Yutian Li - Nutrient-Driven Activation of Regenertion Through Systemic Energy Reallocation

Added: 2026-05-07

[00:00:05]Some animals such as axelottals can regrow an entire limb after amputation, but we humans cannot. This striking disparity raises a fundamental question.

[00:00:16]Is regeneration a privilege that only certain animals have? To answer this question, in my thesis, I first asked whether regeneration can be induced at all in animals that do not regenerate.

[00:00:30]Through years of screening, my collaborators and I have found that a combination of nutrient factors, including specific amino acids and the growth hormone insulin, can actually induce regeneration in multiple animals that normally do not regenerate, including in mice, jellyfish, and fruit flies. This is a fruitfly limb immediately after amputation and the same limb 22 days after amputation. With nutrient treatment, we see that um flies can significantly reduce tissue loss, reactivate processes for tissue replenishment and even induce partial limb regrowth. Although this regrowth is not perfect, but it tells us a fundamental um principle that regeneration is not completely absent in these animals that do not normally regenerate. It's just waiting for the right nutrient condition to be reactivated. To understand how this works, I further studied um joa because of its small body size and its experimental tractability. What I found that is um regeneration is not limited to local tissue repair at the limb. It is actually a whole body response.

[00:01:44]Flies that activate regeneration actually remodels different organs to adapt to this um energy reallocation.

[00:01:52]For example, regenerating flies expand their midgots to adapt to the increased energy needs for uh tissue reboot. At the same time they re reduce their reproductive behavior. These are ovaries for regenerating flies. You can see the regenerating flies have much smaller ovaries indicating a tradeoff between the two energy uh demanding processes regeneration and reproduction. Um such coordinated tissue remodeling in the fruitfly indicates that regeneration is not about just repair local tissues. It is actually about coordining such changes as a whole body integrating nutrient sensing as well as multiorgan communications. Um because nutrient and hormonal regulations are also uh conserved across species. These findings suggest that regeneration is not only uh is not absent in animals like us which we don't have good uh regeneration capacity. It is actually hidden and can be unlocked if appropriate nutrient conditions are met.

[00:03:02]Thank you.