Unravelling key genes associated with ovine Brucellosis by differential gene expression analysis: A holistic bioinformatics study

Abstract

Ovine Brucellosis, caused by Brucella ovis bacteria, is a pathognomonic reproductive infectious disease of sheep that causes epididymitis in rams (male sheep) and placental inflammation in ewes (female sheep) leading to reduced fertility. The specific molecular process that causes alterations in genome of sheep during brucellosis is not yet fully understood. This study aimed to identify key host genes associated with the pathogenesis of ovine brucellosis caused by B. ovis. The GSE35614 dataset containing six healthy and six Brucella ovis infected sample of rams in the chronic phase 2 was obtained from the NCBI GEO database to examine and detect any differences in gene expression (DEGs). Functional and pathway enrichment analyse of the DEGs were performed along with the construction of protein-protein interaction network. Next, functional modules and hub genes were clustered and identified respectively, using the MCODE plugin. As a result, a total of 316 differentially expresses genes were filtered according to the provided cut-off criteria. The enriched DEGs were related to extracellular matrix interaction, cell adhesion mediated by integrin, angiogenesis, and inflammatory response. Furthermore, the hub gene analysis resulted in five hub genes namely, FN1, FBN1, CDH1, CD44, and SPP1, were up-regulated during the infection which could lead to reproductive disorders in sheep. In conclusion, the DEGs, functional and pathways terms, along with hub genes identified in the current study can provide prospective targets for the early diagnosis and treatment of brucellosis and provide insight into the molecular mechanism underlying the alterations that occur during brucellosis in sheep.