TitleSarcopterygian fin ontogeny elucidates the origin of hands with digits.
Publication TypeJournal Article
Year of Publication2020
AuthorsWoltering JM, Irisarri I, Ericsson R, Joss JMP, Sordino P, Meyer A
JournalSci Adv
Volume6
Issue34
Paginationeabc3510
Date Published2020 Aug
ISSN2375-2548
Abstract

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.

DOI10.1126/sciadv.abc3510
Alternate JournalSci Adv
PubMed ID32875118
PubMed Central IDPMC7438105
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