Format

Send to

Choose Destination
Proc Natl Acad Sci U S A. 2014 Oct 14;111(41):14828-33. doi: 10.1073/pnas.1415580111. Epub 2014 Sep 16.

Genomic donor cassette sharing during VLRA and VLRC assembly in jawless vertebrates.

Author information

1
Emory Vaccine Center and Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322;
2
Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; and.
3
National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894.
4
Emory Vaccine Center and Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322; mdcoope@emory.edu boehm@immunbio.mpg.de.
5
Department of Developmental Immunology, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany; and mdcoope@emory.edu boehm@immunbio.mpg.de.

Abstract

Lampreys possess two T-like lymphocyte lineages that express either variable lymphocyte receptor (VLR) A or VLRC antigen receptors. VLRA(+) and VLRC(+) lymphocytes share many similarities with the two principal T-cell lineages of jawed vertebrates expressing the αβ and γδ T-cell receptors (TCRs). During the assembly of VLR genes, several types of genomic cassettes are inserted, in step-wise fashion, into incomplete germ-line genes to generate the mature forms of antigen receptor genes. Unexpectedly, the structurally variable components of VLRA and VLRC receptors often possess partially identical sequences; this phenomenon of module sharing between these two VLR isotypes occurs in both lampreys and hagfishes. By contrast, VLRA and VLRC molecules typically do not share their building blocks with the structurally analogous VLRB receptors that are expressed by B-like lymphocytes. Our studies reveal that VLRA and VLRC germ-line genes are situated in close proximity to each other in the lamprey genome and indicate the interspersed arrangement of isotype-specific and shared genomic donor cassettes; these features may facilitate the shared cassette use. The genomic structure of the VLRA/VLRC locus in lampreys is reminiscent of the interspersed nature of the TCRA/TCRD locus in jawed vertebrates that also allows the sharing of some variable gene segments during the recombinatorial assembly of TCR genes.

KEYWORDS:

adaptive immunity; agnatha; molecular evolution; selection

PMID:
25228758
PMCID:
PMC4205630
DOI:
10.1073/pnas.1415580111
[Indexed for MEDLINE]
Free PMC Article

Publication types, MeSH terms, Substance, Secondary source ID, Grant support

Publication types

MeSH terms

Substance

Secondary source ID

Grant support

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center