Development of a Hemoglobin Beta Chain Gene Knockout Syrian Hamster Model for β-Thalassemia and Oxidative Stress

Background/Objectives: Notable similarities in lipid metabolism exist between human and golden Syrian hamster relative to most other rodents. A model for β-thalassemia in hamster was sought via knocking out the hemoglobin β-chain (HBB) gene. There are two HBB genes, as well as seven β-like alleles, predicted in the hamster genome, yet none have been functionally characterized. Methods: To develop a β-thalassemia hamster model and genetically interrogate the functions of the HBB genes in the hamster, we employed CRISPR/Cas9-mediated gene targeting technique and successfully knocked out one of the two hamster HBB genes. Results: Surprisingly, mass spectrometry analysis of the hemolysates from wild type, heterozygous, and homozygous knockout (KO) hamsters showed no changes in the hemoglobin β-chains at protein level. This indicates that the HBB gene that we chose to target does not code for proteins. Interestingly, lipid oxidation during storage was elevated in leg muscle of homozygous KO female hamsters compared to wild type females (P<0.05). Conclusions: Our study provided a path toward developing a hamster β-thalassemia animal model, and related findings suggest an effect of a non-translated HBB gene on oxidative stress. In addition, mass spectrometry provides a way to quickly identify non-protein-coding-genes in species where genomic/transcriptomic annotation is not fully developed.