Social stress is unlikely to play a major role in reproductive suppression of female subordinate naked mole-rats and Damaraland mole-rats

The dissection of a despotic society: exploration, dominance and hormonal traits

“…The role of stress-related glucocorticoids in naked mole-rat colonies and reproductive suppression has been under much debate [65][66][67]. However, stress responses are of considerable importance in the suppression of reproduction in social mole-rat species [67].…”

The best of both worlds: no apparent trade-off between immunity and reproduction in two group-living African mole-rat species

“…Increased levels of progesterone in BF Damaraland mole-rats compared with those of NBFs are correlated to increased immunocompetence, while testosterone and cortisol did not affect the immunocompetence of female Damaraland mole-rats. As BFs ovulate and fall pregnant, progesterone levels are higher in BFs than NBFs [18,39]. Human and animal studies' data demonstrate that progesterone influences most components of innate and adaptive immunity [54].…”

“…Group members that are reproductively suppressed are often referred to as non-breeders or subordinates [10], and reproductive suppression is often more common in females in co-operatively breeding species. Reproductive suppression in females can range from infanticide of the subordinate's offspring, anovulation of female non-breeding subordinates and, in some extreme cases, a lack of follicular maturation in the ovaries of nonbreeding female (NBF) subordinates, with NBF anovulation and lack of follicular maturation being more common in co-operatively breeding mammal species that show a high reproductive skew and suppression [15][16][17][18].…”

“…Furthermore, this study also attempted to investigate the relationship between the immune and endocrine systems using the endocrine profiles of BF and NBF Damaraland mole-rats. A comprehensive bidirectional relationship between the immune and endocrine systems has been well documented, with sex hormones, such as progesterone and testosterone (which have been recorded to be significantly higher in BFs compared with NBFs [39,40]), and hormones related to group maintenance, such as cortisol (which has been recorded to be higher in NBFs compared with BFs, but not significantly so [18,39,41]), being observed to possess both an immuno-enhancing and an immuno-suppressive role [42][43][44][45][46].…”

Validation of Enzyme Immunoassays via an Adrenocorticotrophic Stimulation Test for the Non-Invasive Quantification of Stress-Related Hormone Metabolites in Naked Mole-Rats

“…The role of stress In cooperatively breeding species such as naked mole-rats is under much debate [ 53 , 54 , 55 ]. Our results suggest preliminary evidence that the role of stress in naked mole-rat colonies is possibly sex-dependent.…”