Sarcopterygian fin ontogeny elucidates the origin of hands with digits.
|Title||Sarcopterygian fin ontogeny elucidates the origin of hands with digits.|
|Publication Type||Journal Article|
|Year of Publication||2020|
|Authors||Woltering JM, Irisarri I, Ericsson R, Joss JMP, Sordino P, Meyer A|
|Date Published||2020 Aug|
How the hand and digits originated from fish fins during the Devonian fin-to-limb transition remains unsolved. Controversy in this conundrum stems from the scarcity of ontogenetic data from extant lobe-finned fishes. We report the patterning of an autopod-like domain by during fin development of the Australian lungfish, the most closely related extant fish relative of tetrapods. Differences from tetrapod limbs include the absence of digit-specific expansion of and and distal limitation of and , which potentially evolved through an enhanced response to signaling in limbs. These developmental patterns indicate that the digit program originated in postaxial fin radials and later expanded anteriorly inside of a preexisting autopod-like domain during the evolution of limbs. Our findings provide a genetic framework for the transition of fins into limbs that supports the significance of classical models proposing a bending of the tetrapod metapterygial axis.
|Alternate Journal||Sci Adv|
|PubMed Central ID||PMC7438105|