bioRxiv preprint doi: https://doi.org/10.1101/379735; this version posted May 18, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Evolution of limb development in cephalopod mollusks Oscar A. Tarazona1,2,*, Davys H. Lopez1, Leslie A. Slota2, and Martin J. Cohn1,2,# 1Department of Molecular Genetics and Microbiology, 2Department of Biology, UF Genetics Institute, University of Florida, Gainesville, FL 32610 USA. #Corresponding author:
[email protected] Current addresses: O.A.T.: Department of Genetics, Harvard Medical School, Boston, MA 02115; D.H.L.: Department of Genetics and Development, Columbia University, 3227 Broadway, Quad 9A, MC9891 New York, NY; L.A.S.: Department of Cell Biology, Duke University Medical Center, Box 3709, Durham, NC 27710 bioRxiv preprint doi: https://doi.org/10.1101/379735; this version posted May 18, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Abstract 2 Cephalopod mollusks evolved numerous anatomical novelties, including arms and 3 tentacles, but little is known about the developmental mechanisms underlying 4 cephalopod limb evolution. Here we show that all three axes of cuttlefish limbs are 5 patterned by the same signaling networks that act in vertebrates and arthropods, 6 although they evolved limbs independently. In cuttlefish limb buds, Hedgehog is 7 expressed anteriorly. Posterior transplantation of Hedgehog-expressing cells induced 8 mirror-image limb duplications. Bmp and Wnt signals, which establish dorsoventral 9 polarity in vertebrate and arthropod limbs, are similarly polarized in cuttlefish.