Expression analysis of turkey (Meleagris gallopavo) toll-like receptors and molecular characterization of avian specific TLR15.
Toll-like receptors (TLRs) constitute a multi-gene family, which plays a pivotal role in sensing invading pathogens by virtue of conserved microbial patterns. TLR repertoire of chicken and zebra finch has been well studied. However TLR family of other avian species is yet to be characterized. In the present study, we identified TLR repertoire of turkey, characterized avian specific receptor TLR15 in turkey and profiled the TLRs expressions in a range of tissues of turkey poults. All ten TLR genes orthologous to chicken TLR repertoire were found in turkey. Turkey TLR genes showed 81-93 % similarity at amino acid level to their chicken counter parts. Phylogenetic analysis confirmed the orthologous relationship of turkey TLRs with chicken and zebra finch TLRs. Open reading frame of turkey TLR15 was 2,607 bp long encoding 868 amino acids similar to that of broiler chicken and showed 92.4, 91.1 and 69.5 % identity at amino acid levels with chicken, Japanese quail and zebra finch TLR15 sequences respectively. Overall TLR expression was highest for TLR4 and lowest for TLR21. TLR1A, 2A, 2B and 21 were significantly higher in liver than other tissues investigated (P < 0.01). TLR3 expression was significantly higher in bone marrow (BM) and spleen in comparison to other tissues studied (P < 0.01). Furthermore, no significant differences in the expression levels of TLR1B, 4, 5, 7 and 15 genes were detected among the tissues studied. Our findings contribute to the characterization of innate immune system of birds and show the innate preparedness of young turkey poults to a range of pathogens.
Indian Veterinary Research Institute, Bareilly 243122, Uttar Pradesh, India. trkannaki@gmail.com
Kannaki T
KT
Ramasamy
Maddula R
MR
Reddy
Prem C
PC
Verma
Shanmugam
S
Murugesan
D000595:Amino Acid Sequence; D000818:Animals; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D016678:Genome; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D051193:Toll-Like Receptors / Q000737:chemistry / Q000235:genetics*; D014158:Transcription, Genetic; D014422:Turkeys / Q000235:genetics*
D051193:Toll-Like Receptors