A Mexican fish's gene that enables the species to repair its heart after damage can one day aid in heart failure treatments in humans, say researchers.

A team from Britain's University of Oxford identified a gene called lrrc10 in Mexican tetra fish. The tetra fish (Astyanax Mexicanus) living in northern Mexico's rivers retained their ability to repair their heart tissue even after millions of years. 

Humans suffering from heart failure cannot regenerate their damaged hearts and often the only cure is a heart transplant. Researchers hope that by unlocking the secrets of these remarkable fish we will one day be able to heal human hearts in much the same way.

"A real challenge until now was comparing heart damage and repair in fish with what we see in humans. But by looking at river fish and cave fish side by side, we've been able to pick apart the genes responsible for heart regeneration," said lead author Mathilda Mommersteeg, Associate Professor at Oxford.

In the study, reported in the journal Cell Reports, the team found that fish in one particular cave, called Pachon, have lost the amazing ability to regenerate their heart as well as their colour and ability to see. Mommersteeg and her team compared the genetic code of the river fish to that of the blind cave fish to discover what special mechanisms are required for heart repair in the period after heart injury. 

They found three areas of the fish genome were implicated in the fish's ability to repair their hearts. Two genes -- lrrc10 and caveolin -- were much more active in the river fish and could be key in allowing the river fish to repair their hearts.

Lrrc10 is already linked to a heart condition called dilated cardiomyopathy (DCM) in humans and have previously known to be involved in the way that heart cells contract with every heartbeat, the researchers said.

Further, the team analysed the effect of this gene in the zebrafish, another fish which has the remarkable ability to heal its own heart. When the team inactivated the lrrc10 gene in zebrafish they saw that the fish could no-longer fully repair their hearts.