PRESENCE OF SULFHYDRYL-GROUPS AND DISULFIDE BONDS IN AMPHIBIAN GAMETES

The presence of sulfhydryl groups and disulfide bonds was studied in t he jelly coats of oocytes and in the extracting solution of oocyte's s trings (egg water) of Bufo arenarum (Amphibia, Anura). The results sho w that: a) molecules containing either sulfhydryl or disulfide groups are released into the medium when oocyte's strings are immersed in sal ine solutions, b) the jelly coats contain 2.4 +/- 0.6 mu moles of disu lfide groups per oocyte. On the surface of spermatozoa of Leptodactylu s chaquensis (Amphibia, Anura), about 20 mu moles of sulfhydryl groups per 10(6) spermatozoa were detected. Ln this case no significant vari ation in the amount of sulfhydryl was detected after acrosome breakdow n. When assaying for sulfhydryl groups in the media in which spermatoz oa were incubated, a high correlation was observed between the content of sulfhydryl groups in the media and the acrosome status: a) the inc ubation media of non-reacted spermatozoa (AI = 1) contained about 7.5 mu moles of sulfhydryl/10(6) spermatozoa, b) The media in which sperma tozoa have completed acrosome breakdown (Al = 5) contained about 28 mu moles sulfhydryl/10(6) spermatozoa. The sulfhydryl-containing molecul es are not related to the activity of spermatolysins.