UChicago, 柚子视频Study Illuminates How Fins Evolved into Fingers and Toes

How swimming fish evolved into land-traveling, four-limbed vertebrates is a longstanding mystery.

Twelve years ago, of the University of Chicago unearthed a 370-million-year-old  that was hailed as a 鈥渕issing link鈥 from sea to land animals.

But how, exactly, can a fin turn into a limb?

This week in , Shubin and colleagues report on work initiated at the Marine Biological Laboratory (MBL) that provides major insight into the game-changing fin-to-limb transition. Led by Tetsuya Nakamura, the team showed that a set of genes, called Hox, plays a surprisingly similar role in patterning the rays of fins and the digits of tetrapod limbs.  calls it the discovery of  鈥渁 deep evolutionary connection鈥 between fins and hands and feet.

Markers of the wrists and digits in the limb of a mouse (left) are present in fish and demarcate the fin rays (right). The wrist and digits of tetrapods are the cellular and genetic equivalents of the fin rays of fish. Credit: Andrew Gehrke and Marie Kmita
Markers of the wrists and digits in the limb of a mouse (left) are present in fish and demarcate the fin rays (right). The wrist and digits of tetrapods are the cellular and genetic equivalents of the fin rays of fish. Credit: Andrew Gehrke and Marie Kmita

This work was launched in the MBL鈥檚 Whitman Center in 2014, when Nakamura began studying the role of Hox genes in embryonic skates and sharks. With subsequent training in gene editing (CRISPr鈥揅as9) at the National Xenopus Resource at MBL, Nakamura created zebrafish mutants to further study Hox.

鈥淭his extraordinary study highlights the scientific convening power of the 柚子视频and provides an elegant example of the unique opportunities the laboratory continues to provide to young scientists to take risks and drive forward major questions in biology,鈥 says 柚子视频Director of Research Jonathan Gitlin.