Wednesday, September 11, 2019
Mitochondrial DNA (mtDNA) characteristics and uses Assignment
Mitochondrial DNA (mtDNA) characteristics and uses - Assignment Example DNA sequence determination of the mDNA has been from many organisms including the extinct ones, and the comparison of the sequences outlines the mainstay of phylogenetics. The researchers have therefore been able to elucidate various evolutionary relationships within species. Additionally, the analysis of the relatedness of the populations among organisms has been ascertained and has become vital in the field of anthropology. The human mitochondrion DNA as an example, is commonly present per every cell except in sex cells as elucidated by Brown, George & Wilson, 1979, and is closely related to that of metazoans. The circular double-strand molecule of mDNA has about 15000 to 17000 base pairs and the nucleotide content differentiates the two strands. In animals, the transcribed strand produces molecules of polycistronic RNA. In replication process, the mDNA is replicated by the gamma complex of the enzyme DNA polymerase that is composed of 140 kDa of the catalytic section of the enzyme encoded by the gene POLG and two accessory subunits of 55 kDa encoded by POLG2 gene. During the process of embryogenesis, the mDNA replication is down because it is regulated from the oocyte that is fertilized through the embryo that is pre-implanted. At the stage of blastocyst, Anderson et al, 1981, further exemplifies that onset of the replication of the mDNA is specific to the trophectoderm cells. In contrast, the replication of mDNA is restricted by the inner cell mass cell until they receive signals making them differentiate to specific cell types. In the susceptibility concept, the mDNA does not necessarily accumulate many oxidative base damages than the nuclear DNA. As a result, some other types of the oxidative DNA damage are more efficiently repaired in the mitochondria than in the nucleus. The presence of proteins in the organelle further offers protection just as in the nuclear chromatin. The integrity of
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.