Identification of differentially expressed markers in human follicular cells associated with competent oocytes.
BACKGROUND
The development of an accurate method for selection of high-quality embryos is essential to achieve high pregnancy rates with single embryo transfer in human IVF. The developmental competence of the oocyte is acquired during follicle maturation and strong communication also exists between the follicular cells (FCs) and the oocytes; thus oocyte developmental competence may be determined by markers expressed in the surrounding FCs.


METHODS
From consenting patients (n = 40), FCs were recovered on a per follicle basis by individual follicle puncture. Hybridization analyses using a custom-made complementary DNA microarray containing granulosa/cumulus expressed sequence tags (ESTs) from subtracted libraries and an Affymetrix GeneChip were performed to identify specific genes expressed in follicles leading to a pregnancy. The selected candidate genes were validated by quantitative-PCR (Q-PCR).


RESULTS
Subtractive libraries prepared from pooled samples representing pregnant versus non-pregnant patients produced 1694 ESTs. Hybridization data analysis discriminated 115 genes associated with competent follicles. Selected candidates were confirmed by Q-PCR: 3-beta-hydroxysteroid dehydrogenase 1 (P = 0.0078), Ferredoxin 1 (P = 0.0203), Serine (or cysteine) proteinase inhibitor clade E member 2 (P = 0.0499), Cytochrome P450 aromatase (P = 0.0359) and Cell division cycle 42 (P = 0.0396).


CONCLUSIONS
Microarray technologies are useful to mine the transcriptome of FCs expressed in follicles associated with competent oocytes and could be used to improve embryo selection with the objective of successful single embryo transfer.
Hamel
Melanie
M
Département des Sciences Animales, Centre de Recherche en Biologie de la Reproduction, Université Laval, Québec, Canada G1K 7P4.
Dufort
Isabelle
I
Robert
Claude
C
Gravel
Catherine
C
Leveille
Marie-Claude
MC
Leader
Arthur
A
Sirard
Marc-Andre
MA
D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics; D016564:Amyloid beta-Protein Precursor / Q000235:genetics; D000818:Animals; D001141:Aromatase / Q000235:genetics; D015415:Biomarkers / Q000378:metabolism*; D002417:Cattle; D054885:Cumulus Cells / Q000378:metabolism*; D004624:Embryo Transfer / Q000379:methods; D005260:Female; D005288:Ferredoxins / Q000235:genetics; D020869:Gene Expression Profiling; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D009865:Oocytes / Q000502:physiology*; D011247:Pregnancy; D018873:Pregnancy Rate; D058255:Protease Nexins; D012333:RNA, Messenger / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics; D020764:cdc42 GTP-Binding Protein / Q000235:genetics
D016564:Amyloid beta-Protein Precursor; D015415:Biomarkers; D005288:Ferredoxins; D058255:Protease Nexins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D015096:3-Hydroxysteroid Dehydrogenases; D001141:Aromatase; D020764:cdc42 GTP-Binding Protein