Loss of a-actinin-3 during human evolution provides superior cold resilience and muscle heat generation

To examine if the loss of alpha-actinin-3, a fast skeletal muscle protein, modifies core body temperture following acute cold exposure in humans and a mice Using an Actn3 KO mice model we explore the effects of cold exposure on brown adipose tissue function following exposure to cold (4 degrees C) for 5 hours, compared to control mice housed at either thermoneutrality (30 degrees C) or standard room temperature (22 degrees C) WT and Actn3 KO mice were exposed to altered environmental temperatures and core body temperature was recorded over a 5 hour period. Following euthanasia, brown adipose tissue was collected and frozen in liquid nitrogen prior to RNA being extracted.