Steroid hormones, energetic state, and immunocompetence vary across reproductive contexts in a parthenogenetic lizard

• Published in: General and comparative endocrinology 2020-03, Vol.288, p.113372-113372, Article 113372
• Main Authors: Hudson, S.B., Kluever, B.M., Webb, A.C., French, S.S.
• Format: Article
• Language: English
• Subjects: Aspidoscelis neotesselata; Corticosterone; Energy metabolites; Estradiol; Immunity; Reptile; Seasonality; Vitellogenesis
• ISSN: 0016-6480; 1095-6840
• DOI: 10.1016/j.ygcen.2019.113372

•During breeding CORT and glucose were lower, but immunity and triglycerides were higher.•E2, Triglycerides, and free glycerol were higher at critical periods of vitellogenesis.•E2 levels were positively associated with free glycerol and immunity.•CORT levels were negatively associated with triglycerides and immunity. Reproduction is energetically expensive and investing in this life history trait is likely accompanied by significant changes in physiological activity. Investment strategy necessary for achieving reproductive success in reptiles can vary with reproductive form and pattern, potentiating different consequences for competing fitness-related traits such as those key to survival. The goal of this study was to assess if and how energetic state (i.e., energy metabolites) and self-maintenance (i.e., immunocompetence) are hormonally modulated across reproductive contexts in an oviparous, parthenogenetic lizard, the Colorado Checkered Whiptail Aspidoscelis neotesselata. Here blood plasma samples were collected from lizards within the US Army Fort Carson Military Installation near Colorado Springs, CO, USA, during seasons of reproductive activity (i.e., June) and inactivity (i.e., August). Measures of reproductive (i.e., estradiol) and energy-mobilizing (i.e., corticosterone) hormones, energy metabolites (i.e., glucose, triglycerides, and free glycerol), and innate immunity (i.e., bactericidal ability) were compared by season and reproductive stage. Levels of energy metabolites and bactericidal ability were compared to levels of E2 and CORT. Bactericidal ability was also compared to levels of energy metabolites. Corticosterone and glucose levels were lower during the reproductive season while triglyceride levels and bactericidal ability were higher, but both estradiol and free glycerol levels did not differ between seasons. Throughout vitellogenesis, corticosterone and glucose levels as well as bactericidal ability did not differ, but estradiol levels were higher during early and mid-stage and both triglyceride and free glycerol levels were lower during gravidity. Corticosterone levels were negatively associated with circulating triglycerides and bactericidal ability, but were not related to glucose nor free glycerol levels. Estradiol levels were positively associated with free glycerol levels and bactericidal ability, but were not related to glucose nor triglyceride levels. Finally, bactericidal ability was negatively associated with glucose, but posi