Mitochondrial DNA Essay Example | Topics and Well Written Essays - 750 words

Mitochondrial DNA - Essay Example This is accomplished in humans by the sequencing one or more of the hypervariable control regions (HVR1 or HVR2) of the mitochondrial DNA (Schwartz & Vissing 2002). Mitochondrial Eve is referred to as an ancestor who has been hypothesized on the grounds of fossil as well as DNA evidence (Vigilant et al. 1991). Phylogenies are constructed on mtDNA comparison shown that the living humans whose mitochondrial lineages branched earliest from the tree are indigenous Africans, while the lineages of indigenous peoples on other continents all branch off from African lines (Vigilant et al. 1991). Researchers can reason that all humans descend from Africa; and then they migrated out of Africa to populate the rest of the world. If the mitochondrial analysis is accurate, then mitochondrial Eve represents the origin of the mitochondrial family tree. Eve must have predated the mass departure and lived in Africa (Vigilant et al. 1991). Mitochondrial Eve was the most recent matrilineal ancestor of humans alive today. On the other hand, as evident lineages died out, the status of common matrilineal ancestor would have been passed to a descendant of the previous matrilineal ancestor. ... The nucleotide sequence of the hypervariable 1 (HV-1) region of mtDNA was determined from samples of all four groups. There were 275 HV-1 sequences, and a total of 164 haplotypes were observed (Jackson et al.). Jackson reveals that through analysis of molecular inconsistency indicated that the distribution of these haplotypes within the Limba sample was considerably different from the other ethnic groups. He further states that there was no significant difference between the other groups (Jackson et al.). These distinguishing results show genetic differences that can be observed within different ethnic groups in considerably close proximity of each other. Moreover, Jackson, and his group, observed some mtDNA haplotypes that were similar among the Sierra Leone ethnic groups and that have not been published in any other West African studies (Jackson et al.). As a result, there may be evidence for mtDNA lineages that are unique to this region of Western Africa. The methods of sampling w ere cheek swabs, using the BuccalAmp DNA Extraction kit according to the manufacturer's specifications, which were taking from 166 unrelated individuals from all four ethnic groups: Mende, Temne, Loko, and Limba (Jackson et al.). These samples were obtained in pre-arranged meetings and males were primarily observed. This was because matrilineal and patrilineal studies were conducted (Jackson et al.). Matrilineal and patrilineal ethnic lineages over three generations were recorded for each individual. The mtDNA haplotypes were determined by analyzing the nucleotide sequence of the hypervariable region (HV-I). HV1 sequences were allied and edited from positions 16001-16480 to ensure the identification of unambiguous polymorphisms (Jackson et al.). 480 bases of HV-I