Complexity constrains evolution of human brain genes

o sequence several thousand genes expressed in the brain of the macaque monkey and compare them with available genomic sequences from human, chimpanzee, and mice.

What they found was that the "more advanced" species had faster overall rates of evolution. So, on average, the genes from humans and chimpanzees changed faster than genes from monkeys, which changed faster than those from mice.

They explained the trend as a correlate of smaller population size in the more advanced species. Species with smaller population size can more easily escape the harsh scrutiny of natural selection.

When they compared the pace of evolution among genes expressed in the brain, however, the order was reversed. When calibrated against the genomic average, brain genes in humans evolved more slowly than in other primates, which were slower than mice.

"We would expect positive selection to work most effectively on tissue-specific genes, where there would be fewer conflicting requirements," says Wu. "For example, genes expressed only in male reproductive tissues have evolved very rapidly."

Brains, however, "are intriguing in this respect," Wu says. Genes that are expressed only in the brain evolved more slowly than those that are expressed in the brain as well as other tissues, and those genes evolved more slowly than genes expressed throughout the rest of the organism.

The authors attribute the slowdown to mounting complexity of interactions within the brain. "We know that proteins with more interacting partners evolve more slowly," Wu said. "Mutations that disrupt existing interactions aren't tolerated."

Although the gene sequences from human and chimpanzee remain very similar, previous studies in tissues other than the brain have shown that gene expression varies widely. Other studies have found that, within the brain, the abundance of expressed genes per neuron appears to be greater in humans.

"On t

Contact: John Easton
University of Chicago Medical Center

Page: 1 2 3

Related biology news :

1. Clones on task serve greater good, evolutionary study shows
2. New textbook illuminates the close links between evolutionary and molecular biology
3. Coelacanth fossil sheds light on fin-to-limb evolution
4. Genomics study provides insight into the evolution of unique human traits
5. New proteomics research promises to revolutionize biomedical discovery
6. Species detectives track unseen evolution
7. Study identifies energy efficiency as reason for evolution of upright walking
8. Clues to future evolution of HIV come from African green monkeys
9. Tumor painting revolutionizes fight against cancer
10. Revolutionary global environment fund announces $50M expansion
11. A first-principles model of early evolution

Post Your Comments:

(Date:4/13/2016)... April 13, 2016  IMPOWER physicians supporting Medicaid patients ... a new clinical standard in telehealth thanks to a ... the higi platform, IMPOWER patients can routinely track key ... body mass index, and, when they opt in, share ... visit to a local retail location at no cost. ...
(Date:3/29/2016)... March 29, 2016 LegacyXChange, Inc. ... "LEGX" and SelectaDNA/CSI Protect are pleased to announce our ... in a variety of writing instruments, ensuring athletes signatures ... created collectibles from athletes on LegacyXChange will be assured ... the DNA. Bill Bollander , CEO ...
(Date:3/22/2016)... PROVO and SANDY, ... Screening Ontario (NSO), which operates the highest sample volume ... testing, and Tute Genomics and UNIConnect, leaders in clinical ... today announced the launch of a project to establish ... testing panel. NSO has been contracted ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... STACS DNA ... Technical Leader at the Arkansas State Crime Laboratory, has joined STACS DNA as a ... STACS DNA team,” said Jocelyn Tremblay, President and COO of STACS DNA. “In further ...
(Date:6/23/2016)... Ky. , June 23, 2016 ... two Phase 1 clinical trials of its complement ... placebo-controlled, single and multiple ascending dose studies designed ... pharmacodynamics (PD) of subcutaneous injection in healthy adult ... subcutaneously (SC) either as a single dose (ranging ...
(Date:6/23/2016)... -- Andrew D Zelenetz , ... Published recently in Oncology & ... Andrew D Zelenetz , discusses the fact ... placing an increasing burden on healthcare systems worldwide, ... the patents on many biologics expiring, interest in ...
(Date:6/23/2016)... San Francisco, CA (PRWEB) , ... June 23, ... ... capture (EDC) software, is exhibiting at the Pennsylvania Convention Center and will showcase ... DIA Annual conference. ClinCapture will also be presenting a scientific poster on Disrupting ...
Breaking Biology Technology:
Cached News: