Syndicate content

Archive - Dec 5, 2011

Date

Rarest US Bumblebee Rediscovered

A team of scientists from the University of California (UC), Riverside, recently rediscovered the rarest species of bumblebee in the United States (last seen in 1956) living in the White Mountains of south-central New Mexico. Known as "Cockerell's Bumblebee," the bee was originally described in 1913 from six specimens collected along the Rio Ruidoso, with another 16 specimens collected near the town of Cloudcroft, and one more from Ruidoso, the most recent being in 1956. No other specimens had been recorded until three more were collected on weeds along a highway north of Cloudcroft on Aug. 31, 2011. "Most bumblebees in the US are known from dozens to thousands of specimens, but not this species," said Dr. Douglas Yanega, senior museum scientist at UC Riverside. "The area it occurs in is infrequently visited by entomologists, and the species has long been ignored because it was thought that it was not actually a genuine species, but only a regional color variant of another well-known species." Dr. Yanega pointed out that there are nearly 50 species of native US bumblebees, including a few on the verge of extinction, such as the species known as "Franklin's Bumblebee," which has been seen only once since 2003. That species, as rare as it is, is known from a distribution covering some 13,000 square miles, whereas Cockerell's Bumblebee is known from an area of less than 300 square miles, giving it the most limited range of any bumblebee species in the world. "There is much concern lately about declines in our native bumblebee species, and as we now have tools at our disposal to assess their genetic makeup, these new specimens give fairly conclusive evidence that Cockerell's Bumblebee is a genuine species," he said. "With appropriate comparative research, we hope to be able to determine which other species is its closest living relative.

Progress Made Toward Vaccine for Ebola Virus

On August 26, 1976, a time bomb exploded in Yambuku, a remote village in Zaire (now the Democratic Republic of the Congo). A threadlike virus known as Ebola had emerged, soon earning grim distinction as one of the most lethal, naturally occurring pathogens on earth, killing up to 90 percent of its victims, and producing a terrifying constellation of symptoms known as hemorrhagic fever. Now, Dr. Charles Arntzen, a researcher at the Biodesign Institute® at Arizona State University (ASU), along with colleagues from ASU, the University of Arizona College of Medicine-Phoenix, and the United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, have made progress toward a vaccine against the deadly virus. The group's research results appear online on December 5, 2011 in the Proceedings of the National Academy of Science, along with a companion paper by their collaborators at Mapp Pharmaceuticals in San Diego, California, led by Dr. Larry Zeitlin. Dr. Arntzen's group demonstrated that a plant-derived vaccine for Ebola provided strong immunological protection in a mouse model. If early efforts bear fruit, an Ebola vaccine could be stockpiled for use in the United States, should the country fall victim to a natural outbreak or a bioterrorism event in which a weaponized strain of the virus were unleashed on soldiers or the public. To date, Ebola outbreaks have been mercifully rare. For researchers like Dr. Arntzen however, this presents a challenge: "With other lethal viruses like HIV, there is a common pattern of occurrence, allowing for vaccine testing. For example, an AIDS vaccine study is now underway at two locations in Thailand, which were chosen because of a current high incidence of the disease." By contrast, Ebola events are fleeting, episodic, and largely unpredictable. For this reason, Dr.

Streamlined Approach for Reconstructing Accurate DNA Sequence

Researchers at the Genome Institute of Singapore (GIS) have, for the very first time, developed a computational tool that comes with a guarantee on its reliability when reconstructing the DNA sequence of organisms, thus enabling a more streamlined process for reconstructing and studying genomic sequences. The work, lead by Dr. Niranjan Nagarajan, Assistant Director of Computational and Mathematical Biology at the GIS, was reported in the November 10, 2011 issue of the Journal of Computational Biology. The genomic study of life (plants and animals alike) is based on computational tools that can first piece together the DNA sequence of these organisms, a process called genome assembly, that is similar to solving a giant puzzle or putting together the words in a book from a shredded copy. Due to the sheer scale of this challenge, existing approaches for genome assembly rely on heuristics and often result in incorrect reconstructions of the genome. The work reported here represents the first algorithmic solution for genome assembly that provides a quality guarantee and scales to large datasets. A new and improved implementation for this algorithm called Opera is now freely available at http://sourceforge.net/projects/operasf/ and has been used at the GIS for successfully assembling large plant and animal genomes. The assembled genome of an organism forms the basis for a range of downstream biological investigations and serves as a critical resource for the research community. The draft human genome, for example, was obtained at the expense of billions of dollars, serves as a fundamental resource for biomedical research and is, in fact, still being refined.

Orphan Experiences Alter Genome Function

Children who experience the stress of separation at birth from biological parents and are brought up in orphanages undergo biological consequences such as changes in their genome functioning, Yale School of Medicine researchers report in a new study. Published online on November 29, 2011 in Development and Psychopathology, the study reports differences in DNA methylation, one of the main regulatory mechanisms of gene expression, or genome functioning. The investigators compared two cohorts: 14 children raised since birth in institutional care and 14 children raised by their biological parents. Senior author Dr. Elena Grigorenko, associate professor at the Yale Child Study Center, and her colleagues took blood samples from children aged 7 to 10 living in orphanages and children growing up in typical families in the northwest region of the Russian Federation. The researchers then profiled the genomes of all the children to identify which biological processes and pathways might be affected by deprivation of parental attention and care. The team found that in the institutionalized group, there was a greater number of changes in the genetic regulation of the systems controlling immune response and inter-cellular interactions, including a number of important mechanisms in the development and function of the brain. "Our study shows that the early stress of separation from a biological parent impacts long-term programming of genome function; this might explain why adopted children may be particularly vulnerable to harsh parenting in terms of their physical and mental health," said Dr. Grigorenko.