Transcriptome Dynamics During Turbot Spermatogenesis Predicting the Potential Key Genes Regulating Male Germ Cell Proliferation and Maturation

Xueying Wang,Jun Li,Rui Xue,Haixia Zhao,Chengcheng Feng,Shihong Xu,Zongcheng Song,Qinghua Liu,Yongshuang Xiao,Yanfeng Wang

doi:10.1038/s41598-018-34149-5

Abstract

Spermatogenesis is a dynamic developmental process in which spermatogonial stem cells proliferate, differentiate and mature into functional spermatozoa. These processes require an accurate gene regulation network. Here, we investigated the dynamic changes that occur during spermatogenesis through a combination of histological and transcriptome analyses of different developmental stages of the testis. We constructed 18 testis transcriptome libraries, and the average length, N50, and GC content of the unigenes were 1,795 bp; 3,240 bp and 49.25%, respectively. Differentially expressed genes (DEGs) that were related to germ cell proliferation and maturation, such as NANOS3, RARs, KIFs, steroid hormone synthesis-related genes and receptor genes, were identified between pairs of testis at different developmental stages. Gene ontology annotation and pathway analyses were conducted on DEGs with specific expression patterns involved in the regulation of spermatogenesis. Nine important pathways such as steroid hormone biosynthesis related to spermatogenesis were identified. A total of 21 modules that ranged from 49 to 7,448 genes were designed by a weighted gene co-expression network analysis. Furthermore, a total of 83 candidate miRNA were identified by computational methods. Our study provides the first transcriptomic evidence for differences in gene expression between different developmental stages of spermatogenesis in turbot (Scophthalmus maximus).

Highlights

IntroductionDetailed information about the genes and pathways that regulate the proliferation and maturation of male germ cells, especially at certain developmental stages, is lacking
Genes and steroid hormones coordinate the spermatogenesis process
Male germ cell proliferation mainly occurred at MSII and MSIII stages

Summary

Introduction

Detailed information about the genes and pathways that regulate the proliferation and maturation of male germ cells, especially at certain developmental stages, is lacking. During the early spermatogenesis period, mitosis of the spermatogonia and meiosis of the spermatocyte are accompanied by a cytoskeleton rearrangement At these stages, the genes and pathways involved in cell signalling and cell division, such as MAPs, regulate male germ cell proliferation. The genes and pathways involved in cell signalling and cell division, such as MAPs, regulate male germ cell proliferation Steroid hormones, such as progestogens, androgens and oestrogens show important variations during male gonad www.nature.com/scientificreports/. The aims of the present study were to assess the transcriptome and the gene expression dynamics of six developmental stages of turbot ranging from MSII to MSVI and to identify pivotal differentially expressed genes (DEGs), gene families, and miRNA that may regulate spermatogenesis. The present study will provide useful information for the exploration of possible spermatogenesis mechanisms at the molecular level for marine fish species

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