title: Meiotic progression of rat spermatocytes requires mitogen-activated protein kinases of Sertoli cells and close contacts between the germ cells and the Sertoli cells.
abstract: Progression of germ cells through meiosis is regulated by phosphorylation events. We previously showed the key role of cyclin dependent kinases in meiotic divisions of rat spermatocytes co-cultured with Sertoli cells (SC). In the present study, we used the same culture system to address the role of mitogen-activated protein kinases (MAPKs) in meiotic progression. Phosphorylated ERK1/2 were detected in vivo and in freshly isolated SC and in pachytene spermatocytes (PS) as early as 3 h after seeding on SC. The yield of the two meiotic divisions and the percentage of highly MPM-2-labeled pachytene and secondary spermatocytes (SII) were decreased in co-cultures treated with U0126, an inhibitor of the ERK-activating kinases, MEK1/2. Pre-incubation of PS with U0126 resulted in a reduced number of in vitro formed round spermatids without modifying the number of SII or the MPM-2 labeling of PS or SII. Conversely, pre-treatment of SC with U0126 led to a decrease in the percentage of highly MPM-2-labeled PS associated with a decreased number of SII and round spermatids. These results show that meiotic progression of spermatocytes is dependent on SC-activated MAPKs. In addition, high MPM-2 labeling was not acquired by PS cultured alone in Sertoli cell conditioned media, indicating a specific need for cell-cell contact between germ cells and SC.
authors.affiliation: Institut de Génomique Fonctionnelle de Lyon, Université de Lyon, Lyon F-69003, France. godet@lyon.inserm.fr
authors.forename: Murielle
authors.initials: M
authors.lastname: Godet
authors.forename: Odile
authors.initials: O
authors.lastname: Sabido
authors.forename: Jérôme
authors.initials: J
authors.lastname: Gilleron
authors.forename: Philippe
authors.initials: P
authors.lastname: Durand
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D018920:Coculture Techniques; D004789:Enzyme Activation; D019084:Fluorescent Antibody Technique, Indirect; D005456:Fluorescent Dyes / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D008540:Meiosis / Q000502:physiology*; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012235:Rhodamines / Q000378:metabolism; D012708:Sertoli Cells / Q000201:enzymology* / Q000502:physiology; D013090:Spermatocytes / Q000166:cytology* / Q000201:enzymology*
chemical_list: D005456:Fluorescent Dyes; D012235:Rhodamines; C009434:tetramethylrhodamine isothiocyanate; D020928:Mitogen-Activated Protein Kinases