The goal was to understand the role of heat shock at the zygote stage in causing infertility. Culture at 40°C reduced the percentage of inseminated oocytes that became a morula or blastocyst by d 6 or that were a blastocyst at d 8. An additional experiment was done to test whether effects of heat shock occur early in development or at the time of morula formation. Exposure to 40°C for 24 h decr...

KCNJ11-encoded Kir6.2 assembles with ATP-binding cassette sulphonylurea receptors to generate ATP-sensitive K+ (KATP) channel complexes. Expressed in tissues with dynamic metabolic flux, these evolutionarily conserved yet structurally and functionally unique heteromultimers serve as high-fidelity rheostats that adjust membrane potential-dependent cell functions to match energetic demand. Geneti...

The type specimens of the genus Anthaxia Eschscholtz, 1829 described from Angola by A. Théry (1947) were studied, critically evaluated and some of them synonymised: Anthaxia (Cratomerus) reticollis Quedenfeldt, 1886 = A. (C.) coelestis Théry, 1947, syn. nov., A. (Haplanthaxia) egena Kerremans, 1913 = A. (H.) decimata Théry, 1947, syn. nov., A. (H.) duvivieri Kerremans, 1898 = A. (H.) eumede Thé...

BACKGROUND Recent work has shown that mitochondrial biogenesis and mitochondrial functions are critical determinants of embryonic development. However, the expression of the factors controlling mitochondrial biogenesis in early embryogenesis has received little attention so far. METHODS We used real-time quantitative PCR to quantify mitochondrial DNA (mtDNA) in bovine oocytes and in various s...

In mouse blastocysts segregation of the inner cell mass (ICM) and the trophectoderm (TE) is regulated by the mutually antagonistic effects of the transcription factors Oct4 and Cdx2 expressed in the ICM and TE, respectively. In contrast, in other species such as bovine and human, Oct4 is not restricted to the ICM and continues to be expressed in the Cdx2-positive TE. A recent comparative study ...

BACKGROUND Vitrification has been shown as one of the most effective methods of cryopreservation for mammalian embryos. However, there is no consensus which stage of embryonic development is the most appropriate for vitrification with subsequent maximal development after thawing. This study was carried out to explore and compare the effect(s) of vitrification on mouse 2-cell, 4-cell, 8-cell, mo...

Mouse embryos at different morphological stages in the transition from morula to blastocyst were analysed for the qualitative pattern of their polypeptide synthesis. The first appearance of the individual species of polypeptides specific to trophectoderm or ICM occurred progressively over this developmental period. Populations of inside cells recovered from morulae and early blastocysts synthes...

BACKGROUND In a previous study, we investigated the short-term effects of in utero retinoic acid (RA) exposure on early development at the cleavage stage before implantation to understand the possible roles of RA in blastocyst formation. We designed the present study to investigate the long-term effects of RA exposure on pre-implantation embryos in vivo and in vitro. METHOD To evaluate late p...

objective: vitrification has been shown as one of the most effective methods of cryopreservation for mammalian embryos. however, there is no consensus which stage of embryonic development is the most appropriate for vitrification with subsequent maximal development after thawing. this study was carried out to explore and compare the effect(s) of vitrification on mouse 2-cell, 4-cell, 8-cell, mo...

In mammals, active demethylation of sperm pronuclear DNA shortly after fertilisation is thought to be important for reprogramming subsequent embryonic development [1–3]. A further passive loss of methylation has been observed as DNA replicates between 2-cell and morula stages, with somatic cell levels being re-established at or after the blastocyst stage when differentiated lineages are first f...