Japan Scientists Breed Salmon from Surrogate Parents

Japan scientists have achieved a scientific breakthrough by breeding a type of salmon through surrogate parents from different species.

A team of scientists led by chief researcher Goro Yoshizaki from the Tokyo University of Marine Science and Technology froze the testes of the yamame salmon, a species indigenous to Japan that spends its entire life in fresh water.

The primordial germ cells of the salmon, called spermatogonia, were then extracted and implanted into sterile rainbow trout hatchlings.

The hatchlings' growing body used the spermatogonia to develop functional sperm and viable eggs depending on their gender. The sperm cells and the egg cells can be combined via in-vitro fertilization to produce healthy yamame salmon species, Yoshizaki told the Agence France-Presse news agency.

"As far as these kinds of trout and salmon are concerned, I can say this methodology is complete, and we can recreate sperm and eggs, and individuals, of the original species any time," Yoshizaki told AFP.

"We have confirmed the technology can also apply to tiger pufferfish as well," he said.

Yamame salmon is one of the two varieties of masu salmon, a migratory and freshwater fish found in the Pacific Ocean along countries like Japan, Korea and Russia.

Yoshizaki and his team are planning to follow the breeding process to protect the endangered species. They will also check if the same process could be used to breed amphibians.

The findings of the study appear in the journal of the Proceedings of the National Academy of Sciences.