HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal My Folders Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Barisone, G. A. Articles by Cabada, M. O. Search for Related Content PubMed PubMed Citation Articles by Barisone, G. A. Articles by Cabada, M. O. Agricola Articles by Barisone, G. A. Articles by Cabada, M. O.

Vitelline Envelope of Bufo arenarum: Biochemical and Biological Characterization¹

^a Division Biología del Desarrollo, Instituto de Biología Molecular y Celular de Rosario (IBR) (CONICET-UNR); Facultad de Ciencias Bioquímicas y Farmacéuticas (UNR), Rosario S2002LRK, Argentina ^b Section of Molecular and Cellular Biology, University of California, Davis, California 95616

Vitelline envelopes (VEs) of Bufo arenarum were isolated in order to study their composition and their role in fertilization. VEs are composed of four glycoproteins, with molecular masses of 120, 75, 41, and 38 kDa. To characterize its biological properties, we quantitatively determined sperm-VE binding and the induction of the acrosome reaction. Heterologous binding of B. arenarum sperm to Xenopus laevis VE components was observed with about one-third the efficiency of homologous binding. Equivalent binding of X. laevis sperm to the B. arenarum VE was observed. When B. arenarum sperm were incubated with fluorescein isothiocyanate-labeled VE, the labeled glycoproteins bound to the anterior end of the sperm head, showing a lateral distribution. Induction of the acrosome reaction was evaluated by incubating sperm in hypotonic saline media with VE glycoproteins. VEs induced the acrosome reaction in a time- and concentration-dependent manner. The acrosome reaction was maximal after 10 min. The half-maximal effect was obtained at a glycoprotein concentration of 1 µg/ml. Specificity was determined using fertilization envelope glycoproteins, which failed to induce the acrosome reaction. The B. arenarum VE is biochemically similar to other egg envelopes. It also seems that its biological properties are similar to other species in regard to sperm binding and induction of the acrosome reaction. However, as far as we are aware, this is the first observation of the VE inducing the sperm acrosome reaction in amphibians. The relatively small differences observed in heterologous sperm-VE binding in X. laevis and B. arenarum are inconsistent with the current paradigm that species specificity in fertilization is regulated at the sperm-VE binding step.

First decision: 24 July 2001.

¹ This work was supported in part by research grant 802/OC-AR from Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), UNR, and the ANPCyT BID program of Argentina awarded to M.O.C., and by National Science Foundation grant MCB9728447 awarded to J.L.H. M.O.C. is a member of the CONICET research staff. G.A.B. is a CONICET fellow.

² Correspondence: Marcelo O. Cabada, Área Biología, Fac. Cs. Bioquímicas y Farmacéuticas, U.N.R., Suipacha 531, Rosario S2002LRK, Argentina. FAX: 54 341 4804601; cabada{at}elsitio.net

This article has been cited by other articles:

				D. Krapf, E. D. O'Brien, M. O. Cabada, P. E. Visconti, and S. E. Arranz Egg Water from the Amphibian Bufo arenarum Modulates the Ability of Homologous Sperm to Undergo the Acrosome Reaction in the Presence of the Vitelline Envelope Biol Reprod, February 1, 2009; 80(2): 311 - 319. [Abstract] [Full Text] [PDF]