title: Socially regulated reproductive development: analysis of GnRH-1 and kisspeptin neuronal systems in cooperatively breeding naked mole-rats (Heterocephalus glaber).
abstract: In naked mole-rat (NMR) colonies, breeding is monopolized by the queen and her consorts. Subordinates experience gonadal development if separated from the queen. To elucidate the neuroendocrine factors underlying reproductive suppression/development in NMRs, we quantified plasma gonadal steroids and GnRH-1- and kisspeptin-immunoreactive (ir) neurons in subordinate adults and in those allowed to develop into breeders, with or without subsequent gonadectomy. In males and females, respectively, plasma testosterone and progesterone are higher in breeders than in subordinates. No such distinction occurs for plasma estradiol; its presence after gonadectomy and its positive correlation with adrenal estradiol suggest an adrenal source. Numbers of GnRH-1-ir cell bodies do not differ between gonad-intact breeders and subordinates within or between the sexes. As in phylogenetically related guinea pigs, kisspeptin-ir processes pervade the internal and external zones of the median eminence. Their distribution is consistent with actions on GnRH-1 neurons at perikaryal and/or terminal levels. In previously investigated species, numbers of kisspeptin-ir cell bodies vary from substantial to negligible according to sex and/or reproductive state. NMRs are exceptional: irrespective of sex, reproductive state, or presence of gonads, substantial numbers of kisspeptin-ir cell bodies are detected in the rostral periventricular region of the third ventricle (RP3V) and in the anterior periventricular (PVa), arcuate, and dorsomedial hypothalamic nuclei. Nevertheless, the greater number in the RP3V/PVa of female breeders compared with female subordinates or male breeders suggests that emergence from a hypogonadotrophic state in females may involve kisspeptin-related mechanisms similar to those underlying puberty or seasonal breeding in other species.
authors.affiliation: Reproductive Neurobiology, Division of Women's Health, School of Medicine, King's College London, London, UK.
authors.forename: Shuzhi
authors.initials: S
authors.lastname: Zhou
authors.forename: Melissa M
authors.initials: MM
authors.lastname: Holmes
authors.forename: Nancy G
authors.initials: NG
authors.lastname: Forger
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Goldman
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Lovern
authors.forename: Alain
authors.initials: A
authors.lastname: Caraty
authors.forename: Imre
authors.initials: I
authors.lastname: Kalló
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Faulkes
authors.forename: Clive W
authors.initials: CW
authors.lastname: Coen
mesh_terms: D000818:Animals; D001835:Body Weight; D001921:Brain / Q000166:cytology*; D002369:Castration; D002452:Cell Count; D003299:Cooperative Behavior; D004958:Estradiol / Q000097:blood; D005260:Female; D059648:Kisspeptins / Q000378:metabolism*; D008297:Male; D019577:Mole Rats; D009474:Neurons / Q000378:metabolism*; D011374:Progesterone / Q000097:blood; D011863:Radioimmunoassay; D011966:Receptors, LHRH / Q000378:metabolism*; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013739:Testosterone / Q000097:blood
chemical_list: C106628:KISS1 protein, human; D059648:Kisspeptins; D011966:Receptors, LHRH; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol
keywords: GnRH-1; Heterocephalus glaber; RP3V; anteroventral periventricular nucleus; arcuate nucleus; cooperation; dorsomedial hypothalamic nucleus; estradiol; eusociality; kisspeptin; naked mole-rat; progesterone; reproductive suppression; social behavior; social status; testosterone