Anti-Müllerian hormone as a predictor of oocyte yield following controlled ovarian stimulation in the rhesus macaque.

Anti-Müllerian hormone (AMH) is widely used in the clinic as a biomarker for ovarian reserve and to predict ovarian response to gonadotropin stimulation. Patients with higher AMH levels tend to yield more oocytes and have better outcomes from assisted reproductive technology (ART) procedures. The goal of this study is to determine if AMH can be used to predict the outcome of controlled ovarian stimulation in rhesus macaques, which are commonly used in biomedical research, to refine animal use while maximizing oocyte yield.

Generation of Rhesus Macaque Embryos with Expanded CAG Trinucleotide Repeats in the Gene.

Huntington's disease (HD) arises from expanded CAG repeats in exon 1 of the () gene. The resultant misfolded HTT protein accumulates within neuronal cells, negatively impacting their function and survival. Ultimately, HTT accumulation results in cell death, causing the development of HD.

Influence of substance use on male reproductive health and offspring outcomes.

The prevalence of substance use globally is rising and is highest among men of reproductive age. In Africa, and South and Central America, cannabis use disorder is most prevalent and in Eastern and South-Eastern Europe, Central America, Canada and the USA, opioid use disorder predominates. Substance use might be contributing to the ongoing global decline in male fertility, and emerging evidence has linked paternal substance use with short-term and long-term adverse effects on offspring development and outcomes.

Establishing the normal range of sperm DNA fragmentation index (% DFI) for rhesus macaques.

The Sperm Chromatin Structure Assay (SCSA) is a robust test with high repeatability and precision. It is a clinically accepted assay that defines risk for infertility in men by measuring the degree of DNA fragmentation (% DFI) in sperm. The objective of this study was to adapt and validate the SCSA for rhesus macaques (Macaca mulatta) and establish a range for % DFI in fertile males.

A Comparison of Oocyte Yield between Ultrasound-Guided and Laparoscopic Oocyte Retrieval in Rhesus Macaques.

Obtaining quality oocytes is a prerequisite for ART-based studies. Here we describe a method for transabdominal ultrasound-guided (US) oocyte retrieval in rhesus macaques () and compare it to the standard surgical approach using laparoscopy (LAP). We analyzed oocyte yield from six continuous reproductive seasons (2017-2023) that included = 177 US-guided and = 136 laparoscopic oocyte retrievals.

Cessation of chronic delta-9-tetrahydrocannabinol use partially reverses impacts on male fertility and the sperm epigenome in rhesus macaques.

Objective: To determine whether discontinuation of delta-9-tetrahydrocannabinol (THC) use mitigates THC-associated changes in male reproductive health using a rhesus macaque model of daily THC edible consumption.

Design: Research animal study.

Setting: Research institute environment.

CRISPR/Cas9 editing of the MYO7A gene in rhesus macaque embryos to generate a primate model of Usher syndrome type 1B.

Mutations in the MYO7A gene lead to Usher syndrome type 1B (USH1B), a disease characterized by congenital deafness, vision loss, and balance impairment. To create a nonhuman primate (NHP) USH1B model, CRISPR/Cas9 was used to disrupt MYO7A in rhesus macaque zygotes. The targeting efficiency of Cas9 mRNA and hybridized crRNA-tracrRNA (hyb-gRNA) was compared to Cas9 nuclease (Nuc) protein and synthetic single guide (sg)RNAs.

Rapid, accurate mapping of transgene integration in viable rhesus macaque embryos using enhanced-specificity tagmentation-assisted PCR.

Genome engineering is a powerful tool for research and the creation of novel model organisms and has growing clinical applications. Randomly integrating vectors, such as lentivirus- or transposase-based methods, are simple and easy to use but carry risks arising from insertional mutagenesis. Here we present enhanced-specificity tagmentation-assisted PCR (esTag-PCR), a rapid and accurate method for mapping transgene integration and copy number.

Chronic exposure to delta-9-tetrahydrocannabinol impacts testicular volume and male reproductive health in rhesus macaques.

Objective: To determine the dose-dependent effect of delta-9-tetrahydrocannabinol (THC) exposure on male testes and reproductive health in a nonhuman primate model.

Design: Research animal study.

Setting: Research institute.

The effects of delta-9-tetrahydrocannabinol exposure on female menstrual cyclicity and reproductive health in rhesus macaques.

Objective: To determine the dose-dependent effect of contemporary marijuana exposure on female menstrual cyclicity and reproductive endocrine physiology in a nonhuman primate model.

Design: Research animal study.

Setting: Research institute environment.

Effects of marijuana on reproductive health: preconception and gestational effects.

Purpose Of Review: Recent widespread legalization changes have promoted the availability of marijuana and its increased potency and perceived safety. The limited evidence on reproductive and perinatal outcomes from marijuana exposure is enough to warrant concern and action. The objective of this review is to provide a current and relevant summary of the recent literature surrounding this topic.

Improved Training and Semen Collection Outcomes Using the Closed Box Chair for Macaques.

Collaborative semen collection in monkeys is a valuable tool in research, animal collection management, and conservation efforts. To obtain samples, monkeys are often restrained in open restraint chairs (ORC) with the "pole and collar" technique. While commonly used, this restraint is not tolerated by all individuals; some become anxious or aggressive towards the poles and people.

Cryopreservation and Preparation of Thawed Spermatozoa from Rhesus Macaques () for In Vitro Fertilization.

Advances in assisted reproductive technologies in rhesus macaques have allowed the development of valuable models of human disease, particularly when combined with recent techniques for gene editing. While the ability to perform in vitro fertilization (IVF) in rhesus macaques is well established, this procedure has not yet been optimized. Specifically, damage to the sperm caused by cryopreservation (cryodamage) may lead to unsuccessful artificial insemination and low fertilization and blastocyst formation rates in vitro.

Postpubertal spermatogonial stem cell transplantation restores functional sperm production in rhesus monkeys irradiated before and after puberty.

Background: Cancer treatment of prepubertal patients impacts future fertility due to the abolition of spermatogonial stem cells (SSCs). In macaques, spermatogenesis could be regenerated by intratesticular transplantation of SSCs, but no studies have involved cytotoxic treatment before puberty and transplantation after puberty, which would be the most likely clinical scenario.

Objectives: To evaluate donor-derived functional sperm production after SSC transplantation to adult monkeys that had received testicular irradiation during the prepubertal period.

Metabolomics analysis of follicular fluid coupled with oocyte aspiration reveals importance of glucocorticoids in primate periovulatory follicle competency.

Gonadotropin administration during infertility treatment stimulates the growth and development of multiple ovarian follicles, yielding heterogeneous oocytes with variable capacity for fertilization, cleavage, and blastocyst formation. To determine how the intrafollicular environment affects oocyte competency, 74 individual rhesus macaque follicles were aspirated and the corresponding oocytes classified as failed to cleave, cleaved but arrested prior to blastulation, or those that formed blastocysts following in vitro fertilization. Metabolomics analysis of the follicular fluid (FF) identified 60 unique metabolites that were significantly different between embryo classifications, of which a notable increase in the intrafollicular ratio of cortisol to cortisone was observed in the blastocyst group.

Development of WEE2 kinase inhibitors as novel non-hormonal female contraceptives that target meiosis†.

WEE2 oocyte meiosis inhibiting kinase is a well-conserved oocyte specific kinase with a dual regulatory role during meiosis. Active WEE2 maintains immature, germinal vesicle stage oocytes in prophase I arrest prior to the luteinizing hormone surge and facilitates exit from metaphase II arrest at fertilization. Spontaneous mutations at the WEE2 gene locus in women have been linked to total fertilization failure indicating that selective inhibitors to this kinase could function as non-hormonal contraceptives.

Identification and Screening of Selective WEE2 Inhibitors to Develop Non-Hormonal Contraceptives that Specifically Target Meiosis.

We used a progressive elimination strategy to identify oocyte-specific WEE2 kinase inhibitors for potential non-hormonal contraceptives that target meiosis. Beginning with an in-house library of over 300,000 compounds, virtual high throughput screening identified 57 WEE2 inhibitors with preferential predicted binding over the somatic variant WEE1. Seven compounds were further evaluated by enzyme-linked immunosorbent assay to measure biochemical inhibition on WEE1 and WEE2 phosphorylation of CDK1.

Chronically elevated androgen and/or consumption of a Western-style diet impairs oocyte quality and granulosa cell function in the nonhuman primate periovulatory follicle.

Purpose: To investigate the impact of chronically elevated androgens in the presence and absence of an obesogenic diet on oocyte quality in the naturally selected primate periovulatory follicle.

Methods: Rhesus macaques were treated using a 2-by-2 factorial design (n = 10/treatment) near the onset of menarche with implants containing either cholesterol (C) or testosterone (T, 4-5-fold increase above C) and a standard or "Western-style" diet alone (WSD) or in combination (T+WSD). Following ~ 3.

Phosphodiesterase 3 (PDE3) inhibition with cilostazol does not block in vivo oocyte maturation in rhesus macaques (Macaca mulatta).

Objective: Studies in mice suggest that cilostazol, an FDA-approved phosphodiesterase 3 (PDE3) inhibitor, might have a contraceptive effect within the approved dose range. We sought to evaluate the potential contraceptive effects of cilostazol in a nonhuman primate model.

Study Design: Adult female rhesus macaques were stimulated to develop multiple preovulatory follicles by administering human recombinant gonadotropins, and oocytes were collected by follicle aspiration 36 h after an ovulatory stimulus (human chorionic gonadotropin).

Ovarian germline stem cells: an unlimited source of oocytes?

While there has been progress in directing the development of embryonic stem cells and induced pluripotent stem cells toward a germ cell state, their ability to serve as a source of functional oocytes in a clinically relevant model or situation has yet to be established. Recent studies suggest that the adult mammalian ovary is not endowed with a finite number of oocytes, but instead possesses stem cells that contribute to their renewal. The ability to isolate and promote the growth and development of such ovarian germline stem cells (GSCs) would provide a novel means to treat infertility in women.

Identification of phosphodiesterase 9A as a cyclic guanosine monophosphate-specific phosphodiesterase in germinal vesicle oocytes: a proposed role in the resumption of meiosis.

Objective: To identify a cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase (PDE) in nonhuman primate germinal vesicle (GV) oocytes and establish a proposed effect on oocyte maturation through preliminary experiments in mouse GV oocytes.

Design: Controlled nonhuman primate and rodent experiments.

Setting: Academic research institution.

Expression of insulin-like 3 (INSL3) and differential splicing of its receptor in the ovary of rhesus macaques.

Background: Although insulin-like 3 (INSL3) has been identified in the gonad of both sexes in many species, there are only limited reports on the distribution of INSL3 and its receptor, relaxin/insulin-like family peptide receptor 2 (RXFP2), in the primate ovary. Since the hormone-receptor pair is believed to play a role in female reproduction, investigating the transcription of INSL3/RXFP2 genes and the spatiotemporal expression of INSL3 in the nonhuman primate may shed light on the functional aspects of the system in humans.

Methods: Database mining, molecular and immunological methods were applied.

WEE2 is an oocyte-specific meiosis inhibitor in rhesus macaque monkeys.

WEE1 homolog 2 (WEE2, also known as WEE1B) is a newly identified member of the WEE kinase family that is conserved from yeast to humans. The aim of the present study was to determine the spatiotemporal expression pattern and the function of WEE2 during oocyte maturation in a nonhuman primate species, the rhesus macaque. Among 11 macaque tissues examined, WEE2 transcript is predominantly expressed in the ovary and only weakly detectable in the testis.