Effect of follicle size on mRNA expression in cumulus cells and oocytes of Bos indicus: an approach to identify marker genes for developmental competence.
To identify the genes related to oocyte competence, we quantified transcripts for candidate genes in oocytes (H1Foo, H2A, H3A, GHR, GDF9, BMP15, OOSP1) and cumulus cells (FSHR, EGFR, GHR, PTX3, IGFII) using the follicle size model to select oocytes of better developmental quality. Follicles were dissected and distributed into four groups according to diameter as follows: 1.0-3.0, 3.1-6.0, 6.1-8.0 and >or=8.1 mm. Cumulus-oocyte complexes (COCs) were released, classified morphologically, matured, fertilised and cultured in vitro or denuded for measurement of diameter and determination of gene expression. Denuded germinal vesicle oocytes and their cumulus cells were used for gene expression analysis by reverse transcription-polymerase chain reaction. The blastocyst rate was highest for oocytes recovered from follicles>6 mm in diameter. In the oocyte, expression of the H2A transcript only increased gradually according to follicle size, being greater (P<0.05) in oocytes from follicles>or=8.1 mm in diameter than in oocytes from follicles<6.0 mm in diameter. In cumulus cells, expression of FSHR, EGFR and GHR mRNA increased with follicular size. In conclusion, we confirmed the importance of H2A for developmental competence and identified important genes in cumulus cells that may be associated with oocyte competence.
Caixeta
Ester Siqueira
ES
Faculdade de Agronomia e Veterinária, Ciências Animais, Universidade de Brasília, Brasília, DF 70910-970, Brazil.
Ripamonte
Paula
P
Franco
Maurício Machaim
MM
Junior
José Buratini
JB
Dode
Margot Alves Nunes
MA
D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism; D002417:Cattle / Q000378:metabolism*; D002450:Cell Communication / Q000502:physiology; D002478:Cells, Cultured; D054885:Cumulus Cells / Q000166:cytology / Q000378:metabolism*; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D005819:Genetic Markers; D006657:Histones / Q000235:genetics / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D006080:Ovarian Follicle / Q000166:cytology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D011962:Receptors, FSH / Q000235:genetics / Q000378:metabolism; D011986:Receptors, Somatotropin / Q000235:genetics / Q000378:metabolism
D005819:Genetic Markers; D006657:Histones; D012333:RNA, Messenger; D011962:Receptors, FSH; D011986:Receptors, Somatotropin; D066246:ErbB Receptors