Wallace Kyra M E, Hart Daniel W, Hagenah Nicole, Ganswindt Andre, Bennett Nigel C
Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa.
Department of Zoology and Entomology, University of Pretoria, Pretoria 0002, South Africa.
Gen Comp Endocrinol. 2023 Mar 1;333:114194. doi: 10.1016/j.ygcen.2022.114194. Epub 2022 Dec 17.
In species where sociality and group cohesion are primarily determined by the maintenance of a reproductive division of labour and cooperative behaviours, the eusocial Damaraland mole-rat (Fukomys damarensis) presents a model which provides behavioural and endocrine distinctions between sex (males and females) and reproductive class (breeders and non-breeders). Although previous studies have demonstrated the endocrine aspects of reproductive suppression and behaviour in Damaraland mole-rats, they have focused on one hormone separately and on different conspecifics and samples across time. Unfortunately, this could introduce extrinsic biases when using these studies to compile complete hormonal profiles for comparisons. This study, therefore, set out to obtain a profile of the reproductive hormones from breeding and non-breeding male and female Damaraland mole-rats at a single point in time, from which circulating plasma prolactin and urinary progesterone, testosterone, and cortisol were measured. As expected, plasma prolactin and urinary cortisol did not differ between the breeders and non-breeders. However, breeders (both male and female) possessed increased urinary testosterone and progesterone concentrations compared to their non-breeding counterparts. These results, in conjunction with the variation in the expression of the respective hormonal receptors within the brains of breeders and non-breeders suggest that elevated testosterone and progesterone in breeders establish a neural dominance phenotype, which ultimately aids in controlling breeding activities. This study has emphasised the need for holistic, comprehensive profiling of reproductive endocrine systems.
在社会性和群体凝聚力主要由生殖分工和合作行为的维持所决定的物种中，真社会性的达马拉兰鼹形鼠（南非裸鼹鼠）提供了一个模型，该模型展现了性别（雄性和雌性）与生殖等级（繁殖者和非繁殖者）之间在行为和内分泌方面的差异。尽管先前的研究已经证明了达马拉兰鼹形鼠生殖抑制和行为的内分泌方面，但它们分别聚焦于一种激素，且随着时间推移研究的是不同的同种个体和样本。不幸的是，在利用这些研究来编制完整的激素谱以进行比较时，这可能会引入外在偏差。因此，本研究着手在一个时间点获取繁殖和非繁殖的雄性及雌性达马拉兰鼹形鼠的生殖激素谱，从中测量循环血浆中的催乳素以及尿液中的孕酮、睾酮和皮质醇。正如预期的那样，繁殖者和非繁殖者之间的血浆催乳素和尿液皮质醇没有差异。然而，与非繁殖的同类相比，繁殖者（雄性和雌性）尿液中的睾酮和孕酮浓度有所增加。这些结果，连同繁殖者和非繁殖者大脑中各自激素受体表达的差异，表明繁殖者体内升高的睾酮和孕酮建立了一种神经优势表型，这最终有助于控制繁殖活动。本研究强调了对生殖内分泌系统进行全面、综合分析的必要性。
