[1] Inst Nacl Ciencias Med & Nutr Salvador Zubiran, Mexico City, DF, Mexico
[2] Inst Nacl Ciencias Med & Nutr SZ, Catedras Biol Reprod, CONACyT, Mexico City, DF, Mexico
[3] Univ Wyoming, Laramie, WY 82071 USA
[4] Inst Politecn Nacl, Mexico City, DF, Mexico