Navigation Links
Fast-mutating DNA sequences shape early development; guided evolution of uniquely human traits
Date:11/10/2013

SAN FRANCISCO, CANovember 11, 2013What does it mean to be human? According to scientists the key lies, ultimately, in the billions of lines of genetic code that comprise the human genome. The problem, however, has been deciphering that code. But now, researchers at the Gladstone Institutes have discovered how the activation of specific stretches of DNA control the development of uniquely human characteristicsand tell an intriguing story about the evolution of our species.

In the latest issue of Philosophical Transactions of the Royal Society B, researchers in the laboratory of Gladstone Investigator Katherine Pollard, PhD, use the latest sequencing and bioinformatics tools to find genomic regions that guide the development of human-specific characteristics. These results offer new clues as to how the activation of similar stretches of DNAshared between two speciescan sometimes result in vastly different outcomes.

"Advances in DNA sequencing and supercomputing have given us the power to understand evolution at a level of detail that just a few years ago would have been impossible," said Dr. Pollard, who is also a professor of epidemiology and biostatistics at the University of California, San Francisco's (UCSF's) Institute for Human Genetics. "In this study, we found stretches of DNA that evolved much more quickly than others. We believe that these fast-evolving stretches were crucial to our human ancestors becoming distinct from our closest primate relatives."

These stretches are called human accelerated regions, or HARs, so-called because they mutate at a relatively fast rate. In addition, the majority of HARs don't appear to encode specific genes. The research team hypothesized that HARs instead acted as "enhancers," controlling when and for how long certain genes were switched on during embryonic development.

Through experiments in embryonic animal models, combined with powerful computational genomics analyses, the research team identified more than 2,600 HARs. Then, they created a program called EnhancerFinder to whittle down that list to just the HARs were likely to be enhancers.

"EnhancerFinder is a machine-learning algorithm that takes in basic genetic informationa HAR sequence, known evolutionary patterns, other functional genomics dataand returns a prediction of that HAR's function," explained Tony Capra, PhD, the study's lead author. "Using this approach, we predicted that nearly eight hundred HARs act as enhancers at a specific point during embryonic development. Confirming this prediction for several dozen HARs, our next goal was to see whether any of these HARs enhanced patterns of gene activation that were uniquely human."

Additional analyses revealed five such HARs, which were active in both human and chimpanzee genomes, but which activated genes in different embryonic regions. For example, the human versions of HARs 2xHAR.164 and 2xHAR.170 are active in a region of the brain between the midbrain and hindbrain, while the chimp versions are not. This so-called "gain of function" of these two HARs in human embryos may point to differences in the development of key brain regions such as the cerebellum, which is known to regulate not only motor control but may also regulate higher cognitive functions, such as language, fear and pleasure.

"These results, while preliminary, offer an unprecedented glimpse into how very recent changes to the human genome have modified the genetic programs that control embryonic development to potentially yield different results," said Dr. Capra. "We anticipate that if we were to look at the activity of HARs that are enhancers during later developmental stages, we would see even more differences between humans and chimpanzees."

"It's been 10 years since the Human Genome Project was declared 'complete,' but the amount of genomic knowledge we've gleaned since thenin large part due to advances in bioinformatics and supercomputinghave catapulted us far beyond what we thought we knew," added Dr. Pollard. "I'm confident that as we continue to dive deep into important regions such as HARs, we'll come ever closer to answering the question: what makes us human?'"


'/>"/>

Contact: Anne Holden
anne.holden@gladstone.ucsf.edu
415-734-2534
Gladstone Institutes
Source:Eurekalert  

Related biology news :

1. Long-term research reveals causes and consequences of environmental change
2. New approach to spell checking gene sequences
3. Revolutionary project will obtain entire genome sequences in fight against Alzheimers
4. Research reveals contrasting consequences of a warmer Earth
5. DNA sequences need quality time too - guidelines for quality control published
6. Computers taught to ID regulating gene sequences
7. Global warming may have severe consequences for rare Haleakalā silverswords
8. Global warming may have severe consequences for rare Haleakalā silverswords
9. FASEB SRC announces: Molecular Mechanisms & Physiological Consequences of Protein Aggregation
10. College kids who dont drink milk could face serious consequences
11. Saving the parrots: Texas A&M team sequences genome of endangered macaw birds
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Fast-mutating DNA sequences shape early development; guided evolution of uniquely human traits
(Date:5/24/2016)... Ampronix facilitates superior patient care by providing unparalleled technology to leaders of ... the latest premium product recently added to the range of products distributed by Ampronix. ... ... ... Medical Display- Ampronix News ...
(Date:5/3/2016)... VILNIUS, Lithuania , May 3, 2016 /PRNewswire/ ... today released the MegaMatcher Automated Biometric Identification ... deployment of large-scale multi-biometric projects. MegaMatcher ABIS can ... and accuracy using any combination of fingerprint, face ... of MegaMatcher SDK and MegaMatcher ...
(Date:4/19/2016)... The new GEZE SecuLogic access ... "all-in-one" system solution for all door components. It can ... door interface with integration authorization management system, and thus ... minimal dimensions of the access control and the optimum ... offer considerable freedom of design with regard to the ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... ... 2016 , ... Supplyframe, the Industry Network for electronics hardware ... . Located in Pasadena, Calif., the Design Lab’s mission is to bring together ... built and brought to market. , The Design Lab is Supplyframe’s physical representation ...
(Date:6/23/2016)... 2016  Blueprint Bio, a company dedicated to identifying, ... community, has closed its Series A funding round, according ... "We have received a commitment from Forentis Fund ... to meet our current goals," stated Matthew Nunez ... to complete validation on the current projects in our ...
(Date:6/23/2016)... ... June 23, 2016 , ... Regulatory Compliance Associates® Inc. (RCA), ... free webinar on Performing Quality Investigations: Getting to Root Cause. ... no charge. , Incomplete investigations are still a major concern to the Regulatory ...
(Date:6/22/2016)... , June 22, 2016 Cell ... will allow them to produce up to one ... one lot within one week. These high-quality, consistent ... laboriously preparing cells and spend more time doing ... through a proprietary, high-volume manufacturing process that produces ...
Breaking Biology Technology: