TAIPEI (Taiwan News) — Researchers at Academia Sinica recently discovered a complete muscle replacement mechanism in zebrafish, challenging traditional theories on how vertebrates develop.

Chen Chen-hui (陳振輝), an associate research fellow at Academia Sinica’s Institute of Cellular and Organismic Biology, who led the team, said the findings could inspire new directions in regenerative medicine, such as addressing sarcopenia in the elderly, per CNA.

In an interview with CNA, Chen said the traditional understanding of vertebrate development involved muscle growth through the continuous division and proliferation of muscle stem cells, or the fusion of muscle stem cells with existing muscle cells, leading to increased muscle mass and overall growth.

However, using multicolor live cell labeling techniques to study zebrafish, the team found that the muscle cells of larval zebrafish are entirely decomposed and replaced during development, he said.

“The muscle cells in larvae are decomposed and replaced, similar to how children lose and grow new teeth,” Chen explained. “The larval muscle cells gradually update until they are completely replaced by muscle cells that differ in size, shape, and function in the adult fish.”

Given that their findings challenge the basic understanding of vertebrate development, Chen said the review process involved many questions, such as whether the replacement truly involved all muscle cells and whether their research tools were flawless. The entire process from research to publication took six years of work.

The team’s research was published in “The EMBO Journal” on June 5.