Tubal embryo transfer in cynomologus monkeys: effects of hyperstimulation and synchrony

Abstract

To date the main limitation of in-vitro fertilization-embryo transfer (IVF-ET) programmes is that transcervical transfer of embryos results in a rate of low implantation. On the other hand, the technique of gamete intra-Fallopian transfer (GIFT) does not contribute to information on oocyte fertilization rates, and the time of oocyte exposure to sperm may be limited. The development of ultrasonically guided follicular aspiration will allow transfer of embryos generated in vitro to the Fallopian tubes performing only one surgical procedure in the process. We have performed 25 intra-tubal embryo transfers in the cynomolgus monkey (Macaca fascicularis). Ovarian stimulation, follicular aspiration and IVF procedures have been reported previously by Balmaceda. ETs were performed via laparotomy. Embryos at the 2-, 4- or 9-cell stage were loaded into a tom-cat catheter in 5 microliter of culture medium and delivered to the mid-ampullary portion of the tube. Seven ETs performed during stimulated cycles resulted in one pregnancy, and 18 ETs performed in synchronized recipients resulted in six pregnancies. Ten ETs were performed 0-24 h, eight performed 24-48 h and seven performed 72-110 h after follicular aspiration or ovulation, and resulted in 4, 3 and 0 pregnancies respectively. Our results demonstrate that intra-tubal embryo transfer can result in normal intra-uterine pregnancies and suggest that both ovarian stimulation and cycle synchronization affect the probability of embryo implantation.

Efficient reproduction of cynomolgus monkey using pronuclear embryo transfer technique

“…Since the first birth of a rhesus macaque after IVF in the mid-1980s (1), several laboratories have reported successfully obtaining infants of rhesus, cynomolgus monkey, and pigtailed macaque by IVF or ICSI (8)(9)(10)(11)(12)(13)(14). However, the success rate has been low in comparison with that for rodents and humans.…”

“…To date there has been no report using a pronuclear embryo transfer technique for the production of in vitro-fertilized nonhuman primates, including cynomolgus monkey (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Based on our and other researchers' extensive experiences in producing transgenic mice (15,(18)(19)(20)(21)(22), it is reasonable to postulate that transferring embryos at the pronuclear stage can come with the certain benefits, such as decreasing the risk of losing embryo quality during the course of long-term in vitro culture.…”

Biology of primate relaxin: A paracrine signal in early pregnancy?

“…Many of the difficulties associated with mating and natural conception in macaques that make the study of implantation and early pregnancy difficult can be circumvented by the use of IVF/ET. Previous studies have shown some success with IVF/ET procedures in M. fascicularis , with implantation rates of 8.3%–12.0% achieved using 1–4 embryos transferred per recipient during natural cycles [147-149]. …”

In vitro fertilization‐embryo transfer in nonhuman primates: The technique and its applications

“…That estradiol receptors were not detected in any ovarian compartment, except the surface epithelium, during the normal menstrual cycle (Hild-Petito et al, 1988) questions a local role for estradiol during folliculogenesis. Likewise, the re- Balmaceda et al, 1988Wolf et al, 1989Lanzendorf et al, 1990b Ovulation (day 0) estimated as athe day of sex skin breakdown, bfirst time a corpus luteum was identified at laparoscopy, or '24 hours after midcycle LH surge.…”