PUBLICATION

Immune gene variation associated with chromosome-scale differences among individual zebrafish genomes

Authors
McConnell, S.C., Hernandez, K.M., Andrade, J., de Jong, J.L.O.
ID
ZDB-PUB-230514-44
Date
2023
Source
Scientific Reports   13: 77777777 (Journal)
Registered Authors
de Jong, Jill, McConnell, Sean
Keywords
none
MeSH Terms
  • Animals
  • Chromosomes/genetics
  • Exons
  • Genome*/genetics
  • Haplotypes/genetics
  • Zebrafish*/genetics
PubMed
37179373 Full text @ Sci. Rep.
Abstract
Immune genes have evolved to maintain exceptional diversity, offering robust defense against pathogens. We performed genomic assembly to examine immune gene variation in zebrafish. Gene pathway analysis identified immune genes as significantly enriched among genes with evidence of positive selection. A large subset of genes was absent from analysis of coding sequences due to apparent lack of reads, prompting us to examine genes overlapping zero coverage regions (ZCRs), defined as 2 kb stretches without mapped reads. Immune genes were identified as highly enriched within ZCRs, including over 60% of major histocompatibility complex (MHC) genes and NOD-like receptor (NLR) genes, mediators of direct and indirect pathogen recognition. This variation was most highly concentrated throughout one arm of chromosome 4 carrying a large cluster of NLR genes, associated with large-scale structural variation covering more than half of the chromosome. Our genomic assemblies uncovered alternative haplotypes and distinct complements of immune genes among individual zebrafish, including the MHC Class II locus on chromosome 8 and the NLR gene cluster on chromosome 4. While previous studies have shown marked variation in NLR genes between vertebrate species, our study highlights extensive variation in NLR gene regions between individuals of the same species. Taken together, these findings provide evidence of immune gene variation on a scale previously unknown in other vertebrate species and raise questions about potential impact on immune function.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping