This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Braundmeier, A. G. Articles by Miller, D. J. Search for Related Content PubMed PubMed Citation Articles by Braundmeier, A. G. Articles by Miller, D. J.

Examination of the Binding Ability of Bovine Spermatozoa to the Zona Pellucida as an Indicator of Fertility

RICHARD G. SAACKE

From the ^* Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois; and the Department of Dairy Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia.

Correspondence to: Dr David Miller, 328 Animal Sciences Laboratory, 1207 W Gregory Dr, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (e-mail: d-mille{at}uiuc.edu).

Despite the development of many new techniques, laboratory assays still do not predict male fertility accurately. To identify targets for laboratory assessment, we first need to determine which steps in fertilization are most often defective in subfertile males. We developed a competitive in vitro fertilization assay in which spermatozoa from 2 different males, stained with different lipophilic dyes, are incubated together with oocytes in a droplet. By exposing mixed spermatozoa to the same oocytes, this assay controls for many of the variables of in vitro fertilization and should allow identification of the most common faulty steps in fertilization. The relationship of zona-binding ability to fertility is controversial. Therefore, as a first step, we determined if zona pellucida-binding ability, measured by this competitive assay, was related to bovine spermatozoal fertility. Fertility data were collected from 2 groups of bulls by 2 means of evaluation, nonreturn to estrus rates postinsemination and competitive insemination. In the nonreturn to estrus study, semen samples from 15 bulls were effectively ranked by zona-binding ability, using pairwise competitive in vitro zona-binding assays (R² = 0.84). However, this ranking was not significantly correlated with nonreturn rates (r = -0.04). In the competitive insemination study, semen samples from 8 bulls were effectively ranked by pairwise comparison using the competitive zona-binding assay (R² = 0.67). Again, this ranking was not significantly correlated to the competitive insemination index calculated for these bulls (r = 0.29). In the third study, we tested 3 bulls to determine if in vivo zona binding, assessed by the number of accessory spermatozoa, was correlated with in vitro zona binding. The number of accessory spermatozoa on oocytes recovered from cows after mating was not correlated with in vitro competitive binding of the spermatozoa. In conclusion, in vitro competitive zona binding was not correlated with bovine fertility or binding of accessory spermatozoa to oocytes in vivo.

     Key words: Fertilization, oocyte, accessory, cattle, nonreturn, heterospermic

This article has been cited by other articles:

				A. G. Braundmeier, J. M. Demers, R. D. Shanks, and D. J. Miller The relationship of porcine sperm zona-binding ability to fertility J Anim Sci, February 1, 2004; 82(2): 452 - 458. [Abstract] [Full Text] [PDF]