title: Genetic distance in housekeeping genes between Plasmodium falciparum and Plasmodium reichenowi and within P. falciparum.
abstract: The time to the most recent common ancestor of the extant populations of Plasmodium falciparum is controversial. The controversy primarily stems from the limited availability of sequences from Plasmodium reichenowi, a chimpanzee malaria parasite closely related to P. falciparum. Since the rate of nucleotide substitution differs in different loci and DNA regions, the estimation of genetic distance between P. falciparum and P. reichenowi should be performed using orthologous sequences that are evolving neutrally. Here, we obtained full-length sequences of two housekeeping genes, sarcoplasmic and endoplasmic reticulum Ca2+ -ATPase (serca) and lactate dehydrogenase (ldh), from 11 isolates of P. falciparum and 1 isolate of P. reichenowi and estimate the interspecific genetic distance (divergence) between the two species and intraspecific genetic distance (polymorphism) within P. falciparum. Interspecific distance and intraspecific distance at synonymous sites of interspecies-conserved regions of serca and ldh were 0.0672 +/- 0.0088 and 0.0011 +/- 0.0007, respectively, using the Nei and Gojobori method. Based on the ratio of interspecific distance to intraspecific distance, the time to the most recent common ancestor of P. falciparum was estimated to be (8.30 +/- 5.40) x 10(4) and (11.62 +/- 7.56) x 10(4) years ago, assuming the divergence time of the two parasite species to be 5 and 7 million years ago, respectively.
authors.affiliation: Laboratory of Biology, faculty of Engineering, Osaka Institute of Technology, Ohmiya 5-16-1, Asahi-ku, Osaka 535-8585, Japan. kztanabe@ge.oit.ac.jp
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Tanabe
authors.forename: Naoko
authors.initials: N
authors.lastname: Sakihama
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hattori
authors.forename: Lisa
authors.initials: L
authors.lastname: Ranford-Cartwright
authors.forename: Ira
authors.initials: I
authors.lastname: Goldman
authors.forename: Ananias A
authors.initials: AA
authors.lastname: Escalante
authors.forename: Altaf A
authors.initials: AA
authors.lastname: Lal
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D000252:Calcium-Transporting ATPases / Q000737:chemistry; D017124:Conserved Sequence / Q000235:genetics; D019143:Evolution, Molecular; D017125:Genes, Protozoan / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D010961:Plasmodium / Q000145:classification / Q000235:genetics*; D010963:Plasmodium falciparum / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D000252:Calcium-Transporting ATPases