Barzilai University Medical Center

27 Research Day 2020 Barzilai University Medical Center 14 LINKAGE ANALYSIS AND NEXT GENERATION SEQUENCING – A COMBINED STRATEGY IN THE EXPLORATION OF THE GENETIC BASIS OF SALT-SENSITIVE HYPERTENSION Ronen Levi-Varadi, Chana Yagil and Yoram Yagil Laboratory for Molecular Medicine and Israeli Rat Genome Center, Barzilai University Medical Center, Ashkelon and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba, Israel Background The genetic basis of hypertension remains unknown, although it is already clear that in most cases, it is the result of the interaction of multiple genes with environmental factors, each contributing differentially to the phenotype. Hypothesis: No single genetic approach can reliably detect the genes involved in the pathogenesis of salt-sensitive hypertension and an integrative strategy incorporating multiple genetic approaches is required to achieve the goal. Objectives Our aim was to identify the genes involved in salt-sensitive hypertension, using linkage analysis which identifies the chromosomal location of the culprit genes, combined with whole genome sequencing to detect sequence variations that affect gene function. Methods The study was carried out in the Sabra model of salt-susceptibility, contrasting the SBH/y salt-sensitive with the SBN/y salt-resistant rat strains. Linkage analysis was based on two separate F2 crosses, consisting altogether of 471 males and 300 females. For sequencing, we used the whole genome next generation sequencing approach in one animal from each strain. Results Quantitative trait loci for salt-sensitive hypertension were identified on rat chromosomes (RNO) 1, 6 and 9. The QTL span (95% confidence interval) on RNO1 was 10 cM, on RNO6 7 cM and on RNO9 4.5 cM. According to the UCSC database, these QTLs incorporate 121, 222 and 153 genes respectively. Within the RNO1 QTL, we identified sequence variations in 4 genes with non-synonymous SNPs or INDEL that were unique to SBH/y or SBN/y; within RNO6 we found 22 such genes; within RNO9, we detected only 2 such genes. Conclusions The current investigative approach allowed us to narrow down the number of candidate genes from 496 in the initial QTL analysis to a total of 28 candidate genes located on 3 separate genomic locations. Further studies are required to define the role of these individual genes and their interaction in the pathophysiology of salt-sensitive hypertension