200 EFFECT OF OOCYTE SIZE AND MICROMANIPULATION TECHNIQUES (ICSI AND EMBRYO BIOPSY) ON GOAT EMBRYO QUALITY
A. R. Jimenez-Macedo A , B. Anguita A , D. Izquierdo A , R. Romaguera A , R. Morato A , T. Mogas A and M. T. Paramio AAUniversitat Autonoma de Barcelona, Bellaterra, Spain
Reproduction, Fertility and Development 19(1) 217-217 https://doi.org/10.1071/RDv19n1Ab200
Submitted: 12 October 2006 Accepted: 12 October 2006 Published: 12 December 2006
Abstract
The aim of this study was to evaluate embryo quality of prepubertal goat oocytes after micromanipulation techniques: ICSI and embryo biopsy. Prepubertal goat oocytes were recovered from a slaughterhouse and matured in IVM medium (TCM-199 with serum, hormones, and cystamine) for 27 h. Spermatozoa were selected by swim-up and capacitated with heparin (10 µg mL−1) plus ionomycin (200 nM) for 15 min. A total of 930 IVM oocytes were divided into 4 groups depending on size (Group I: 110–125 µm, and Group II: >125 µm) and fertilization procedure: ICSI or IVF. Zygotes were cultured in TALP fertilization medium. At 24 h post-insemination (hpi), zygotes were cultured in SOF. At 48 hpi, oocyte cleavage was recorded. Four days after insemination, a sample of 8-cell embryos was biopsied by removal of one blastomere. After biopsy, embryos were cultured in SOF for a further 4 days. Blastocysts were stained by TUNEL to assess apoptotic cell percentage. Results are shown in Table 1. Biopsied and non-biopsied embryos from Group II had higher blastocyst rates than those in Group I both in ICSI and IVF (P ≤ 0.02). Group II had also larger blastocyst cell numbers than Group I both in ICSI and in IVF (P ≤ 0.001). Moreover, blastocysts from Group II non-biopsied embryos had statistically larger cell numbers than those from the biopsied ones (P ≤ 0.05). Blastocysts from Group II had a lower apoptotic rate than those in Group I both in ICSI and IVF (P ≤ 0.05). In conclusion, oocytes larger than 125 µm were more competent to achieve embryo development than smaller oocytes. ICSI did not reduce embryo quality, either in blastocyst cell number or apoptotic index, when compared with IVF. Furthermore, embryo biopsy did not reduce blastocyst rates or apoptotic index. However, embryo biopsy reduced blastocyst cell number in Group II-derived blastocysts.
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