(HP05) Defining the Liver Transcriptome in Cats Using Total RNA sequencing: A Pilot Study

Abstract:

Background: Cats develop a variety of idiopathic, inflammatory, and neoplastic diseases of the liver. Defining the liver transcriptome could be beneficial in identifying gene expression patterns that are associated with different diseases. The normal liver transcriptome in cats has not been previously investigated.

Objectives: To define the hepatic transcriptome of cats using total RNA sequencing of liver biopsy samples from healthy animals.

Animals: Two healthy purpose-bred adult cats.

Methods: Surgical liver biopsies were obtained during routine ovariectomy. RNA was extracted and subjected to Illumina sequencing. Sequence files were aligned with the reference cat genome and assembled using Partek flow software. The top 250 expressed genes were identified along with their function, and pathway analysis was performed using open-source software.

Results: A total of 19,565 protein coding genes were sequenced. The most highly expressed genes included albumin, apolipoprotein, haptoglobin, and serotransferrin. Of the 100 most expressed genes, 27% were metabolite interconversion enzymes, with the second most abundant category being chromatin/chromatin-binding, or -regulatory proteins (14.4%) followed by 8% of genes classified as protein modifying enzymes. Other highly expressed genes were classified as metabolite interconversion enzymes, protein modifying enzymes, and translational proteins. The most highly expressed pathways were those associated with metabolic processes.

Conclusions and Clinical Importance: These studies provided unique new insights into the normal hepatic transcriptome in cats, and the data provides an important resource for helping to identify abnormal pathways in cats with hepatic diseases. This database can also assist with the design of targeted gene expression analysis tools.