Abstract
Variable lymphocyte receptors (VLR) generate enormous diversity through assembling highly diverse leucine-rich repeat (LRR) modules and presumably function as antigen receptors in jawless vertebrates. The hagfish, which constitute major extant members of jawless vertebrates along with lampreys, have two VLR genes designated VLRA and VLRB, whereas only a single VLR gene has been identified in the lamprey. In the present study, we show by fluorescence in situ hybridization (FISH) that hagfish VLRA and VLRB are located on the same chromosome, but are far apart from each other. Analysis of available inshore hagfish complementary DNA sequences indicates that VLRA and VLRB do not share a LRR module with an identical nucleotide sequence. Physical separation of VLRA and VLRB is consistent with this observation and indicates that the two VLR genes function as separate units. The FISH protocol developed in this study should be useful for the analysis of the agnathan genome.
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Alder MN, Rogozin IB, Iyer LM, Glazko GV, Cooper MD, Pancer Z (2005) Diversity and function of adaptive immune receptors in a jawless vertebrate. Science 310:1970–1973
Cooper MD, Alder MN (2006) The evolution of adaptive immune systems. Cell 124:815–822
Flajnik MF (2002) Comparative analyses of immunoglobulin genes: surprises and portents. Nat Rev Immunol 2:688–698
Flajnik MF, Kasahara M (2001) Comparative genomics of the MHC: glimpses into the evolution of the adaptive immune system. Immunity 15:351–362
Kasahara M, Suzuki T, Du Pasquier L (2004) On the origins of the adaptive immune system: novel insights from invertebrates and cold-blooded vertebrates. Trends Immunol 25:105–111
Klein J, Nikolaidis N (2005) The descent of the antibody-based immune system by gradual evolution. Proc Natl Acad Sci USA 102:169–174
Kohno S, Kubota S, Nakai Y (1998) Chromatin diminution and chromosome elimination in hagfishes. In: Jøgensen JM, Lomholt JP, Weber RE, Malte H (eds) The biology of hagfishes. Chapman & Hall, London, pp 81–100
Kohno S, Nakai Y, Satoh S, Yoshida M, Kobayashi H (1986) Chromosome elimination in the Japanese hagfish, Eptatretus burgeri (Agnatha, Cyclostomata). Cytogenet Cell Genet 41:209–214
Litman GW, Cannon JP, Dishaw LJ (2005) Reconstructing immune phylogeny: new perspectives. Nat Rev Immunol 5:866–879
Pancer Z, Cooper MD (2006) The evolution of adaptive immunity. Annu Rev Immunol 24:497–518
Pancer Z, Amemiya CT, Ehrhardt GR, Ceitlin J, Gartland GL, Cooper MD (2004) Somatic diversification of variable lymphocyte receptors in the agnathan sea lamprey. Nature 430:174–180
Pancer Z, Saha NR, Kasamatsu J, Suzuki T, Amemiya CT, Kasahara M, Cooper MD (2005) Variable lymphocyte receptors in hagfish. Proc Natl Acad Sci USA 102:9224–9229
Acknowledgment
We thank Dr. Hideyuki Tanabe, Department of Biosystems Science, School of Advanced Sciences, the Graduate University for Advanced Studies (Sokendai), for his valuable advice on the FISH protocol, and Ms. Kayano, Sekikatsu, for the supply of hagfish. This work was supported by grants-in-aid for scientific research from the Ministry of Education, Culture, Sports, Science and Technology of Japan. J. K. is supported by the research fellowship for Young Scientists from the Japan Society for the Promotion of Science.
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J. K. is a research fellow of the Japan Society for the Promotion of Science.
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Kasamatsu, J., Suzuki, T., Ishijima, J. et al. Two variable lymphocyte receptor genes of the inshore hagfish are located far apart on the same chromosome. Immunogenetics 59, 329–331 (2007). https://doi.org/10.1007/s00251-007-0200-3
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DOI: https://doi.org/10.1007/s00251-007-0200-3