Efficient production of cynomolgus monkeys with a toolbox of enhanced assisted reproductive technologies.

Yunhan Ma,Guoping Feng,Qunshan Huang,Ge Wang,Sien Qiu,Andy Peng Xiang,Liang Gao,Shihua Yang,Qi Zhou,Haifeng Wan,Yang Zhou,Qiong Ke,Jiayu Li

doi:10.1038/srep25888

Abstract

The efficiency of assisted reproductive technologies (ARTs) in nonhuman primates is low due to no screening criterions for selecting sperm, oocyte, and embryo as well as its surrogate mothers. Here we analyzed 15 pairs of pregnant and non-pregnant cynomolgus monkeys, each pair of which received embryos from one batch of fertilized oocytes, and found ratio of endometrial to myometrial thicknesses in abdominal ultrasonic transverse section of uterus is a reliable indicator for selection of recipients for embryo transfer. We performed 305 ovarian stimulations in 128 female cynomolgus monkeys and found that ovarian stimulation can be performed in a whole year and repeated up to six times in the same monkey without deteriorating fertilization potential of eggs until a poor response to stimulation happened. Fertilization can be efficiently achieved with both conventional and piezo-driven intracytoplasmic sperm injection procedures. In semen collection, semen quality is higher with the penile robe electrical stimulus method compared with the rectal probe method. Moreover, caesarean section is an effective strategy for increasing baby survival rates of multiple pregnancies. These findings provide a practical guidance for the efficient use of ARTs, facilitating their use in genetic engineering of macaque monkeys for basic and translational neuroscience research.

Highlights

Cynomolgus monkey is an attractive primate animal for genetic engineering of disease models due to its year-round reproductive capability, moderate size, complex behaviors and similarity to humans in physiology and pathology
To evaluate the influence of both ejaculation methods on sperm motility, sperm cells and seminal plasma were exchanged between REM and PEM semen, and our results showed that REM sperm became more vital after being mixed with PEM seminal plasma while PEM sperm were less vital when suspended in REM seminal plasma (Fig. 1C)
Our findings demonstrate that in cynomolgus monkeys, ovarian stimulation can be repeated six times if good responses were achieved at previous stimulation. (Fig. 2D,D’) That is to say that ovarian stimulation should not be repeated any more whenever the monkey shows a poor response to stimulation

Summary

Introduction

Cynomolgus monkey is an attractive primate animal for genetic engineering of disease models due to its year-round reproductive capability, moderate size, complex behaviors and similarity to humans in physiology and pathology. There are few reproductive researches in cynomolgus monkeys, which result in a slow development of its ARTs. In this study, we systematically compared several key procedures in ARTs including stimulated ejaculation, seasonal variation of reproduction, superovulation, intracytoplasmic sperm injection (ICSI), embryo transfer and cesarean section. We systematically compared several key procedures in ARTs including stimulated ejaculation, seasonal variation of reproduction, superovulation, intracytoplasmic sperm injection (ICSI), embryo transfer and cesarean section These results enhance the efficiency of ARTs and should increase the success of generating genetically modified monkeys, which helps for the creation of advanced animal models to make key breakthroughs on primate neuropathic diseases research

Methods

Results

Conclusion