OBJECTIVE To develop a preimplantation genetic diagnosis (PGD) protocol that allows any form of chromosome imbalance to be detected. DESIGN Case report employing a method based on whole-genome amplification and comparative genomic hybridization (CGH). SETTING Clinical IVF laboratory. PATIENT(S) A 40-year-old IVF patient. INTERVENTION(S) Polar body and blastomere biopsy. MAIN OUTCOME M...

Optimal development of fertilized eggs into preimplantation embryos is essential for reproduction. Although mammalian oocytes ovulated after luteinizing hormone (LH) stimulation can be fertilized and promoted into early embryos in vitro, little is known about ovarian factors important for the conditioning of eggs for early embryo development. Because LH interacts only with ovarian somatic cells...

Tetraploid Crassostrea gigas were first successfully produced in 1993 by inhibiting the first Ž polar body of eggs from triploids that had been fertilized with sperm from diploids Guo and . Allen method . However, attempts to repeatedly produce high yields of tetraploids were inconsistent. Because of these uncertainties, we examined some of the fundamental aspects of tetraploid production in an...

To determine whether chromosomes in the porcine first polar body (PB1) can complete the second meiotic division and subsequently undergo normal pre-implantation embryonic development, we examined the developmental competence of PB1 chromosomes injected into enucleated MII stage oocytes by nuclear transfer method (chromosome replacement group, CR group). After parthenogenetic activation (PA) or ...

The golden hamster is an attractive model organism for studying reproductive physiology, oncology, genetics and virology. In an effort to establish experimental protocols necessary for cloning golden hamsters, we examined changes in the reciprocal position of the FPB (first polar body) and chromosome set of MII (the second meiotic metaphase) oocytes of golden hamsters. Oocytes were collected un...

Mammalian oocyte maturation is distinguished by highly asymmetric meiotic divisions during which a haploid female gamete is produced and almost all the cytoplasm is maintained in the egg for embryo development. Actin-dependent meiosis I spindle positioning to the cortex induces the formation of a polarized actin cap and oocyte polarity, and it determines asymmetric divisions resulting in two po...

Improved methods are needed to reliably and accurately evaluate oocyte quality prior to fertilization and transfer into the woman of human embryos created through in vitro fertilization (IVF). All oocytes that are retrieved and matured in culture are exposed to sperm with little in the way of evaluating the oocyte quality. Furthermore, embryos created through IVF are currently evaluated for dev...

Nuclear reprogramming of somatic cells can be induced by oocyte factors. Despite numerous attempts, the factors responsible for successful nuclear reprogramming remain elusive. In the present study, we found that porcine oocytes with the first polar body collected at 42 h of in vitro maturation had a stronger ability to support early development of cloned embryos than porcine oocytes with the f...