Background: For several years, mammalian cloning by splitting an early embryo or nuclear transfer into oocytes method has been successfully performed. Cloning is now also possible using adult somatic cells. Although it has now been 15 years since the first cloned mammals were generated from somatic cells using nuclear transfer (NT), the success rate for producing live offspring by cloning is lo...

introduction: in order to study the morphogenetic role of cell death in the development, a series of comparative studies on the structure of the interdigital membrane of chick (with free digit) and duck (webbed digits) embryos was done. materials and methods: chick embryos ranging from 6.5 to 10 days of incubation (stag 30-36 h-h) and duck embryos ranging from 8.5 to 12 days of incubation at 12...

background: hla-g is a major histocompatibility complex (mhc), class ib molecule that is selectively expressed at the fetal–maternal interface. it is thought to play a role in protecting the fetus from the maternal immune response. interestingly, the preimplantation embryo development (ped) gene product qa-2 is also a mouse mhc class ib protein that affects cleavage and division of preimplantat...

Background: Because of the protection of surplus embryos, Cryopreservation is usually used in ART. It is not clear, the vitrified-warmed embryos that have normal morphology, be normal in genetic level, too. DNA methylation of gene regulatory regions can causes inhibition of gene expression. We study effect of vitrification method of cryopreservation on DNA methylation and gene expression level ...

The presence of multinuclear blastomeres (MNB) has been widely reported in in-vitro-cultured embryos. Multinucleation at the first mitotic division and affecting both blastomeres is considered abnormal and such embryos are not transferred. The objective of this study was to use fluorescent in-situ hybridization (FISH) and probes specific for chromosomes X, Y and 18 to examine the genetic consti...

Genetic aberrations are commonly seen in human preimplantation embryos. Non-disjunction and premature division of a chromosome are common in both meiosis and mitosis divisions. The expected result for meiotic aneuploidies is full aneuploidy in the later stages whereas mosaicism is the most frequent event in the cleavage and blastocyst stages. The main causes for mosaicism are post-zygotic event...