Evolution of limb and digit identity genes since the tetrapod ancestor; The degeneration and adaptive evolution of ratite digits
The datasets are used to create the analysis of "Evolution of limb and digit identity genes since the tetrapod ancestor" and also "The degeneration and adaptive evolution of ratite digits". Natural selection has sculpted tetrapod limbs, particularly the digits, into a tremendous morphological diversity, but the underlying developmental mechanism remains unclear. Here we are employing comparative transcriptomic of the digits from 6 species to identify gene expression differences associated with the evolution of digit morphology. Also, by comparing the digit transcriptomes of ratite digits to those of chicken and alligator, we identified different gene networks in skeleton/muscle development responsible for the degenerated digits in archosaur ancestor and emu, but those in skin development for the load-bearing digit of ostrich. These results provide new clues for developmental programs of different cell types between different digits, on which natural selection can convergently operate.