Expression of Transcripts in Marmoset Oocytes Retrieved during Follicle Isolation Without Gonadotropin Induction

Abstract

The in vitro maturation of oocytes is frequently used as an assisted reproductive technique (ART), and has been successfully established in humans and rodents. To overcome the limitations of ART, novel procedures for the in vitro maturation of early follicles are emerging. During the follicle isolation procedure, the unintended rupture of each follicle leads to a release of extra oocytes. Such oocytes, which are obtained during follicle isolation from marmosets, can be used for early maturation studies. Marmoset (Callithrix jacchus), which is classified as a new-world monkey, is a novel model that has been employed in reproductive biomedical research, as its reproductive physiology is similar to that of humans in several aspects. The ovaries of female marmosets were collected, and the excess oocytes present during follicle isolation were retrieved without pre-gonadotropin induction. Each oocyte was matured in vitro for 48 h in the presence of various concentrations of human chorionic gonadotropin (hCG) and epidermal growth factor (EGF), and the maturity of oocytes and optimal maturation conditions were evaluated. Each oocyte was individually reverse-transcribed, and the expression of mRNAs and microRNAs (miRs) were analyzed. Concentrations of hCG significantly affected the maturation rate of oocytes [the number of metaphase II (MII) oocytes]. The expression of BMP15 and ZP1 was highest when the oocytes were matured using 100 IU/L of hCG without pre-treatment with gonadotropins, and that of Cja-mir-27a was highest when cultured with follicle stimulating hormone. These results suggest that these up-regulated miRs affect the maturation of oocytes. Interactions with other protein networks were analyzed, and a strong association of BMP15 and ZP1 with sperm binding receptor (ACR), anti-Müllerian hormone (AMH), and AMH receptor was demonstrated, which is related to the proliferation of granulosa cells. Collectively, on the basis of these results, the authors propose optimal maturation conditions of excess oocytes of marmoset without in vivo gonadotropin treatment, and demonstrated the roles of miRs in early oocyte maturation at the single-cell level in marmosets.

Transcriptome Analyses Identify Potential Key microRNAs and Their Target Genes Contributing to Ovarian Reserve

“…Further studies are needed to elucidate the functions of these miRNAs as regulators of the ovarian reserve. We will further study the roles of these miRNAs during in vitro follicular development based on non-human primate models, which are physiologically closer to humans [ 76 , 77 , 78 ].…”

Reference values of hematological and biochemical parameters in young-adult cynomolgus monkey (Macaca fascicularis) and rhesus monkey (Macaca mulatta) anesthetized with ketamine hydrochloride

“…For example, rodents, who are evolutionary and genetically distant from humans, share only 64% genome identity with humans [1], while macaques and humans are 92% genetically similar [2]. The cynomolgus (Macaca fascicularis) and the rhesus macaque (Macaca mulatta) are the most widely used NHP models in various biomedical research fields, including genomic analysis [3] and neurodegenerative disease [4,5], as well as reproductive biomedical research [6][7][8].…”

Integrated analysis of miRNA–mRNA interaction in ovaries of Turpan Black Sheep during follicular and luteal phases

“…Among them, miR‐150 is putatively involved in cattle follicular atresia (Donadeu et al., 2017) and promotes ovine granulosa cell apoptosis (Zhou et al., 2019). MiR‐27a affects the maturation of oocyte (Kim et al., 2019), promotes human granulosa cell apoptosis by targeting SMAD5 (Nie et al., 2015) and may be related to premature ovarian insufficiency (POI) (Guo et al., 2017). Recent researches show that miR‐125b contributes to Yak granulosa cells apoptosis through targeting BMPR1B (Yao et al., 2018) and affects the expression of androgen synthesis‐related enzymes and testosterone secretion through targeting PAK3/ERK1/2 signalling in mouse preantral follicles (Zhang et al., 2020).…”