Cardiac regenerative potential across mammalian phylogeny

Summer 2017

Alison Hoang : Molecular & Cell Biology

Mentor: Guo Huang

The heart, especially in adult mammals, is one of the least regenerative organs as evident in the ongoing battle against cardiovascular diseases. While higher mammals lack the ability to proficiently regenerate myocardial tissue, lower vertebrates, such as zebrafish and newts, experience a robust regenerative response even after major injury. Phylogeny then implies that higher mammals must have lost their cardiac regenerative potential sometime during their evolutionary history. The phylogenic distribution of cardiac regeneration in mammals is not well understood but could serve as an important platform to identify evolutionary pressures and factors controlling regenerative capacity. We hypothesize that orders that have diverged earliest from the higher mammal lineage – monotremes, marsupials, and xenarthrans - may have intermediate potential for myocardial regeneration, more representative of that of lower vertebrates. I will be analyzing nuclear content and percent mononucelation of lower mammal cardiomyocytes, proxies for regenerative potential. Secondly, I will be looking at the cardiomyocyte proliferation rate and gene expression of naked mole-rats, a rodent that we hypothesize to have an unusually high regenerative potential.

Dear Rose Hills Foundation, Thank you again for this opportunity. Prior to this summer, I had very little direction academically and professionally. I was tired of my courses, anxious and unsure about my future. I tried to follow the traditional pre-medical path, like the majority of my peers, but I found no joy in any of the work. However through this fellowship, I found that I adored lab work and research. I woke up in the mornings wondering how my experiments came out and was always itching to learn more. With confidence, I can now say that I want continue studying biology as a graduate student. Thank you for not only helping me find my bearings but also rekindling my curiosity for the world and for knowledge.