Abstract:

This study aimed to investigate the transcriptomic signature of claw horn disruption lesions (CHDL) in peripheral blood leucocytes (PBL) in dairy cattle. The PBL transcriptome of 24 cows, twelve cows susceptible (cases) and 12 resistant (controls) to CHDL were compared. Total RNA was extracted for RNA sequencing using Illumina technology. Raw reads were mapped to the cattle genome (ARS-UCD1.2) using the STAR aligner and differentially expressed gene (DEG) analysis was performed using DESeq2. Eighty-eight DEG genes were found between CHDL cases and controls; 82 were downregulated in CHDL cases. We found enrichment for Ca²⁺ transport and immune system related signalling among the DEG. In addition, the mineralisation associated genes SPARC and CLEC3B were downregulated and upregulated in CHDL cases, respectively. Moreover, three genes (YAP1, DSP and PALLD) associated with keratinocyte development were upregulated in the CHDL cases, which may suggest the presence of a reparative mechanism in the CHDL cases.