Mannose binding lectin (MBL) copy number polymorphism in Zebrafish (D. rerio) and identification of haplotypes resistant to L. anguillarum
- 235 Downloads
We describe a novel extension of the Genomic Matching Technique (GMT) that defines haplotypes of the mannose binding lectin (MBL) region in Zebrafish (D. rerio). Four ancestral haplotypes have been identified to date, with at least one of these demonstrating a significant increase in resistance to L. anguillarum. MBL activates the lectin pathway of the complement system and stimulates the development of the complement cascade and the Membrane Attack Complex. Polymorphisms in humans have been associated with increased susceptibility and severity to a number of pathogenic organisms. As teleosts have a relatively immature acquired immune system, polymorphisms within MBL and other innate defence genes are likely to be critical in defining their susceptibility/resistance to various pathogenic organisms. We report multiple copies of MBL-like genes in D. rerio, with up to three copies tightly linked within a cluster spanning ∼15 kb on chromosome 2. Genomic analysis suggests that duplication, retroviral insertion and possibly gene mutation and/or deletion have been key factors in the evolution of this cluster. Molecular analysis has revealed extensive polymorphism, including at least five distinct amplicons and haplospecific gene copy number variation. This study demonstrates polymorphism within a critical component of the teleost innate immune system. The polymorphisms and the haplotypes encoding the unique variants are likely to be informative in defining susceptibility/resistance to infectious agents commonly encountered within aquatic environments. Future investigations will define other important haplotypes and transfer the knowledge to other finfish species, thereby enabling selection of broodstock for the aquaculture industry.
KeywordsZebrafish Lectin pathway MBL Ancestral haplotypes Genomic matching technique L. anguillarum
The authors thank Nicki Buller and Brian Jones of the Animal Health Laboratories (Department of Agriculture and Food, Western Australia) for supplying bacterial pathogens and advice on pathogen culturing. This study is supported by Genetic Technologies Ltd., Fitzroy, Victoria, 3065, Australia and the C.Y. O’Connor ERADE Village Foundation. Collectively, the authors associated with the C.Y. O’Connor ERADE Village Foundation have an interest in Genetic Technologies.
The project was vetted then approved by the Murdoch University Animal Ethics Committee. All fish used were maintained and treated humanely and euthanased at the completion of work.
- Accelrys Inc. (2006) Gene. San Diego: Accelrys SoftwareGoogle Scholar
- Aitman TJ, Dong R, Vyse TJ, Norsworthy PJ, Johnson MD, Smith J, Mangion J, Roberton-Lowe C, Marshall AJ, Petretto E, Hodges MD, Bhangal G, Patel SG, Sheehan-Rooney K, Duda M, Cook PR, Evans DJ, Domin J, Flint J, Boyle JJ, Pusey CD, Cook HT (2006) Copy number polymorphism in Fcgr3 predisposes to glomerulonephritis in rats and humans 439:851–855Google Scholar
- Bohlson SS, Fraser DA, Tenner AJ (2007) Complement proteins C1q and MBL are pattern recognition molecules that signal immediate and long-term protective immune functions. Molecular Immunology, XXI International Complement Workshop Beijing, China, pp 44:33–43 (October 22–26, 2006)Google Scholar
- Christiansen FT, Zhang WJ, Griffiths M, Mallal SA, Dawkins RL (1991) Major histocompatibility complex (MHC) complement deficiency, ancestral haplotypes and systemic lupus erythematosus (SLE): C4 deficiency explains some but not all of the influence of the MHC. J Rheumatol 18:1350–1358PubMedGoogle Scholar
- Ewart KV, Johnson SC, Ross NW (1999) Identification of a pathogen-binding lectin in salmon serum. Comp Biochem Physiol Part C: Pharmacol Toxicol 123:9–15Google Scholar
- Holmskov U (2000) Collectins and collectin receptors in innate immunity. APMIS Suppl 108:1–59Google Scholar
- Nakao M, Kajiya T, Sato Y, Somamoto T, Kato-Unoki Y, Matsushita M, Nakata M, Fujita T, Yano T (2006) Lectin pathway of bony fish complement: identification of two homologs of the mannose-binding lectin associated with MASP2 in the common carp (Cyprinus carpio). J Immunol 177:5471–5479PubMedGoogle Scholar
- Redon R, Ishikawa S, Fitch KR, Feuk L, Perry GH, Andrews TD, Fiegler H, Shapero MH, Carson AR, Chen W, Cho EK, Dallaire S, Freeman JL, Gonzalez JR, Gratacos M, Huang J, Kalaitzopoulos D, Komura D, MacDonald JR, Marshall CR, Mei R, Montgomery L, Nishimura K, Okamura K, Shen F, Somerville MJ, Tchinda J, Valsesia A, Woodwark C, Yang F, Zhang J, Zerjal T, Zhang J, Armengol L, Conrad DF, Estivill X, Tyler-Smith C, Carter NP, Aburatani H, Lee C, Jones KW, Scherer SW, Hurles ME (2006) Global variation in copy number in the human genome. Nature 444:444–454PubMedCrossRefGoogle Scholar
- Tay GK, Witt CS, Christiansen FT, Charron D, Baker D, Herrmann R, Smith LK, Diepeveen D, Mallal S, McCluskey J, Lester S, Loiseau P, Teisserenc H, Chapman J, Tait B, Dawkins RL (1995) Matching for MHC haplotypes results in improved survival following unrelated bone marrow transplantation. Bone Marrow Transplant 15:381–385PubMedGoogle Scholar
- Zhang WJ, Degli-Esposti MA, Cobain TJ, Cameron PU, Christiansen FT, Dawkins RL (1990) Differences in gene copy number carried by different MHC ancestral haplotypes. Quantitation after physical separation of haplotypes by pulsed field gel electrophoresis. J Exp Med 171:2101–2114PubMedCrossRefGoogle Scholar