Attempts at in vitrofertilization and culture of in vitromatured oocytes in sei (Balaenoptera borealis) and Bryde's (B. edeni) whales.

M. M. U. Bhuiyan; Y. Suzuki; H. Watanabe; K. Matsuoka; Y. Fujise; H. Ishikawa; S. Ohsumi; Y. Fukui

SummaryThe cumulus?oocyte?complexes (COCs) recovery rates with respect to reproductive status per sei (Balaenoptera borealis) and Bryde's (B. edeni) whales were determined in Experiment 1. The number of COCs recovered ranged from 16.0 to 30.6 and from 6.7 to 26.8 per sei and Bryde's whales, respectively. The effects of COCs grades and protein supplementation in embryo culture medium on development of in vitrofertilized (IVF) embryos were evaluated in sei and Bryde's whales in Experiment 2. The COCs were classified into either Grade A (COCs with five or more layers of compact cumulus cells) or Grade B (COCs with less than five layers of compact or expanded cumulus cells) before being cultured for IVM. The cleavage (12.0 to 19.5%), 4-cell (8.0 to 12.0%) and 8-cell (4.0 to 8.0%) formation rates in sei whales did not vary significantly between embryos derived from either grade A or B oocytes and between embryos cultured in either fetal whale serum (FWS)- or bovine serum albumin (BSA)-supplemented medium. The cleavage (4.0 to 14.8%), 4-cell (0.0 to 7.5%) and 8-cell (0.0 to 2.6%) formation rates in Bryde's whales did not vary significantly between embryos derived from either grade A or B oocytes and between embryos cultured in either FWS- or BSA-supplemented medium. The grade B oocytes cultured in FWS-supplemented medium developed to morula stage (1.1%) in sei whales. In conclusion, the present study indicates that IVF in sei whales is possible to achieve cleaved embryos developing to morula stage. This is the first in vitroembryo production attempt in sei and Bryde's whales.

FERTILIZATION in vitro; CULTURES (Biology); OVUM; SEI whale; BRYDE whale; MAMMAL reproduction; DEVELOPMENTAL biology; REPRODUCTIVE technology

Zygote, 2009, Vol 17, Issue 1, p19

0967-1994

Academic Journal

10.1017/S0967199408004887