This is consistent with gene loss
being a major contributor to reductive genomes in this phylum [10, 31].
Laser captured hepatocytes show association of butyrylcholinesterase gene loss
and fibrosis progression in hepatitis C-infected drug users.
U of T Department of Ecology and Evolutionary Biology (EEB) professor Spencer Barrett, co-investigator of a study, said in humans, the Y chromosome has undergone extensive gene loss
over its roughly 200-million-year evolutionary history, and now retains only about three per cent of its ancestral genes.
It has been postulated that progressive gene loss
, primarily at the terminal ends of the genome, has been a driving force behind the evolution of these viruses (7).
The data revealed two unusual mishaps that occurred in the process of cell division about 27 and 80 million years ago, when an extensive expansion of genes arose from an entire extra copy of the genome, followed by extensive gene loss
. Fei explains, "The kiwifruit genome has undergone two recent whole-genome duplication events." When genes are duplicated, the extra genes can mutate to perform entirely new functions that were not previously present in the organism.
The study seeks to see if there are genetic advantages to sexual reproduction that justify its evolutionary costs, advantages such as avoiding genetic mutations or gene loss
This landmark study revealed massive gene loss
across most functional categories as part of a broader picture of severe genome reduction.
Those who did not show ERG/ETV1 genetic aberrations with no PTEN gene loss
had excellent prognosis, evidenced by an 85% survival rate after 11 years.
CI may accelerate the rate of tumor suppressor gene loss
, and/or actually amplify oncogenes by duplication of the chromosomes on which they are located, contributing to tumorigenesis (Rajagopalan et al.).
(30) Philippe and Forterre (31) demonstrated that the phylogenies were highly confusing due to the combining effects of gene duplication, gene loss
, lateral gene transfer, and tree reconstruction artifacts.
"We think that gene loss
is still the simplest explanation," says Michael Stanhope of Glaxo-SmithKline in Collegeville, Pa.