Evolution's toolkit seen in developing hands and arms

Jul 03, 2013

Thousands of sequences that control genes are active in the developing human limb and may have driven the evolution of the human hand and foot, a comparative genomics study led by Yale School of Medicine researchers has found

The research, published online July 3 in the journal Cell, does not pinpoint the exact that control development of human limbs, but instead provides scientists with the first genome-wide view of candidates to investigate.

"We now have a parts list that may account for these biological changes," said James P. Noonan, associate professor of genetic, investigator for the Kavli Institute and senior author of the study.

Uniquely human features in the limbs can be seen early in human development, suggesting the genetic changes that underlie these traits are active in the human embryo. Previous studies compared the human genome to genomes of other in order to identify changes in genetic sequences that may have occurred during human evolution. Noonan and colleagues used this approach in 2008 to identify a single human gene regulatory sequence showing human-specific activity in the developing limb that may have contributed to the evolution of the human thumb. However, it was unclear at the time how many of these elements exist within the human genome.

To address this, Noonan's group looked for differences in the activity of these across the entire genomes of human, , and mouse during limb development.

The team built maps of active gene regulatory sequences in developing limbs from each species using a known to identify such sequences. Their analysis suggests that while the genetics of limb development are generally similar in all three species, a fraction of regulatory sequences are active specifically in the human embryonic limb. These sequences likely gained activity since humans' divergence from the rhesus monkey about 25 million years ago.

Noonan said he plans to transfer some of these human-specific regulatory elements into the mouse genome to investigate what aspects of human limb development they may control.

"It has been difficult to understand how human traits evolved, because we didn't have any idea where the important genetic changes might be," Noonan said. "Now we do, and we have the experimental tools to determine what biological effects these changes may have. Our study also provides a roadmap for understanding other human-specific traits that arise during development, such as increased brain size and complexity."

Explore further: Heaven scent: Finding may help restore fragrance to roses

Related Stories

Genetic switches play big role in human evolution

Jun 12, 2013

(Phys.org) —A Cornell study offers further proof that the divergence of humans from chimpanzees some 4 million to 6 million years ago was profoundly influenced by mutations to DNA sequences that play roles ...

Gene enhancer in evolution of human opposable thumb

Sep 04, 2008

Scientists have discovered a gene enhancer, known as HACNS1, that may have contributed to the evolution of the uniquely opposable human thumb, and possibly also modifications in the ankle or foot that allow humans to walk ...

Genome-wide atlas of gene enhancers in the brain online

Jan 31, 2013

Future research into the underlying causes of neurological disorders such as autism, epilepsy and schizophrenia, should greatly benefit from a first-of-its-kind atlas of gene-enhancers in the cerebrum (telencephalon). ...

Recommended for you

Study on pesticides in lab rat feed causes a stir

Jul 02, 2015

French scientists published evidence Thursday of pesticide contamination of lab rat feed which they said discredited historic toxicity studies, though commentators questioned the analysis.

International consortium to study plant fertility evolution

Jul 02, 2015

Mark Johnson, associate professor of biology, has joined a consortium of seven other researchers in four European countries to develop the fullest understanding yet of how fertilization evolved in flowering plants. The research, ...

Making the biofuels process safer for microbes

Jul 02, 2015

A team of investigators at the University of Wisconsin-Madison and Michigan State University have created a process for making the work environment less toxic—literally—for the organisms that do the heavy ...

Why GM food is so hard to sell to a wary public

Jul 02, 2015

Whether commanding the attention of rock star Neil Young or apparently being supported by the former head of Greenpeace, genetically modified food is almost always in the news – and often in a negative ...

The hidden treasure in RNA-seq

Jul 01, 2015

Michael Stadler and his team at the Friedrich Miescher institute for Biomedical Research (FMI) have developed a novel computational approach to analyze RNA-seq data. By comparing intronic and exonic RNA reads, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.