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Analysis of Somatic Hypermutation in the JH4 intron of Germinal Center B cells from Mouse Peyer's Patches
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Analysis of Somatic Hypermutation in the JH4 intron of Germinal Center B cells from Mouse Peyer's Patches

Published on: April 20, 2021

A new model of sheep Ig diversification: shifting the emphasis toward combinatorial mechanisms and away from

Craig N Jenne1, Laurie J Kennedy, Peter McCullagh

  • 1Immunology Research Group, University of Calgary, Calgary, Canada.

Journal of Immunology (Baltimore, Md. : 1950)
|March 21, 2003
PubMed

The current model of Ig repertoire development in sheep focuses on the rearrangement of a small number (approximately 20) of Vlambda gene segments. It is believed that this limited combinatorial repertoire is then further diversified through postrearrangement somatic hypermutation. This process has been reported to introduce as many as 110 mutations/1000 nucleotides. In contrast, our data have that indicated somatic hypermutation may diversify the preimmune repertoire to a much lesser extent. We have identified 64 new Vlambda gene segments within the rearranged Ig repertoire. As a result, many of the unique nucleotide patterns thought to be the product of somatic hypermutation are actually hard-coded within the germline. We suggest that combinatorial rearrangement makes a much larger contribution, and somatic hypermutation makes a much smaller contribution to the generation of diversity within the sheep Ig repertoire than is currently acknowledged.

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