Phenotypic plasticity in female naked mole-rats after removal from reproductive suppression.
Naked mole-rats are fossorial African rodents that live in large, eusocial groups. Adult subordinate female mole-rats are reproductively suppressed by the dominant breeding female in their colonies. As a result, subordinate females remain reproductively quiescent for their entire lives unless they are removed from the suppressive presence of the dominant female. This makes subordinate female mole-rats a tractable model for studying phenotypic plasticity. We measured skeletal growth of subordinate, suppressed females as they changed reproductive status. After housing subordinate female mole-rats separately from their home colonies, these animals experienced a growth surge that dramatically increased their body mass and length. After removal from reproductive suppression, females showed an 82% increase in body mass and a 37% increase in the length of their lumbar spines. The lumbar vertebrae were the only skeletal structures that exhibited this puberty-like growth. After colony separation, body mass and lumbar vertebrae growth rates peaked and remained elevated for several weeks before returning to control levels--suggestive of a puberty-like 'growth spurt'. Although previous studies have characterized pregnancy-induced lumbar spine elongation in female mole-rats, we demonstrate a significant change in the body morphology of female mole-rats after removal from reproductive suppression but before the first pregnancy.
Neuroscience Graduate Program, Vanderbilt University, Nashville, TN 37235, USA. christine.crish@vanderbilt,edu
Christine M
CM
Dengler-Crish
Kenneth C
KC
Catania
D000818:Animals; D001835:Body Weight; D005260:Female; D008159:Lumbar Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008297:Male; D019577:Mole Rats / Q000502:physiology*; D010641:Phenotype; D011859:Radiography; D012098:Reproduction / Q000502:physiology*; D013997:Time Factors; D015430:Weight Gain