Zebrafish made to grow pre-hands instead of fins








































PERHAPS the little fish embryo shown here is dancing a jig because it has just discovered that it has legs instead of fins. Fossils show that limbs evolved from fins, but a new study shows how it may have happened, live in the lab.













Fernando Casares of the Spanish National Research Council and his colleagues injected zebrafish with the hoxd13 gene from a mouse. The protein that the gene codes for controls the development of autopods, a precursor to hands, feet and paws.












Zebrafish naturally carry hoxd13 but produce less of the protein than tetrapods - all four-limbed vertebrates and birds - do. Casares and his colleagues hoped that by injecting extra copies of the gene into the zebrafish embryos, some of their cells would make more of the protein.












One full day later, all of those fish whose cells had taken up the gene began to develop autopods instead of fins. They carried on growing for four days but then died (Cell, DOI: 10.1016/j.devcel.2012.10.015).












"Of course, we haven't been able to grow hands," says Casares. He speculates that hundreds of millions of years ago, the ancestors of tetrapods began expressing more hoxd13 for some reason and that this could have allowed them to evolve autopods.


















































If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not own rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.




































All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us.


If you are having a technical problem posting a comment, please contact technical support.








You're reading an article about
Zebrafish made to grow pre-hands instead of fins
This article
Zebrafish made to grow pre-hands instead of fins
can be opened in url
http://newsvailer.blogspot.com/2012/12/zebrafish-made-to-grow-pre-hands.html
Zebrafish made to grow pre-hands instead of fins