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BACKGROUND: Human female meiosis is particularly error prone, leading to the generation of aneuploidy, a problem which increases dramatically with advancing age. Despite being of great clinical importance, the genesis of oocyte aneuploidy remains poorly understood. Cumulus cells (CCs) surround oocytes in antral follicles and play a crucial role in regulating their maturation. During this investigation, we aimed to obtain an insight into the follicular environment of oocytes that become aneuploid and identify non-invasive markers of oocyte chromosome status and competence. METHODS: Microarray comparative genomic hybridization was used to assess oocyte ploidy. Expression of 96 genes was examined via a large real-time PCR experiment in 51 CC samples, whereas an additional 26 CC clumps were used for a more focused real-time PCR experiment assessing just three genes. Gene selection was based on the results of a previous microarray analysis comparing the transcriptome of CCs from normal and aneuploid oocytes. RESULTS: Fifty eight of the investigated genes were confirmed to be expressed in CCs. Patterns of expression were generally similar among all CC samples, regardless of the chromosomal status of the corresponding oocyte. However, two genes, SPSB2 and TP53I3, were both significantly down-regulated in CCs from chromosomally abnormal oocytes (P

While somatic cell nuclear transfer (SCNT) techniques have been successfully implemented in several species to produce cloned embryos and offspring, the efficiencies of the procedures are extremely low, possibly due to insufficient reprogramming of somatic nuclei. Employing GeneChip microarrays, we describe global gene expression analysis of bovine in vitro fertilized (IVF) and SCNT blastocysts as well as respective donor cell lines to characterize differences in their transcription profiles. Gene expression profiles of our donor cell lines were significantly different from each other; however, the SCNT and IVF blastocysts displayed surprisingly similar gene expression profiles, suggesting that a major reprogramming activity had been exerted on the somatic nuclei. Despite this remarkable phenomenon, a small set of genes appears to be aberrantly expressed and may affect critical developmental processes responsible for the failures observed in SCNT embryos. Our data provide the most comprehensive transcriptome database of bovine IVF and SCNT blastocysts to date.