Newts have an extraordinary ability to regenerate tissues. For example, they can re-grow fully functional limbs after amputation. In addition, regeneration of parts of the central nervous system, the heart, and the lens has been characterized, making them an excellent model organism for studying regenerative processes. However, because of their enormous genome size (10 times that of human), the molecular mechanisms behind this amazing regenerative process are largely unknown.
A research group at the Max Plank Institute recently published a de novo assembly of the transcriptome of the urodelian amphibian Notophthalmus viridescens (Looso M. et al. ). The researchers combined 454, Illumina, and Sanger sequencing data from both normalized and non-normalized cDNA libraries. The resulted transcriptome comprises over 120,000 non-redundant transcripts. Homology search using BLAST led to annotation of 38,000 transcripts. Importantly, they found 800 transcripts, whose protein-coding potential was validated by mass spectrometry, that show no similarity to any know transcripts or show similarity to urodele-specific EST sequences. Some of these transcripts belong to novel protein families.
It is an interesting hypothesis that some of those newt-specific proteins may provide mechanistic insights into regeneration processes unique to these animals. Their work will definitely be an important resource for subsequent studies in tissue regeneration and may benefit future research in regenerative medicine.