Genetics & Molecular Biology

Students of the evolution of social behavior got a big boost with the publication of the newly sequenced honeybee genome in October 2006. The honeybee (Apis mellifera) belongs to the rarified cadre of insects that pool resources, divide tasks, and communicate with each other in highly structured colonies. Understanding how this advanced state of organization evolved from a solitary lifestyle has been an enduring question in biology.


A honeybee gene originally used in egg production has become an important behavioral modulator and a timekeeper of social life.

At unprecedented levels of difficulty involving highly biodiverse and continent-sized landscapes, scientists have successfully tested their ability to identify and DNA "barcode" entire assemblages of species -- the prelude to a genetic portrait of all animal life on Earth.

Revealing their results in the UK journal Molecular Ecology Notes, they report having assembled a genetic portrait of birdlife in the U.S.

 
A University of Queensland microbiologist is part of an international team that has identified a bacterial gene that may affect climate and weather.
 
Dr Phil Bond, from UQ's Advanced Wastewater Management Centre, and his former colleagues at the University of East Anglia in England, have found how a particular type of marine bacteria – Marinomonas – generates a compound that is a key component in global sulfur and carbon cycles.

“Marine algae can produce large amounts of a compound (dimethylsulfoniopropionate or DMSP) that when broken down by bacteria produces dimethyl sulfide (DMS),” Dr Bond said.

Scientific studies of why foods such as Brussels sprouts and stout beer are horribly bitter-tasting to some people but palatable to others are shedding light on a number of questions, from the mechanisms of natural selection to understanding how our genes affect our dietary habits.

Dr. Stephen Wooding, a population geneticist at UT Southwestern Medical Center in Dallas, studies how slight variations in genes give rise to variations in traits among a given human population.

Part of Dr. Wooding's research focuses on variations in the genes responsible for bitter-taste receptors, tiny receptacles on the tongue that intercept harsh-tasting chemicals from food.

Blurring boundaries

High up on the bluffs overlooking the Pacific Ocean in southern California, strange animals scurry about in their cages. They eat, drink, copulate and occasionally try to run away from human hands that enter their confined quarters. If you didn't know better, you would think they were ordinary mice. But these particular animals contain a hidden component not present in their naturally conceived cousins. Inside their brains are living human neurons that help them to see, hear and think.

The Allen Brain Atlas, a genome-wide map of the mouse brain on the Internet, has been hailed as “Google of the brain.” The atlas now has a companion or the brain’s working molecules, a sort of pop-up book of the proteins, or proteome map, that those genes express.

The protein map is “the first to apply quantitative proteomics to imaging,” said Richard D. Smith, Battelle Fellow at the Department of Energy’s Pacific Northwest National Laboratory, who led the mapping effort with Desmond Smith of UCLA’s David Geffen School of Medicine.


Caption: Abundance profiles of four different proteins compiled from 1 millimeter cubes (voxels) in a mouse brain.

For cells that hold so much promise, stem cells' potential has so far gone largely untapped. But new research from Rockefeller University and Howard Hughes Medical Institute scientists now shows that adult stem cells taken from skin can be used to clone mice using a procedure called nuclear transfer. The findings are reported in the Feb. 12 online edition of the Proceedings of the National Academy of Sciences.


Using a technique called nuclear transfer, mice were cloned using adult skin stem cells (right) and a more differentiated type of skin cell (left). The mouse on the right is almost two years old and the mouse on the right is one and a half.

Mice engineered to have cleft palates can be rescued in utero by injecting the mothers with a small molecule to correct the defect, say scientists at the Stanford University School of Medicine and Lucile Packard Children's Hospital. In addition to shedding light on the biology of cleft palate, the research raises hopes that it may one day be possible to prevent many types of human birth defects by using a similar vaccination-type technique in pregnant women likely to have affected fetuses.

"This is a really important baby step that opens the door to the development of fetal therapies," said pediatric craniofacial surgeon Michael Longaker, MD.

The first draft of the horse genome sequence has been deposited in public databases and is freely available for use by biomedical and veterinary researchers around the globe, leaders of the international Horse Genome Sequencing Project announced today.


Photo of Twilight the horse. NHGRI-supported researchers have sequenced the genome of this Thoroughbred mare from Cornell University in Ithaca, N.Y. (Courtesy of Doug Antzak, Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University)

Sucrose plays a vital role in coffee organoleptic quality. A team from CIRAD and the Agricultural Institute of Paraná in Brazil has recently identified the genes responsible for sucrose accumulation in coffee beans. This is a new step along the way to producing exceptional coffees.


The sucrose accumulated in the beans is one of the organoleptic compounds in coffee. (Photo Credit: Pierre Marraccini, CIRAD)