BACKGROUND The cells of mammalian female reproductive tract have been widely used for in vitro fertilization (IVF). This study was designed to study the effects of oviductal epithelial cells (OECs) and their conditioned medium during IVF on subsequent embryonic development and the relative abundance of zygote arrest 1 (Zar1) transcript in ovine zygotes. METHODS The in vitro matured ovine oocy...

BACKGROUND It is known that repeated failure of assisted reproduction treatment (ART) can be due to a paternal effect. This study was undertaken to analyse the possible relationship between ART failure and sperm DNA fragmentation. METHODS Zygote morphology and the percentage of spermatozoa with fragmented DNA (assessed by TUNEL) were compared in two groups using donor oocytes for ICSI attempt...

After fertilization, the sperm and oocyte genomes undergo extensive epigenetic reprogramming to form a totipotent zygote. The dynamic epigenetic changes during early embryo development primarily involve DNA methylation and demethylation. We have previously identified Gse (gonad-specific expression gene) to be expressed specifically in germ cells and early embryos. Its encoded protein GSE is pre...

The sexual cycle of the unicellular Chlamydomonas reinhardtii culminates in the formation of diploid zygotes that differentiate into dormant spores that eventually undergo meiosis. Mating between gametes induces rapid cell wall shedding via the enzyme g-lysin; cell fusion is followed by heterodimerization of sex-specific homeobox transcription factors, GSM1 and GSP1, and initiation of zygote-sp...

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...

The twn2 mutant of Arabidopsis exhibits a defect in early embryogenesis where, following one or two divisions of the zygote, the decendents of the apical cell arrest. The basal cells that normally give rise to the suspensor proliferate abnormally, giving rise to multiple embryos. A high proportion of the seeds fail to develop viable embryos, and those that do, contain a high proportion of parti...

cytotoxicity evaluation of daphne mucronata (thymelaeaceae) extract and one of its active purified components, using seven different cancerous cell lines, revealed the strong antiproliferative activity of the plant. using flow cytometry technique, it was found that treatment of the most responsive cells (k562) with the plant extract or the active component inhibited the progression of cells thr...

Early embryogenesis in Arabidopsis (Arabidopsis thaliana) is distinguished by a predictable pattern of cell divisions and is a good system for investigating mechanisms of developmental pattern formation. Here, we identified a gene called LONO1 (LNO1) in Arabidopsis in which mutations can abolish the first asymmetrical cell division of the zygote, alter planes and number of cell divisions in ear...

Although around 1-4% of human zygotes have been found to be tripronuclear, there is little information about the subsequent development and chromosomal composition of embryos that derive from these zygotes. Herein, we report a pregnancy and subsequent delivery of a healthy newborn after the transfer of a blastocyst that developed from a tripronuclear zygote that had a euploid microarray result.

The aim of this study is to describe the ultrastructural changes of the egg apparatus associated with fertilisation of the natural tetraploid Trifolium pratense. The pollen tube enters one of the synergids through the filliform apparatus from the micropyle. Before the entry of the pollen tube into the embryo sac, one of the synergids begins to degenerate, as indicated by increased electron dens...