Genetically modified beetles grow working third eye

When scientists deactivated the gene responsible in part for developing and shaping the heads of scarab beetles, the insects hatched with an extra set of compound eyes in the middle of their heads, sometimes forming together into one big third eye. And now, the scientists have learned that the extra eyes actually work.

Biologists from Indiana University discovered last year how a gene called orthodenticle prevented scarab beetles from developing these extra eyes during development. When the biologists disabled the gene, the beetles developed an extra eye (or pair of eyes). It's a common practice in science: Learn how something works, take it apart one piece at a time and see what changes.

In a new experiment, published online Oct. 24 in the journal Proceedings of the National Academy of Sciences, the same team used scanning electron microscopes to reveal that the new eyes had a complex structure, including connections to the beetle's nervous system. These eyes were no decorative or excess structures merely sitting on the beetle's head; the insects could use their new eyes, the researchers said.

https://www.livescience.com/60935-beetles-grow-functional-third-eye.html