Differential Expression of Toll-like Receptors (tlrs) in Gold Fish, Carassius Auratus Infested with Fresh Water Lice of Argulus Sp

Toll like-receptors (TLRs) are pattern recognition receptors (PRRs) that are involved in the recognition of the pathogens based on their conserved motifs, called pathogen associated molecular patterns (PAMPs). As the information on the TLR/s involved in the recognition of the parasitic ligand is limited, the objective of this study was to assess the expression profiles of six different TLRs (2, 3, 4, 7, 9 and 22) in various organs viz., skin, intestine, liver and kidney of gold fish, Carassius auratus in response to parasitic infestation with freshwater lice of Argulus sp., by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Observations of the study showed tissue-specific and differential expression of TLRs in tissues of C.auratus. TLRs 2, 4 and 7 expressions were upregulated in all the tissues studied. TLR 9 expression was down regulated in all the tissues studied. TLR22 was upreglated significantly in liver and in skin the organ immediately affected by the parasite. Expression of TLRs 2, 3, 4, 7, 9 and 22 in gold fish are modulated during infestation by Argulus sp., in C.auratus