10.22376/ijpbs.2019.10.1.p1-12 Volume 3 Issue 4 2012(October - December) 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 lessThan i greaterThan viz., lessThan /i greaterThan skin, intestine, liver and kidney of gold fish, lessThan i greaterThan Carassius auratus lessThan /i greaterThan  in response to parasitic infestation with freshwater lice of lessThan i greaterThan Argulus lessThan /i greaterThan 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 lessThan i greaterThan C.auratus lessThan /i greaterThan . 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 lessThan i greaterThan Argulus lessThan /i greaterThan sp., in lessThan i greaterThan C.auratus lessThan /i greaterThan A.UMA, G.REBECCA AND K.SARAVANABAVA Gold fish, TLR expression, Argulus, parasitic ligand, semi-quantitative RT-PCR. 652-658