Differential expression of duck Toll-like receptor 7 (dTLR7) in various organs of indigenous ducks

Aim: The present molecular study was taken up with an aim of investigating the expression profile of duck TLR7 mRNA in various tissues of indigenous ducks of Tamil Nadu. Materials and Methods: A total of 36 ducks which are reared in extensive system have been chosen as research material for the present experiment. Ducks were sacrificed and tissue samples namely lungs, spleen and gastrointestinal tract (duodenum, jejunum, ileum and caecum) were collected in RNA later solution. Total RNA was extracted and converted to cDNA. Gene specific primers were designed and quantitative SYBR Green based Real-time Reverse Transcriptase PCR (qRT-PCR) was performed to study the gene expression levels. The qRT-PCR data was normalized to ‚-actin, house keeping gene as endogenous control. Results: Real-time quantitative RT-PCR analysis revealed higher expression in lungs and spleen, while expression being lower in digestive organs. Among gut associated tissues, ileum showed highest expression followed by caecum. Statistically no significant difference (P<0.05) in TLR7 expression was found between duodenum and jejunum. Conclusion: These findings have indicated that considerable level of dTLR7 is expressed in different tissues of ducks. The results suggest that TLR7 mediated innate immune response mechanism exists in native ducks, to fight against single stranded RNA viruses.