Differential Gene Expression Analysis of Whole Blood Transcriptome Between Young and Old Border Collie Dogs

Aging is the most significant risk factor for many diseases and increased mortality, and it is influenced by both genetic and environmental factors. In this study, our primary goal was to investigate age-related gene expression changes in whole blood samples collected from dogs and identify potential biomarkers of healthy aging. We sequenced the mRNA fraction of whole blood samples from five young and five old border collie dogs and performed differential gene expression and differential transcript usage analyses. The raw sequencing data exhibited high quality. Multidimensional scaling analysis failed to differentiate age clusters. Moreover, we identified only a limited number of differentially expressed genes (n = 61) and 30 genes with differential transcript usage between the blood transcriptomes of young and old dogs. Our results align with publicly available data on dogs. However, studies on other species, such as wolves, have identified more significant age-related genes. In conclusion, while some of our findings are promising, further research is needed to standardize environmental factors affecting blood gene expression levels in dogs. Additionally, we recommend implementing pre-sequencing hemoglobin depletion to improve the analysis of whole blood in future studies.