Some embryos of Ciona intestinalis which were permanently cleavage-arrested with cytochalasin B at the 1-cell, 4-cell, or 8-cell stages produced, after 12 or 16 h of development time (18 degrees C), a level of muscle acetylcholinesterase activity equal to that found in normal early and later larval stage embryos of the same age. Enzyme activity was measured quantitatively in single whole embryo...

Background: It was reported in a literature that approximately one third of the 4-cell stage embryos did not exhibit a tetrahedral shape. Non-tetrahedral embryos showed a lower in vitro developmental potential than tetrahedral embryos. Recently vitrification technology has been widely employed for embryo cryopreservation. The objective of this study was to prove our hypothesis that vitrified - ...

Sea Urchin is one of the most useful tools in developmental biology studies because this organism has the simplest kind of developmental stages. We aimed to determine developmental stages and timetable of Echinometra mathaei embryo (the species of Persian Gulf). The spawning of E. mathaei was induced by 0.5M KCl injection (1ml) into the coelomic cavity. After fertilization, embryos were placed ...

objective: the aim of the study was to compare the effects of two different concentrations of cryoprotectants by cryotopvitrification on survival, developmental capacity and heat shock protein 72 (hsp72) expression of two-cell mouse embryos. materials and methods: in this experimental study, transcript analysis of hsp72 gene was performed on non-vitrified and vitrified 2-cell mouse embryos via ...

A total of 340 patients referred for in-vitro fertilization was included in a retrospective, comparative study in which zygotes were studied regarding alignment and polarization of nucleolar precursor bodies (NPB) and also early cleavage in relation to implantation and pregnancy rates for the 680 transferred embryos. At assessment of the pronucleus 18-19 h after sperm injection, NPB were checke...

BACKGROUND An estimated 3.5 million children have been born to date using assisted reproduction technologies. We reviewed the data in order to evaluate current knowledge of medical outcome for IVF/ICSI children born after cryopreservation, slow freezing and vitrification of early cleavage stage embryos, blastocysts and oocytes. METHODS A systematic review was performed. We searched the PubMed...

This study was undertaken to compare the efficiency of fresh and frozen-thawed buck semen on in vitro fertilization (IVF) of goat oocytes. Cumulus oocytes complexes (COCs) were collected by aspiration of 2-6 mm diameter follicles, which were obtained from slaughterhouse. Upon grading, only normal quality COCs were maturated in TCM-199 for 48 hours. The percentage of COCs reached to the M-II sta...

A number of non-invasive methods have been proposed to evaluate embryo viability in human in-vitro fertilization programmes. In addition to biochemical analyses, a common method for the selection of embryos prior to transfer involves assessment of embryo quality and morphology. We propose a new method to evaluate embryo viability based on the timing of the first cell division. Fertilized embryo...