Nucleic Acids Research, 1988, Vol. 16, No. 13 5945-5955
© 1988
Articles |
Conformational mutation in human mtDNA detected by direct sequencing of enzymatically amplified DNA
Department of Biochemistry, University of California Berkeley, CA 94720, USA
Received March 21, 1988. Revised June 2, 1988. Accepted June 2, 1988.
Restriction enzyme analysis of 241 human mtDNAs revealed polymorphism in the electrophoretic mobility of a fragment corresponding to part of the ND4 gene. Enzymatic amplification and direct sequencing of this fragment demonstrates that a single T C transition correlates with the faster mobility exhibited by the fragment in seven mtDNAs from Papua New Guinea. The enhanced mobility caused by this transition could result from disrupting an AT-rich region near the middle of the fragment that might make it curve. An analogous mutation at an adjacent position in a European mtDNA causes a similar but more pronounced alteration in mobility. The seven New Guineans with this substitution are all from the Eastern Highlands Province and constitute one clade in a genealogical tree based upon restriction analysis. The additional information provided by sequencing allows refinement of the genealogical tree but does not require modification of higher order branching structure.