Functional variants surrounding endothelin 2 are associated with mycobacterium avium subspecies paratuberculosis infection

Authors: KISER, JENNIFER - Washington State University; WANG, ZEPING - (NCE, CECR)networks Of Centres Of Exellence Of Canada, Centres Of Excellence For Commercilization A; ZANELLA, RICARDO - Washington State University; SCRAGGS, ERIC - Washington State University; Neupane, Mahesh; CANTRELL, BONNIE - Washington State University; Van Tassell, Curtis - Curt; White, Stephen; TALOR, JEREMY - University Of Missouri; NEIBERGS, HOLLY - Washington State University

Submitted to: Frontiers in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2021
Publication Date: 5/5/2021
Citation: Kiser, J.N., Wang, Z., Zanella, R., Scraggs, E., Neupane, M., Cantrell, B., Van Tassell, C.P., White, S.N., Talor, J.F., Neibergs, H.L. 2021. Functional variants surrounding endothelin 2 are associated with mycobacterium avium subspecies paratuberculosis infection. Frontiers in Veterinary Science. https://doi.org/10.3389/fvets.2021.625323.
DOI: https://doi.org/10.3389/fvets.2021.625323

Interpretive Summary: Bovine paratuberculosis, caused by Mycobacterium avium subspecies paratuberculosis (MAP), continues to impact the dairy industry through increased morbidity, mortality and lost production of affected cattle. Although genome-wide association analyses (GWAA) have identified loci associated with susceptibility to MAP, limited progress has been made in identifying causal susceptibility mutations for the disease. A 70 kb region on Bos taurus chromosome 3 (BTA3) encompassing EDN2 is one locus previously associated with MAP infection. The objective of this study was to identify putative causal mutations surrounding EDN2 in Holstein and Jersey cattle. Fine mapping identified 17 putative causal variants (P <0.01) located in the 5' region of EDN2, while the most significant SNP (P = 0.00009) was located in the 3' UTR of EDN2. MicroRNA interference assays, mRNA stability assays, and electrophoretic mobility shift assays were performed to determine if allelic changes at each SNP resulted in differences in EDN2 stability or expression. Two SNPs (rs109651404 [G/A] and rs110287192 [G/T]) located within the promoter region of EDN2 displayed differential affinity binding of the variant SNP alleles. The luciferase reporter assay demonstrated that the transcriptional activity of the EDN2 promoter was increased (P < 0.05) with the G allele for both rs109651404 and rs110287192. These results suggest that the functional variants rs109651404 and rs110287192 may be causal mutations that result in altered susceptibility to MAP tissue infection in Holstein and Jersey cattle that could be used to improve selective breeding to reduce susceptibility to Johne's disease in cattle.

Technical Abstract: Bovine paratuberculosis, caused by Mycobacterium avium subspecies paratuberculosis (MAP), continues to impact the dairy industry through increased morbidity, mortality and lost production of affected cattle. Although genome-wide association analyses (GWAA) have identified loci associated with susceptibility to MAP, limited progress has been made in identifying causal susceptibility mutations for the disease. A 70 kb region on Bos taurus chromosome 3 (BTA3) encompassing EDN2 is one locus previously associated with MAP infection. The objective of this study was to identify putative causal mutations surrounding EDN2 in Holstein and Jersey cattle. Using sequencing data from 10 Holstein and 10 Jersey cattle, common variants within the 70 kb region containing EDN2 were identified and used in a custom SNP array to fine map the region in 221 Holstein and 51 Jersey cattle. Fine mapping identified 17 putative causal variants (P <0.01) located in the 5' region of EDN2, while the most significant SNP (P = 0.00009) was located in the 3' UTR of EDN2. MicroRNA interference assays, mRNA stability assays, and electrophoretic mobility shift assays were performed to determine if allelic changes at each SNP resulted in differences in EDN2 stability or expression. Two SNPs (rs109651404 [G/A] and rs110287192 [G/T]) located within the promoter region of EDN2 displayed differential affinity binding of the variant SNP alleles. The luciferase reporter assay demonstrated that the transcriptional activity of the EDN2 promoter was increased (P < 0.05) with the G allele for both rs109651404 and rs110287192. These results suggest that the functional variants rs109651404 and rs110287192 may be causal mutations that result in altered susceptibility to MAP tissue infection in Holstein and Jersey cattle.