Sex- and brain region-specific patterns of gene expression associated with socially-mediated puberty in a eusocial mammal

• DOI: 10.1371/journal.pone.0193417
• Publication Date: 2018-02-23T19:19:31Z
• Authors: Mariela Faykoo-Ma...; D. Ashley Monks; Iva B. Zovkic; Melissa M. Holmes
• Keywords: Male; 0301 basic medicine; Sex Characteristics; Science; Gene Expression Profiling; Mole Rats; Q; Body Weight; R; Brain; 03 medical and health sciences; Organ Specificity; Medicine; Animals; Female; Steroids; Sexual Maturation; Social Behavior; Research Article

The social environment can alter pubertal timing through neuroendocrine mechanisms that are not fully understood; it is thought that stress hormones (e.g., glucocorticoids or corticotropin-releasing hormone) influence the hypothalamic-pituitary-gonadal axis to inhibit puberty. Here, we use the eusocial naked mole-rat, a unique species in which social interactions in a colony (i.e. dominance of a breeding female) suppress puberty in subordinate animals. Removing subordinate naked mole-rats from this social context initiates puberty, allowing for experimental control of pubertal timing. The present study quantified gene expression for reproduction- and stress-relevant genes acting upstream of gonadotropin-releasing hormone in brain regions with reproductive and social functions in pre-pubertal, post-pubertal, and opposite sex-paired animals (which are in various stages of pubertal transition). Results indicate sex differences in patterns of neural gene expression. Known functions of genes in brain suggest stress as a key contributing factor in regulating male pubertal delay. Network analysis implicates neurokinin B (Tac3) in the arcuate nucleus of the hypothalamus as a key node in this pathway. Results also suggest an unappreciated role for the nucleus accumbens in regulating puberty.