Molecular characterization and expression of interferon-gamma of Asian elephant (Elephas maximus).
Tuberculosis (TB) caused by Mycobacterial organisms has emerged as one of the major diseases in captive elephants. In vitro Interferon-gamma (IFN-gamma) assay is being used as an ancillary test for early detection of TB in domestic and captive wild animals. In the present study, basic sequence information and immunological cross-reactivity of this major cytokine of Asian elephants were explored. At predicted amino acid level, IFN-gamma of Asian elephant showed maximum identity to that of horse (73%). Other IFN-gamma amino acid sequences that showed high level identity were that of giant panda (72%), dog (71%), nine-banded armadillo (69%), cattle (63%) and human (62%). IFN-gamma promoter sequences of Asian elephant, human, cattle and mouse showed high level conservation of the putative transcription factor binding sites, TATA box and transcriptional start site. The functionally important human IFN-gamma promoter elements, such as AP-2IRE-BE, YY1-gammaIFN-BED, ATFCS and AP-1gammaINF binding sites, were absolutely conserved in the corresponding elephant sequence. There was only a single nucleotide variation in the other two important elements, NFAT-gammaINF and IFN-gammaPE, indicating the highly conserved regulation of IFN-gamma expression across different species. Phylogenetic analysis based on IFN-gamma protein sequences revealed a closer relation of Asian elephants and nine-banded armadillo. This shows a closer evolution of these members of Afrotheria and Xenarthra, respectively; and supports the previous reports based on mitochondrial DNA studies. In Western blot analysis, IFN-gamma of Asian elephant expressed in Escherichia coli was detected using an anti-bovine IFN-gamma monoclonal antibody, indicating immunological cross-reactivity.
Sreekumar
E
E
Rajiv Gandhi Centre for Biotechnology (RGCB), Thycaud P.O., Thiruvananthapuram 695014, Kerala, India. esreekumar@gmail.com
Janki
M B V
MB
Arathy
D S
DS
Hariharan
R
R
Premraj
C Avinash
CA
Rasool
T J
TJ
D000595:Amino Acid Sequence; D000818:Animals; D001208:Asia; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004606:Elephants / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D007371:Interferon-gamma / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics
D018076:DNA, Complementary; D007371:Interferon-gamma