A Mexican cavefish with a scarred heart

November 20, 2018, Cell Press
A surface fish (left) and cavefish (right) from the Pachón cave. Credit: Colin Beesley

Scientists are studying a guppy-sized, blind, translucent fish that lives in the cave systems of northern Mexico to figure out why some animals can regenerate their hearts, while others just scar. Their research appears November 20 in the journal Cell Reports.

"Millions of years ago, some fish living in rivers flooded into , became trapped when river levels retreated, and lost their eyes and pigment to adapt to cave life," says co-senior author Mathilda Mommersteeg, developmental scientist at the University of Oxford. "We have discovered that, like zebrafish, the river surface fish regenerate their , while some cavefish cannot and form a permanent scar. We introduce the Mexican cavefish as a new model for heart regeneration research."

Mommersteeg and her team bred both surface and cavefish in the laboratory, performing surgery on some fish to remove a piece of their hearts. After surgery, surface fish slowly regenerated the missing tissue, while cavefish developed a scar. When they cross-bred the cavefish with surface fish and performed the surgery, their offspring showed differing levels of regeneration, indicating that the ability to regenerate heart tissue is heritable in these fish.

They tested the regenerative role of lrrc10, a mysterious gene unique to that the fish shares with mice and humans, using knockout models and quantitative trait locus analysis. They found that lrrc10 and three DNA segments may play a role in heart regeneration.

"Quantitative trait locus analysis is a method that has allowed us to find out what part of all the surface fish DNA is most crucial for heart regeneration," says co-senior author Yoshiyuki Yamamoto, developmental biologist at University College London. "We have identified three regions in the DNA that contain genes that make the difference between regeneration or scarring after heart injury."

The next want to find out which genes in the regions they've identified are the key regulators of heart regeneration.

"The next step is to find out what the reason is that surface can regenerate their hearts, but cavefish cannot," says Mommersteeg. "What is it that happened during their adaptation to cave life that stopped them from regenerating their hearts?"

Explore further: Researchers identify how eye loss occurs in blind cavefish

More information: Cell Reports, Stockdale et al.: "Heart regeneration in the Mexican cavefish" http://www.cell.com/cell-reports/fulltext/S2211-1247(18)31676-0 , DOI: 10.1016/j.celrep.2018.10.072

Related Stories

Researchers identify how eye loss occurs in blind cavefish

May 29, 2018

Loss of eye tissue in blind cavefish (Astyanax mexicanus), which occurs within a few days of their development, happens through epigenetic silencing of eye-related genes, according to a study led by the National Institutes ...

Complete skin regeneration system of fish unraveled

April 24, 2018

Fish and amphibians such as newts can perfectly regenerate tissue without scar tissue in the event that they lose organs such as their limbs. Studying the mechanisms of regeneration and homeostasis of tissues has potential ...

Recommended for you

Scientists ID another possible threat to orcas: pink salmon

January 19, 2019

Over the years, scientists have identified dams, pollution and vessel noise as causes of the troubling decline of the Pacific Northwest's resident killer whales. Now, they may have found a new and more surprising culprit: ...

Researchers come face to face with huge great white shark

January 18, 2019

Two shark researchers who came face to face with what could be one of the largest great whites ever recorded are using their encounter as an opportunity to push for legislation that would protect sharks in Hawaii.

Why do Hydra end up with just a single head?

January 18, 2019

Often considered immortal, the freshwater Hydra can regenerate any part of its body, a trait discovered by the Geneva naturalist Abraham Trembley nearly 300 years ago. Any fragment of its body containing a few thousands cells ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.