In search of the transcriptional blueprints of a competent oocyte

ABSTRACT

The oocyte undergoes a remarkably long andelaborated journey within the follicle before becomingfully equipped to sustain embryonic development. Itsability to support early embryonic development relieslargely on the maternal transcripts accumulated duringits growth and maturation. However, it is still not clearwhat transcriptome blueprint composes a competentoocyte. A number of extensive studies provided adetailed characterization of the mRNA molecules thatare gradually accumulated in the oocyte cytoplasm. Thedetail of our knowledge has gradually increased throughthe years also thanks to the development andimprovement of the analytical techniques. From realtimePCR analysis of single transcripts, to the wholetranscriptome approach of gene arrays and newgenereation sequencing, scientists accumulated anexponentially growing amount of new information.More recently, the discovery of non-coding RNAsrevealed a new layer of complexity in the mechanismsthat modulate gene expression at the mRNA level, infolliculogenesis and oogenesis. In particular, data areemerging on the potential role of microRNAs incontrolling ovarian function, oocyte maturation and theoocyte-somatic cell cross talk. This review will try tosummarize the vast amount of data currently available onthe mRNAs and microRNAs associated with the ovarianfunction and to find their biological significance.