Most experimental embryological studies performed on the early mouse embryo have led to the conclusion that there are no mosaically distributed developmental determinants in the zygote and early embryo (for example see [1-6]). It has been suggested recently that "the cleavage pattern of the early mouse embryo is not random and that the three-dimensional body plan is pre-patterned in the egg" (i...

BACKGROUND The reduction of multiple pregnancies by using elective single embryo transfers (eSET) requires critical and careful selection of the embryo for transfer. The current study was undertaken to assess whether early cleavage could be used as a marker of embryo competence in eSET procedures. METHODS The study included analysis of 178 eSET procedures. All embryos were checked for early c...

introduction: pronuclear size, morphology and orientation are known to affect embryo quality and implantation. the present study was aimed at evaluation of the possible relationship between protamine deficiency with pronuclear morphology and also cleavage and embryo quality. material and methods: semen sample of 160 candidate icsi and ivf couples were analyzed for sperm concentration, and motil...

In order to clarify the relationships between the first cleavage plane and the embryonic axes, early cleavage pattern of the fertilized eggs of the starfish. Asterina pectinifera was reexamined. It was ascertained that the polar bodies were formed at the site to which the germinal vesicle had closely located before the initiation of the meiotic division, and that the first cleavage plane passed...

Microstructure evolution and mechanical properties in an Fe-17Cr-4Ni-4Cu alloy aged at 475 °C after different aging times were studied. Conventional transmission electron microscopy (TEM) high-resolution (HREM) studies revealed the formation of 9R-structure Cu-rich precipitates Cr-rich α’ phase by spinodal decomposition samples 100–1000 h. The fine lead to a significant increase hardness, toget...

The paper presents the results of detailed structural analysis and 40 Ar/ 39 Ar dating deformations in Golets Vysochaishii deposit area. geological studies showed folded-deformation sequence from large lying folds through axial-plane cleavage formation to quartz-filled fractures. syntectonic sericite yielded ages two Hercynian tectonic impulses – 340 320 Ma. This stage is characterized by earli...

Mitochondria of early Drosophila embryos were observed with a transmission electron microscope and a fluorescent microscope after vital staining with rhodamine 123, which accumulates only in active mitochondria. Rhodamine 123 accumulated particularly in the posterior pole region in early cleavage embryos, whereas the spatial distribution of mitochondria in an embryo was uniform throughout cleav...

This study was undertaken to elucidate detailed event of early embryogenesis in chicken embryos using a noninvasive egg retrieval technique before oviposition. White Leghorn intrauterine eggs were retrieved from 95 cyclic hens aged up to 54-56 weeks and morphogenetic observation was made under both bright field and fluorescent image in a time course manner. Differing from mammals, asymmetric cl...