CHROMOSOME ANALYSIS OF MURRAH BUFFALO (BUBALUS-BUBALIS) SPERMATOZOA USING ZONA-FREE HAMSTER OOCYTES

An interspecific in vitro fertilization system was adopted to analyse sperm chromosomes of Murrah buffalo (Bubalus bubalis). Superovulation was induced in mature female golden hamsters (Mesocricetus auratus) to obtain a large number of oocytes. The zona pellucidae were digested b y trypsin treatment. Zona free hamster oocytes were penetrated by buff alo spermatozoa capacitated with calcium ionophore A23187. fertilized ova were cultured in Te 199 medium supplemented with 10% fetal calf se rum (FCS). Podophyllotoxin and vinblastine were used to interrupt kary ogamy and tubulin polymerization, respectively. Oocytes were fixed by modified gradual fixation air drying method. Slides were stained with 2% Giemsa for 45 min. Analyzable metaphase chromosome spreads were obt ained from 22.4+3.8% of the penetrated oocytes. Of the 70 sexed sperma tozoa, 38 were X-bearing and 32 were Y-bearing spematozoa.