243 IN VITRO PRODUCTION OF LLAMA EMBRYOS BY IVF OR ICSI
P. A. Conde A , C. Herrera A , M. G. Chaves B , S. M. Giuliano B , A. Director B , V. L. Trasorras B , M. Pinto B , M. I. Sarchi C , D. Stivale C , B. Rutter B , A. Agüero B , M. H. Miragaya B and R. S. Pasqualini AA Halitus Biotecnología, Capital Federal, Buenos Aires, Argentina
B Facultad de Veterinaria, Universidad de Buenos Aires, Capital Federal, Buenos Aires, Argentina
C Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Capital Federal, Buenos Aires, Argentina
Reproduction, Fertility and Development 19(1) 237-238 https://doi.org/10.1071/RDv19n1Ab243
Submitted: 12 October 2006 Accepted: 12 October 2006 Published: 12 December 2006
Abstract
Interest in South American camelids has increased in the last few years. Assisted reproduction techniques, such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) with epididymal spermatozoa, have shown poor results in these species (Tibary et al. 2005 Theriogenology 64, 618–638). The aim of the present study was to compare the efficacy of IVF vs. ICSI for in vitro embryo production in llama (Lama glama) using oocytes collected from ovarian follicles of different sizes. A total of 193 oocytes were collected from 223 follicles aspirated from 21 adult females by flank laparotomy after ovarian stimulation. Before aspiration, the diameter of each follicle was measured, and oocytes from each female were randomly assigned to either IVF or ICSI treatment. Semen samples were collected by electroejaculation and incubated in 25% (v/v) collagenase solution at 37°C to reduce viscosity. For IVF, spermatozoa were either non-treated or treated with heparin, penicillamine, and hypotaurine as capacitating agents. For ICSI, some oocytes were activated immediately after sperm injection with 5 µM of ionomycin for 10 min and 2 mM of 6-DMAP for 3 h, while others were subjected only to sperm injection. Spermatozoa used for ICSI were not treated with capacitating agents. All presumptive zygotes were cultured in SOFaas for 8 days. The percentage of total oocytes and mature (MII) oocytes recovered from follicles <7 mm and >7 mm in diameter were compared in each female. The proportion of oocytes inseminated via IVF and ICSI that cleaved and developed to the blastocyst stage was compared. The proportion of total oocytes, MII-oocytes, cleaved embryos, and blastocysts were compared between treatments by chi-square and Fisher's tests. The percentages of total (77/100; 77%) and MII (9/31; 29%) oocytes collected from <7 mm follicles were significantly lower than those of total (116/126; 92%) and MII (43/55; 78%) oocytes collected from >7 mm follicles (P < 0.01). The highest cleavage rates were observed in oocytes collected from follicles >7 mm in diameter and fertilized by IVF with (56%) or without (50%) capacitating agents; these rates were significantly different from those of the other treatments (P < 0.05, Table 1). Further studies will determine if the present results can be obtained with a higher number of oocytes. The results of the present study provide the first demonstration that Lama glama embryos can be produced in vitro using fresh semen. In addition, we have provided the initial description of blastocyst development after culture of ICSI-derived embryos in a defined medium.
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