title: Genomic cloning and sequence analysis of Interleukin-10 from Labeo rohita.
abstract: Interleukin-10 (IL-10) is a pleiotropic cytokine and plays an important role in inflammation, immunoregulation and the pathogenesis of various diseases. Therefore, it is our interest to isolate, clone, sequence and characterize IL-10 gene from the fish Labeo rohita (Lr). The gene was amplified using genomic DNA isolated from head kidney with primers designed on conserved sequence homologues of fishes belonging to Cyprinidae family. The gLrIL-10 is 1467 nucleotides long with five exons and four introns sharing the same organization as of mammalian IL-10 genes. An open reading frame of 537 bp was found to encode a putative 179 amino acid protein with a signal peptide of 22 amino acids with conserved signature sequence motif. Sequence analysis showed similarity with the IL-10 from most fresh water fishes of Cyprinidae family. LrIL-10 has 27.2 % identity and 54.95 % similarity with the human IL-10. Sequence analysis followed by phylogenetic studies showed highest identity with Catla catla (98%) followed by Cyprinus carpio (93%), Hypophthalmichthys molitrix (89%) and is distantly related to human, rhesus monkey and frog. These data from primary sequence characterization may be used to further understand transcriptional regulation and functional characterization of LrIL-10 in relation to species-specific molecular immunology.
  
  
  BACKGROUND
  IL-10 - Interleukin-10, Lr - Labeo rohita, nt - nucleotides.
authors.affiliation: Gene Regulation Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi - 110 067, India.
authors.forename: Sweta
authors.initials: S
authors.lastname: Karan
authors.affiliation: Gene Regulation Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi - 110 067, India.
authors.forename: Himani
authors.initials: H
authors.lastname: Kaushik
authors.affiliation: Gene Regulation Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi - 110 067, India.
authors.forename: Nipun
authors.initials: N
authors.lastname: Saini
authors.affiliation: Fish Health Management Division, Central Institute of Freshwater Aquaculture, Kausalyaganga, Bhubaneswar - 751 002, India.
authors.forename: Pramod K
authors.initials: PK
authors.lastname: Sahoo
authors.affiliation: School of Biotechnology, Jawaharlal Nehru University, New Delhi - 110 067, India.
authors.forename: Aparna
authors.initials: A
authors.lastname: Dixit
authors.affiliation: Gene Regulation Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi - 110 067, India.
authors.forename: Lalit C
authors.initials: LC
authors.lastname: Garg
keywords: Interleukin-10; Labeo rohita; cloning