Expression profiles of meiotic genes in male vs. female gonads and gametes: Insights into fertility issues

Abstract

Gametes are specialized cells that, at fertilization, give rise to a totipotent zygote capable of generating an entire organism. Female and male germ cells undergo meiosis to produce mature gametes; however, sex-specific events of oogenesis and spermatogenesis contribute to specific roles of gametes in reproductive issues. We investigate the differential gene expression (DGE) of meiosis-related genes in human female and male gonads and gametes in normal and pathological conditions. The transcriptome data for the DGE analysis was obtained through the Gene Expression Omnibus repository, comprising human ovary and testicle samples of the prenatal period and adulthood, additionally to male (non-obstructive azoospermia (NOA) and teratozoospermia), and female (polycystic ovary syndrome (PCOS) and advanced maternal age) reproductive conditions. Gene ontology terms related to meiosis were associated with 678 genes, of which 17 genes in common were differentially expressed between the testicle and ovary during the prenatal period and adulthood. Except for SERPINA5 and SOX9, the 17 meiosis-related genes were downregulated in the testicle during the prenatal period and upregulated in adulthood compared to the ovary. No differences were observed in the oocytes of PCOS patients; however, meiosis-related genes were differentially expressed according to the patient’s age and maturity of the oocyte. In NOA and teratozoospermia, 145 meiosis-related genes were differentially expressed in comparison to the control, including OOEP; despite no recognized role in male reproduction, OOEP was co-expressed with genes related to male fertility. Taking together, these results shed light on potential genes that might be relevant to comprehend human fertility disorders.

Revealing the expression profile of genes that encode the Subcortical Maternal Complex in human reproductive failures

“…Interestingly, the co-expression network demonstrated that the four validated SCMC genes are co-expressed with genes related to male reproduction. Interestingly, a previous work of our group evidenced OOEP downregulation in patients with teratozoospermia or non-obstructive azoospermia ( Rockenbach et al, 2023 ), evidencing possible new roles for the SCMC genes in both embryonic development and in female and male reproduction. Moreover, the results presented here shed light on a possible role of SCMC gene expression profile in later reproductive conditions, such as in post-implantation gestational events.…”

“…Although the SCMC is confirmedly present only in oocytes and early embryos ( Li et al., 2008b ; Zhu et al, 2014 ), it is not settled whether the proteins of the SCMC could act as single molecules in other tissues, not being aggregated to form the multi-protein complex. Literature reports based on the evaluation of conditions such as male fertility ( Rockenbach et al, 2023 ), and imprinting disorders ( Eggermann et al, 2021 ), have helped to instigate this hypothesis. However, not limited to tissue variability, we speculate whether the individual members of the SCMC could have roles in processes such as embryonic implantation and even in later steps, such as the maintenance of pregnancy.…”