Abstract
The organization and evolution of major histocompatibility complex (MHC) genes vary considerably among vertebrate lineages. MHC genes have been well characterized in mammals, birds, amphibians and fish, but little is known about their organization in reptiles, despite the fact that reptiles occupy an important phylogenetic position for understanding the evolutionary history of both mammalian and avian MHC genes. Here we describe the characterization of the first MHC class II B cDNA sequences from a non-avian reptile, the tuatara (Sphenodon spp.). Three class II B sequences were isolated from a tuatara cDNA library, and four additional partial sequences were isolated by reverse transcriptase–polymerase chain reaction. Six of these sequences appear to belong to the same gene family, which we have named SppuDAB. The remaining sequence (named SppuDBB) shares only 43.9% amino acid similarity with SppuDAB and thus appears to represent a separate gene family. SppuDBB may be a non-classical locus as it does not contain all the conserved residues expected of a classical MHC class II gene. Southern blot analysis indicates that only a single copy of SppuDBB exists in tuatara, but that multiple loci related to SppuDAB are present. The SppuDAB sequences have the highest amino acid similarity (57.2–62.4%) with class II B sequences from the spectacled caiman, but only 26.4–48.7% similarity with sequences from other vertebrates. The tuatara sequences do not strongly group with other reptile sequences on a phylogenetic tree, reflecting the antiquity of the Sphenodon lineage and the lack of closely related sequences for comparison.
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References
Afanassieff M, Goto RM, Ha J, Sherman MA, Zhong LW, Auffray C, Coudert F, Zoorob R, Miller MM (2001) At least one class I gene in restriction fragment pattern-Y (Rfp-Y), the second MHC gene cluster in the chicken, is transcribed, polymorphic, and shows divergent specialization in antigen binding region. J Immunol 166:3324–3333
Alfonso C, Karlsson L (2000) Nonclassical MHC class II molecules. Annu Rev Immunol 18:113–142
Beck S, Trowsdale J (1999) Sequence organisation of the class II region of the human MHC. Immunol Rev 167:201–210
Belov K, Lam MKP, Hellman L, Colgan DJ (2003) Evolution of the major histocompatibility complex: isolation of class II B cDNAs from two monotremes, the platypus and the short-beaked echidna. Immunogenetics 55:402–411
Belov K, Lam MKP, Colgan DJ (2004) Marsupial MHC class II B genes are not orthologous to the eutherian B gene families. J Heredity 95:338–345
Bjorkman PJ, Parham P (1990) Structure, function and diversity of class I major histocompatibility molecules. Ann Rev Biochem 59:253–288
Brown JH, Jardetzky TS, Gorga JC, Stern LJ, Urban RG, Strominger JL, Wiley DC (1993) Three-dimensional structure of the human class II histocompatibility antigen HLA-DR1. Nature 364:33–39
Burnham DK, Keall SN, Nelson NJ, Daugherty CH (2005) T cell function in tuatara (Sphenodon punctatus). Comp Immunol Microbiol Infect Dis 28:213–222
Cammarota G, Schierle A, Takacs B, Doran DM, Knorr R, Bannworth W, Guardiola J, Sinigaglia F (1992) Identification of a CD4 binding site on the B2 domain of HLA-DR molecules. Nature 356:799
Daugherty CH, Cree A, Hay JM, Thompson MB (1990) Neglected taxonomy and continuing extinctions of tuatara (Sphendon). Nature 347:177–179
Edwards SV, Grahn M, Potts WK (1995) Dynamics of Mhc evolution in birds and crocodilians: amplification of class II genes with degenerate primers. Mol Ecol 4:719–729
Edwards SV, Hess CM, Gasper J, Garrigan D (1999) Toward an evolutionary genomics of the avian Mhc. Immunol Rev 167:119–132
Felsenstein J (2004) PHYLIP (Phylogeny Inference Package) version 3.6. Distributed by the author. Department of Genome Sciences, University of Washington, Seattle
Guindon S, Gascuel O (2003) A simple, fast, and accurate algorithm to estimate large phylogenies by maximum likelihood. Syst Biol 52:696–704
Hall B (2004) TuneClustalX. http://homepage.mac.com/barryghall/TuneClustalX.html
Hess CM, Edwards SV (2002) The evolution of the major histocompatibility complex in birds. Bioscience 52:423–431
Hughes AL, Nei M (1990) Evolutionary relationships of class II major histocompatibility complex genes in mammals. Mol Biol Evol 7:491–514
Kappes D, Strominger JL (1988) Human class II major histocompatibility complex genes and proteins. Ann Rev Biochem 57:991–1028
Kaufman J, Salomonsen J, Flajnik M (1994) Evolutionary conservation of MHC class I and class II molecules—different yet the same. Semin Immunol 6:411–424
Kaufman J, Milne S, Gobel TWF, Walker BA, Jacob JP, Auffray C, Zoorob R, Beck S (1999) The chicken B locus is a minimal essential major histocompatibility complex. Nature 401:923–925
Kelley J, Walter L, Trowsdale J (2005) Comparative genomics of major histocompatibility complexes. Immunogenetics 56:683–695
Klein J (1986) Natural history of the major histocompatibility complex. Wiley, New York
Klein J, Bontrop RE, Dawkins RL, Ehrlich HA, Gyllensten U (1990) Nomenclature for the major histocompatibility complexes for different species: a proposal. Immunogenetics 31:217–219
Miller HC, Lambert DM (2004) Gene duplication and gene conversion in class II MHC genes of New Zealand robins (Petroicidae). Immunogenetics 56:178–191
Nei M, Gu X, Sitnikova T (1997) Evolution by the birth-and-death process in multigene families of the vertebrate immune system. Proc Natl Acad Sci USA 94:7799–7806
Rest JS, Ast JC, Austin CC, Waddell PJ, Tibbetts EA, Hay JM, Mindell DP (2003) Molecular systematics of primary reptilian lineages and the tuatara mitochondrial genome. Mol Phylogenet Evol 29:289–297
Takahashi K, Rooney AP, Nei M (2000) Origins and divergence times of mammalian class II MHC gene clusters. J Heredity 91:198–204
Thompson JD, Gibson TJ, Plewniak F, Jeanmougin F, Higgins DG (1997) The ClustalX windows interface: flexible strategies for multiple sequence alignment aided by quality analysis tools. Nucleic Acids Res 25:4876–4882
Van Tuinen M, Hadly EA (2004) Error in estimation of rate and time inferred from the early amniote fossil record and avian molecular clocks. J Mol Evol 59:267–276
Wang J-H, Meijers R, Xiong Y, Liu J-H, Sakihama T, Zhang R, Joachimiak A, Reinherz EL (2001) Crystal structure of the human CD4 N-terminal two-domain fragment complexed to a class II MHC molecule. Proc Natl Acad Sci U S A 98:10799–10804
Westerdahl H, Wittzell H, von Schantz T (2000) Mhc diversity in two passerine birds: no evidence for a minimal essential Mhc. Immunogenetics 52:92–100
Wittzell H, Bernot A, Auffray C, Zoorob R (1999) Concerted evolution of two MHC class II loci in pheasants and domestic chickens. Mol Biol Evol 16:479–490
Acknowledgements
We thank Nicky Nelson, Sue Keall, Kim Burnham and Anne Laflamme for assistance with sample preparation and for sharing tuatara immunology data. We also thank Don Colgan and the staff of the Evolutionary Biology Unit, Australian Museum, for providing lab facilities and Des Cooper (Macquarie University) and Scott Edwards (Harvard University). This work was supported by the Centre of Research Excellence funding, the NZ Department of Conservation (WE/51/FAU and LIZ0410) and the people of Ngati Koata and Te Atiawa. Blood sampling was approved by Victoria University of Wellington Animal Ethics committee (2003R14 and 2003R16), and recombinant DNA work was approved by the NZ Environmental Risk Management Authority (GMD 03106).
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Nucleotide sequence data reported are available in the GenBank database under accession numbers DQ124231–DQ124238
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Miller, H.C., Belov, K. & Daugherty, C.H. Characterization of MHC class II genes from an ancient reptile lineage, Sphenodon (tuatara). Immunogenetics 57, 883–891 (2005). https://doi.org/10.1007/s00251-005-0055-4
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DOI: https://doi.org/10.1007/s00251-005-0055-4