Vertebrate oocytes proceed through the first and the second meiotic division without an intervening S-phase to become haploid. Although DNA replication does not take place, unfertilized oocytes acquire the competence to replicate DNA one hour after the first meiotic division by accumulating an essential factor of the replicative machinery, Cdc6. Here, we show that the turnover of Cdc6 is precis...

MicroRNAs (miRNAs) are small, endogenous, regulatory RNA molecules that can bind to partially complementary regions on target messenger RNAs and impede their expression or translation. We rationalized that miRNAs, being localized to the cytoplasm, will be maternally inherited during fertilization and may play a role in early development. Although Dicer is known to be essential for the transitio...

BACKGROUND Although numerous studies have been published on the chromosomal constitution of in-vitro unfertilized human oocytes, data remain highly variable and controversial because of the size of oocyte samples, technical reservations and potential misinterpretation. METHODS A cytogenetic study was undertaken on 3042 unfertilized human oocytes recovered from 792 women participating in an IV...

Islet-brain1/JNK-interacting protein-1 (IB1/JIP-1) is a scaffold protein that organizes the JNK, MKK7, and MLK1 to allow signaling specificity. Targeted disruption of the gene MAPK8IP1 encoding IB1/JIP-1 in mice led to embryonic death prior to blastocyst implantation. In culture, no IB1/JIP-1(-/-) embryos were identified indicating that accelerated cell death occurred during the first cell cycl...

The aim of the study was to assess the fatty acid composition of human fertilization-failed oocytes. A total of 150 unfertilized oocytes from 43 women undergoing in-vitro fertilization (IVF) were analysed using capillary gas chromatography. The majority of fatty acids were saturated (79.22%), of which stearic (38.65%) and palmitic (32.66%) acids were the most abundant. Of the monounsaturated fa...

Transcriptome regionalization is an essential polarity determinant among metazoans, directing embryonic axis formation during normal development. Although conservation of this principle in mammals is assumed, recent evidence is conflicting and it is not known whether transcriptome asymmetries exist within unfertilized mammalian eggs or between the respective cleavage products of early embryonic...

In human fertilization, the sperm centrosome nucleates a radial array of microtubules called the sperm aster. The sperm aster is responsible for apposition of male and female pronuclei, and later gives rise to the first meiotic spindle. The objective of this study was to determine microtubule assembly and chromatin configuration in rabbit oocytes following intracytoplasmic injection with human ...

in human fertilization, the sperm centrosome nucleates a radial array of microtubules called the sperm aster. the sperm aster is responsible for apposition of male and female pronuclei, and later gives rise to the first meiotic spindle. the objective of this study was to determine microtubule assembly and chromatin configuration in rabbit oocytes following intracytoplasmic injection with human ...