title: Fsh and Lh direct conserved and specific pathways during flatfish semicystic spermatogenesis.
abstract: The current view of the control of spermatogenesis by Fsh and Lh in non-mammalian vertebrates is largely based on studies carried out in teleosts with cystic and cyclic spermatogenesis. Much less is known concerning the specific actions of gonadotropins during semicystic germ cell development, a type of spermatogenesis in which germ cells are released into the tubular lumen where they transform into spermatozoa. In this study, using homologous gonadotropins and a candidate gene approach, for which the genes' testicular cell-type-specific expression was established, we investigated the regulatory effects of Fsh and Lh on gene expression during spermatogenesis in Senegalese sole (Solea senegalensis), a flatfish with asynchronous and semicystic germ cell development. During early spermatogenesis, Fsh and Lh upregulated steroidogenesis-related genes and nuclear steroid receptors, expressed in both somatic and germ cells, through steroid-dependent pathways, although Lh preferentially stimulated the expression of downstream genes involved in androgen and progestin syntheses. In addition, Lh specifically promoted the expression of spermatid-specific genes encoding spermatozoan flagellar proteins through direct interaction with the Lh receptor in these cells. Interestingly, at this spermatogenic stage, Fsh primarily regulated genes encoding Sertoli cell growth factors with potentially antagonistic effects on germ cell proliferation and differentiation through steroid mediation. During late spermatogenesis, fewer genes were regulated by Fsh or Lh, which was associated with a translational and posttranslational downregulation of the Fsh receptor in different testicular compartments. These results reveal that conserved and specialized gonadotropic pathways regulate semicystic spermatogenesis in flatfish, which may spatially adjust cell germ development to maintain a continuous reservoir of spermatids in the testis.
authors.affiliation: Institut de Recerca i Tecnologia Agroalimentàries (IRTA)-Institut de Ciències del MarConsejo Superior de Investigaciones Científicas (CSIC), Passeig marítim 37-49, 08003 Barcelona, SpainDepartament de Fisiologia i ImmunologiaFacultat de Biologia, Universitat de Barcelona, i Institut de Biomedicina de la Universitat de Barcelona (IBUB), 08028 Barcelona, Spain.
authors.forename: François
authors.initials: F
authors.lastname: Chauvigné
authors.affiliation: Institut de Recerca i Tecnologia Agroalimentàries (IRTA)-Institut de Ciències del MarConsejo Superior de Investigaciones Científicas (CSIC), Passeig marítim 37-49, 08003 Barcelona, SpainDepartament de Fisiologia i ImmunologiaFacultat de Biologia, Universitat de Barcelona, i Institut de Biomedicina de la Universitat de Barcelona (IBUB), 08028 Barcelona, Spain.
authors.forename: Cinta
authors.initials: C
authors.lastname: Zapater
authors.affiliation: Institut de Recerca i Tecnologia Agroalimentàries (IRTA)-Institut de Ciències del MarConsejo Superior de Investigaciones Científicas (CSIC), Passeig marítim 37-49, 08003 Barcelona, SpainDepartament de Fisiologia i ImmunologiaFacultat de Biologia, Universitat de Barcelona, i Institut de Biomedicina de la Universitat de Barcelona (IBUB), 08028 Barcelona, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Crespo
authors.affiliation: Institut de Recerca i Tecnologia Agroalimentàries (IRTA)-Institut de Ciències del MarConsejo Superior de Investigaciones Científicas (CSIC), Passeig marítim 37-49, 08003 Barcelona, SpainDepartament de Fisiologia i ImmunologiaFacultat de Biologia, Universitat de Barcelona, i Institut de Biomedicina de la Universitat de Barcelona (IBUB), 08028 Barcelona, Spain.
authors.forename: Josep V
authors.initials: JV
authors.lastname: Planas
authors.affiliation: Institut de Recerca i Tecnologia Agroalimentàries (IRTA)-Institut de Ciències del MarConsejo Superior de Investigaciones Científicas (CSIC), Passeig marítim 37-49, 08003 Barcelona, SpainDepartament de Fisiologia i ImmunologiaFacultat de Biologia, Universitat de Barcelona, i Institut de Biomedicina de la Universitat de Barcelona (IBUB), 08028 Barcelona, Spain joan.cerda@irta.cat.
authors.forename: Joan
authors.initials: J
authors.lastname: Cerdà
mesh_terms: D000728:Androgens / Q000097:blood / Q000378:metabolism; D000818:Animals; D016000:Cluster Analysis; D005412:Flatfishes / Q000502:physiology*; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006062:Gonadotropins / Q000378:metabolism; D007150:Immunohistochemistry; D007986:Luteinizing Hormone / Q000378:metabolism*; D008297:Male; D009928:Organ Specificity / Q000235:genetics; D011962:Receptors, FSH / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D013091:Spermatogenesis / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology; D013737:Testis / Q000166:cytology / Q000378:metabolism
chemical_list: D000728:Androgens; D006062:Gonadotropins; D011962:Receptors, FSH; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone
keywords: follicle-stimulating hormone; luteinizing hormone; semicystic spermatogenesis; teleost; transcription