Agarose gel electrophoresis of PCR product of buffalo ALK6 in different tissues. 1, skin; 2, bone; 3, granular cells; 4, cumulus cells; 5, ovary; 6, testis; 7, muscle; 8, genital ridge; 9, heart; 10, liver; 11, lung; 12, kidney; 13, brain; 14, hypophysis; 15, hypothalamus; 16, water.