A mitochondrial chromosome
sequencing-based association study looked into the sequence variations that could account for the varying phenotypes in these subjects.
"With very few exceptions, all these animals have a single circular mitochondrial chromosome
," Shao says.
And on most animals the mitochondrial chromosome contains 37 genes.
According to co-author Dr Renfu Shao, the mini-chromosomes "seem to sit at the summit of mitochondrial chromosome evolution".
"The mitochondrial chromosomes of head lice, in this sense, are extreme genomes," Shao added.
They assumed that there are variant and invariant sites along the DNA of the mitochondrial chromosome, then calculated from these data the relative likelihood that a transition or a transversion would occur.
We saw in the preceding section that a substantial subset of the sites in this region of the human mitochondrial chromosome appear more mutable than the rest.
Thus, the initial sequence represented the mitochondrial Eve, and the simulations followed what happened to the descendants of Eve's mitochondrial chromosome. Simulations involving population subdivision and changing population size were not investigated, although it should be pointed out that in an expanding population the rate of accumulation of diversity will not be affected by population size (Nei and Li 1979).
Each mitochondrion consists of 2-10 mitochondrial chromosomes
, so, each cell contains thousands of mitochondrial chromosomes
The Y and mitochondrial chromosomes
apparently dispersed throughout the human population at different rates, suggest geneticist Peter A.