Screening candidate genes related to tenderness trait in Qinchuan cattle by genome array.

In order to screen candidate genes related to tenderness trait in Qinchuan cattle, we investigated the gene expression profile of Longuissimus dorsi muscle (LDM) tissue and screened differentially expressed genes in LDM from both male and female Qinchuan cattle at 36 months of age utilising Bovine Genome Array. Significance Analysis of Microarrays (SAM) was used to identify the differentially expressed genes, Go (Gene Ontology) and pathways analysis were conducted on which by a free web-based Molecular Annotation System 2.0 (MAS 2.0). Approximately 11,000 probe sets representing 10,000 genes were detected in LDM of 36 month old Qinchuan cattle. After SAM analysis of the microarray data, 598 genes were shown to be differentially expressed. These genes were predominantly involved in cell adhesion, collagen fibril organization and synthesis, immune responses and cell-matrix adhesion. They included cell adhesion molecules (CAMs) and ECM-receptor interaction molecules. Real-time PCR was performed to validate nine of the differentially expressed genes identified by microarray. The results suggest that at the transcriptional level the residual hardness caused by connective tissues, stroma protein and muscle tissues could mainly result in tenderness differences between male and female Qinchuan cattle.