135 RECOMBINANT BOVINE SOMATOTROPIN ON THE IN VITRO PRODUCTION OF BOVINE EMBRYOS
L. Berté A , L. Vasconcelos B , L. Hatamoto-Zervoudakis A , W. Yamazaki B , L. Yamazaki B and G. Santos BA Federal University of Mato Grosso State, Cuiabá, Mato Grosso, Brazil;
B Bioembryo- Biotecnologia da Reproduço Animal, Cuiabá, Mato Grosso, Brazil
Reproduction, Fertility and Development 26(1) 181-181 https://doi.org/10.1071/RDv26n1Ab135
Published: 5 December 2013
Abstract
Bovine growth hormone (bGH) has been used to improve the results for in vitro production of bovine embryos. Inclusion of bGH in the maturation medium increases both rate of cleavage and frequency of blastocyst development. Thus, the purpose of the present study was to evaluate the effect of recombinant bovine somatotropin (rBST) on cleavage and blastocyst development of bovine embryos when included during in vitro maturation (IVM) only (Group 1), during both IVM and in vitro culture (IVC; Group 2), during IVC only (Group 3), or not included during either IVM or IVC (Group 4). Specifically, in Group 1, oocytes were matured in TCM 199 (Earle's salts) supplemented with 10% FCS, LH, FSH, oestradiol, and amikacin (IVM medium), plus 100 ng mL–1 of rBST and cultured in SOFaaci supplemented with essential amino acids, tri-sodium citrate, myo-inositol, and 5% FBS. In group 2, oocytes were matured in IVM medium containing 100 ng mL–1 of rBST and cultured in SOFaaci supplemented with essential amino acid, tri-sodium citrate, myo-inositol, 5% FBS; on Day 5, rBST (50 ng mL–1) was added. In Group 3, oocytes were matured in IVM medium without rBST; on Day 5, rBST (50 ng mL–1) was added. Group 4 was the control, without rBST supplementation. The treatment groups were analysed using the SAS® (SAS Institute Inc., Cary, NC, USA) in a completely randomised design (P < 0.05). Somatotropin has receptors in cumulus cells and in the zona pellucida acting directly in the oocyte; however, the increase in cleavage rate seen in previous studies after rBST treatment was not observed in the present study. Supplementation of culture medium with rBST during Day 2 to 6 of IVC has been shown to increase the number of trophoblast and subsequent pregnancy rate following transfer. However, in the present study, addition of 50 and 100 ng mL–1 of rBST to the maturation or culture medium did not affect the cleavage rate of embryos and blastocyst production.
|
