Toward developing recombinant gonadotropin-based hormone therapies for increasing fertility in the flatfish Senegalese sole.
Captive flatfishes, such as the Senegalese sole, typically produce very low volumes of sperm. This situation is particularly prevalent in the first generation (F1) of reared sole males, which limits the development of artificial fertilization methods and the implementation of selective breeding programs. In this study, we investigated whether combined treatments with homologous recombinant follicle-stimulating (rFsh) and luteinizing (rLh) hormones, produced in a mammalian host system, could stimulate spermatogenesis and enhance sperm production in Senegalese sole F1 males. In an initial autumn/winter experiment, weekly intramuscular injections with increasing doses of rFsh over 9 weeks resulted in the stimulation of gonad weight, androgen release, germ cell proliferation and entry into meiosis, and the expression of different spermatogenesis-related genes, whereas a subsequent single rLh injection potentiated spermatozoa differentiation. In a second late winter/spring trial corresponding to the sole's natural prespawning and spawning periods, we tested the effect of repeated rLh injections on the amount and quality of sperm produced by males previously treated with rFsh for 4, 6, 8 or 10 weeks. These latter results showed that the combination of rFsh and rLh treatments could increase sperm production up to 7 times, and slightly improve the motility of the spermatozoa, although a high variability in the response was found. However, sustained administration of rFsh during spawning markedly diminished Leydig cell survival and the steroidogenic potential of the testis. These data suggest that in vivo application of rFsh and rLh is effective at stimulating spermatogenesis and sperm production in Senegalese sole F1 males, setting the basis for the future establishment of recombinant gonadotropin-based hormone therapies to ameliorate reproductive dysfunctions of this species.
Institut de Recerca i Tecnologia Agroalimentàries (IRTA)-Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.
François
F
Chauvigné
Institut de Recerca i Tecnologia Agroalimentàries (IRTA)-Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.
Judith
J
Ollé
IRTA, Sant Carles de la Ràpita, Tarragona, Spain.
Wendy
W
González
IRTA, Sant Carles de la Ràpita, Tarragona, Spain.
Neil
N
Duncan
Rara Avis Biotec, S. L., Valencia, Spain.
Ignacio
I
Giménez
Institut de Recerca i Tecnologia Agroalimentàries (IRTA)-Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.
Joan
http://orcid.org/0000-0003-2568-6398
J
Cerdà
D000728:Androgens / Q000378:metabolism; D000818:Animals; D005260:Female; D005298:Fertility / Q000187:drug effects*; D005412:Flatfishes / Q000378:metabolism / Q000502:physiology*; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008297:Male; D008540:Meiosis / Q000187:drug effects; D006080:Ovarian Follicle / Q000187:drug effects / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology*; D012098:Reproduction / Q000187:drug effects; D013091:Spermatogenesis / Q000187:drug effects; D013737:Testis / Q000187:drug effects / Q000378:metabolism
D000728:Androgens; D011994:Recombinant Proteins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone