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Heavy Chain V Region Diversity in the Duck-Billed Platypus (Ornithorhynchus anatinus): Long and Highly Variable Complementarity-Determining Region 3 Compensates for Limited Germline Diversity

Citation

Johansson, J and Aveskogh, M and Munday, BL and Hellman, L, Heavy Chain V Region Diversity in the Duck-Billed Platypus (Ornithorhynchus anatinus): Long and Highly Variable Complementarity-Determining Region 3 Compensates for Limited Germline Diversity, The Journal of Immunology, 168 pp. 5155-5162. ISSN 0022-1767 (2002) [Refereed Article]

DOI: doi:10.4049/jimmunol.168.10.5155

Abstract

In this work, to study the emergence of the H chain V region repertoire during mammalian evolution, we present an analysis of 25 independent H chain V regions from a monotreme, the Australian duck-billed platypus, Ornithorhynchus anatinus. All the sequences analyzed were found to form a single branch within the clan III of mammalian V region sequences in a distance tree. However, compared with a classical V gene family this branch was more diversified in sequence. Sequence analysis indicates that the apparent lack of diversity in germline V segments is well compensated for by relatively long and highly diversified D and N nucleotides. In addition, extensive sequence variation was observed in the framework region 3. Furthermore, at least five and possibly seven different J segments seem to be actively used in recombination. Interestingly, internal cysteine bridges in the complementarity-determining region (CDR)3 loop, or between the CDR2 and CDR3 loops, are found in ∼ 36 % of the platypus V H sequences. Such cysteine bridges have also been observed in cow, camel, and shark. Internal cysteine bridges may play a role in stabilizing long and diversified CDR3 and thereby have a role in increasing the affinity of the Ab-Ag interaction.

Item Details

Item Type:Refereed Article
Research Division:Agricultural and Veterinary Sciences
Research Group:Veterinary Sciences
Research Field:Veterinary Immunology
Objective Division:Environment
Objective Group:Flora, Fauna and Biodiversity
Objective Field:Farmland, Arable Cropland and Permanent Cropland Flora, Fauna and Biodiversity
Author:Munday, BL (Dr Barry Munday)
ID Code:24336
Year Published:2002
Web of Science® Times Cited:38
Deposited By:Health Sciences A
Deposited On:2002-08-01
Last Modified:2003-04-01
Downloads:0

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