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Li Y, Xu W, Wang Y, Kou J, Zhang J, Hu S, Zhang L, Wang J, Liu J, Liu H, Luo L, Wang C, Lan J, Hou R, Shen F. An improved, chromosome-level genome of the giant panda (Ailuropoda melanoleuca). Genomics 2022; 114:110501. [PMID: 36270383 DOI: 10.1016/j.ygeno.2022.110501] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 09/21/2022] [Accepted: 10/04/2022] [Indexed: 01/14/2023]
Abstract
BACKGROUND The iconic giant panda (Ailuropoda melanoleuca), as both a flagship and umbrella species endemic to China, is a world famous symbol for wildlife conservation. The giant panda has several specific biological traits and holds a relatively small place in evolution. A high-quality genome of the giant panda is key to understanding the biology of this vulnerable species. FINDINGS We generated a 2.48-Gb chromosome-level genome (GPv1) of the giant panda named "Jing Jing" with a contig N50 of 28.56 Mb and scaffold N50 of 134.17 Mb, respectively. The total length of chromosomes (n = 21) was 2.39-Gb, accounting for 96.4% of the whole genome. Compared with the previously published four genomes of the giant panda, our genome is characterized by the highest completeness and the correct sequence orientation. A gap-free and 850 kb length of immunoglobulin heavy-chain gene cluster was manually annotated in close proximity to the telomere of chromosome 14. Additionally, we developed an algorithm to predict the centromere position of each chromosome. We also constructed a complete chromatin structure for "Jing Jing", which includes inter-chromosome interaction pattern, A/B compartment, topologically associated domain (TAD), TAD-clique and promoter-enhancer interaction (PEI). CONCLUSIONS We presented an improved chromosome-level genome and complete chromatin structure for the giant panda. This is a valuable resource for the future genetic and genomic studies on giant panda.
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Affiliation(s)
- Yan Li
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Wei Xu
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Ye Wang
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Jie Kou
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Jiaman Zhang
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, China
| | - Silu Hu
- Institute of Animal Genetics and Breeding, College of Animal Science and Technology, Sichuan Agricultural University, China
| | - Liang Zhang
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Juan Wang
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Jiawen Liu
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Hong Liu
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Li Luo
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Chengdong Wang
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Jingchao Lan
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China
| | - Rong Hou
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China.
| | - Fujun Shen
- Chengdu Research Base of Giant Panda Breeding, China; Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, China.
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Huttener R, Thorrez L, Veld TI, Potter B, Baele G, Granvik M, Van Lommel L, Schuit F. Regional effect on the molecular clock rate of protein evolution in Eutherian and Metatherian genomes. BMC Ecol Evol 2021; 21:153. [PMID: 34348656 PMCID: PMC8336415 DOI: 10.1186/s12862-021-01882-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 07/22/2021] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Different types of proteins diverge at vastly different rates. Moreover, the same type of protein has been observed to evolve with different rates in different phylogenetic lineages. In the present study we measured the rates of protein evolution in Eutheria (placental mammals) and Metatheria (marsupials) on a genome-wide basis and we propose that the gene position in the genome landscape has an important influence on the rate of protein divergence. RESULTS We analyzed a protein-encoding gene set (n = 15,727) common to 16 mammals (12 Eutheria and 4 Metatheria). Using sliding windows that averaged regional effects of protein divergence we constructed landscapes in which strong and lineage-specific regional effects were seen on the molecular clock rate of protein divergence. Within each lineage, the relatively high rates were preferentially found in subtelomeric chromosomal regions. Such regions were observed to contain important and well-studied loci for fetal growth, uterine function and the generation of diversity in the adaptive repertoire of immunoglobulins. CONCLUSIONS A genome landscape approach visualizes lineage-specific regional differences between Eutherian and Metatherian rates of protein evolution. This phenomenon of chromosomal position is a new element that explains at least part of the lineage-specific effects and differences between proteins on the molecular clock rates.
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Affiliation(s)
- Raf Huttener
- Gene Expression Unit, Dept. of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, O&N1, Bus 901, 3000, Leuven, Belgium
| | - Lieven Thorrez
- Tissue Engineering Laboratory, Department of Development and Regeneration, KU Leuven, Kortrijk, Belgium
| | - Thomas In't Veld
- Gene Expression Unit, Dept. of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, O&N1, Bus 901, 3000, Leuven, Belgium
| | - Barney Potter
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Leuven, Belgium
| | - Guy Baele
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, Leuven, Belgium
| | - Mikaela Granvik
- Gene Expression Unit, Dept. of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, O&N1, Bus 901, 3000, Leuven, Belgium
| | - Leentje Van Lommel
- Gene Expression Unit, Dept. of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, O&N1, Bus 901, 3000, Leuven, Belgium
| | - Frans Schuit
- Gene Expression Unit, Dept. of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, O&N1, Bus 901, 3000, Leuven, Belgium.
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Coevolution of Mucosal Immunoglobulins and the Polymeric Immunoglobulin Receptor: Evidence That the Commensal Microbiota Provided the Driving Force. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/541537] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Immunoglobulins (Igs) in mucosal secretions contribute to immune homeostasis by limiting access of microbial and environmental antigens to the body proper, maintaining the integrity of the epithelial barrier and shaping the composition of the commensal microbiota. The emergence of IgM in cartilaginous fish represented the primordial mucosal Ig, which is expressed in all higher vertebrates. Expansion and diversification of the mucosal Ig repertoire led to the emergence of IgT in bony fishes, IgX in amphibians, and IgA in reptiles, birds, and mammals. Parallel evolution of cellular receptors for the constant (Fc) regions of Igs provided mechanisms for their transport and immune effector functions. The most ancient of these Fc receptors is the polymeric Ig receptor (pIgR), which first appeared in an ancestor of bony fishes. The pIgR transports polymeric IgM, IgT, IgX, and IgA across epithelial cells into external secretions. Diversification and refinement of the structure of mucosal Igs during tetrapod evolution were paralleled by structural changes in pIgR, culminating in the multifunctional secretory IgA complex in mammals. In this paper, evidence is presented that the mutualistic relationship between the commensal microbiota and the vertebrate host provided the driving force for coevolution of mucosal Igs and pIgR.
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Das S, Hirano M, Tako R, McCallister C, Nikolaidis N. Evolutionary genomics of immunoglobulin-encoding Loci in vertebrates. Curr Genomics 2012; 13:95-102. [PMID: 23024601 PMCID: PMC3308330 DOI: 10.2174/138920212799860652] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 12/13/2011] [Accepted: 01/14/2012] [Indexed: 11/22/2022] Open
Abstract
Immunoglobulins (or antibodies) are an essential element of the jawed vertebrate adaptive immune response system. These molecules have evolved over the past 500 million years and generated highly specialized proteins that recognize an extraordinarily large number of diverse substances, collectively known as antigens. During vertebrate evolution the diversification of the immunoglobulin-encoding loci resulted in differences in the genomic organization, gene content, and ratio of functional genes and pseudogenes. The tinkering process in the immunoglobulin-encoding loci often gave rise to lineage-specific characteristics that were formed by selection to increase species adaptation and fitness. Immunoglobulin loci and their encoded antibodies have been shaped repeatedly by contrasting evolutionary forces, either to conserve the prototypic structure and mechanism of action or to generate alternative and diversified structures and modes of function. Moreover, evolution favored the development of multiple mechanisms of primary and secondary antibody diversification, which are used by different species to effectively generate an almost infinite collection of diverse antibody types. This review summarizes our current knowledge on the genomics and evolution of the immunoglobulin-encoding loci and their protein products in jawed vertebrates.
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Affiliation(s)
- Sabyasachi Das
- Department of Pathology and Laboratory Medicine, Emory Vaccine Center, School of Medicine, Emory University, USA
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Ukaji T, Kai O. Isotype analysis of gerbil-mouse heterohybridomas by RT-PCR. J Immunol Methods 2012; 386:108-11. [PMID: 22974835 DOI: 10.1016/j.jim.2012.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 08/31/2012] [Accepted: 09/04/2012] [Indexed: 11/19/2022]
Abstract
We designed primer sets specific to the immunoglobulin (Ig) heavy-chain constant region (IGHC) genes in Mongolian gerbil (Meriones unguiculatus) to amplify five gerbil IGHC cDNA sequences, Cμ, Cγ1, Cγ2, Cε, and Cα. Five gerbil-mouse heterohybridomas B11D2(C2), B11E2(D5).M, B5-3, D5, and C11 respectively expressed Cγ1, Cμ, Cγ2, Cγ2, and Cγ1. In contrast, a commercial isotyping kit for mouse Igs identified Cγ1, Cμ, Cγ3, Cγ3, and Cγ1, respectively, misidentifying gerbil IgG2 as IgG3 by cross-reactivity with anti-mouse IgG3 polyclonal antibody. These primer sets will allow the accurate estimation of gerbil Ig classes and IgG subclasses. These results from three gerbil strains indicate that the primer sets can be used for isotype analysis of gerbil mAbs and for evaluation of humoral immunity.
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Affiliation(s)
- Takao Ukaji
- Department of Animal Science and Resources, College of Bioresource Sciences, Nihon University, Kameino 1866, Fujisawa 252-0880, Japan
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Wang T, Sun Y, Shao W, Cheng G, Li L, Cao Z, Yang Z, Zou H, Zhang W, Han B, Hu Y, Ren L, Hu X, Guo Y, Fei J, Hammarström L, Li N, Zhao Y. Evidence of IgY subclass diversification in snakes: evolutionary implications. THE JOURNAL OF IMMUNOLOGY 2012; 189:3557-65. [PMID: 22933626 DOI: 10.4049/jimmunol.1200212] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mammalian IgG and IgE are thought to have evolved from IgY of nonmammalian tetrapods; however, no diversification of IgY subclasses has been reported in reptiles or birds, which are phylogenetically close to mammals. To our knowledge, we report the first evidence of the presence of multiple IgY-encoding (υ) genes in snakes. Two υ genes were identified in the snake Elaphe taeniura, and three υ genes were identified in the Burmese python (Python molurus bivittatus). Although four of the υ genes displayed a conventional four-H chain C region exon structure, one of the υ genes in the Burmese python lacked the H chain C region 2 exon, thus exhibiting a structure similar to that of the mammalian γ genes. We developed mouse mAbs specific for the IgY1 and IgY2 of E. taeniura and showed that both were expressed in serum; each had two isoforms: one full-length and one truncated at the C terminus. The truncation was not caused by alternative splicing or transcriptional termination. We also identified the μ and δ genes, but no α gene, in both snakes. This study provides valuable clues for our understanding of Ig gene evolution in tetrapods.
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Affiliation(s)
- Tao Wang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing 100094, People's Republic of China
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Huang T, Zhang M, Wei Z, Wang P, Sun Y, Hu X, Ren L, Meng Q, Zhang R, Guo Y, Hammarstrom L, Li N, Zhao Y. Analysis of immunoglobulin transcripts in the ostrich Struthio camelus, a primitive avian species. PLoS One 2012; 7:e34346. [PMID: 22479606 PMCID: PMC3315531 DOI: 10.1371/journal.pone.0034346] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 02/26/2012] [Indexed: 11/21/2022] Open
Abstract
Previous studies on the immunoglobulin (Ig) genes in avian species are limited (mainly to galliformes and anseriformes) but have revealed several interesting features, including the absence of the IgD and Igκ encoding genes, inversion of the IgA encoding gene and the use of gene conversion as the primary mechanism to generate an antibody repertoire. To better understand the Ig genes and their evolutionary development in birds, we analyzed the Ig genes in the ostrich (Struthio camelus), which is one of the most primitive birds. Similar to the chicken and duck, the ostrich expressed only three IgH chain isotypes (IgM, IgA and IgY) and λ light chains. The IgM and IgY constant domains are similar to their counterparts described in other vertebrates. Although conventional IgM, IgA and IgY cDNAs were identified in the ostrich, we also detected a transcript encoding a short membrane-bound form of IgA (lacking the last two CH exons) that was undetectable at the protein level. No IgD or κ encoding genes were identified. The presence of a single leader peptide in the expressed heavy chain and light chain V regions indicates that gene conversion also plays a major role in the generation of antibody diversity in the ostrich. Because the ostrich is one of the most primitive living aves, this study suggests that the distinct features of the bird Ig genes appeared very early during the divergence of the avian species and are thus shared by most, if not all, avian species.
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Affiliation(s)
- Tian Huang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
| | - Min Zhang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
| | - Zhiguo Wei
- College of Animal Science and Technology, Henan University of Science and Technology, Henan, People's Republic of China
| | - Ping Wang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
| | - Yi Sun
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
| | - Xiaoxiang Hu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
| | - Liming Ren
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
| | - Qingyong Meng
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
| | - Ran Zhang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
| | - Ying Guo
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
| | - Lennart Hammarstrom
- Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Ning Li
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
| | - Yaofeng Zhao
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, People's Republic of China
- Key Laboratory of Animal Reproduction and Germplasm Enhancement in Universities of Shandong, College of Animal Science and Technology, Qingdao Agricultural University, Qingdao, People's Republic of China
- * E-mail:
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Ramirez-Gomez F, Greene W, Rego K, Hansen JD, Costa G, Kataria P, Bromage ES. Discovery and Characterization of Secretory IgD in Rainbow Trout: Secretory IgD Is Produced through a Novel Splicing Mechanism. THE JOURNAL OF IMMUNOLOGY 2011; 188:1341-9. [DOI: 10.4049/jimmunol.1101938] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Edholm ES, Bengten E, Wilson M. Insights into the function of IgD. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2011; 35:1309-16. [PMID: 21414345 DOI: 10.1016/j.dci.2011.03.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 02/02/2011] [Accepted: 03/06/2011] [Indexed: 05/13/2023]
Abstract
IgD, previously thought to be a recent addition to the immunoglobulin classes, has long been considered an enigmatic molecule. For example, it was debated if IgD had a specific function other than as an antigen receptor co-expressed with IgM on naive B cells and if it had an important role in mammalian immunity. However, during the past decade extensive sequencing of vertebrate genomes has shown that IgD homologs are present in all vertebrate taxa, except for birds. Moreover, recent functional studies indicate that IgD likely performs a unique role in vertebrate immune responses. The goal of this review is to summarize the IgD gene organization and structural data, which demonstrate that IgD has an ancient origin, and discuss the findings in catfish and humans that provide insight into the possible function of this elusive immunoglobulin isotype.
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Affiliation(s)
- Eva-Stina Edholm
- University of Mississippi Medical Center, Jackson, MS 39216, USA
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Sun Y, Wei Z, Hammarstrom L, Zhao Y. The immunoglobulin δ gene in jawed vertebrates: a comparative overview. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2011; 35:975-81. [PMID: 21182859 DOI: 10.1016/j.dci.2010.12.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 12/11/2010] [Accepted: 12/14/2010] [Indexed: 05/13/2023]
Abstract
Immunoglobulin D (IgD) was recently suggested to be an ancient Ig class, as old as IgM, arising approximately 500 million years ago. Its encoding gene has now been identified in nearly all classes of jawed vertebrates (except birds). Variance in the number of CH encoding exons and alternative RNA splicing confers this Ig class a marked structural plasticity, which differs substantially from IgM. Expression of the δ gene can be achieved through co-transcription with the μ gene or by class switching. Although a recent study has suggested that IgD functions as an immunomodulator in immunity and inflammation in humans, its functions are still far from clear. Further studies at the protein levels in additional species may help answer this question.
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Affiliation(s)
- Yi Sun
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, National Engineering Laboratory for Animal Breeding, China Agricultural University, Beijing, PR China
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Guo Y, Bao Y, Wang H, Hu X, Zhao Z, Li N, Zhao Y. A preliminary analysis of the immunoglobulin genes in the African elephant (Loxodonta africana). PLoS One 2011; 6:e16889. [PMID: 21364892 PMCID: PMC3045440 DOI: 10.1371/journal.pone.0016889] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Accepted: 01/06/2011] [Indexed: 11/18/2022] Open
Abstract
The genomic organization of the IgH (Immunoglobulin heavy chain), Igκ (Immunoglobulin kappa chain), and Igλ (Immunoglobulin lambda chain) loci in the African elephant (Loxodonta africana) was annotated using available genome data. The elephant IgH locus on scaffold 57 spans over 2,974 kb, and consists of at least 112 V(H) gene segments, 87 D(H) gene segments (the largest number in mammals examined so far), six J(H) gene segments, a single μ, a δ remnant, and eight γ genes (α and ε genes are missing, most likely due to sequence gaps). The Igκ locus, found on three scaffolds (202, 50 and 86), contains a total of 153 V(κ) gene segments, three J(κ) segments, and a single C(κ) gene. Two different transcriptional orientations were determined for these V(κ) gene segments. In contrast, the Igλ locus on scaffold 68 includes 15 V(λ) gene segments, all with the same transcriptional polarity as the downstream J(λ)-C(λ) cluster. These data suggest that the elephant immunoglobulin gene repertoire is highly diverse and complex. Our results provide insights into the immunoglobulin genes in a placental mammal that is evolutionarily distant from humans, mice, and domestic animals.
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Affiliation(s)
- Yongchen Guo
- State Key Laboratory of AgroBiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Yonghua Bao
- Department of Basic Immunology, Xinxiang Medical University, Xinxiang, People's Republic of China
- * E-mail: (YZ); (YB)
| | - Hui Wang
- Department of Basic Immunology, Xinxiang Medical University, Xinxiang, People's Republic of China
| | - Xiaoxiang Hu
- State Key Laboratory of AgroBiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Zhihui Zhao
- Agricultural Division, College of Animal Science and Veterinary Medicine, Jilin University, Changchun, People's Republic of China
| | - Ning Li
- State Key Laboratory of AgroBiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
| | - Yaofeng Zhao
- State Key Laboratory of AgroBiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China
- College of Animal Science and Technology, Qingdao Agricultural University, Qingdao, People's Republic of China
- * E-mail: (YZ); (YB)
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Das S, Hirano M, McCallister C, Tako R, Nikolaidis N. Comparative genomics and evolution of immunoglobulin-encoding loci in tetrapods. Adv Immunol 2011; 111:143-78. [PMID: 21970954 DOI: 10.1016/b978-0-12-385991-4.00004-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The immunoglobulins (Igs or antibodies) as an integral part of the tetrapod adaptive immune response system have evolved toward producing highly diversified molecules that recognize a remarkably large number of different antigens. Antibodies and their respective encoding loci have been shaped by different and often contrasting evolutionary forces, some of which aim to conserve an established pattern or mechanism and others to generate alternative and diversified structural and functional configurations. The genomic organization, gene content, ratio between functional genes and pseudogenes, number and position of recombining genetic elements, and the different levels of divergence present at the germline of the Ig-encoding loci have been evolutionarily shaped and optimized in a lineage- and, in some cases, species-specific mode aiming to increase organismal fitness. Further, evolution favored the development of multiple mechanisms of primary and secondary antibody diversification, such as V(D)J recombination, class switch recombination, isotype exclusion, somatic hypermutation, and gene conversion. Diverse tetrapod species, based on their specific germline configurations, use these mechanisms in several different combinations to effectively generate a vast array of distinct antibody types and structures. This chapter summarizes our current knowledge on the Ig-encoding loci in tetrapods and discusses the different evolutionary mechanisms that shaped their diversification.
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Affiliation(s)
- Sabyasachi Das
- Department of Pathology and Laboratory Medicine, Emory Vaccine Center, School of Medicine, Emory University, Atlanta, Georgia, USA
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Wei Z, Wu Q, Ren L, Hu X, Guo Y, Warr GW, Hammarström L, Li N, Zhao Y. Expression of IgM, IgD, and IgY in a reptile, Anolis carolinensis. THE JOURNAL OF IMMUNOLOGY 2009; 183:3858-64. [PMID: 19717516 DOI: 10.4049/jimmunol.0803251] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The reptiles are the last major group of jawed vertebrates in which the organization of the IGH locus and its encoded Ig H chain isotypes have not been well characterized. In this study, we show that the green anole lizard (Anolis carolinensis) expresses three Ig H chain isotypes (IgM, IgD, and IgY) but no IgA. The presence of the delta gene in the lizard demonstrates an evolutionary continuity of IgD from fishes to mammals. Although the germline delta gene contains 11 C(H) exons, only the first 4 are used in the expressed IgD membrane-bound form. The mu chain lacks the cysteine in C(H)1 that forms a disulfide bond between H and L chains, suggesting that (as in IgM of some amphibians) the H and L polypeptide chains are not covalently associated. Although conventional IgM transcripts (four C(H) domains) encoding both secreted and membrane-bound forms were detected, alternatively spliced transcripts encoding a short membrane-bound form were also observed and shown to lack the first two C(H) domains (VDJ-C(H)3-C(H)4-transmembrane region). Similar to duck IgY, lizard IgY H chain (upsilon) transcripts encoding both full-length and truncated (IgYDeltaFc) forms (with two C(H) domains) were observed. The absence of an IgA-encoding gene in the lizard IGH locus suggests a complex evolutionary history for IgA in the saurian lineage leading to modern birds, lizards, and their relatives.
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Affiliation(s)
- Zhiguo Wei
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, Peoples Republic of China
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Zhao Y, Cui H, Whittington CM, Wei Z, Zhang X, Zhang Z, Yu L, Ren L, Hu X, Zhang Y, Hellman L, Belov K, Li N, Hammarström L. Ornithorhynchus anatinus (platypus) links the evolution of immunoglobulin genes in eutherian mammals and nonmammalian tetrapods. THE JOURNAL OF IMMUNOLOGY 2009; 183:3285-93. [PMID: 19675164 DOI: 10.4049/jimmunol.0900469] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The evolutionary origins of mammalian immunoglobulin H chain isotypes (IgM, IgD, IgG, IgE, and IgA) are still incompletely understood as these isotypes differ considerably in structure and number from their counterparts in nonmammalian tetrapods. We report in this study that the platypus (Ornithorhynchus anatinus) Ig H chain constant region gene locus contains eight Ig encoding genes, which are arranged in an mu-delta-omicron-gamma2-gamma1-alpha1-epsilon-alpha2 order, spanning a total of approximately 200 kb DNA, encoding six distinct isotypes. The omicron (omicron for Ornithorhynchus) gene encodes a novel Ig H chain isotype that consists of four constant region domains and a hinge, and is structurally different from any of the five known mammalian Ig classes. This gene is phylogenetically related to upsilon (epsilon) and gamma, and thus appears to be a structural intermediate between these two genes. The platypus delta gene encodes ten heavy chain constant region domains, lacks a hinge region and is similar to IgD in amphibians and fish, but strikingly different from that in eutherian mammals. The platypus Ig H chain isotype repertoire thus shows a unique combination of genes that share similarity both to those of nonmammalian tetrapods and eutherian animals and demonstrates how phylogenetically informative species can be used to reconstruct the evolutionary history of functionally important genes.
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Affiliation(s)
- Yaofeng Zhao
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, People's Republic of China.
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