Intrafollicular testosterone concentration and sex ratio in individually cultured bovine embryos
Manuel García-Herreros A , Pablo Bermejo-Álvarez B , Dimitrios Rizos B , Alfonso Gutiérrez-Adán B , Alan G. Fahey A and Patrick Lonergan A CA School of Agriculture, Food Science and Veterinary Medicine, College of Life Sciences, University College Dublin, Belfield, Dublin 4, Ireland.
B Dep. Reproducción Animal y Conservación de Recursos Zoogenéticos, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Madrid, Spain.
C Corresponding author. Email: pat.lonergan@ucd.ie
Reproduction, Fertility and Development 22(3) 533-538 https://doi.org/10.1071/RD09157
Submitted: 3 July 2009 Accepted: 17 September 2009 Published: 15 February 2010
Abstract
Recent studies have suggested a relationship between bovine follicular fluid testosterone concentration and the likelihood of the oocyte being fertilised by an X- or Y-bearing spermatozoon; however, this theory has been challenged. To further test this hypothesis, follicles were dissected from the ovaries of slaughtered heifers, measured and carefully ruptured. The cumulus–oocyte complex (COC) was removed and the follicular fluid collected and testosterone concentration determined by radioimmunoassay. COCs were matured, fertilised and cultured in an individually identifiable manner; all cleaved embryos (2- to 4-cell stage, n = 164) had their sex determined by PCR. Testosterone concentrations were positively skewed. There was no significant difference between follicular fluid testosterone concentrations in male and female embryos (mean ± s.e.m. 51.5 ± 5.59 and 49.5 ± 7.42 ng mL–1, respectively). Linear, quadratic and cubic logistical regression showed that follicular testosterone concentration could not reliably predict the sex of the embryo with odds ratios of 1.001, 1.013 and 1.066, repectively, and coefficient of determination (R2) values of 0.0003, 0.0126 and 0.0567, respectively. Follicular size and testosterone concentration were not related (R2 = 0.087). Finally, follicular size had no influence on embryo sex determination (P = 0.70). In conclusion, under the conditions of the present study, the likelihood of an oocyte being fertilised by an X- or Y-bearing spermatozoon was not affected by the size of the follicle from which it was derived, nor by the testosterone concentration in the follicular fluid.
Additional keyword: follicular fluid.
Acknowledgements
The authors thank Mary Wade and Niamh Hynes for excellent technical assistance and to the staff of Kepak and Kildare Chilling for allowing access to bovine tissues. MGH was funded by a post-doctoral fellowship from the Spanish Government (2008-0198).
Agung, B. , Otoi, T. , Wongsrikeao, P. , Taniguchi, M. , Shimizu, R. , Watari, H. , and Nagai, T. (2006). Effect of maturation culture period of oocytes on the sex ratio of in vitro-fertilized bovine embryos. J. Reprod. Dev. 52, 123–127.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Kochhar, H. S. , Kochhar, K. P. , Basrur, P. K. , and King, W. A. (2003). Influence of the duration of gamete interaction on cleavage, growth rate and sex distribution of in vitro-produced bovine embryos. Anim. Reprod. Sci. 77, 33–49.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Mao, J. , and Rosenfeld, C. S. (2009). Usage of X- and Y-chromosome fluorescent in situ hybridization to determine whether the murine oocytes selectively attract one class of spermatozoa over another. Mol. Reprod. Dev. 76, 320.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS |
Martinez, F. , Kaabi, M. , Martinez-Pastor, F. , Alvarez, M. , Anel, E. , Boixo, J. C. , de Paz, P. , and Anel, L. (2004). Effect of the interval between estrus onset and artificial insemination on sex ratio and fertility in cattle: a field study. Theriogenology 62, 1264–1270.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS |
Osborn, J. C. , and Moor, R. M. (1983). The role of steroid signals in the maturation of mammalian oocytes. J. Steroid Biochem. 19, 133–137.
| PubMed | CAS |
Pursley, J. R. , Silcox, R. W. , and Wiltbank, M. C. (1998). Effect of time of artificial insemination on pregnancy rates, calving rates, pregnancy loss and gender ratio after synchronization of ovulation in lactating dairy cows. J. Dairy Sci. 81, 2139–2144.
| PubMed | CAS |
Rizos, D. , Bermejo-Alvarez, P. , Gutierrez-Adan, A. , and Lonergan, P. (2008). Effect of duration of oocyte maturation on the kinetics of cleavage, embryo yield and sex ratio in cattle. Reprod. Fertil. Dev. 20, 734–740.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Roelofs, J. B. , Bouwman, E. B. , Pedersen, H. G. , Rasmussen, Z. R. , Soede, N. M. , Thomsen, P. D. , and Kemp, B. (2006). Effect of time of artificial insemination on embryo sex ratio in dairy cattle. Anim. Reprod. Sci. 93, 366–371.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS |
Rorie, R. W. , Lester, T. D. , Lindsey, B. R. , and McNew, R. W. (1999). Effect of timing of artificial insemination on gender ratio in beef cattle. Theriogenology 52, 1035–1041.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS |
Schoenfelder, M. , Schams, D. , and Einspanier, R. (2003). Steroidogenesis during in vitro maturation of bovine cumulus–oocyte complexes and possible effects of tri-butyltin on granulosa cells. J. Steroid Biochem. Mol. Biol. 84, 291–300.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS |
Seidel, G. E. (2009). Sperm sexing technology – the transition to commercial application. An introduction to the symposium “update on sexing mammalian sperm”. Theriogenology 71, 1–3.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Shimada, M. , Kawano, N. , and Terada, T. (2002). Delay of nuclear maturation and reduction in developmental competence of pig oocytes after mineral oil overlay of in vitro maturation media. Reproduction 124, 557–564.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS |
Silva, C. C. , and Knight, P. G. (2000). Effects of androgens, progesterone and their antagonists on the developmental competence of in vitro-matured bovine oocytes. J. Reprod. Fertil. 119, 261–269.
| PubMed | CAS |
Vázquez, M. I. , Molina, A. , Mazón, M. S. , Brito, J. L. , Soto-Camargo, R. , and Martínez, R. D. (1993). Determinación del estado reproductivo del ganado bovino sacrificado en tres rastros municipals del estado de Guerrero. Vet. Méx. 24, 155–157.
Wehner, G. R. , Wood, C. , Tague, A. , Barker, D. , and Hubert, H. (1997). Efficiency of the OVATEC unit for estrus detection and calf sex control in beef cows. Anim. Reprod. Sci. 46, 27–34.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS |
Younis, A. I. , Brackett, B. G. , and Fayrer-Hosken, R. A. (1989). Influence of serum and hormones on bovine oocyte maturation and fertilization in vitro. Gamete Res. 23, 189–201.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS |
Zuccotti, M. , Sebastiano, V. , Garagna, S. , and Redi, C. A. (2005). Experimental demonstration that mammalian oocytes are not selective towards X- or Y-bearing sperm. Mol. Reprod. Dev. 71, 245–246.
| Crossref | GoogleScholarGoogle Scholar | PubMed | CAS |
