Variation in Salamanders: An Essay on Genomes, Development, and Evolution
Regeneration is studied in a few model species of salamanders, but the ten families of salamanders show considerable variation, and this has implications for our understanding of salamander biology. The most recent classification of the families identifies the cryptobranchoidea as the basal group which diverged in the early Jurassic. Variation in the sizes of genomes is particularly obvious, and reflects a major contribution from transposable elements which is already present in the basal group.Limb development has been a focus for evodevo studies, in part because of the variable property of pre-axial dominance which distinguishes salamanders from other tetrapods. This is thought to reflect the selective pressures that operate on a free-living aquatic larva, and might also be relevant for the evolution of limb regeneration. Recent fossil evidence suggests that both pre-axial dominance and limb regeneration were present 300 million years ago in larval temnospondyl amphibians that lived in mountain lakes. A satisfying account of regeneration in salamanders may need to address all these different aspects in the future.
Key wordsNewt Axolotl Limb regeneration
I thank Peng Zhang for his help in relation to salamander phylogeny and Anoop Kumar for help with the figures.
- 3.Duellman WE, Trueb L (1994) Biology of amphibians. Johns Hopkins University Press, Baltimore, MDGoogle Scholar
- 5.Carroll R (2009) The rise of amphibians. The Johns Hopkins University Press, Baltimore, MDGoogle Scholar
- 6.Wake DB, Marks SB (1993) Development and evolution of Plethodontid salamanders: a review of prior studies and a prospectus for future research. Herpetologica 49:194–203Google Scholar
- 7.Wake DB, Hanken J (1996) Direct development in the lungless salamanders: what are the consequences for developmental biology, evolution and phylogenesis? Int J Dev Biol 40:859–869Google Scholar
- 21.Looso M, Preussner J, Sousounis K, Bruckskotten M, Michel CS, Lignelli E, Reinhardt R, Hoffner S, Kruger M, Tsonis PA, Borchardt T, Braun T (2013) A de novo assembly of the newt transcriptome combined with proteomic validation identifies new protein families expressed during tissue regeneration. Genome Biol 14(2):R16. doi: 10.1186/gb-2013-14-2-r16 CrossRefGoogle Scholar
- 22.Stewart R, Rascon CA, Tian S, Nie J, Barry C, Chu LF, Ardalani H, Wagner RJ, Probasco MD, Bolin JM, Leng N, Sengupta S, Volkmer M, Habermann B, Tanaka EM, Thomson JA, Dewey CN (2013) Comparative RNA-seq analysis in the unsequenced axolotl: the oncogene burst highlights early gene expression in the blastema. PLoS Comput Biol 9(3):e1002936. doi: 10.1371/journal.pcbi.1002936 CrossRefGoogle Scholar
- 23.Macfarlan TS, Gifford WD, Driscoll S, Lettieri K, Rowe HM, Bonanomi D, Firth A, Singer O, Trono D, Pfaff SL (2012) Embryonic stem cell potency fluctuates with endogenous retrovirus activity. Nature 487:57–63Google Scholar
- 24.Macia A, Blanco-Jimenez E, Garcia-Perez JL (2014) Retrotransposons in pluripotent cells: impact and new roles in cellular plasticity. Biochim Biophys Acta doi: 10.1016/j.bbagrm.2014.07.007
- 30.Vorobyeva EI, Hinchliffe JR (1996) Developmental pattern and morphology of Salamandrella keyserlingii limbs (Amphibia, Hynobiidae) including some evolutionary aspects. Russ J Herpetol 3:68–81Google Scholar
- 33.Shubin NH, Wake DB (2003) Morphological variation, development, and evolution of the limb skeleton of salamanders. In: Heatwole H, Davies M (eds) Amphibian biology, vol 5. Surrey Beatty and Sons, Chipping Norton, NSW, pp 1782–1808Google Scholar
- 42.Hanken J (1986) Developmental evidence for amphibian origins. Evolut Biol 20:389–417Google Scholar
- 46.Ghosh S, Thorogood P, Ferretti P (1994) Regenerative capability of upper and lower jaws in the newt. Int J Dev Biol 38:479–490Google Scholar