Genome shows mutant gene gives pigeons fancy hairdos

Jan. 31, 2013 University of Utah researchers decoded the genetic blueprint of the rock pigeon, unlocking secrets about pigeons' Middle East origins, feral pigeons' kinship with escaped racing birds, and how mutations give pigeons traits like a fancy feather hairdo known as a head crest.

"Birds are a huge part of life on Earth, and we know surprisingly little about their genetics," especially compared with mammals and fish, says Michael D. Shapiro, one of the study's two principal authors and an assistant professor of biology at the University of Utah. "There are more than 10,000 species of birds, yet we know very little about what makes them so diverse genetically and developmentally."

He adds that in the new study, "we've shown a way forward to find the genetic basis of traits -- the molecular mechanisms controlling animal diversity in pigeons. Using this approach, we expect to be able to do this for other traits in pigeons, and it can be applied to other birds and many other animals as well."

The study appears Jan. 31 on Science Express, the website of the journal Science. Shapiro led the research with Jun Wang of China's BGI-Shenzhen (formerly Beijing Genomics Institute) and other scientists from BGI, the University of Utah, Denmark's University of Copenhagen and the University of Texas M.D. Anderson Cancer Center in Houston.

Key findings of the study of pigeons, which first were domesticated some 5,000 years ago in the Mediterranean region:

"The researchers sequenced the genome, or genetic blueprint, of the rock pigeon, Columba livia, among the most common and varied bird species on Earth. There are some 350 breeds with different sizes, shapes, colors, color patterns, beaks, bone structure, vocalizations and arrangements of feathers on the feet and head -- including head crests that come in shapes known as hoods, manes, shells and peaks.

"The pigeon is among the few bird genomes sequenced so far, along with those of the chicken, turkey, zebra finch and a common parakeet known as a budgerigar or budgie, so "this will give us new insights into bird evolution," Shapiro says.

Using innovative software developed by study co-author Mark Yandell, a University of Utah professor of human genetics, the scientists revealed that a single mutation in a gene named EphB2 causes head and neck feathers to grow upward instead of downward, creating head crests.

"This same gene in humans has been implicated as a contributor to Alzheimer's disease as well as prostate cancer and possibly other cancers," Shapiro says, noting that more than 80 of the 350 pigeon breeds have head crests, which play a role in attracting mates in many bird species.

The researchers compared the pigeon genome to those of chickens, turkeys and zebra finches. "Despite 100 million years of evolution since these bird species diverged, their genomes are very similar," Shapiro says.

Follow this link:
Genome shows mutant gene gives pigeons fancy hairdos