Modular genetic control of social status in a cichlid fish

Abstract

Competing interest:We have no competing interests. Author's contributions: Conceptualization, B.A.A., R.D.F., S.A.J.; Methodology, B.A.A, S.A.J, C.J.S.; Investigation, B.A.A., C.J.S., R.A.Y, V.L.; Writing -Original Draft, B.A.A.; Writing -Review & Editing, B.A.A., R.A.Y, S.A.J.; Supervision, B.A.A. AbstractSocial hierarchies are ubiquitous in social species, yet the mechanisms underlying social status are unclear. In the African cichlid fish Astatotilapia burtoni, males stratify along a dominance hierarchy that varies based on testes mass, coloration, and behavior. Using androgen receptor (AR) mutant A. burtoni generated using CRISPR/Cas9, we find that two AR genes control social dominance. ARb, but not ARa, is required for testes growth and bright coloration, while ARa, but not ARb, is required for the performance of reproductive behavior and aggressive displays. Neither receptor is required for attacking males. Analysis of AR double mutants revealed that either AR is sufficient for attacking males. Social status in A. burtoni males is modularly controlled by ARa and ARb, indicating that these genes have undergone subfunctionalization.One Sentence Summary: Genetic dissection of social dominance in a cichlid using CRISPR/Cas9 gene editing reveals dissociable roles for distinct androgen receptor genes. Main textSocial animals -such as humans, non-human primates, mice, and fish -often organize into hierarchies (1). Within these social hierarchies dominant and non-dominant individuals exist, differing markedly along multiple behavioral and physiological dimensions. Dominant individuals typically behave more aggressively and have more mating opportunities than non-dominant individuals. Higher-ranking animals also tend to have higher levels of sex steroid hormones such as androgens (e.g., testosterone) and estrogens and larger gonads. Despite these compelling patterns, the mechanistic basis of social status remains to be established. Understanding what controls social status is important for several reasons. For instance, the underlying mechanisms of social status likely are involved in an animal's ability to interpret and navigate their social

A phylogenetics-based nomenclature system for steroid receptors in teleost fishes

“…This challenge at first may seem inconsequential, but a lack of a logical nomenclature system for novel teleost steroid receptor paralogs may hinder a clear understanding of their functions. With the advent of CRISPR/Cas9 gene editing technologies, numerous non-traditional laboratory species, including teleost fishes, are emerging as genetically tractable for a variety of research questions (reviewed in Alward et al, 2023; Jackson et al, 2023; Juntti, 2019), including those related to steroid hormone function (Alward et al, 2020; Crowder et al, 2018; Faught and Vijayan, 2019, 2018; Muto et al, 2013; Yin et al, 2017; Yong et al, 2017; Ziv et al, 2013). Therefore, it is important for logical, consistent nomenclature to be used for steroid receptors and their genes across teleost fishes.…”