical Anthropology, Faculty of Veterinary, University of Santiago de Compostela, Lugo, Spain.

Abstract

The freshwater mussel Hyriopsis schlegelii is a cultured bivalve in China, and the quality of the pearls produced is affected by the type of gonads. However, because of the lack of a published genome and the complexity of sex determination, research on sex reversal and development of this species is limited. In this study, Illumina RNA-seq and PacBio Isoform Sequencing (Iso-Seq) were combined to analyze the gonads of H. schlegelii. A total of 201,481 high-quality transcripts were generated. The study identified 7,922 differentially expressed genes in three comparison group (females versus males, hermaphrodites versus females, and hermaphrodites versus males). Twenty-four genes were identified as potential sex-related genes, including sox9 and wnt4 involved in sex determination, and vtg, cyp17a1 and 17β-hsd2 involved in gonadal development. We also speculated a possible pathways for the formation of hermaphroditism in H. schlegelii. The data provide a clear view of the transcriptome for H. schlegelii gonads and will be valuable in elucidating the mechanisms of gonad development.

Keywords: 17β-hsd2; Hyriopsis schlegelii; Iso-seq; RNA-seq; gonad.