There are two populations of sperm in bull semen. One consists of X-chromosome-bearing sperm; the other consists of Y-chromosome-bearing sperm. In contrast, all cattle ova contain an X chromosome. That is why when an X-chromosome-bearing sperm fertilizes the ovum a female (XX) develops, and when a Y-chromosome-bearing sperm fertilizes the ovum, a male (XY) develops. Ratios of the number of male...

to develop until the tenth or twelfth week, the case usually terminates in rupture of the tube, with its well-known symptoms. But at an earlier period than this, during the first five or six weeks, other changes may take place, involving both the developing ovum and the tube in which it is contained. Of these changes, one of the most important and interesting is that of tubal abortion. We may, ...

So far, all preimplantation genetic diagnosis (PGD) protocols in use produce results after the eggs have been fertilized. However, these approaches are not acceptable for patients with moral objections to the generation and discard of supernumerary zygotes or embryos. In these circumstances, only those oocytes to be replaced may be inseminated. The purpose of this study was to develop a PGD pro...

Our Department of Experimental Embryology originated from The Laboratory of Embryo Biotechnology, which was organized and directed by Dr. Maria Czlonkowska until her premature death in 1991. Proving successful international transfer of frozen equine embryos and generation of an embryonic sheep-goat chimaera surviving ten years were outstanding achievements of her term. In the 1990s, we produced...

The slaughtered cows or heifers have a large number of immature oocytes within primordial follicles or developing follicles. Therefore, it is useful to aspirate immature oocytes, which would be wasted if left unprocessed, from ovaries; subsequently they are matured in vitro (IVM), fertilized in vitro (IVF), and cultured in vitro (IVC). Also most recently it has been shown that immature oocytes ...

The recent development of genomic selection induces dramatic changes in the way genetic selection schemes are to be conducted. This review describes the new context and corresponding needs for genomic based selection schemes and how reproductive technologies can be used to meet those needs. Information brought by reproductive physiology will provide new markers and new improved phenotypes that ...

Retinoids have been shown to enhance developmental competence of the oocyte in cattle, sheep and pigs. In this study we investigated whether exogenous retinol stimulates the bovine oocyte during its intrafollicular growth and the time limits of exposure to exogenous retinol. In addition, we also determined the efficiency of ovum pick-up techniques in combination with retinol treatment and the v...

The Ovum Pick Up-In vitro Production (OPU-IVP) of embryos is an advanced reproductive technology used in cattle production but the complex biological mechanisms behind IVP outcomes are not fully understood. In this study we sequenced RNA of granulosa cells collected from Holstein cows at oocyte aspiration prior to IVP, to identify candidate genes and biological mechanisms for favourable IVP-rel...

The present study offers a meta-analysis of published randomized controlled trials (RCTs) evaluating the outcomes of in vitro fertilization (IVF) cycles using corifollitropin alfa for controlled ovarian stimulation (COS) in comparison with daily recombinant FSH (rFSH). The study examined seven RCTs including 2138 patients receiving corifollitropin alfa and 1788 women receiving daily rFSH for CO...