This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Abeydeera, L. R. Articles by Niwa, K. Search for Related Content PubMed Articles by Abeydeera, L. R. Articles by Niwa, K.

Ability of in vitro maturing bovine oocytes to transform sperm nuclei to metaphase chromosomes

Summary. Bovine oocytes at the germinal vesicle stage were inseminated in Brackett & Oliphant's medium with bovine serum albumin, caffeine and heparin. Eight hours after insemination, oocytes were transferred into tissue culture medium-199 containing 10% fetal calf serum and cultured for 5–40 h at 39°C in 5% CO₂ in air. The proportions of unpenetrated and penetrated oocytes reaching metaphase II increased as the time of examination increased, reaching 70 and 65% 40 h after transfer, respectively. When oocytes were penetrated by more than four spermatozoa, meiotic maturation was greatly retarded. Sperm nuclei were decondensed in most (81%) penetrated oocytes 5 h after transfer. The decondensed sperm nuclei were recondensed and then transformed to metaphase chromosomes which were morphologically compacted at first but became slightly dispersed later. The formation of the metaphase chromosomes was observed in 86% of penetrated oocytes examined 40 h after transfer, and occurred in all metaphase II oocytes at that time. In oocytes penetrated by more than nine spermatozoa, no such transformation of sperm nuclei was observed. Well-developed male and female pronuclei were observed in only three (6%) of 51 oocytes penetrated 40 h after transfer.

Keywords: cow; oocytes; sperm penetration; sperm metaphase chromosomes; in vitro

This article has been cited by other articles:

				M. Nakai, N. Kashiwazaki, A. Takizawa, N. Maedomari, M. Ozawa, J. Noguchi, H. Kaneko, M. Shino, and K. Kikuchi Morphologic changes in boar sperm nuclei with reduced disulfide bonds in electrostimulated porcine oocytes. Reproduction, March 1, 2006; 131(3): 603 - 611. [Abstract] [Full Text] [PDF]