Ghostly pale, sightless cavefish normally develop shrunken, degenerate orbs in place of eyes. But, very young cavefish can instead develop a normal eye after receiving the lens of a sighted, surface-dwelling fish of the same species, researchers report in the 28 July issue of the journal, Science.
This discovery may suggest a new way to study the genetic factors involved in eye growth and development, says biologist William R. Jeffery of the University of Maryland at College Park.
Such basic research ultimately may help set the stage for better understanding certain forms of sight loss, according to Jeffery, who coauthored the Science paper with Yoshiyuki Yamamoto, a postdoctoral researcher.
"Eye surgeons continue to make advances in the field of blindness research, including exciting new processes such as cornea transplantation," Jeffery says. "Our group hopes to contribute fundamental insights into the genetic factors involved in eye development and growth. Our current research focuses on identifying basic developmental mechanisms in fish embryos that can be studied in the laboratory."
Jeffery and Yamamoto can't say yet whether developing cavefish gain sight after lens transplantation. But, the small, dark-dwelling creatures suggest a simple method for quickly testing various potential eye-growth factors.
"We now have preliminary confirmation that the lens is the seat of a signaling mechanism that somehow causes the eye to grow," explains Jeffery, a professor and chairperson of biology at the university. "We think we could coat a bead with a factor of interest, such as fibroblast growth factor, which is secreted by the normal lens, put that i
Contact: Ginger Pinholster
American Association for the Advancement of Science