| Functional |
"Adaptive nonshivering thermogenesis (NST) of placental mammals is predominantly mediated by uncoupling protein 1 (UCP1), which resides at high levels in the mitochondrial inner membrane of brown adipose tissue (BAT) (1)." |
10.1126/sciadv.1602878 |
| Methodology & Validation |
"We thus verified this deletion in both African and Asian elephant (Elephas maximus) DNA samples via PCR and Sanger sequencing techniques. PCR was also used to obtain ucp1 sequences from the three-toed brown-throated sloth (B. variegatus), silky anteater (Cyclopes didactylus), bowhead whale (Balaena mysticetus), Grant’s zebra (Equus quagga boehmi), black rhinoceros (Diceros bicornis), and Indian rhinoceros (Rhinoceros unicornis). Specimen information is provided in table S7 (64, 69–71)." |
10.1126/sciadv.1602878 |
| Timing of Loss |
"Notably, the non-delphinid cetacean UCP1 primary sequences presented in the latter study show premature stop codons stemming from both nonsense and frameshift mutations (as also seen in Fig. 1), whereas the presented killer whale and bottlenose dolphin “UCP1 sequences correspond to UCP2 and UCP3, respectively. Our results further indicate that the pseudogenization of ucp1 also immediately predates strong increases in body size during the early amphibious stages of archaeocete evolution [that is, from 15- to 30-kg Himalayacetus (52.5 Ma) to 590- to 720-kg Ambulocetus/Rodhocetus (48 Ma) (50, 51)]" |
10.1126/sciadv.1602878 |