Found genes that help to find a way home
Biologists from Duke University and the University of North Carolina at chapel hill have identified genes that, according to the researchers, are responsible for the ability of rainbow trout to return to their native rivers after several years of sailing in the sea.
The study is published in the journal Biology Letters.
As suggested by the authors, the ability of these fish is based on the sensitivity to the magnetic field of the Earth. It is known that in this way can navigate birds, bees, salamanders, sea turtles and some other animals. But it was unclear what ensures that the operation of this mechanism at the cellular and molecular level.
To study the genetic basis of the process the authors followed the changes in gene expression of fish at a time when their usual magnetic field is violated. For this one fish was placed in an aquarium, surrounded by wire. It was electrified, a fraction of a second to create a magnetic field. Then the researchers compared the transcripts in the brain of fish from ten experimental and ten control groups and determined that the change of the magnetic field reacted 181 gene of about 40 thousand. Among them were genes responsible for the production of ferritin, the protein that transports iron inside the cell, and for the development of the optic nerve.
The results correspond with the assumption that animals can navigate based on the “testimony” of tiny particles of iron compounds, acting like a compass needle. Something like biologists found in the beaks of birds, the abdomen of bees and the nasal passages of rainbow trout.