Kisspeptins and their receptors are differentially expressed in the brain-pituitary-gonadal axis during gametogenesis in Odontesthes bonariensis.

TOVAR MO; MECHALY AS; ELISIO M; CHALDE T; CANOSA LF; MIRANDA LA; SOMOZA GM

Gotemburgo

Simposio; 8 ISFE; 2016

ISFE

Kisspeptins and their receptors are differentially expressed in the brain-pituitary-gonadalaxis during gametogenesis in Odontesthesbonariensis. Oswaldo Tovar1,Alejandro S Mechaly1, Mariano Elisio2, Tomás Chalde3,Fabián Canosa1, Leandro A Miranda1 and Gustavo MSomoza1 1IIB-INTECH(CONICET-UNSAM). 2INIDEP.3CADIC(CONICET), Argentina somoza@intech.gov.ar The brain-pituitary-gonadal(BPG) axis is implicated in the regulation of vertebrate reproduction, andkisspeptin has emerged as a key player of this axis. Two ligands, kiss1 and kiss2 and receptors, kissr2and kissr3, were characterized in Odontesthes bonariensis, and changes inthe expression profile of these transcripts were analyzed at the BPG axis duringfemale and male gametogenesis. Adult fish were collected every month from thewild, and the relative abundance of these transcripts was measured by real-timePCR. In females, brain kiss1 levelswere higher at final maturation (FM); meanwhile kiss2 levels were high at primary growth stage, with no differencesin receptors levels. At the pituitary, kiss1and kiss2 peaked at the corticalalveoli (Ca) stage, and kissr3 at initialvitellogenesis. Finally, there was an increase of kiss1, kissr2 and kissr3 in the ovary during the Ca stageand kissr2 and kissr3 at FM. These results showed that these genes were differentiallyexpressed at the three levels of the BPG axis throughout oogenesis. Changes ofbrain kiss1 expression levels suggestedthat it could be related to FM, in relation with the rise of gnrh1 observed at the same stage.Meanwhile kiss2 seemed to be associatedwith initial stages of gametogenesis.In males, the fourgenes were highly expressed in the brain at the arrested stage. In the pituitary,kiss2 peaked at spermatogonial (SG)and spermatocytary (SC) stages; while kissr3reached a peak at the spermiogenic stage (SP). In testes, kiss1 and kiss2significantly increased during the SG and SC stages; meanwhile, kissr2 increases at SG and SC, whereas kissr3 levels were significantly high atSC and SP stages.Taken together, theseresults suggested that kisspeptin ligands and receptors are involved in the regulationof pejerrey gonadal development at the three levels of the BPG axis, showingdifferential expression profiles in both sexes, suggesting different roles in femaleand male gametogenesis.