NIH Selects 13 More Organisms for Genome Sequencing

The first group of targets consists of nine mammals. Eight mammals will be sequenced at low-density draft coverage, created by sequencing their genomes two times over. This sequencing strategy, begun last year on another set of mammals, is used primarily to identify features that are similar, or conserved, among the genomes of the human and other mammals. Sequences that have been conserved throughout evolution often reveal important functional regions of the human genome. Initial data show that using low-density sequencing for such comparisons is almost as effective as more costly, high-density sequencing. The eight mammals are: 13-lined ground squirrel (Spermophilis tridecemlineatus), megabat (Cynopterus species), microbat (Microchiroptera species), tree shrew (Tupaia belangeri), bushbaby (Otolemur garnetti), hyrax (Procavia capensis), pangolin (Manis species) and sloth (Bradypus or Choloepus species).

The ninth mammal is the Northern white-cheeked gibbon (Nomascus leucogenys). This non-human primate species belongs to a major evolutionary branch that has not yet had the genome of any of its members sequenced. The gibbon genome is unique because it contains many chromosomal rearrangements, which makes it valuable for studying how such rearrangements have contributed to the evolution and speciation of humans and other non-human primates. To identify chromosomal rearrangements, researchers will need to sequence only small portions of the gibbon genome through a process known as Bacterial Artificial Chromosome (BAC)-end sequencing.

Also selected in the latest round were four non-mammalian organisms. Three of the organisms have been targeted for six-fold, or “high-quality draft,” sequencing. They are: M and S strains of a malaria-carrying mosquito (Anopheles gambiae) and a roundworm (Heterorhabditis bacteriophora). Researchers will also construct a physical map of the zebra finch (Taeniopygia guttata) genome, paving the way for later efforts to sequence selected regions of the songbird’s genome.

Message posted by: Rashmi Nemade