THE PRODUCTION OF ANTI-H-Y MONOCLONAL-ANTIBODIES - THEIR POTENTIAL USE IN A SEX TEST FOR BOVINE EMBRYOS

In an attempt to improve the accuracy of sexing bovine embryos, new an ti-H-Y monoclonal antibodies were produced and selected, using an exte nded screening procedure. In addition to the commonly used screening o f soluble H-Y antigen sources, such as testis supernatant and Daudi su pernatant, the binding specificity to cell surface H-Y antigen was tes ted also. A radioimmunoassay (RIA) employing male and, as a control, f emale bovine lymphocytes, and enzyme-linked immunosorbent assays (ELIS As) on solubilized membrane fractions resulted in the selection of a n umber of clones producing monoclonal antibody (mAb) with male-enhanced binding. Four of the anti-H-Y mAb were assessed for binding to Day 7 or 8 bovine embryos. The accuracy of sexing bovine embryos ranged from 58% to 71%. Two of the four antibodies did not react with presumed so luble H-Y antigen-containing sources in an ELISA. These results raise doubts about the suitability of the presumed soluble H-Y antigen sourc es, Daudi, TM4 and testis supernatant, to be used in screening tests f or anti-H-Y antibodies.