Which came first? The spigot or the spinnaret?


Tarantulas produce silk from their feet:

"Researchers have found for the first time that tarantulas can produce silk from their feet as well as their spinnerets, a discovery with profound implications for why spiders began to spin silk in the first place."

I love these sorts of discoveries. Now we have an interesting project - what evolved first and why? Silk for climbing or silk for spinning and prey capture? Some previous work suggested that orb web spinning evolved twice, with one group spinning dry silk webs that use electrostatic forces to capture prey, while another group evolved glue-covered silk to do this. There are as many as seven kinds of silk. If this new silk is homologous with one of the spinnaret based silks, then one will have evolved from the other, since the likelihood that such genes would evolve more than once is vanishingly small. But which was first? The spigot on the legs or the spinnaret on the abdomen? Watch this space (well, watch the journals, anyway).

More like this

There was some big news yesterday in transgenic silk from Notre Dame and the University of Wyoming, where scientists have genetically engineered silkworms to produce silk
Silk is an amazing biomaterial, cultivated and prized for more than 5,000 years. The silk threads that we weave into our shiny fabrics are actually enormous protein crystals produced by insects.
Tougher than steel and Kevlar, the silk of the black widow spider has long been coveted by manufacturing companies, defense contractors and comic-book reading nerds as a possible material of the future.
My silkworms are starting to turn into silkmoths! The first moth emerged from his cocoon this weekend, I hope more are close behind so that he can mate before he dies!