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Developmental Capacity In Vitro of Prepubertal Oocytes
Author(s) -
Palma G. A.,
Tortonese D. J.,
Sinowatz F.
Publication year - 2001
Publication title -
anatomia, histologia, embryologia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.34
H-Index - 35
eISSN - 1439-0264
pISSN - 0340-2096
DOI - 10.1046/j.1439-0264.2001.00324.x
Subject(s) - oocyte , andrology , human fertilization , follicle stimulating hormone , blastocyst , biology , ovary , in vitro fertilisation , follicle , in vitro maturation , hormone , embryo , endocrinology , medicine , luteinizing hormone , embryogenesis , anatomy , microbiology and biotechnology
A 2‐year comparative study was carried out to evaluate the effect of ovary size, follicle size and oocyte quality of 3‐month‐old Simmental calves and the efficiency of using calf ovaries in an in vitro fertilization (IVF) programme. We evaluated the effects of different concentrations of follicle‐stimulating hormone (FSH) and oestradiol‐17β (E‐17β) in the maturation medium on the in vitro development of calf oocytes into morula and blastocysts. The proportion of recovered oocytes (62.1%; 42.8%; 25.3%) and the percentage of good quality cumulus oocyte complexes (84.2%; 59.8%; 45.9%) decreased significantly ( P < 0.01) with decreasing ovary size (L, M and S). The rates of two or more cells on Day 2 and of blastocysts on Day 7 and Day 9 were significantly lower ( P < 0.01) for calf oocytes (61.5%; 18.9%; 15.9%) compared with those from sexually matured females (70.1%; 32.3%; 22.2%). Calf oocytes, matured in medium supplemented with 20 μg/ml or 10 μg/ml FSH plus 2 μg/ml E‐17β had higher rates of cleavage on Day 2 (64.1% and 64.7%) and blastocysts on Day 7 (24.5% and 22.4%) than the control supplemented with 10 μg/ml FSH (55.6% and 19.2%, respectively). Groups supplemented with 20 μg/ml FSH plus 2 μg/ml E‐17β and 10 mg/ml plus 4 mg/ml E‐17β showed a significantly lower developmental rate of blastocysts on Day 7 (14.6% and 14.5%). High concentrations of E‐17β (4 μg/ml) resulted in a significantly lower development of blastocysts on Day 9 (8.1%) and hatched blastocysts on Day 13 (3.5%) ( P < 0.01). We conclude that the proportion of calf oocytes obtained from immature animals and their suitability for IVF are lower than those of cows. Thus, the use of oocytes from sexually immature females would decrease the relative efficiency of IVF programmes. Supplementation with high concentrations of FSH can improve the maturation and developmental capacity of oocytes from prepubertal calves.