File:Dolphin limb development 01.jpg

Hind-limb loss in embryos of the dolphin

S. attenuata. (A and B) Embryo (LACM 94706, section 183a, coronal section) at the stage of largest hind-limb development (Carnegie Stage 15). Hind-limb bud (hl) with apical ectodermal ridge (aer) is visible on either side of the abdomen of the embryo, with notochord (no) and neural tube (nt) in the median plane. (C and D) Embryo (LACM 94747, section 238, cross section) with reduced hind limbs and missing AER (Carnegie Stage 16). Chondrification is taking place in the vertebral column (vc). Boxes in A and C indicate location of enlargements found in B and D, respectively.

Original file name: Fig. 1. http://www.pnas.org/content/103/22/8414/F1.large.jpg

Reference

Thewissen JG, Cohn MJ, Stevens LS, Bajpai S, Heyning J & Horton WE. (2006). Developmental basis for hind-limb loss in dolphins and origin of the cetacean bodyplan. Proc. Natl. Acad. Sci. U.S.A. , 103, 8414-8. PMID: 16717186 DOI.

Copyright

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Cozzarelli NR, Fulton KR, Sullenberger DM. Liberalization of PNAS copyright policy: noncommercial use freely allowed. Proc Natl Acad Sci U S A. 2004 Aug 24;101(34):12399. PMID15314225 "Our guiding principle is that, while PNAS retains copyright, anyone can make noncommercial use of work in PNAS without asking our permission, provided that the original source is cited."

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