JERUSALEM, Dec. 9 (Xinhua) -- A new Israeli study found that fish embryos actively control timing for hatching through a neural hormone, the Hebrew University of Jerusalem (HU) said in a statement on Monday.
Hatching is a crucial survival process for all egg-laying animals. Improper timing, whether too early or too late, can result in the death of the young, leaving them unprepared to face challenges like evading predators and breathing.
The study, conducted by HU and the Volcani Institute and published in Science, uncovered a hidden neural mechanism that controls the hatching process, directly affecting the embryos' survival.
The mechanism is based on thyrotropin-releasing hormone (TRH), which triggers the release of enzymes that dissolve the egg wall.
The researchers found that fish embryos initiate the hatching process via a TRH signal from the brain through the bloodstream to a specialized gland, where it activates the release of the enzymes that allow the embryo to hatch.
The critical neural hatching circuit develops just before the event and disappears shortly afterward. Without TRH, embryos are unable to release the necessary enzymes, leading to their death inside the egg.
The researchers said that their findings reveal significant evolutionary implications, offering new insights into neurobiology, survival strategies, and environmental adaptation in vertebrates.
The research also highlights the remarkable embryo's ability to make survival-critical decisions and the complex interplay between neurobiology and environmental factors.
In their future studies, the researchers plan to explore such hatching processes in other species. ■
