Follicular growth in vitro: detection of growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) during in vitro culture of ovine cortical slices.
Primordial follicles from different mammal species can survive and enter the growth phase in vitro but do not develop beyond the primary stage. The hypothesis was that, in sheep, in vitro follicular growth is arrested because of a lack of secretion of GDF9 and/or BMP15. Cortical slices of 0.3-0.5 mm thickness issued from 5- to 6-month-old lambs were cultured for 15 days. The pieces were fixed on days 0, 2, 4, 7, 10, and 15 of culture. Follicle morphology, RT-PCR exploration of GDF9 and BMP15 mRNA, immunohistochemical location of their proteins and their receptor BMPRIB and BMPRII were assessed at different time of culture. The mean percentage of primordial follicles decreased from 58.6% (day 0) to 13.4% (day 15) (P<0.01), whereas that of primary follicles increased from 3.2% (day 0) to 31.5% on day 4 (P<0.01), then remained stable until day 15 (35.6%). The percentage of atretic follicles increased from 14.7% (day 0) to 27.1% (day 15) (P<0.05). A few secondary follicles were observed on days 4 and 10, representing 1.0%, and 2.1% of the total number of follicles. GDF9 and BMP15 mRNAs were detected from harvesting (day 0) up to day 15 following culture. At the same time, positive immunoreactions for GDF9, BMP15 and for BMPRIB and BMPRII were also found in oocyte cytoplasm. In conclusion, expression of GDF9, BMP15 and their receptors BMPRIB and BMPRII are detected during in vitro culture of ovine cortical slices.
Mery
Lionel
L
Département de Médecine et Biologie de la Reproduction, Hôpital Edouard Herriot/CECOS, Lyon, France. lionel.mery@chu-lyon.fr
Lefevre
Annick
A
Benchaib
Mehdi
M
Demirci
Banu
B
Salle
Bruno
B
Guerin
Jean-Francois
JF
Lornage
Jacqueline
J
D000818:Animals; D052005:Bone Morphogenetic Protein Receptors, Type I / Q000378:metabolism; D052006:Bone Morphogenetic Protein Receptors, Type II / Q000378:metabolism; D005260:Female; D055429:Growth Differentiation Factor 9; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D009924:Organ Culture Techniques; D006080:Ovarian Follicle / Q000254:growth & development* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012756:Sheep
D055429:Growth Differentiation Factor 9; D036341:Intercellular Signaling Peptides and Proteins; D052005:Bone Morphogenetic Protein Receptors, Type I; D052006:Bone Morphogenetic Protein Receptors, Type II