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 (4oC) for 5 hours, compared to control mice housed at either thermoneutrality (30oC) or standard room temperature (22oC) Overall design: WT and Actn3 KO mice were exposed to altered environmental temperatures and core body tempertaure was recovredd over a 5 hour peroid. Following euthenasia, brown adipose tissue was collected and frozen in liquid nitrogen prior to RNA being extracted.