Post-thaw viability of european bison (Bison bonasus) semen frozen with extenders containing egg yolk or lipids of plant origin and examined with a heterologous in vitro fertilization assay.

Basic characteristics of European bison (Bison bonasus) semen were described and the efficacies of two extenders-Triladyl, containing egg yolk, and a synthetic extender, containing soybean lipids-were tested for semen cryopreservation. Seven ejaculates were collected by electroejaculation from a 10-yr-old, European bison bull. Each ejaculate was diluted at 37 degrees C to a final concentration of 200 x 10(6) sperm/ml with Triladyl or the synthetic extender.

Preimplantation genetic diagnosis reduces pregnancy loss in women aged 35 years and older with a history of recurrent miscarriages.

Objective: To determine whether preimplantation genetic diagnosis (PGD) and transfer of euploid embryos would decrease spontaneous abortion rates in recurrent miscarriage (RM) patients.

Design: Controlled clinical study.

Setting: In vitro fertilization centers and PGD reference laboratory.

Predictability of preimplantation genetic diagnosis of aneuploidy and translocations on prospective attempts.

The aim of this study was to determine if the outcomes of aneuploidy and translocation testing by preimplantation genetic diagnosis (PGD) at the 8-cell stage have a predictive value for new genetic diagnosis cycles. In total, 83 cycles (39 patients) undergoing PGD of translocations and 378 cycles (176 patients) of aneuploidy were included. Predictability, defined as having similar rate (+/-20%) of euploid embryos in the first and successive cycles, was found in 66% of patients undergoing aneuploidy testing.

Differences in chromosome susceptibility to aneuploidy and survival to first trimester.

The purpose of this study was to find specific rates of aneuploidy in cleavage-stage embryos compared with first trimester data and to evaluate post-zygotic selection against aneuploidy. A total of 2058 embryos were analysed by flurorescence in-situ hybridization (FISH), and specific aneuploidy rates were obtained for 14 chromosomes. Data from morphologically abnormal embryos could be pooled with data from preimplantation genetic diagnosis (PGD) cycles because it was observed that they had similar rates of aneuploidy; thus, for the purpose of studying aneuploidy they could be, and were, pooled.

Differential expression of two genes located on the X chromosome between male and female in vitro-produced bovine embryos at the blastocyst stage.

The potentially unbalanced expression at preimplantation developmental stages of X-linked genes might be responsible of the faster development of male than female embryos in vitro. Two genes located on the X chromosome, glucose-6-phosphate dehydrogenase (G6PD) and hypoxanthine phosphoribosyl transferase (HPRT), are involved in controlling the amount of oxygen radicals, and hence they might have influence in embryo development. We have quantified mRNA expression of these two genes, using in vitro fertilized-in vitro cultured male and female bovine embryos.