AUTHOR=Xiong Lei , Yang Mengli , Zheng Kai , Wang Ziming , Gu Shengli , Tong Jiucui , Liu Jianjun , Shah Nadar Ali , Nie Liuwang 

TITLE=Comparison of Adult Testis and Ovary MicroRNA Expression Profiles in Reeves’ Pond Turtles (Mauremys reevesii) With Temperature-Dependent Sex Determination

JOURNAL=Frontiers in Genetics

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2020.00133

DOI=10.3389/fgene.2020.00133

ISSN=1664-8021

ABSTRACT=<p>Some differentially expressed genes (DEGs) that encode key enzymes involved in steroidogenic biosynthesis (<italic>CYP19A1</italic>) and key molecules related to gonadal functions (<italic>DMRT1</italic>, <italic>SOX9</italic>, <italic>AMH</italic>, <italic>FOXL2</italic>, <italic>WNT4</italic>, <italic>RSPO2</italic>, and <italic>GDF9</italic>) have been identified in adult gonadal RNA-seq studies of Reeves’ pond turtle (<italic>Mauremys reevesii</italic>) with temperature-dependent sex determination (TSD). Gonadal functional maintenance and gametogenesis comprises a highly regulated and coordinated biological process, and increasing evidence indicates that microRNAs (miRNAs) may be involved in this dynamic program. However, it is not clear how the regulatory network comprising miRNAs changes the expression levels of these genes. In this study, miRNA sequencing of adult testis and ovary tissues from <italic>M. reevesii</italic> detected 25 known and 379 novel miRNAs, where 60 miRNAs were differentially expressed in the testis and ovary. A total of 1,477 target genes based on the differentially expressed miRNAs were predicted, where 221 target genes also exhibited differential expression. To verify the accuracy of the sequencing data, 10 differentially expressed miRNAs were validated by quantitative reverse transcription real-time PCR, and were found to be consistent with the transcriptome sequencing results. Moreover, several miRNA/target gene pairs, i.e., mre-let-7a-5p/mre-let-7e-5p and <italic>CYP19A1</italic>, mre-miR-200a-3p and <italic>DMRT1</italic>, mre-miR-101-3p and <italic>SOX9</italic>, and mre-miR-138-5p and <italic>AMH</italic> were identified. To explore the regulatory role of miRNAs, we conducted target gene enrichment analysis of the miRNAs and 221 target genes in the regulatory network. The signaling pathways related to gonadal functional maintenance and gametogenesis based on the DEGs and target genes were then compared. Our findings provide crucial information to facilitate further research into the regulatory mechanisms involving miRNAs in turtle species with TSD.</p>