Genomic Anatomy of a Premier Major Histocompatibility Complex Paralogous Region on Chromosome 1q21–q22
Human chromosomes 1q21–q25, 6p21.3–22.2, 9q33–q34, and 19p13.1–p13.4 carry clusters of paralogous loci, to date best defined by the flagship 6p MHC region. They have presumably been created by two rounds of large-scale genomic duplications around the time of vertebrate emergence. Phylogenetically, t...
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Published in | Genome research Vol. 11; no. 5; pp. 789 - 802 |
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Main Authors | , , , , , , , , , , , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
Cold Spring Harbor Laboratory Press
01.05.2001
|
Subjects | |
Online Access | Get full text |
ISSN | 1088-9051 1549-5469 1549-5469 |
DOI | 10.1101/gr.175801 |
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Summary: | Human chromosomes 1q21–q25, 6p21.3–22.2, 9q33–q34, and 19p13.1–p13.4 carry clusters of paralogous loci, to date best defined by the flagship 6p MHC region. They have presumably been created by two rounds of large-scale genomic duplications around the time of vertebrate emergence. Phylogenetically, the 1q21–25 region seems most closely related to the 6p21.3 MHC region, as it is only the MHC paralogous region that includes bona fide
MHC
class I genes, the
CD1
and
MR1
loci. Here, to clarify the genomic structure of this model MHC paralogous region as well as to gain insight into the evolutionary dynamics of the entire quadriplication process, a detailed analysis of a critical 1.7 megabase (Mb) region was performed. To this end, a composite, deep, YAC, BAC, and PAC contig encompassing all five
CD1
genes and linking the centromeric +P5 locus to the telomeric
KRTC7
locus was constructed. Within this contig a 1.1-Mb BAC and PAC core segment joining
CD1D
to
FCER1A
was fully sequenced and thoroughly analyzed. This led to the mapping of a total of 41 genes (12 expressed genes, 12 possibly expressed genes, and 17 pseudogenes), among which 31 were novel. The latter include 20 olfactory receptor (
OR
) genes, 9 of which are potentially expressed. Importantly,
CD1, SPTA1, OR
, and
FCERIA
belong to multigene families, which have paralogues in the other three regions. Furthermore, it is noteworthy that 12 of the 13 expressed genes in the 1q21–q22 region around the
CD1
loci are immunologically relevant. In addition to
CD1A-E,
these include
SPTA1, MNDA, IFI-16, AIM2, BL1A, FY
and
FCERIA
. This functional convergence of structurally unrelated genes is reminiscent of the 6p MHC region, and perhaps represents the emergence of yet another antigen presentation gene cluster, in this case dedicated to lipid/glycolipid antigens rather than antigen-derived peptides.
[The nucleotide sequence data reported in this paper have been submitted to the DDBJ, EMBL, and GenBank databases under accession nos.
AB045357
–
AB045365
.] |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Corresponding author. |
ISSN: | 1088-9051 1549-5469 1549-5469 |
DOI: | 10.1101/gr.175801 |