Upon fertilization Chlamydomonas reinhardtii zygotes undergo a program of differentiation into a diploid zygospore that is accompanied by transcription of hundreds of zygote-specific genes. We identified a distinct sequence motif we term a zygotic response element (ZYRE) that is highly enriched in promoter regions of C reinhardtii early zygotic genes. A luciferase reporter assay was used to sho...

Background The aim of this study was to establish a cell-free sequential culture system that can support high levels of in vitro embryo development and blastocyst formation from bovine zygotes. To this end, this investigation was carried out to evaluate the effects of glucose, serum and EDTA on bovine zygote in vitro development. MaterialsAndMethods Bovine presumptive zygotes were derived from ...

Fertilization and zygote formation in the multicellular green alga Ulva mutabilis Foyn were studied with the aid of transmission and scanning electron microscopes. The growth mutant 'slender' was used in this investigation. The initial contact between mating gametes is made by the flagella, whereupon cytoplasmic contact is established within a few seconds. Fusion of the cytoplasm of the 2 cells...

Aneuploidy, the most common chromosomal abnormality at birth and the main ascertained cause of pregnancy loss in humans, originates primarily from chromosome segregation errors during oogenesis. Here, we report that heterozygosity for a mutation in the mitotic checkpoint kinase gene, Bub1, induces aneuploidy in female germ cells of mice and that the effect increases with advancing maternal age....

The topology of tubulin and actin during mating of Saccharomyces cerevisiae was analysed by fluorescence microscopy with the monoclonal anti-tubulin antibody Tu01 and rhodamine-labelled phalloidin. Preconjugatory cells displayed an asymmetric distribution of the microtubule and actin cytoskeleton and an overall polarization of the cells preceding cell fusion. Prior to karyogamy, the haploid spi...

Microinjection into cells and embryos is a common technique that is used to study a wide range of biological processes. In this method a small amount of treatment solution is loaded into a microinjection needle that is used to physically inject individual immobilized cells or embryos. Despite the need for initial training to perform this procedure for high-throughput delivery, microinjection of...

Abstract Study question Are neonatal outcomes normal up to 3 years of ages from the transfer blastocysts derived mono-pronuclear(1PN) zygotes? Summary answer There was no effect on growth in babies born 1PN-implanted blastocysts. What is known already In human ART, 1PN zygotes are observed at low rates. We have previously reported that 80.7% had a biparental chromosome using Live-Cell imaging t...

Early events 'in the vegetative development of higher land plants are difficult to investigate because the young embryo is encased in the ovarian tissue of the previous gametophytic and sporophytic generations. Recently, genetic approaches have succeeded in identifying mutations that alter early development (Jürgens, 1995; see also Laux and Jürgens, 1997, in this issue), but cellular and physio...