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Braasch I, Gehrke AR, Smith JJ, Kawasaki K, Manousaki T, Pasquier J, Amores A, Desvignes T, Batzel P, Catchen J, Berlin AM, Campbell MS, Barrell D, Martin KJ, Mulley JF, Ravi V, Lee AP, Nakamura T, Chalopin D, Fan S, Wcisel D, Cañestro C, Sydes J, Beaudry FEG, Sun Y, Hertel J, Beam MJ, Fasold M, Ishiyama M, Johnson J, Kehr S, Lara M, Letaw JH, Litman GW, Litman RT, Mikami M, Ota T, Saha NR, Williams L, Stadler PF, Wang H, Taylor JS, Fontenot Q, Ferrara A, Searle SMJ, Aken B, Yandell M, Schneider I, Yoder JA, Volff JN, Meyer A, Amemiya CT, Venkatesh B, Holland PWH, Guiguen Y, Bobe J, Shubin NH, Di Palma F, Alfo¨ldi J, Lindblad-Toh K, Postlethwait JH. Erratum: Corrigendum: The spotted gar genome illuminates vertebrate evolution and facilitates human-teleost comparisons. Nat Genet 2016; 48:700. [DOI: 10.1038/ng0616-700c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Rodriguez-Nunez I, Wcisel DJ, Litman RT, Litman GW, Yoder JA. The identification of additional zebrafish DICP genes reveals haplotype variation and linkage to MHC class I genes. Immunogenetics 2016; 68:295-312. [PMID: 26801775 DOI: 10.1007/s00251-016-0901-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 01/07/2016] [Indexed: 10/22/2022]
Abstract
Bony fish encode multiple multi-gene families of membrane receptors that are comprised of immunoglobulin (Ig) domains and are predicted to function in innate immunity. One of these families, the diverse immunoglobulin (Ig) domain-containing protein (DICP) genes, maps to three chromosomal loci in zebrafish. Most DICPs possess one or two Ig ectodomains and include membrane-bound and secreted forms. Membrane-bound DICPs include putative inhibitory and activating receptors. Recombinant DICP Ig domains bind lipids with varying specificity, a characteristic shared with mammalian CD300 and TREM family members. Numerous DICP transcripts amplified from different lines of zebrafish did not match the zebrafish reference genome sequence suggesting polymorphic and haplotypic variation. The expression of DICPs in three different lines of zebrafish has been characterized employing PCR-based strategies. Certain DICPs exhibit restricted expression in adult tissues whereas others are expressed ubiquitously. Transcripts of a subset of DICPs can be detected during embryonic development suggesting roles in embryonic immunity or other developmental processes. Transcripts representing 11 previously uncharacterized DICP sequences were identified. The assignment of two of these sequences to an unplaced genomic scaffold resulted in the identification of an alternative DICP haplotype that is linked to a MHC class I Z lineage haplotype on zebrafish chromosome 3. The linkage of DICP and MHC class I genes also is observable in the genomes of the related grass carp (Ctenopharyngodon idellus) and common carp (Cyprinus carpio) suggesting that this is a shared character with the last common Cyprinidae ancestor.
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Affiliation(s)
- Ivan Rodriguez-Nunez
- Department of Molecular Biomedical Sciences and Center for Comparative Medicine and Translational Research, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA
| | - Dustin J Wcisel
- Department of Molecular Biomedical Sciences and Center for Comparative Medicine and Translational Research, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA
| | - Ronda T Litman
- Department of Pediatrics, University of South Florida Morsani College of Medicine, USF/ACH Children's Research Institute, 140 7th Avenue South, St. Petersburg, FL, 33701, USA
| | - Gary W Litman
- Department of Pediatrics, University of South Florida Morsani College of Medicine, USF/ACH Children's Research Institute, 140 7th Avenue South, St. Petersburg, FL, 33701, USA.,Department of Molecular Genetics, All Children's Hospital Johns Hopkins Medicine, 501 6th Avenue South, St. Petersburg, FL, 33701, USA
| | - Jeffrey A Yoder
- Department of Molecular Biomedical Sciences and Center for Comparative Medicine and Translational Research, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA.
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Kortum AN, Rodriguez-Nunez I, Yang J, Shim J, Runft D, O'Driscoll ML, Haire RN, Cannon JP, Turner PM, Litman RT, Kim CH, Neely MN, Litman GW, Yoder JA. Differential expression and ligand binding indicate alternative functions for zebrafish polymeric immunoglobulin receptor (pIgR) and a family of pIgR-like (PIGRL) proteins. Immunogenetics 2014; 66:267-79. [PMID: 24469064 DOI: 10.1007/s00251-014-0759-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 01/10/2014] [Indexed: 01/17/2023]
Abstract
The polymeric immunoglobulin (Ig) receptor (pIgR) is an integral transmembrane glycoprotein that plays an important role in the mammalian immune response by transporting soluble polymeric Igs across mucosal epithelial cells. Single pIgR genes, which are expressed in lymphoid organs including mucosal tissues, have been identified in several teleost species. A single pigr gene has been identified on zebrafish chromosome 2 along with a large multigene family consisting of 29 pigr-like (PIGRL) genes. Full-length transcripts from ten different PIGRL genes that encode secreted and putative inhibitory membrane-bound receptors have been characterized. Although PIGRL and pigr transcripts are detected in immune tissues, only PIGRL transcripts can be detected in lymphoid and myeloid cells. In contrast to pIgR which binds Igs, certain PIGRL proteins bind phospholipids. PIGRL transcript levels are increased after infection with Streptococcus iniae, suggesting a role for PIGRL genes during bacterial challenge. Transcript levels of PIGRL genes are decreased after infection with Snakehead rhabdovirus, suggesting that viral infection may suppress PIGRL function.
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Affiliation(s)
- Amanda N Kortum
- Department of Molecular Biomedical Sciences and Center for Comparative Medicine and Translational Research, North Carolina State University, 1060 William Moore Drive, Raleigh, NC, 27607, USA
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Haire RN, Cannon JP, O'Driscoll ML, Ostrov DA, Mueller MG, Turner PM, Litman RT, Litman GW, Yoder JA. Genomic and functional characterization of the diverse immunoglobulin domain-containing protein (DICP) family. Genomics 2012; 99:282-91. [PMID: 22386706 DOI: 10.1016/j.ygeno.2012.02.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2011] [Revised: 01/31/2012] [Accepted: 02/10/2012] [Indexed: 11/26/2022]
Abstract
A heretofore-unrecognized multigene family encoding diverse immunoglobulin (Ig) domain-containing proteins (DICPs) was identified in the zebrafish genome. Twenty-nine distinct loci mapping to three chromosomal regions encode receptor-type structures possessing two classes of Ig ectodomains (D1 and D2). The sequence and number of Ig domains, transmembrane regions and signaling motifs vary between DICPs. Interindividual polymorphism and alternative RNA processing contribute to DICP diversity. Molecular models indicate that most D1 domains are of the variable (V) type; D2 domains are Ig-like. Sequence differences between D1 domains are concentrated in hypervariable regions on the front sheet strands of the Ig fold. Recombinant DICP Ig domains bind lipids, a property shared by mammalian CD300 and TREM family members. These findings suggest that novel multigene families encoding diversified immune receptors have arisen in different vertebrate lineages and affect parallel patterns of ligand recognition that potentially impact species-specific advantages.
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Affiliation(s)
- Robert N Haire
- Department of Pediatrics, University of South Florida College of Medicine, USF/ACH Children's Research Institute, 140 7th Avenue South, St. Petersburg, FL 33701, USA
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Dishaw LJ, Ota T, Mueller MG, Cannon JP, Haire RN, Gwatney NR, Litman RT, Litman GW. The basis for haplotype complexity in VCBPs, an immune-type receptor in amphioxus. Immunogenetics 2010; 62:623-31. [PMID: 20652563 DOI: 10.1007/s00251-010-0464-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Accepted: 07/02/2010] [Indexed: 01/04/2023]
Abstract
Innate immune gene repertoires are restricted primarily to germline variation. Adaptive immunity, by comparison, relies on somatic variation of germline-encoded genes to generate extraordinarily large numbers of non-heritable antigen recognition motifs. Invertebrates lack the key features of vertebrate adaptive immunity, but have evolved a variety of alternative mechanisms to successfully protect the integrity of "self"; in many cases, these appear to be taxon-specific innovations. In the protochordate Branchiostoma floridae (amphioxus), the variable region-containing chitin-binding proteins (VCBPs) constitute a multigene family (comprised of VCBPs 1-5), which possesses features that are consistent with innate immune-type function. A large number of VCBP alleles and haplotypes are shown to exhibit levels of polymorphism exceeding the elevated overall levels determined for the whole amphioxus genome (JGI). VCBP genes of the 2 and 5 types are distinguished further by a highly polymorphic segment (exon 2) in the N-terminal immunoglobulin domain, defined previously as a "hypervariable region" or a "hotspot." Genomic deoxyribonucleic acid (DNA) and complementary DNA (cDNA) sequences from large numbers of animals representing different populations reveal further significant differences in sequence complexity within and across VCBP2/5 haplotypes that arise through overlapping mechanisms of genetic exchange, gene copy number variation as well as mutation and give rise to distinct allelic lineages. The collective observations suggest that mechanisms were in place at the time of divergence of the cephalochordates that could selectively hyperdiversify immune-type receptors within a multigene family.
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Affiliation(s)
- Larry J Dishaw
- Department of Molecular Genetics, All Children's Hospital, St. Petersburg, FL, USA
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Cannon JP, Dishaw LJ, Haire RN, Litman RT, Ostrov DA, Litman GW. Recognition of additional roles for immunoglobulin domains in immune function. Semin Immunol 2009; 22:17-24. [PMID: 20004115 DOI: 10.1016/j.smim.2009.11.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Accepted: 11/16/2009] [Indexed: 01/08/2023]
Abstract
Characterization of immune receptors found in phylogenetically disparate species at the genetic, structural and functional levels has provided unique insight into the evolutionary acquisition of immune function. The roles of variable- and intermediate-type immunoglobulin (Ig) domains in direct recognition of ligands and other functions are far wider than previously anticipated. Common mechanisms of multigene family diversification and expansion as well as unique adaptations that relate to function continue to provide unique insight into the numerous patterns, processes and complex interactions that regulate the host response to infectious challenge.
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Affiliation(s)
- John P Cannon
- University of South Florida, Department of Pediatrics, USF/ACH Children's Research Institute, 140 Seventh Avenue South, St. Petersburg, FL 33701, USA.
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Dishaw LJ, Mueller MG, Gwatney N, Cannon JP, Haire RN, Litman RT, Amemiya CT, Ota T, Rowen L, Glusman G, Litman GW. Genomic complexity of the variable region-containing chitin-binding proteins in amphioxus. BMC Genet 2008; 9:78. [PMID: 19046437 PMCID: PMC2632668 DOI: 10.1186/1471-2156-9-78] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Accepted: 12/01/2008] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The variable region-containing chitin-binding proteins (VCBPs) are found in protochordates and consist of two tandem immunoglobulin variable (V)-type domains and a chitin-binding domain. We previously have shown that these polymorphic genes, which primarily are expressed in the gut, exhibit characteristics of immune genes. In this report, we describe VCBP genomic organization and characterize adjacent and intervening genetic features which may influence both their polymorphism and complex transcriptional repertoire. RESULTS VCBP genes 1, 2, 4, and 5 are encoded in a single contiguous gene-rich chromosomal region and VCBP3 is encoded in a separate locus. The VCBPs exhibit extensive haplotype variation, including copy number variation (CNV), indel polymorphism and a markedly elevated variation in repeat type and density. In at least one haplotype, inverted repeats occur more frequently than elsewhere in the genome. Multi-animal cDNA screening, as well as transcriptional profilingusing a novel transfection system, suggests that haplotype-specific transcriptional variants may contribute to VCBP genetic diversity. CONCLUSION The availability of the Branchiostoma floridae genome (Joint Genome Institute, Brafl1), along with BAC and PAC screening and sequencing described here, reveal that the relatively limited number of VCBP genes present in the amphioxus genome exhibit exceptionally high haplotype variation. These VCBP haplotypes contribute a diverse pool of allelic variants, which includes gene copy number variation, pseudogenes, and other polymorphisms, while contributing secondary effects on gene transcription as well.
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Affiliation(s)
- Larry J Dishaw
- All Children's Hospital, Department of Molecular Genetics, 801 Sixth Street South, St. Petersburg, FL 33701, USA
- H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Avenue, Tampa, FL 33612, USA
| | - M Gail Mueller
- All Children's Hospital, Department of Molecular Genetics, 801 Sixth Street South, St. Petersburg, FL 33701, USA
| | - Natasha Gwatney
- Department of Pediatrics, University of South Florida College of Medicine, USF/ACH Children's Research Institute, 830 First Street South, St. Petersburg, FL 33701, USA
| | - John P Cannon
- H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Avenue, Tampa, FL 33612, USA
- Department of Pediatrics, University of South Florida College of Medicine, USF/ACH Children's Research Institute, 830 First Street South, St. Petersburg, FL 33701, USA
| | - Robert N Haire
- Department of Pediatrics, University of South Florida College of Medicine, USF/ACH Children's Research Institute, 830 First Street South, St. Petersburg, FL 33701, USA
| | - Ronda T Litman
- Department of Pediatrics, University of South Florida College of Medicine, USF/ACH Children's Research Institute, 830 First Street South, St. Petersburg, FL 33701, USA
| | - Chris T Amemiya
- Benaroya Research Institute, 1201 Ninth Avenue, Seattle, WA 98101, USA
| | - Tatsuya Ota
- Department of Evolutionary Studies of Biosystems, The Graduate University for Advanced Studies, Kamiyamaguchi 1560-35, Hayama 240-0193 Japan
| | - Lee Rowen
- Institute for Systems Biology, 1441 N. 34th St, Seattle, WA, 98103, USA
| | - Gustavo Glusman
- Institute for Systems Biology, 1441 N. 34th St, Seattle, WA, 98103, USA
| | - Gary W Litman
- All Children's Hospital, Department of Molecular Genetics, 801 Sixth Street South, St. Petersburg, FL 33701, USA
- H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Avenue, Tampa, FL 33612, USA
- Department of Pediatrics, University of South Florida College of Medicine, USF/ACH Children's Research Institute, 830 First Street South, St. Petersburg, FL 33701, USA
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Yoder JA, Cannon JP, Litman RT, Murphy C, Freeman JL, Litman GW. Evidence for a transposition event in a second NITR gene cluster in zebrafish. Immunogenetics 2008; 60:257-65. [PMID: 18330557 DOI: 10.1007/s00251-008-0285-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Accepted: 02/12/2008] [Indexed: 11/24/2022]
Abstract
Novel immune-type receptors (NITRs) are immunoglobulin-variable (V) domain-containing cell surface proteins that possess characteristic activating/inhibitory signaling motifs and are expressed in hematopoietic cells. NITRs are encoded by multigene families and have been identified in bony fish species. A single gene cluster, which encodes 36 NITRs that can be classified into 12 families, has been mapped to zebrafish chromosome 7. We report herein the presence of a second NITR gene cluster on zebrafish chromosome 14, which is comprised of three genes (nitr13, nitr14a, and nitr14b) representing two additional NITR gene families. Phylogenetic analyses indicate that the V domains encoded by the nitr13 and nitr14 genes are more similar to each other than any other zebrafish NITR suggesting that these genes arose from a tandem gene duplication event. Similar analyses comparing zebrafish Nitr13 and Nitr14 to NITRs from other fish species indicate that the nitr13 and nitr14 genes are phylogenetically related to the catfish IpNITR13 and IpNITR15 genes. Sequence features of the chromosomal region encoding nitr13 suggest that this gene arose via retrotransposition.
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Affiliation(s)
- Jeffrey A Yoder
- Department of Molecular Biomedical Sciences and Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
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Cannon JP, Haire RN, Mueller MG, Litman RT, Eason DD, Tinnemore D, Amemiya CT, Ota T, Litman GW. Ancient divergence of a complex family of immune-type receptor genes. Immunogenetics 2006; 58:362-73. [PMID: 16738934 PMCID: PMC3701310 DOI: 10.1007/s00251-006-0112-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Accepted: 03/13/2006] [Indexed: 10/24/2022]
Abstract
Multigene families of activating/inhibitory receptors belonging to the immunoglobulin superfamily (IgSF) regulate immunological and other cell-cell interactions. A new family of such genes, termed modular domain immune-type receptors (MDIRs), has been identified in the clearnose skate (Raja eglanteria), a phylogenetically ancient vertebrate. At least five different major forms of predicted MDIR proteins are comprised of four different subfamilies of IgSF ectodomains of the intermediate (I)- or C2-set. The predicted number of individual IgSF ectodomains in MDIRs varies from one to six. MDIR1 contains a positively charged transmembrane residue and MDIR2 and MDIR3 each possesses at least one immunoreceptor tyrosine-based inhibitory motif in their cytoplasmic regions. MDIR4 and MDIR5 lack characteristic activating/inhibitory signalling motifs. MDIRs are encoded in a particularly large and complex multigene family. MDIR domains exhibit distant sequence similarity to mammalian CMRF-35-like molecules, polymeric immunoglobulin receptors, triggering receptors expressed on myeloid cells (TREMs), TREM-like transcripts, NKp44 and FcR homologs, as well as to sequences identified in several different vertebrate genomes. Phylogenetic analyses suggest that MDIRs are representative members of an extended family of IgSF genes that diverged before or very early in evolution of the vertebrates and subsequently came to occupy multiple, fully independent distributions in the present day.
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Affiliation(s)
- John P. Cannon
- Department of Pediatrics, University of South Florida College of Medicine, and USF/ACH Children’s Research Institute, 830 First Street South, St. Petersburg, FL 33701, USA
- Immunology Program, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Avenue, Tampa, FL 33612, USA
| | - Robert N. Haire
- Department of Pediatrics, University of South Florida College of Medicine, and USF/ACH Children’s Research Institute, 830 First Street South, St. Petersburg, FL 33701, USA
- Immunology Program, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Avenue, Tampa, FL 33612, USA
| | - M. Gail Mueller
- Department of Molecular Genetics, All Children’s Hospital, 801 Sixth Street South, St. Petersburg, FL 33701, USA
| | - Ronda T. Litman
- Department of Pediatrics, University of South Florida College of Medicine, and USF/ACH Children’s Research Institute, 830 First Street South, St. Petersburg, FL 33701, USA
| | - Donna D. Eason
- Department of Pediatrics, University of South Florida College of Medicine, and USF/ACH Children’s Research Institute, 830 First Street South, St. Petersburg, FL 33701, USA
- Immunology Program, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Avenue, Tampa, FL 33612, USA
| | - Deborah Tinnemore
- Molecular Genetics Program, Benaroya Research Institute at Virginia Mason, 1201 Ninth Avenue, Seattle, WA 98101, USA
| | - Chris T. Amemiya
- Molecular Genetics Program, Benaroya Research Institute at Virginia Mason, 1201 Ninth Avenue, Seattle, WA 98101, USA
| | - Tatsuya Ota
- Department of Biosystems Science and Hayama Center for Advanced Studies, The Graduate University for Advanced Studies (Sokendai), Hayama, Kanagawa 240-0193, Japan
| | - Gary W. Litman
- Department of Pediatrics, University of South Florida College of Medicine, and USF/ACH Children’s Research Institute, 830 First Street South, St. Petersburg, FL 33701, USA
- Immunology Program, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Avenue, Tampa, FL 33612, USA
- Department of Molecular Genetics, All Children’s Hospital, 801 Sixth Street South, St. Petersburg, FL 33701, USA, , Tel.: +1-727-5533602, Fax: +1-727-5533610
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Yoder JA, Litman RT, Mueller MG, Desai S, Dobrinski KP, Montgomery JS, Buzzeo MP, Ota T, Amemiya CT, Trede NS, Wei S, Djeu JY, Humphray S, Jekosch K, Hernandez Prada JA, Ostrov DA, Litman GW. Resolution of the novel immune-type receptor gene cluster in zebrafish. Proc Natl Acad Sci U S A 2004; 101:15706-11. [PMID: 15496470 PMCID: PMC524843 DOI: 10.1073/pnas.0405242101] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The novel immune-type receptor (NITR) genes encode a unique multigene family of leukocyte regulatory receptors, which possess an extracellular Ig variable (V) domain and may function in innate immunity. Artificial chromosomes that encode zebrafish NITRs have been assembled into a contig spanning approximately 350 kb. Resolution of the complete NITR gene cluster has led to the identification of eight previously undescribed families of NITRs and has revealed the presence of C-type lectins within the locus. A maximum haplotype of 36 NITR genes (138 gene sequences in total) can be grouped into 12 distinct families, including inhibitory and activating receptors. An extreme level of interindividual heterozygosity is reflected in allelic polymorphisms, haplotype variation, and family-specific isoform complexity. In addition, the exceptional diversity of NITR sequences among species suggests divergent evolution of this multigene family with a birth-and-death process of member genes. High-confidence modeling of Nitr V-domain structures reveals a significant shift in the spatial orientation of the Ig fold, in the region of highest interfamily variation, compared with Ig V domains. These studies resolve a complete immune gene cluster in zebrafish and indicate that the NITRs represent the most complex family of activating/inhibitory surface receptors thus far described.
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Affiliation(s)
- Jeffrey A Yoder
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606, USA
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Eason DD, Litman RT, Luer CA, Kerr W, Litman GW. Expression of individual immunoglobulin genes occurs in an unusual system consisting of multiple independent loci. Eur J Immunol 2004; 34:2551-8. [PMID: 15307187 DOI: 10.1002/eji.200425224] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Humoral immunity is effected through the rearrangement of immunoglobulin (Ig) genes in individual somatic cells committed to the B lymphocyte lineage. Haplotype or allelic exclusion restricts B lymphocytes to the expression of a single Ig receptor that can sustain further somatic modification. In most species, a specific Ig chain is encoded at a single genetic locus. However, in cartilaginous fish, hundreds of independent Ig heavy- (IgH) and Ig light-chain (IgL) gene loci are present, many of which are joined in the germ line. Ig gene transcripts have been amplified from single peripheral blood lymphocytes isolated from the clearnose skate (Raja eglanteria) using reverse-transcription PCR, and a single productive IgH transcript was detected in the majority of cells analyzed. Similarly, only a single IgL transcript was detected in over half of the individual cells. Taken together, these findings suggest that a mechanism for haplotype exclusion arose early in the evolution of antibody diversity and is independent of a single genetic locus.
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Affiliation(s)
- Donna D Eason
- Department of Molecular Genetics, All Children's Hospital, St. Petersburg, FL, USA
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Hawke NA, Yoder JA, Haire RN, Mueller MG, Litman RT, Miracle AL, Stuge T, Shen L, Miller N, Litman GW. Extraordinary variation in a diversified family of immune-type receptor genes. Proc Natl Acad Sci U S A 2001; 98:13832-7. [PMID: 11698645 PMCID: PMC61127 DOI: 10.1073/pnas.231418598] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2001] [Indexed: 11/18/2022] Open
Abstract
Immune inhibitory receptor genes that encode a variable (V) region, a unique V-like C2 (V/C2) domain, a transmembrane region, and a cytoplasmic tail containing immunoreceptor tyrosine-based inhibition motifs (ITIMs) have been described previously in two lineages of bony fish. In the present study, eleven related genes encoding distinct structural forms have been identified in Ictalurus punctatus (channel catfish), a well characterized immunological model system that represents a third independent bony fish lineage. Each of the different genes encodes an N-terminal V region but differs in the number of extracellular Ig domains, number and location of joining (J) region-like motifs, presence of transmembrane regions, presence of charged residues in transmembrane regions, presence of cytoplasmic tails, and/or distribution of ITIM(s) within the cytoplasmic tails. Variation in the numbers of genomic copies of the different gene types, their patterns of expression, and relative levels of expression in mixed leukocyte cultures (MLC) is reported. V region-containing immune-type genes constitute a far more complex family than recognized originally and include individual members that might function in inhibitory or, potentially activatory manners.
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Affiliation(s)
- N A Hawke
- Department of Medical Microbiology, University of South Florida Children's Research Institute, 140 Seventh Avenue South, St. Petersburg, FL 33701, USA
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Yoder JA, Mueller MG, Wei S, Corliss BC, Prather DM, Willis T, Litman RT, Djeu JY, Litman GW. Immune-type receptor genes in zebrafish share genetic and functional properties with genes encoded by the mammalian leukocyte receptor cluster. Proc Natl Acad Sci U S A 2001; 98:6771-6. [PMID: 11381126 PMCID: PMC34428 DOI: 10.1073/pnas.121101598] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An extensive, highly diversified multigene family of novel immune-type receptor (nitr) genes has been defined in Danio rerio (zebrafish). The genes are predicted to encode type I transmembrane glycoproteins consisting of extracellular variable (V) and V-like C2 (V/C2) domains, a transmembrane region and a cytoplasmic tail. All of the genes examined encode immunoreceptor tyrosine-based inhibition motifs in the cytoplasmic tail. Radiation hybrid panel mapping and analysis of a deletion mutant line (b240) indicate that a minimum of approximately 40 nitr genes are contiguous in the genome and span approximately 0.6 Mb near the top of zebrafish linkage group 7. One flanking region of the nitr gene complex shares conserved synteny with a region of mouse chromosome 7, which shares conserved synteny with human 19q13.3-q13.4 that encodes the leukocyte receptor cluster. Antibody-induced crosslinking of Nitrs that have been introduced into a human natural killer cell line inhibits the phosphorylation of mitogen-activated protein kinase that is triggered by natural killer-sensitive tumor target cells. Nitrs likely represent intermediates in the evolution of the leukocyte receptor cluster.
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Affiliation(s)
- J A Yoder
- Department of Pediatrics, University of South Florida, Children's Research Institute, St. Petersburg, FL 33701, USA
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Miracle AL, Anderson MK, Litman RT, Walsh CJ, Luer CA, Rothenberg EV, Litman GW. Complex expression patterns of lymphocyte-specific genes during the development of cartilaginous fish implicate unique lymphoid tissues in generating an immune repertoire. Int Immunol 2001; 13:567-80. [PMID: 11282996 DOI: 10.1093/intimm/13.4.567] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cartilaginous fish express canonical B and T cell recognition genes, but their lymphoid organs and lymphocyte development have been poorly defined. Here, the expression of Ig, TCR, recombination-activating gene (Rag)-1 and terminal deoxynucleosidase (TdT) genes has been used to identify roles of various lymphoid tissues throughout development in the cartilaginous fish, Raja eglanteria (clearnose skate). In embryogenesis, Ig and TCR genes are sharply up-regulated at 8 weeks of development. At this stage TCR and TdT expression is limited to the thymus; later, TCR gene expression appears in peripheral sites in hatchlings and adults, suggesting that the thymus is a source of T cells as in mammals. B cell gene expression indicates more complex roles for the spleen and two special organs of cartilaginous fish-the Leydig and epigonal (gonad-associated) organs. In the adult, the Leydig organ is the site of the highest IgM and IgX expression. However, the spleen is the first site of IgM expression, while IgX is expressed first in gonad, liver, Leydig and even thymus. Distinctive spatiotemporal patterns of Ig light chain gene expression also are seen. A subset of Ig genes is pre-rearranged in the germline of the cartilaginous fish, making expression possible without rearrangement. To assess whether this allows differential developmental regulation, IgM and IgX heavy chain cDNA sequences from specific tissues and developmental stages have been compared with known germline-joined genomic sequences. Both non-productively rearranged genes and germline-joined genes are transcribed in the embryo and hatchling, but not in the adult.
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Affiliation(s)
- A L Miracle
- University of South Florida, Department of Pediatrics, Children's Research Institute, 140 Seventh Avenue South, St Petersburg, FL 33701, USA
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15
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Haire RN, Rast JP, Litman RT, Litman GW. Characterization of three isotypes of immunoglobulin light chains and T-cell antigen receptor alpha in zebrafish. Immunogenetics 2000; 51:915-23. [PMID: 11003385 DOI: 10.1007/s002510000229] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The zebrafish (Danio rerio) has become a significant model for understanding the developmental regulation of gene expression and holds considerable potential for characterizing the development of the immune system. Using a number of different approaches, including heterologous hybridization and short-primer PCR, cDNAs for three different classes of light-chain genes were identified and characterized. The zebrafish light chains are similar to trout type 1, trout type 2, and catfish type F, respectively. T-cell antigen receptor alpha (TCRalpha) was also identified and characterized. A high proportion of unusual transcripts including sterile transcripts, germline VJC transcripts, aberrant splice forms, and V-V transcripts were encountered in the immunoglobulin and TCR cDNAs examined. The light-chain and TCRalpha loci each consist of multiple families of V gene segments, apparent even from the small numbers of cDNAs of each isotype sequenced. The gene sequences reported provide an essential set of markers of both B- and T-cell lineages that will facilitate investigations of immune system development.
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Affiliation(s)
- R N Haire
- Department of Pediatrics, University of South Florida College of Medicine, Children's Research Institute, St. Petersburg 33701, USA
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16
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Kendall SK, Strong SJ, Litman RT, Litman GW, Magnuson T. Genetic analysis of the exed region in mouse. Genesis 2000; 27:174-9. [PMID: 10992327 DOI: 10.1002/1526-968x(200008)27:4<174::aid-gene60>3.3.co;2-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The extraembryonic ectoderm development (exed) mutant phenotype was described in mice homozygous for the c(6H) deletion, a radiation-induced deletion in the tyrosinase region of mouse Chromosome 7. These mutants fail to gastrulate and die around embryonic day 8.0. Several genes including, for example, embryonic ectoderm development (eed), are deleted in the c(6H) mutants; however, the portion of the chromosome responsible for the more severe exed phenotype is localized to a 20-kb region called the "exed-critical region." To understand the genetics behind the exed phenotype, we analyzed this region in two ways. First, to determine whether the 20-kb exed-critical region alone causes the mutant phenotype, we removed it from a wild-type chromosome. The resulting mice homozygous for this deletion were viable and fertile, indicating that the 20-kb exed-critical region by itself is not sufficient to cause the phenotype when deleted. We then sequenced the 20-kb exed-critical region and no expressed exons were found. Several short matches to GenBank Expressed Sequence Tag (EST) databases were identified; however, none of these ESTs mapped to the region. Taken together, these results indicate that the exed phenotype may either be a position effect on a distal gene caused by the c(6H) breakpoint or the result of composite effects of nullizygosity of multiple genes in the deletion homozygotes.
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Affiliation(s)
- S K Kendall
- Department of Genetics, Case Western Reserve University, Cleveland, Ohio, USA
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17
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Kendall SK, Strong SJ, Litman RT, Litman GW, Magnuson T. Genetic analysis of theexed region in mouse. Genesis 2000. [DOI: 10.1002/1526-968x(200008)27:4<174::aid-gene60>3.0.co;2-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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18
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Strong SJ, Mueller MG, Litman RT, Hawke NA, Haire RN, Miracle AL, Rast JP, Amemiya CT, Litman GW. A novel multigene family encodes diversified variable regions. Proc Natl Acad Sci U S A 1999; 96:15080-5. [PMID: 10611341 PMCID: PMC24776 DOI: 10.1073/pnas.96.26.15080] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Antigen recognition in the adaptive immune response by Ig and T-cell antigen receptors (TCRs) is effected through patterned differences in the peptide sequence in the V regions. V-region specificity forms through genetically programmed rearrangement of individual, diversified segmental elements in single somatic cells. Other Ig superfamily members, including natural killer receptors that mediate cell-surface recognition, do not undergo segmental reorganization, and contain type-2 C (C2) domains, which are structurally distinct from the C1 domains found in Ig and TCR. Immunoreceptor tyrosine-based inhibitory motifs that transduce negative regulatory signals through the cell membrane are found in certain natural killer and other cell surface inhibitory receptors, but not in Ig and TCR. In this study, we employ a genomic approach by using the pufferfish (Spheroides nephelus) to characterize a nonrearranging novel immune-type receptor gene family. Twenty-six different nonrearranging genes, which each encode highly diversified V as well as a V-like C2 extracellular domain, a transmembrane region, and in most instances, an immunoreceptor tyrosine-based inhibitory motif-containing cytoplasmic tail, are identified in an approximately 113 kb P1 artificial chromosome insert. The presence in novel immune-type receptor genes of V regions that are related closely to those found in Ig and TCR as well as regulatory motifs that are characteristic of inhibitory receptors implies a heretofore unrecognized link between known receptors that mediate adaptive and innate immune functions.
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Affiliation(s)
- S J Strong
- Department of Pediatrics, University of South Florida College of Medicine, St. Petersburg, FL 33701, USA
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19
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Anderson MK, Strong SJ, Litman RT, Luer CA, Amemiya CT, Rast JP, Litman GW. A long form of the skate IgX gene exhibits a striking resemblance to the new shark IgW and IgNARC genes. Immunogenetics 1999; 49:56-67. [PMID: 9811969 DOI: 10.1007/s002510050463] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Differential screening has been used to identify cDNAs encoding a long form of IgX in Raja eglanteria (clearnose skate). Comparisons of the IgX long form with the previously described short-form IgX cDNAs and the genomic IgX locus indicate that the V and two 5' C regions of the short and long forms of IgX are >90% identical at the nucleotide level. Differences between the V sequences of the long- and short-form IgX genes are concentrated in complementarity determining regions, suggesting that these forms are derived through alternative splicing of the same genomic loci or transcription of highly related loci. The extreme conservation of nucleotide sequence, including third position codons, among different cDNAs as well as the near identity of nucleotide sequence in the intervening sequences of germline IgX, IgX short-form sterile transcripts and IgX long-form sterile transcripts indicate that the multiple IgX loci are recently diverged from one another and/or are under intense gene correction. Phylogenetic analyses of the known cartilaginous fish immunoglobulin loci demonstrate that the long form of IgX is orthologous to IgW/IgNARC (NARC) and is most consistent with: 1) the divergence of the IgX/IgW/NARC and IgM-like loci from a common ancestral locus prior to the divergence of the cartilaginous/bony fish lineages and 2) the divergence of the NAR locus from the IgX/IgW/NARC gene(s) after the cartilaginous/bony fish split but prior to the shark/skate split, approximately 220 million years ago.
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Affiliation(s)
- M K Anderson
- Division of Biology 156-29, California Institute of Technology, 1201 E. California Blvd., Pasadena, CA 91125, USA
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20
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Rast JP, Amemiya CT, Litman RT, Strong SJ, Litman GW. Distinct patterns of IgH structure and organization in a divergent lineage of chrondrichthyan fishes. Immunogenetics 1998; 47:234-45. [PMID: 9435342 DOI: 10.1007/s002510050353] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Immunoglobulin heavy chain (IgH) genes in representative chondrichthyan fishes (sharks and skates) consist of independently functioning clusters, containing separate variable (VH), diversity (DH), and joining (JH) region elements and constant (CH) region exons. IgH loci have been characterized in Hydrolagus colliei (spotted ratfish), a modern representative of a major independent chondrichthyan lineage. Three distinct families of IgH gene clusters were identified. The most numerous genes consist of unjoined VH-D1-D2-JH segments that correspond to the most abundant Hydrolagus spleen (cDNA) transcripts which apparently arise from a diversified gene family. In the second cluster type, VH, DH, and JH segments are germline-joined, whereas the CH exons exhibit typical organization. This gene type is found in only a few copies per haploid genome and both transmembrane and secretory transcripts have been identified. A third cluster type has been identified that consists of unjoined VH elements but lacks a typical CH1 exon, which is substituted with a second CH2-like exon. Transcripts from this third cluster type also appear to derive from a diversified gene family. Genomic D regions of the two unjoined clone types exhibit structural differences that are consistent with incorporation of recombination machinery-mediated events. Genomic library screening indicates that 90% of VH+ clones are truncated, nearly identical pseudogenes (lacking JH and CH). These studies demonstrate an early phylogenetic origin for the cluster type of gene organization and document extensive organizational diversification within an apparent single class of IgH genes.
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Affiliation(s)
- J P Rast
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, 801 Sixth Street South, St. Petersburg, FL 33701, USA
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21
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Haire RN, Ohta Y, Strong SJ, Litman RT, Liu Y, Prchal JT, Cooper MD, Litman GW. Unusual patterns of exon skipping in Bruton tyrosine kinase are associated with mutations involving the intron 17 3' splice site. Am J Hum Genet 1997; 60:798-807. [PMID: 9106525 PMCID: PMC1712487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Seven individuals with the diagnosis of X-linked agammaglobulinemia were analyzed for mutations in Bruton tyrosine kinase (Btk) gene at both the cDNA transcript and genomic DNA levels. In addition, maternal carrier status was determined in six of the seven families by examining X chromosome-inactivation patterns for B cells in comparison with other types of blood cells. Three categories of mutations were identified: (1) three patients have missense mutations in either the pleckstrin or SH2 domains of Btk; (2) three patients exhibit mutations at or near intron/exon splice sites, two of which represent inherited mutations within the kinase domain; and (3) one patient has inherited a 2.5-kb deletion with the loss of a DNA segment encoding three exons of the kinase domain. Variation in the lengths of Btk transcripts was evident in two patients with splice-site mutations and in the patient with the DNA deletion. Sequences of the different cDNA transcripts from the patients with 3' splice-site mutations reveal complex patterns of exon skipping involving from one to four exons of the kinase domain. These findings implicate 3' splice sites of the penultimate exon in the recognition or processing of upstream exons.
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Affiliation(s)
- R N Haire
- University of South Florida, All Children's Hospital, St. Petersburg 33701, USA
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22
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Abstract
A series of products were amplified using a PCR strategy based on short minimally degenerate primers and R. eglanteria (clearnose skate) spleen cDNA as template. These products were used as probes to select corresponding cDNAs from a spleen cDNA library. The cDNA sequences exhibit significant identity with prototypic (alpha, beta, gamma, and delta T cell antigen receptor (TCR) genes. Characterization of cDNAs reveals extensive variable region diversity, putative diversity segments, and varying degrees of junctional diversification. This demonstrates expression of both alpha/beta and gamma/delta TCR genes at an early level of vertebrate phylogeny and indicates that the three major known classes of rearranging antigen receptors were present in the common ancestor of the present-day jawed vertebrates.
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MESH Headings
- Amino Acid Sequence
- Animals
- Biological Evolution
- DNA, Complementary/genetics
- Gene Rearrangement, T-Lymphocyte
- Genes
- Genes, Immunoglobulin
- Humans
- Mice
- Molecular Sequence Data
- Phylogeny
- Polymerase Chain Reaction/methods
- Polymorphism, Restriction Fragment Length
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, gamma-delta/genetics
- Sequence Alignment
- Sequence Homology, Amino Acid
- Sequence Homology, Nucleic Acid
- Sharks/genetics
- Sharks/immunology
- Skates, Fish/genetics
- Skates, Fish/immunology
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Affiliation(s)
- J P Rast
- Department of Pediatrics, University of South Florida, All Children's Hospital, St. Petersburg 33701, USA
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23
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Haire RN, Ota T, Rast JP, Litman RT, Chan FY, Zon LI, Litman GW. A third Ig light chain gene isotype in Xenopus laevis consists of six distinct VL families and is related to mammalian lambda genes. The Journal of Immunology 1996. [DOI: 10.4049/jimmunol.157.4.1544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Xenopus laevis is a unique model for studying the ontogenetic development of immune functions. A short primer PCR amplification method was employed to amplify fragments from Xenopus genomic DNA that are related to Ig light chains and TCR. One fragment was identified that appeared to represent a novel type of light chain and was used as a probe to recover the corresponding cDNA from a spleen cDNA library. We designate these light chains type III. Using an iterative screening procedure, six families of VL genes, two distinct JL and two distinct CL sequences, were identified. In a comparison of phylogenetically diverse light chains, the type III genes align with higher vertebrate lambda genes. Southern blot hybridization analyses with genomic DNA from different animals showed the VL and CL sequences to be both diverse and polymorphic. Intrafamily sequence comparisons of VL genes revealed additional diversity. Collectively, these studies confirm the existence of a third type of light chain gene in Xenopus, establish a high degree of genetic variation in the sequences encoding the light chain V regions, and provide the most significant evidence to date for the presence of a lambda-like light chain gene at the phylogenetic level of the amphibians.
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Affiliation(s)
- R N Haire
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg 33701, USA
| | - T Ota
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg 33701, USA
| | - J P Rast
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg 33701, USA
| | - R T Litman
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg 33701, USA
| | - F Y Chan
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg 33701, USA
| | - L I Zon
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg 33701, USA
| | - G W Litman
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg 33701, USA
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24
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Haire RN, Ota T, Rast JP, Litman RT, Chan FY, Zon LI, Litman GW. A third Ig light chain gene isotype in Xenopus laevis consists of six distinct VL families and is related to mammalian lambda genes. J Immunol 1996; 157:1544-50. [PMID: 8759737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Xenopus laevis is a unique model for studying the ontogenetic development of immune functions. A short primer PCR amplification method was employed to amplify fragments from Xenopus genomic DNA that are related to Ig light chains and TCR. One fragment was identified that appeared to represent a novel type of light chain and was used as a probe to recover the corresponding cDNA from a spleen cDNA library. We designate these light chains type III. Using an iterative screening procedure, six families of VL genes, two distinct JL and two distinct CL sequences, were identified. In a comparison of phylogenetically diverse light chains, the type III genes align with higher vertebrate lambda genes. Southern blot hybridization analyses with genomic DNA from different animals showed the VL and CL sequences to be both diverse and polymorphic. Intrafamily sequence comparisons of VL genes revealed additional diversity. Collectively, these studies confirm the existence of a third type of light chain gene in Xenopus, establish a high degree of genetic variation in the sequences encoding the light chain V regions, and provide the most significant evidence to date for the presence of a lambda-like light chain gene at the phylogenetic level of the amphibians.
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Affiliation(s)
- R N Haire
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg 33701, USA
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25
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Ohta Y, Haire RN, Amemiya CT, Litman RT, Träger T, Riess O, Litman GW. Human Txk: genomic organization, structure and contiguous physical linkage with the Tec gene. Oncogene 1996; 12:937-42. [PMID: 8632917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Txk is a Tec-family tyrosine kinase expressed in mouse and human T lymphocytes. Among the Tec kinases, Txk is unique in that its amino terminal region does not include a pleckstrin homology domain or other known extended functional region. Txk is encoded at human chromosome 4p12 and at a recognized region of conserved synteny on mouse chromosome 5. The genomic organization of Txk consists of 15 exons with strong exon-intron organizational homology to Btk, the only other Tec-family kinase for which the genomic structure is fully known. The human Tec gene also maps to 4p12 and, based on limited studies reported here, possesses organizational homology with Btk and Txk. We have sequenced a continuous region of DNA that contains 3' Tec and 5' Txk exons separated by only a approximately 1.5 kb intergenic region containing the putative promoter region of Txk. The close physical linkage of these Tec-family tyrosine kinases, which are expressed in different hematopoetic cell lineages, suggests their potential for coordinate cis-regulation.
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Affiliation(s)
- Y Ohta
- Department of Pediatrics, University of South Florida, St. Petersburg 33701, USA
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26
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Anderson MK, Shamblott MJ, Litman RT, Litman GW. Generation of immunoglobulin light chain gene diversity in Raja erinacea is not associated with somatic rearrangement, an exception to a central paradigm of B cell immunity. J Exp Med 1995; 182:109-19. [PMID: 7790811 PMCID: PMC2192082 DOI: 10.1084/jem.182.1.109] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In all vertebrate species examined to date, rearrangement and somatic modification of gene segmental elements that encode portions of the antigen-combining sites of immunoglobulins are integral components of the generation of antibody diversity. In the phylogenetically primitive cartilaginous fishes, gene segments encoding immunoglobulin heavy and light chain loci are arranged in multiple clusters, in which segmental elements are separated by only 300-400 bp. In some cases, segmental elements are joined in the germline of nonlymphoid cells (joined genes). Both genomic library screening and direct amplification of genomic DNA have been used to characterize at least 89 different type I light chain gene clusters in the skate, Raja. Analyses of predicted nucleotide sequences and predicted peptide structures are consistent with the distribution of genes into different sequence groups. Predicted amino acid sequence differences are preferentially distributed in complementarity-determining versus framework regions, and replacement-type substitutions exceed neutral substitutions. When specific germline sequences are related to the sequences of individual cDNAs, it is apparent that the joined genes are expressed and are potentially somatically mutated. No evidence was found for the presence of any type I light chain gene in Raja that is not germline joined. The type I light chain gene clusters in Raja appear to represent a novel gene system in which combinatorial and junctional diversity are absent.
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Affiliation(s)
- M K Anderson
- Department of Biochemistry, University of South Florida, All Children's Hospital, St. Petersburg 33701, USA
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27
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Rast JP, Haire RN, Litman RT, Pross S, Litman GW. Identification and characterization of T-cell antigen receptor-related genes in phylogenetically diverse vertebrate species. Immunogenetics 1995; 42:204-12. [PMID: 7642232 DOI: 10.1007/bf00191226] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Characterization of the structure, multiplicity, organization, and cell lineage-specific expression of T-cell receptor (TCR) genes of nonmammalian vertebrate species is central to the understanding of the evolutionary origins of rearranging genes of the vertebrate immune system. We recently described a polymerase chain reaction (PCR) strategy that relies on short sequence similarities shared by nearly all vertebrate TCR and immunoglobulin (Ig) variable (V) regions and have used this approach to isolate a TCR beta (TCRB) homolog from a cartilaginous fish. Using these short PCR products as probes in spleen cDNA and genomic libraries, we were able to isolate a variety of unique TCR and TCR-like genes. Here we report the identification and characterization of a chicken TCR gamma (TCRG) homolog, apparent Xenopus and pufferfish TCR alpha (TCRA) homologs, and two horned shark TCR delta (TCRD)-like genes. In addition, we have identified what could be a novel representative of the Ig gene superfamily in the pufferfish. This method of using short, minimally degenerate PCR primers should speed progress in the phylogenetic investigations of the TCR and related genes and lend important insights into both the origins and functions of these unique gene systems.
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Affiliation(s)
- J P Rast
- University of South Florida, All Children's Hospital, St. Petersburg 33701, USA
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28
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de la Morena M, Haire RN, Ohta Y, Nelson RP, Litman RT, Day NK, Good RA, Litman GW. Predominance of sterile immunoglobulin transcripts in a female phenotypically resembling Bruton's agammaglobulinemia. Eur J Immunol 1995; 25:809-15. [PMID: 7705412 DOI: 10.1002/eji.1830250327] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The transcription pattern of the heavy chain immunoglobulin gene locus was analyzed in a 6-month-old female with agammaglobulinemia characterized by the absence of mature B cells in peripheral blood, arrested B cell development in the bone marrow and lack of germinal center development. DNA sequencing provided no evidence of mutations within the coding region of the Bruton's tyrosine kinase gene. Polymerase chain reaction-generated cDNA libraries from blood and bone marrow were screened initially using JH and CH oligodeoxynucleotide probes and VH family-specific probes. Only 10% of the transcripts constituted mature VDJC mu recombinations. Ninety percent of the cDNA were sterile immunoglobulin transcripts comprised of: DJC mu (DH-JHC mu), JC mu (JH-C mu), EC mu (enhancer spliced to C mu), SC mu and IC mu [corresponding to switch (S) and intron (I) regions spliced to C mu]. In the mature immunoglobulin transcripts, VH use indicated germline expression with little evidence of somatic mutation. All cDNA were of the C mu type. Different D segments, D-D joining events and unknown D-like elements were noted in the DJC mu and VDJC mu transcripts. This pattern of immunoglobulin rearrangements, along with the phenotypic cell surface antigen characteristics (CD19-), suggest that an earlier arrest in B cell development than is characteristic of Bruton's X-linked agammaglobulinemia has occurred in this patient.
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Affiliation(s)
- M de la Morena
- Department of Pediatrics, University of South Florida, All Children's Hospital, St. Petersburg 33701, USA
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29
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Ohta Y, Haire RN, Litman RT, Fu SM, Nelson RP, Kratz J, Kornfeld SJ, de la Morena M, Good RA, Litman GW. Genomic organization and structure of Bruton agammaglobulinemia tyrosine kinase: localization of mutations associated with varied clinical presentations and course in X chromosome-linked agammaglobulinemia. Proc Natl Acad Sci U S A 1994; 91:9062-6. [PMID: 8090769 PMCID: PMC44747 DOI: 10.1073/pnas.91.19.9062] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
X chromosome-linked agammaglobulinemia is a life-threatening disease that involves a failure in normal development of B lymphocytes and is associated with missense mutations in BTK, a gene encoding a cytoplasmic tyrosine kinase (Bruton agammaglobulinemia tyrosine kinase, EC 2.7.1.112), a member of the Tec family of protein-tyrosine kinases. The genomic organization has been determined by using conventional restriction fragment mapping, extended DNA sequencing, and PCR fragment-sizing approaches. The DNA sequences of the 18 coding exons composing BTK and their flanking-region sequences are reported; an additional exon(s) encodes a 5' untranslated segment. Single-base-pair substitutions and 4-nt deletions resulted in amino acid replacement, premature termination, frameshift, and exon deletion in a group of X chromosome-linked agammaglobulinemia patients exhibiting different clinical presentations and courses. The nature of the mutations is interpreted in terms of the genomic organization of the BTK gene and the disease course in individual patients. Several examples are found in which the same mutation occurs in unrelated patients, and one of these mutations occurs at the same codon that is substituted in the murine form of BTK, resulting in X chromosome-linked immunodeficiency disease. Considerable variation in presentation and disease course in X chromosome-linked agammaglobulinemia appears associated with the nature and position of different missense mutations.
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Affiliation(s)
- Y Ohta
- Department of Pediatrics, University of South Florida College of Medicine, All Children's Hospital, St. Petersburg 33701
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Rast JP, Anderson MK, Ota T, Litman RT, Margittai M, Shamblott MJ, Litman GW. Immunoglobulin light chain class multiplicity and alternative organizational forms in early vertebrate phylogeny. Immunogenetics 1994; 40:83-99. [PMID: 8026868 DOI: 10.1007/bf00188170] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The prototypic chondrichthyan immunoglobulin (Ig) light chain type (type I) isolated from Heterodontus francisci (horned shark) has a clustered organization in which variable (V), joining (J), and constant (C) elements are in relatively close linkage (V-J-C). Using a polymerase chain reaction-based approach on a light chain peptide sequence from the holocephalan, Hydrolagus colliei (spotted ratfish), it was possible to isolate members of a second light chain gene family. A probe to this light chain (type II) detects homologs in two orders of elasmobranchs, Heterodontus, a galeomorph and Raja erinacea (little skate), a batoid, suggesting that this light chain type may be present throughout the cartilaginous fishes. In all cases, V, J, and C regions of the type II gene are arranged in closely linked clusters typical of all known Ig genes in cartilaginous fishes. All representatives of this type II gene family are joined in the germline. A third (kappa-like) light chain type from Heterodontus is described. These findings establish that a degree of light chain class complexity comparable to that of the mammals is present in the most phylogenetically distant extant jawed vertebrates and that the phenomenon of germline-joined (pre-rearranged) genes, described originally in the heavy chain genes of cartilaginous fishes, extends to light chain genes.
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Affiliation(s)
- J P Rast
- University of South Florida, All Children's Hospital, St. Petersburg 33701
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Hinds-Frey KR, Nishikata H, Litman RT, Litman GW. Somatic variation precedes extensive diversification of germline sequences and combinatorial joining in the evolution of immunoglobulin heavy chain diversity. J Exp Med 1993; 178:815-24. [PMID: 8350055 PMCID: PMC2191167 DOI: 10.1084/jem.178.3.815] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In Heterodontus, a phylogenetically primitive shark species, the variable (VH), diversity (DH), joining (JH) segments, and constant (CH) exons are organized in individual approximately 18-20-kb "clusters." A single large VH family with > 90% nucleic acid homology and a monotypic second gene family are identified by extensive screening of a genomic DNA library. Little variation in the nucleotide sequences of DH segments from different germline gene clusters is evident, suggesting that the early role for DH was in promoting junctional diversity rather than contributing unique coding specificities. A gene-specific oligodeoxynucleotide screening method was used to relate specific transcription products (cDNAs) to individual gene clusters and showed that gene rearrangements are intra- rather than intercluster. This provides further evidence for restricted diversity in the immunoglobulin heavy chain of Heterodontus, from which it is inferred that combinatorial diversity is a more recently acquired means for generating diversity. The observed differences between cDNA sequences selected and the sequences of segmental elements derived from conventional genomic libraries as well as from VH segment-specific libraries generated by direct PCR amplification of genomic DNA indicate that the VH repertoire is diversified by both junctional diversity and somatic mutation. Taken together, these findings suggest a heretofore unrecognized contribution of somatic variation that preceded both extensive diversification of the germline repertoire and the combinatorial joining process in the evolution of humoral immunity.
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Affiliation(s)
- K R Hinds-Frey
- Department of Pediatrics, University of South Florida, All Children's Hospital, St. Petersburg, Florida 33701
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Haire RN, Buell RD, Litman RT, Ohta Y, Fu SM, Honjo T, Matsuda F, de la Morena M, Carro J, Good RA. Diversification, not use, of the immunoglobulin VH gene repertoire is restricted in DiGeorge syndrome. J Exp Med 1993; 178:825-34. [PMID: 8350056 PMCID: PMC2191178 DOI: 10.1084/jem.178.3.825] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Immunoglobulin (Ig) genes were isolated from unamplified conventional as well as polymerase chain reaction-generated cDNA libraries constructed from the peripheral blood cells of a patient with complete DiGeorge syndrome. Comparison of the sequences of 36 heavy chain clones to the recently expanded database of human VH genes permitted identification of the germline VH genes that are expressed in this patient as well as placement of 19 of these genes in a partially resolved 0.8-mb region of the human VH locus. The pattern of VH gene use does not resemble the fetal (early) repertoire. However, as in the fetal repertoire, there are a number of cDNAs derived from germline genes that previously have been identified as autoantibodies. Two D mu sequences also were identified, as was another sequence resulting from a unique recombination event linking JH to an unidentified sequence containing a recombination signal sequence-like heptamer. All of the DiGeorge cDNAs are closely related to germline VH genes, showing little or no evidence of somatic mutation. In contrast, comparably selected IgM VH sequences derived from normal adult and age-matched human libraries, and from a second DiGeorge syndrome patient in whom the degree of thymic dysfunction is much less severe, exhibit considerable evidence of somatic mutation. The absence of somatic mutation is consistent with the atypical development of functional antibody responses associated with complete DiGeorge syndrome and implicates a role for T cells in the generation of diversity within the B cell repertoire.
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Affiliation(s)
- R N Haire
- Department of Pediatrics, University of South Florida, All Children's Hospital, St. Petersburg 33701
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Amemiya CT, Ohta Y, Litman RT, Rast JP, Haire RN, Litman GW. VH gene organization in a relict species, the coelacanth Latimeria chalumnae: evolutionary implications. Proc Natl Acad Sci U S A 1993; 90:6661-5. [PMID: 8341683 PMCID: PMC46992 DOI: 10.1073/pnas.90.14.6661] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The living coelacanth Latimeria chalumnae is a relict species whose higher-level phylogenetic relationships have not been resolved clearly by traditional systematic approaches. Previous studies show that major differences in immunoglobulin gene structure and organization typify different phylogenetic lineages. To date, mammalian-, avian-, and elasmobranch-type gene organizations have been identified in representatives of these different phylads. A fourth form or organization is found in Latimeria, which possesses immunoglobulin heavy-chain variable region (VH) elements separated by approximately 190 nucleotides from diversity (D) elements. Adjacency of VH and D elements is characteristic of the elasmobranch "clustered" arrangement, although many other features of coelacanth VH gene organization and structure are more similar to those of bony fishes and tetrapods. These observations strongly support a phylogenetic hypothesis in which Latimeria occupies a sister-group relationship with teleosts and tetrapods.
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Affiliation(s)
- C T Amemiya
- University of South Florida, All Children's Hospital, St. Petersburg 33701
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Litman GW, Rast JP, Shamblott MJ, Haire RN, Hulst M, Roess W, Litman RT, Hinds-Frey KR, Zilch A, Amemiya CT. Phylogenetic diversification of immunoglobulin genes and the antibody repertoire. Mol Biol Evol 1993; 10:60-72. [PMID: 8450761 DOI: 10.1093/oxfordjournals.molbev.a040000] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Immunoglobulins are encoded by a large multigene system that undergoes somatic rearrangement and additional genetic change during the development of immunoglobulin-producing cells. Inducible antibody and antibody-like responses are found in all vertebrates. However, immunoglobulin possessing disulfide-bonded heavy and light chains and domain-type organization has been described only in representatives of the jawed vertebrates. High degrees of nucleotide and predicted amino acid sequence identity are evident when the segmental elements that constitute the immunoglobulin gene loci in phylogenetically divergent vertebrates are compared. However, the organization of gene loci and the manner in which the independent elements recombine (and diversify) vary markedly among different taxa. One striking pattern of gene organization is the "cluster type" that appears to be restricted to the chondrichthyes (cartilaginous fishes) and limits segmental rearrangement to closely linked elements. This type of gene organization is associated with both heavy- and light-chain gene loci. In some cases, the clusters are "joined" or "partially joined" in the germ line, in effect predetermining or partially predetermining, respectively, the encoded specificities (the assumption being that these are expressed) of the individual loci. By relating the sequences of transcribed gene products to their respective germ-line genes, it is evident that, in some cases, joined-type genes are expressed. This raises a question about the existence and/or nature of allelic exclusion in these species. The extensive variation in gene organization found throughout the vertebrate species may relate directly to the role of intersegmental (V<==>D<==>J) distances in the commitment of the individual antibody-producing cell to a particular genetic specificity. Thus, the evolution of this locus, perhaps more so than that of others, may reflect the interrelationships between genetic organization and function.
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Affiliation(s)
- G W Litman
- Department of Pediatrics, University of South Florida
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Haire RN, Ohta Y, Litman RT, Amemiya CT, Litman GW. The genomic organization of immunoglobulin VH genes in Xenopus laevis shows evidence for interspersion of families. Nucleic Acids Res 1991; 19:3061-6. [PMID: 1905399 PMCID: PMC328271 DOI: 10.1093/nar/19.11.3061] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The complete genomic sequences of Xenopus laevis immunoglobulin heavy chain variable region (VH) genes comprising families IV-XI are reported. Using VH family-specific probes, linkage relationships for Xenopus VHI-VHXI have been determined. With the possible exceptions of VHIII and VHVII, Xenopus VH genes appear to be interspersed. When from two to five VH segments are identified in individual clones, the elements are found to be in the same relative transcriptional orientation. Although the relationships of promoter sequences, including the regulatory octamer, resemble those seen in other vertebrate VH genes, several Xenopus VH families are associated with additional 5' octamer sequences and octamer-like motifs. The similarities between the genomic organization of VH genes in Xenopus and higher vertebrates, indicate an early phylogenetic emergence of the mammalian-type of gene organization and regulation.
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Affiliation(s)
- R N Haire
- University of South Florida, Department of Pediatrics, All Children's Hospital, St Petersburg 33701
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Litman GW, Amemiya CT, Harding FA, Haire RN, Hinds KR, Litman RT, Ohta Y, Shamblott MJ, Varner JA. Evolutionary development of immunoglobulin gene diversity. Adv Exp Med Biol 1991; 292:11-7. [PMID: 1950762 DOI: 10.1007/978-1-4684-5943-2_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- G W Litman
- Tampa Bay Research Institute St. Petersburg, Florida
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Harding FA, Amemiya CT, Litman RT, Cohen N, Litman GW. Two distinct immunoglobulin heavy chain isotypes in a primitive, cartilaginous fish, Raja erinacea. Nucleic Acids Res 1990; 18:6369-76. [PMID: 2123029 PMCID: PMC332511 DOI: 10.1093/nar/18.21.6369] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Immunoglobulin heavy chain genes in Raja erinacea (little skate) are organized in clusters consisting of VH, DH, JH segments and CH exons (1). An immunoglobulin heavy chain mu-like isotype that exhibits 61-91% nucleotide sequence identity in coding segments to the Heterodontus francisci (horned shark) mu-type immunoglobulin is described. The overall length of the mu-type clusters is approximately 16 kb; transmembrane exons (TM1 and TM2) are located 3 to CH exon 4 (CH4). In three of four TM-containing genomic clones, a significant deletion is present in TM1. A second isotype of Raja immunoglobulin heavy chain genes has been detected by screening a spleen cDNA library with homologous Raja VH- and CH1-specific probes complementing the respective regions of the mu-like isotype. Weak hybridization with VH-specific probes and no discernable hybridization with C mu-specific probes were considered presumptive evidence for a second immunoglobulin isotype that nominally is designated as X-type. The Vx region of the X-type cDNA is approximately 60% identical at the nucleotide (nt) level to other Raja VH segments and thus represents a second VH family. Putative Dx and Jx sequences also have been identified. The constant region of the X-type immunoglobulin heavy chain gene consists of two characteristic immunoglobulin domains and a cysteine-rich carboxy terminal segment that are only partially homologous with the mu-like isotype. Genomic Southern blotting indicates that the V and C segments of both immunoglobulin heavy chain isotypes are encoded by complex multigene families. Vx- and different Cx-specific probes hybridize to different length transcripts in northern blot analyses of Raja spleen RNA suggesting that the regulation of expression of the X-type genes may involve differential RNA processing.
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Affiliation(s)
- F A Harding
- Tampa Bay Research Institute, St Petersburg, FL 33716
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Litman GW, Litman RT, Henry CJ. Analysis of lipophilic carcinogen-membrane interactions using a model human erythrocyte membrane system. Cancer Res 1976; 36:438-44. [PMID: 816460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Human erythrocytes have been used as a model for evaluating the chemical carcinogen-plasma membrane interaction. The carcinogenic aromatic amines 2-acetylaminofluorene, dimethylaminoazobenzene, and 3'-methyldimethylaminoazobene stabilize erythrocytes against lysis in hypotonic solution. In general, the stabilization potential of these compounds reflects their oil:water partition coefficients and may be related to both their extracellular distribution and ultimate capacity for penetration of target cells. The polycyclic aromatic hydrocarbons, 3-methylcholanthrene and benz[a]anthracene, confer little protection against hemolysis and simultaneous incubation of nonprotective 3-methylcholanthrene and protective 3'-methyldimethylaminoazobenzene slightly alters the stabilization afforded by the latter. 7,12-dimethylbenz[a]anthracene exhibits greater protective capacity than does benz[a]anthracene. Polycyclic aromatic hydrocarbons manifested considerably higher degrees of absolute binding to erythrocytes in isotonic solution than did aromatic amines. The difference in erythrocyte binding and stabilization exhibited by the 2 classes of carcinogens suggest distinct mechanisms of membrane association that may relate to their metabolic disposition.
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Litman GW, Litman RT, Merz DC. Analysis of polypeptide disposition in human erythrocyte membranes employing membrane inversion. Biochim Biophys Acta 1975; 394:348-60. [PMID: 236786 DOI: 10.1016/0005-2736(75)90289-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
High resolution segregation of erythrocyte membrane polypeptides achieved by isoelectric focusing in 8 M urea was employed in conjunction with surface-restricted radioiodination to analyze the disposition of polypeptides within the human erythrocyte membrane. Several membrane polypeptides showed significant uptake of radioiodine, with the principal labeled component migrating between pH values of 3.0 and 3.5. Two approaches were taken in examining membrane polypeptide disposition on both faces of the erythrocyte membrane. Saturation labeling of the outer face of the membrane with one iodine isotope followed by cell lysis and reiodination with a second iodine isotope did not prove feasible and another procedure based on surface iodination with 125-I, formation of sealed inside-out vesicles and re-iodination with 131-I was adopted. Studies of sialic acid release from the membrane surface and trypsin cleavage of radioiodinated peptides indicated that selectively labeled, sealed inside-out vesicles had been formed. The ratio of 125-I to 131-I in membrane polypeptides separated by isoelectric focusing confirmed the existence of externally disposed, internally disposed and spanning proteins.
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Litman GW, Litman RT. Interaction of chemical carcinogens with plasma membranes: the effect of dimethylaminoazobenzene on erythrocyte osmotic fragility. Biochem Biophys Res Commun 1974; 60:865-71. [PMID: 4214279 DOI: 10.1016/0006-291x(74)90321-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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