The gene expression profile of milk somatic cells of small ruminant lentivirus-seropositive and -seronegative dairy goats (Capra hircus) during their first lactation.

Caprine arthritis and encephalitis (CAE), caused by small ruminant lentivirus (SRLV), is a key disease of goats, with chronic inflammation of joints and brain symptoms, leading to losses in milk production and animal trade. In this study we analyzed gene expressions in milk somatic cells (MSCs) of seropositive (SRLV-SP) and seronegative (SRLV-SN) goats to identify transcriptomic changes using a non-invasive sampling method. Materials and Methods: The study was conducted on goats of two Polish breeds (Polish Improved White and Polish Improved Fawn) in their first lactation, kept at the Institute of Genetics and Animal Biotechnology Polish Academy of Sciences. MSCs were isolated from milk and gene expression was analyzed using Goat Gene Expression microarray. The results were verified by RT-qPCR for five genes (DUSP26, PRLR, SCARA3, APBB2, OR4F4). Statistical analysis was performed in Gene Spring 12 software. Results: Microarrays showed reduced expression of DUSP26, PRLR, SCARA3, APBB2 and OR4F4 genes in SRLV-SP goats. RT-qPCR confirmed changes for DUSP26, SCARA3 and APBB2. Functional analysis indicated associations with immune processes and HIV-like pathways. Discussion: The results suggest that SRLV induces transcriptomic perturbations, especially in immunity-related genes. MSCs are an effective model for non-invasive studies, and further studies may support strategies for combating CAE. The experiment was performed on 8 transcriptomic microarrays using a common reference design. The common reference (Cy3) comprised a pool of equal amounts of RNA from 7 healthy goats in 4th lactation from both Polish breeds (PWI n=4 and PFI n=3). Samples were taken after finishing of lactation period. Experimental samples (Cy5) were collected from two groups of goats at the climax of their first lactation were selected for the study; SRLV-seronegative goats (SRLV-SN; N=4) and SRLV-seropositive goats (SRLV-SP; N=4). in 1st lactation and RNA was isolated from MSC.