December 28, 2005

Back mutation in mtDNA haplogroup C

Am J Hum Biol. 2005 Dec 25;18(1):59-65 [Epub ahead of print]

A revertant of the major founder Native American haplogroup C common in populations from northern South America.

Torres MM, Bravi CM, Bortolini MC, Duque C, Callegari-Jacques S, Ortiz D, Bedoya G, Groot de Restrepo H, Ruiz-Linares A.

We examined the mtDNA RFLP diversity of 17 Native American populations from Colombia. Five of the populations studied were found to have variable frequencies of a mtDNA type lacking the characteristic changes of haplogroups A-D. Sequencing of mtDNA HVS-I and II showed that this "null" RFLP type carries all the substitutions characteristic of Native American founder lineage C. A back mutation has therefore recreated the +13,259 HincII/-13,262 AluI restriction sites that tipify RFLP haplogroup C. This revertant C lineage is further characterized by three changes in HVS-II sequence: C/T transitions at positions 115 and 152, and the deletion of an A residue at position 116. This lineage is observed at high frequency mostly in populations from Greenberg's Equatorial-Tucano linguistic family. Genetic structure analyses are consistent with the reversion mutation occurring at an early stage during the tribalization process.


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