Natural genetic variation quantitatively regulates heart rate and dimension

Area of Science:

• Genetics
• Cardiology
• Developmental Biology

Background:

• The polygenic contribution to heart development and function is not fully understood.
• Investigating the genetic basis of quantitative cardiac phenotypes is crucial for understanding health and disease.

Purpose of the Study:

• To gain insight into the genetic basis of quantitative cardiac phenotypes.
• To identify genetic loci associated with heart rate and cardiac development.
• To uncover potential diagnostic and therapeutic targets for cardiac diseases.

Main Methods:

• Utilized highly inbred Japanese rice fish models (Oryzias latipes and Oryzias sakaizumii).
• Employed automated quantification of embryonic heart rates to profile phenotype variability.
• Performed genome-wide mapping in a segregation population (HO5 x HdrR F2 embryos).
• Conducted experimental validation of candidate genes using loss-of-function models.

Main Results:

• Mapped 59 loci (173 genes) associated with heart rate.
• Identified maximal phenotypic contrast in heart rate between HO5 and HdrR strains.
• Experimental validation revealed causal impacts of top candidate genes on heart rate, development, ventricle size, and arrhythmia.

Conclusions:

• Uncovered new diagnostic and therapeutic targets for developmental and electrophysiological cardiac diseases.
• Provided a novel, scalable approach to investigate the genetic architecture of the vertebrate heart.
• Highlighted the importance of polygenic contributions to cardiac health and disease.