beta-mercaptoethanol enhances blastocyst formation rate of bovine in vitro-matured/in vitro-fertilized embryos.
The objectives of this research were to determine the effects of beta-mercaptoethanol (beta-ME) and fetal bovine serum (FBS) on in vitro development of bovine embryos derived from oocytes matured and fertilized in vitro and to examine the mechanism through which beta-ME may influence embryo development. A 2 x 2 factorial treatment arrangement was used to evaluate the effect of 0 or 100 microM beta-ME and 0% or 10% FBS on embryos cultured in Medium 199 (M199) in the absence of somatic cells. Embryos were randomly allocated within stage of development (< 8 cells or 8-16 cells) to one of four treatment combinations and were cultured for 6 days. Both beta-ME and FBS promoted increased (p < 0.01) development of embryos to the blastocyst stage, and their effects were greater (p < 0.01) in 8- to 16-cell embryos than in embryos having fewer than 8 cells at the initiation of treatment. The cysteine and cystine content of M199, with and without beta-ME, were determined by HPLC. Medium supplemented with beta-ME contained neither cysteine nor cystine, and it is suggested that these compounds were converted into a mixed disulfide between cysteine and beta-ME. These results indicate that beta-ME is capable of enhancing bovine embryo development in a cell-free, serum-free culture system.
Caamaño
J N
JN
Department of Animal Science, Iowa State University, Ames 50011-3150, USA.
Ryoo
Z Y
ZY
Thomas
J A
JA
Youngs
C R
CR
D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D002417:Cattle / Q000196:embryology*; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D016895:Culture Media, Serum-Free; D046508:Culture Techniques; D003545:Cysteine / Q000032:analysis; D003553:Cystine / Q000032:analysis; D005314:Embryonic and Fetal Development; D005260:Female; D005307:Fertilization in Vitro; D008623:Mercaptoethanol / Q000494:pharmacology*
D003470:Culture Media; D016895:Culture Media, Serum-Free; D003553:Cystine; D008623:Mercaptoethanol; D003545:Cysteine