Table 2.

Gene expression profiling of human oocytes using microarrays.

Analyses of oocyte gene expression by microarrays
Analyzed oocytes	Expression of genes	Functions of analyzed genes	Study
Seventy seven in vivo matured oocytes at different stages of maturity: 20 GV oocytes (7 patients), 20 MI oocytes (7 patients), 37 MII oocytes, cumulus cells	Identification of new potential regulators and marker genes involved in the human in vivo oocyte maturation	Transcription regulation, DNA repair, cell cycle checkpoint	Gasca et al., 2007 [2]
Individual MII oocytes and groups of 5 MII oocytes	1,361 transcripts expressed in oocytes	Apoptosis, cell cycle, circadian rhythms, cytoskeleton, secretory pathways, exocytosis, endocytosis, kinases, membrane receptors, ion channels, mitochondria, structural nuclear proteins, phospholipases, protein degradation and synthesis, secreted proteins, signaling pathways, DNA, chromatin, RNA, transcription, and others	Bermúdez et al., 2004 [14]
Groups of 10 MII oocytes from women aged <35 years in comparison to 10 different normal human somatic tissues	5,331 transcripts significantly up-regulated and 7,074 transcripts significantly down-regulated in human oocytes	Up-regulated TGF-β pathway, DNA, RNA and protein metabolism, transcription regulation, chromatin modification	Kocabas et al., 2006 [15]
Groups of 20 GV, 20 MI, and 16 MII oocytes	Oocytes expressed in average 8,728 genes. The lowest number of expressed genes in MII oocytes (5,633) and highest in GV oocytes (10,892)	Genes specifically expressed in germinal cells and oocytes, meiosis, components of the maturation-promoting factor (MPF), spindle checkpoint, transforming growth factor-beta superfamily, chromatin remodeling	Assou et al., 2006 [16]
Nine MII and GV oocytes, preimplantation embryos	Human oocytes are low RNA template samples and an amplification step is required to provide sufficient labeled RNA as a microarray target (PCR and serial analysis of gene expression SAGE, microarrays)		Neilson et al., 2000 [20] Dobson et al., 2004 [21]
Seven individuals: 5 GV (primary) and 2 MII (secondary) oocytes and 15 preimplantation embryos	Down-regulation of genes in preimplantation embryos in comparison with oocytes	Oocyte maturation and embryo development	Dobson et al., 2004 [21]
Single and pooled GV oocytes	Oocytes need to be pooled for the starting template for each array and sufficient microarray experiments performed to minimize the variance associated with processing		Jones et al., 2007 [22]
Four individual MII oocytes and four 4-cell and three 8-cell embryos	A total of 631 genes exhibited differential expression in oocytes and embryos. In oocytes 184 genes were expressed more than twofold above the median value. Only two genes were at least twofold below the median value	Interconversion of lactate and pyruvate, lactate dehydrogenase, oocyte maturation, embryo development	Li et al., 2006 [18]
Immature oocytes from primordial, intermediate, and primary follicles	A total of 6,301 unique genes were significantly expressed; extraordinary high expression levels of TMEFF2, OPHN1 and ATP6; expression of oocyte- or germline-specific genes	RNA binding, translation initiation structural molecule activity, BMP receptors, activin receptors, IGFI receptor, fibroblast growth factors, different enzymes	Markholt et al., 2012 [23]
Seventy six GV oocytes from 55 donor patients, hESCs, and human foreskin fibroblasts	10,183 genes were expressed in GV oocytes including oocyte-specific genes. Distinct sets of genes were detected in oocytes, hESCs and fibroblasts	In GV oocytes 4 signaling pathways—MOS-MPF, transforming growth factor-beta, Wnt, and Notch, oocyte maturity, embryo development	Zhang et al., 2007 [24]
GV and MII oocytes, hESCs, somatic tissues	Identified a common oocyte/hESC gene expression profile	Cell cycle, enzymes involved in general cell metabolism, nucleoside synthesis, DNA repair, cell cycle regulatory machinery, regulation of the topologic state of DNA, mitotic spindle assembly checkpoint, pluripotency, chromatin remodelling, transcription factors, ubiquitination, and proteasome pathways	Assou et al., 2009 [25]
GV oocytes, MII oocytes matured in vivo and in vitro	GV, in vivo matured MII oocytes, and in vitro matured MII oocytes expressed 12,219, 9,735, and 8,510 genes. There was an extensive overlap among the all three groups of oocytes, but also some significant differences. There were some immature GV oocyte patterns of gene expression, which still persisted in in vitro matured oocytes	Nuclear maturity, cytoplasmic functions expressed in an immature manner, cellular storage and homeostasis	Wells and Patrizio, 2008 [26]
GV oocytes, MII oocytes matured in vivo and in vitro	More than 2,000 genes were expressed at more than 2-fold higher levels in oocytes matured in vitro than those matured in vivo	Transcription, the cell cycle and its regulation, transport and cellular protein metabolism	Jones et al., 2008 [27]
Fresh, slowly frozen, and vitrified MII oocytes	Oocyte slow freezing and vitrification negatively affected the gene expression profile of human oocytes in comparison with fresh controls	Chromosomal structure maintenance, cell cycle regulation, genes of the ubiquitination pathway	Monzo et al., 2012 [28]
Thirty nine MII oocytes with total fertilization failure and control oocytes	Misexpression of several genes, characterized by important fold changes in oocytes with total fertilization failure	Meiosis, cell growth, and apoptosis control	Gasca et al., 2008 [29]
Fifteen GV oocytes which matured to MII stage overnight and their polar bodies	Transcripts that were present in greater abundance in the single oocytes were also detected in qPCR replicates from single polar bodies, except oocyte-specific H1FOO		Klatsky et al., 2010 [30]
Single MII oocytes and single polar bodies after biopsy	Human polar bodies reflected the oocyte transcript profile. 5,256 mRNAs, or 97%, including miRNAs were expressed in both oocytes and polar bodies		Reich et al., 2011 [31]
MII oocytes of younger (<32 years) and older women (>40 years)	Found that the global gene expression profiles in oocytes are related to female age. Genes were down-regulated in older women	Cell cycle regulation, cytoskeletal structure, energy pathways, transcription control, and stress responses	Steuerwald et al., 2007 [32]
Single MII oocytes of younger (<34 years) and older women (37–39 years)	7,470 genes (10,428 transcripts) were expressed in oocytes; 342 genes were expressed at significantly different expression levels between the two age groups of patients	Cell cycle regulation, chromosome alignment, sister chromatid separation, oxidative stress and ubiquitination, the signaling network of genes for cell cycle and organism development	Grøndahl et al., 2010 [33]
Seven MII oocytes (three normal and four aneuploid) and their polar bodies after biopsy	At comparative genomic hybridization 327 genes were differently expressed in both groups of oocytes; the relation between mRNA transcript numbers and female age	Meiotic spindle assembly, chromosome alignment, production of cell surface, or excretory molecules.	Fragouli et al., 2010 [34]