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

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).

The initiation of puberty in Atlantic salmon brings about large changes in testicular gene expression that are modulated by the energy status

“…3) included Wnt and Tgfβ signaling pathways as well as a broad diversity of genes related to cell division and metabolism. Previous studies on transcriptomic changes during fish spermatogenesis showed functional enrichments similar to those reported here [38, 42–45]. The regulation of spermatogenesis involves a similar set of signaling pathways as in mice [46, 47], suggesting that the global composition of this network is a conserved feature of vertebrate spermatogenesis regulation.…”

“…The regulation of spermatogenesis involves a similar set of signaling pathways as in mice [46, 47], suggesting that the global composition of this network is a conserved feature of vertebrate spermatogenesis regulation. It is interesting to note, however, that previous transcriptomic studies in fish, as well as in mice, covered a broader range of germ cell stages, often [38, 42, 43, 45–47] even the complete spermatogenic process. Our study revealed a similarly broad array of pathway activation, although we investigated only the initial step of pubertal spermatogenesis, the mitotic expansion of Sertoli cells and of undifferentiated type A spermatogonia and the associated increase in androgen production.…”

Plasma proteome profiling of freshwater and seawater life stages of rainbow trout (Oncorhynchus mykiss)

“…Moreover, several proteins that are lower in smolts are related to a series of previously described changes related to a lower resource investment towards some nonessential processes during smoltification. One of them is sexual maturation (kinesin-like protein KIF20B [98]), which is delayed in migrators [99][100][101]. Another is the repression of some immune pathways [20], exemplified here by a decrease in mast cell proliferation (ras-GEF domain-containing family member 1B-A [102,103]).…”

New Insights on Folliculogenesis and Follicular Placentation in Marine Viviparous Fish Black Rockfish (Sebastes Schlegelii)

“…Transcriptome analysis referred to a previous article (Wang et al,. 2018) [70].…”