A STUDY OF THE JELLY ENVELOPES SURROUNDING THE EGG OF THE AMPHIBIAN, XENOPUS LAEVIS x SALLIE B. FREEMAN -Department of Bioloi/y. Emory University, Atlanta. Gconjia 30322 The greatest interest in the oviclucal jelly material deposited around amphibian eggs has centered on its possible significance in the processes of meiosis (Humphries, 1961) and fertilization (Hughes, 1957; Kambara, 1953; Katagiri, 1963b, 1966; McLaughlin, 1967; Nadamitsu, 1957; Hugh, 1935, 1951; Shaver and Barch, 1960; Shivers and Metz, 1962; Subtelny and Bradt, 1961 ; Tchou and \\'ang, 1956). It is generally accepted that the jelly is necessary for successful fertilization of amphibian eggs; however, the particular properties of the jelly which make its presence essential to fertilization are largely unknown. Kambara ( 1 ( >53. p. 84) has suggested that the jelly ' . . . plays the role of a mechanical foothold which enables the sperm to penetrate the eggs." In contrast, Katagiri ( l ( -)u6) proposes that the jelly does not act as a foothold but that a smaller moiety in the jelly may facilitate adherence of the spermatozoa to the egg surface. The recent work of Barbieri and Yilleco ( 1966) also suggests that a small molecular weight substance present in the jelly is necessary for fertilization. It can be expected that additional knowledge of the structure and composition of the jell}' would permit more enlightened studies on precisely what properties of the jelly are necessary for fertilization. Chemical analyses of amphibian jelly have indicated that the main components of the jelly are fucose, hexosamines. one or more hexoses, and protein (Bolognani ct al., 1966; Folkes ct al., 1950; Hiyama. l ( H ( Ja. b, c; Kusa and Ozu, 1961; Lee, 1967; Masamune ar.d Yosizawa, 1953; Masamune ct al.. 1951; Minganti, 1955; Minganti and D'Anna, 1957, 1958; Schulz and Becker, 1935). However, not all of the above investigations dealt with each of these components and in every case all the jellv layers surrounding the egg were analyzed together ; no attention was given to the possible differences among layers. That these differences do exist has been shown by histochemical studies on oviducts and eggs (Ghiara, 1960; Humphries, 1966; Humphries and Hughes, 1959; Kambara, 1956a, b, 1957; Kelly, 1954; Salthe, 1963; Shaver, 1966). The present investigation was undertaken to study the deposition, structure, and composition of the egg jelly of the South African clawed toad, Xcnopus lact'is (Daudin). Since amphibian jelly is deposited in discrete layers, it was considered of prime importance in this study to analyze these layers separately. 1 This work was completed while the author was an NSF predoctoral fellow and was part of a dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Emory University. The work was supported in part by grant GM-09878 from the U. S. "Public Health Service. -Present address : Department of Anatomy, College of Medicine, University of Florida, Gainesville, Florida 32601. 501
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