Red spotted newtWIKIMEDIA, JASON QUINNThe red spotted newt (Notophthalmus viridescens) could sit in the palm of your hand, but its genome is ten times the size of yours—up to 10 billion base pairs. This daunting amount of DNA has kept this species off the radar of any genome sequencing projects, despite plummeting costs. It has also prevented newts and salamanders from becoming regular model organisms, despite their remarkable and medically-relevant ability to regenerate severed limbs and damaged organs.
Recently, a team of German scientists circumvented the difficulties posed by the newt’s huge genome by sequencing its transcriptome instead—the set of RNA produced from its genes. Since some of an animal’s genome is never transcribed, transcriptomes can often be decoded at a fraction of the cost and effort of a full genome, and the newt results, published last month (February 20) in Genome Biology, are part of a growing trend of using transcriptomes to understand lesser-known species.
The team, co-led by Thilo Borchardt from the Max-Planck-Institute for Heart and Lung Research, sequenced more than 120,000 RNA transcripts from newt embryos and larvae, at least 14,000 of which code for proteins, and found that many proteins associated with regeneration are not found in other animals, ...
