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Eslami Rasekh M, Hernández Y, Drinan SD, Fuxman Bass J, Benson G. Genome-wide characterization of human minisatellite VNTRs: population-specific alleles and gene expression differences. Nucleic Acids Res 2021; 49:4308-4324. [PMID: 33849068 PMCID: PMC8096271 DOI: 10.1093/nar/gkab224] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 03/06/2021] [Accepted: 03/18/2021] [Indexed: 11/12/2022] Open
Abstract
Variable Number Tandem Repeats (VNTRs) are tandem repeat (TR) loci that vary in copy number across a population. Using our program, VNTRseek, we analyzed human whole genome sequencing datasets from 2770 individuals in order to detect minisatellite VNTRs, i.e., those with pattern sizes ≥7 bp. We detected 35 638 VNTR loci and classified 5676 as commonly polymorphic (i.e. with non-reference alleles occurring in >5% of the population). Commonly polymorphic VNTR loci were found to be enriched in genomic regions with regulatory function, i.e. transcription start sites and enhancers. Investigation of the commonly polymorphic VNTRs in the context of population ancestry revealed that 1096 loci contained population-specific alleles and that those could be used to classify individuals into super-populations with near-perfect accuracy. Search for quantitative trait loci (eQTLs), among the VNTRs proximal to genes, indicated that in 187 genes expression differences correlated with VNTR genotype. We validated our predictions in several ways, including experimentally, through the identification of predicted alleles in long reads, and by comparisons showing consistency between sequencing platforms. This study is the most comprehensive analysis of minisatellite VNTRs in the human population to date.
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Affiliation(s)
| | - Yözen Hernández
- Graduate Program in Bioinformatics, Boston University, Boston, MA 02215, USA
| | | | - Juan I Fuxman Bass
- Graduate Program in Bioinformatics, Boston University, Boston, MA 02215, USA
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Gary Benson
- Graduate Program in Bioinformatics, Boston University, Boston, MA 02215, USA
- Department of Biology, Boston University, Boston, MA 02215, USA
- Department of Computer Science, Boston University, Boston, MA 02215, USA
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Hirsch M, Kumru K, Desai RR, Fitzgerald BJ, Miyazawa T, Ray KA, Saif N, Spears S, Keatinge-Clay AT. Insights into modular polyketide synthase loops aided by repetitive sequences. Proteins 2021; 89:1099-1110. [PMID: 33843112 DOI: 10.1002/prot.26083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 02/05/2021] [Accepted: 04/02/2021] [Indexed: 11/08/2022]
Abstract
The loops of modular polyketide synthases (PKSs) serve diverse functions but are largely uncharacterized. They frequently contain amino acid repeats resulting from genetic events such as slipped-strand mispairing. Determining the tolerance of loops to amino acid changes would aid in understanding and engineering these multidomain molecule factories. Here, tandem repeats in the DNA encoding 949 modules within 129 cis-acyltransferase PKSs were cataloged, and the locations of the corresponding amino acids within the module were identified. The most frequently inserted interdomain loop corresponds with the updated module boundary immediately downstream of the ketosynthase (KS), while the loops bordering the dehydratase are nearly intolerant to such insertions. From the 949 modules, no repetitive sequence loop insertions are located within ACP, and only 2 reside within KS, indicating the sensitivity of these domains to alteration.
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Affiliation(s)
- Melissa Hirsch
- Department of Chemistry, The University of Texas at Austin, Austin, Texas, USA
| | - Kaan Kumru
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Ronak R Desai
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Brendan J Fitzgerald
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Takeshi Miyazawa
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Katherine A Ray
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Nisha Saif
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Samantha Spears
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Adrian T Keatinge-Clay
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
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Insights into the molecular diversity of Plasmodium vivax merozoite surface protein-3γ (pvmsp3γ), a polymorphic member in the msp3 multi-gene family. Sci Rep 2020; 10:10977. [PMID: 32620822 PMCID: PMC7335089 DOI: 10.1038/s41598-020-67222-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 06/02/2020] [Indexed: 12/17/2022] Open
Abstract
Plasmodium vivax merozoite surface protein 3 (PvMSP3) is encoded by a multi-gene family. Of these, PvMSP3α, PvMSP3β and PvMSP3γ, are considered to be vaccine targets. Despite comprehensive analyses of PvMSP3α and PvMSP3β, little is known about structural and sequence diversity in PvMSP3γ. Analysis of 118 complete pvmsp3γ sequences from diverse endemic areas of Thailand and 9 reported sequences has shown 86 distinct haplotypes. Based on variation in insert domains, pvmsp3γ can be classified into 3 types, i.e. Belem, Salvador I and NR520. Imperfect nucleotide repeats were found in six regions of the gene; none encoded tandem amino acid repeats. Predicted coiled-coil heptad repeats were abundant in the protein and displayed variation in length and location. Interspersed phase shifts occurred in the heptad arrays that may have an impact on protein structure. Polymorphism in pvmsp3γ seems to be generated by intragenic recombination and driven by natural selection. Most P. vivax isolates in Thailand exhibit population structure, suggesting limited gene flow across endemic areas. Phylogenetic analysis has suggested that insert domains could have been subsequently acquired during the evolution of pvmsp3γ. Sequence and structural diversity of PvMSP3γ may complicate vaccine design due to alteration in predicted immunogenic epitopes among variants.
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Ruiz-Romero RA, Cervantes-Olivares RA, Ducoing-Watty AE, Martínez-Gómez D, Díaz-Aparicio E, Méndez-Olvera ET. Genetic Analysis Method for Staphylococcus chromogenes Associated with Goat Mastitis. Pol J Microbiol 2019; 67:171-180. [PMID: 30015455 PMCID: PMC7256767 DOI: 10.21307/pjm-2018-019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2017] [Indexed: 12/25/2022] Open
Abstract
Mastitis in goats is mainly caused by coagulase-negative Staphylococcus (CNS). The identification methods for this group are based on evaluating the expression of phenotypic characteristics such as the ability to metabolize various substrates; however, this is disadvantageous as these methods are dependent on gene expression. In recent years, genotyping methods such as the Multiple Locus Variable-Number Tandem Repeat Analysis (MLVA) and gene identification have been useful for epidemiological study of several bacterial species. To develop a genotyping method, the genome sequence of Staphylococcus chromogenes MU970 was analysed. The analysis showed nine virulence genes described in Staphylococcus aureus. The MLVA was developed using four loci identified in the genome of S. chromogenes MU970. This genotyping method was examined in 23 strains of CNS isolated from goat mastitis. The rate of discrimination for MLVA was 0.8893, and the highest rates of discrimination per the index of Simpson and Hunter-Gaston were 0.926 and 0.968 for the locus 346_06, respectively. The virulence genes were present in all strains of S. chromogenes but not in other CNS. The genotyping method presented in this paper is a viable and easy method for typifying CNS isolates from mastitis cases in different regions and is an ideal mean of tracking this disease.
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Affiliation(s)
- Rocío A Ruiz-Romero
- Departamento de Medicina y Zootecnia de Rumiantes, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México,México
| | - Roberto A Cervantes-Olivares
- Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México,México
| | - Andrés E Ducoing-Watty
- Departamento de Medicina y Zootecnia de Rumiantes, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México,México
| | - Daniel Martínez-Gómez
- Laboratorio de Microbiología Agropecuaria, Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana,México
| | - Efrén Díaz-Aparicio
- Centro Nacional de Investigación Disciplinaria-Microbiología Animal, Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias,México
| | - Estela T Méndez-Olvera
- Laboratorio de Biología Molecular, Departamento de Producción Agrícola y Animal, Universidad Autónoma Metropolitana,México
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The complete organelle genomes of Physochlaina orientalis: Insights into short sequence repeats across seed plant mitochondrial genomes. Mol Phylogenet Evol 2019; 137:274-284. [PMID: 31112782 DOI: 10.1016/j.ympev.2019.05.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/14/2019] [Accepted: 05/17/2019] [Indexed: 11/24/2022]
Abstract
Short repeats (SR) play an important role in shaping seed plant mitochondrial genomes (mtDNAs). However, their origin, distribution, and relationships across the different plant lineages remain unresolved. We focus on the angiosperm family Solanaceae that shows great variation in repeat content and extend the study to a wide diversity of seed plants. We determined the complete nucleotide sequences of the organellar genomes of the medicinal plant Physochlaina orientalis (Solanaceae), member of the tribe Hyoscyameae. To understand the evolution of the P. orientalis mtDNA we made comparisons with those of five other Solanaceae. P. orientalis mtDNA presents the largest mitogenome (∼685 kb in size) among the Solanaceae and has an unprecedented 8-copy repeat family of ∼8.2 kb in length and a great number of SR arranged in tandem-like structures. We found that the SR in the Solanaceae share a common origin, but these only expanded in members of the tribe Hyoscyameae. We discuss a mechanism that could explain SR formation and expansion in P. orientalis and Hyoscyamus niger. Finally, the great increase in plant mitochondrial data allowed us to systematically extend our repeat analysis to a total of 136 seed plants to characterize and analyze for the first time families of SR among seed plant mtDNAs.
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Biological Roles of Protein-Coding Tandem Repeats in the Yeast Candida Albicans. J Fungi (Basel) 2018; 4:jof4030078. [PMID: 29966250 PMCID: PMC6162428 DOI: 10.3390/jof4030078] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 06/16/2018] [Accepted: 06/27/2018] [Indexed: 01/07/2023] Open
Abstract
Tandem repeat (TR) DNA mutates faster than other DNA by insertion and deletion of repeats. Large parts of eukaryotic proteomes are encoded by ORFs containing protein-coding TRs (TR-ORFs, pcTRs) with largely unknown biological consequences. We explored these in the yeast Candida albicans, an opportunistic human pathogen. We found that almost half of C. albicans’ proteins are encoded by TR-ORFs. pcTR frequency differed only moderately between different gene (GO) categories. Bioinformatic predictions of genome-wide mutation rates and clade-specific differences in pcTR allele frequencies indicated that pcTRs (i) significantly increase the genome-wide mutation rate; (ii) significantly impact on fitness and (iii) allow the evolution of selectively advantageous clade-specific protein variants. Synonymous mutations reduced the repetitiveness of many amino acid repeat-encoding pcTRs. A survey, in 58 strains, revealed that in some pcTR regions in which repetitiveness was not significantly diminished by synonymous mutations the habitat predicted which alleles were present, suggesting roles of pcTR mutation in short-term adaptation and pathogenesis. In C. albicans pcTR mutation apparently is an important mechanism for mutational advance and possibly also rapid adaptation, with synonymous mutations providing a mechanism for adjusting mutation rates of individual pcTRs. Analyses of Arabidopsis and human pcTRs showed that the latter also occurs in other eukaryotes.
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Wang X, Liu N, Zhang H, Yang XJ, Huang Y, Lei F. Extreme variation in patterns of tandem repeats in mitochondrial control region of yellow-browed tits (Sylviparus modestus, Paridae). Sci Rep 2015; 5:13227. [PMID: 26288099 PMCID: PMC4541255 DOI: 10.1038/srep13227] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 07/21/2015] [Indexed: 11/09/2022] Open
Abstract
To investigate the evolutionary pattern and origins of tandem repeats in the mitochondrial control region of the yellow-browed tit (Sylviparus modestus), the control region and another four mitochondrial loci from fifteen individuals were analyzed. A 117-bp tandem repeat unit that repeated once, twice or three times in different individuals was found, and a rarely reported arrangement for this tandem repeats region that a 5' imperfect copy at its downstream and a 3' imperfect copy at its upstream was observed. The haplotype network, phylogenetic trees, and ancestral state reconstruction of the combined dataset of five loci suggested multiple origins of the same repeat number. The turnover model via slipped-strand mispairing was introduced to interpret the results, because mispairing occurred so frequently that multiple origins of certain repeat number were observed. Insertion via recombination should be a better explanation for the origin of this tandem repeat unit, considering characteristics of the combined sequence of the 3' and 5' imperfect copy, including identification of its homolog in other passerines and its predicted secondary structure.
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Affiliation(s)
- Xiaoyang Wang
- Co-Innovation Center for Qinba regions' sustainable development, College of Life Sciences, Shaanxi Normal University, No. 199, South Chang'an Road, Xi'an 710062, China
| | - Nian Liu
- Co-Innovation Center for Qinba regions' sustainable development, College of Life Sciences, Shaanxi Normal University, No. 199, South Chang'an Road, Xi'an 710062, China
| | - Hongli Zhang
- College of Life Science, Datong University, Xingyun Street, Datong 037009, China
| | - Xiao-Jun Yang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, No. 32, Jiaochang East Road, Kunming 650223, China
| | - Yuan Huang
- Co-Innovation Center for Qinba regions' sustainable development, College of Life Sciences, Shaanxi Normal University, No. 199, South Chang'an Road, Xi'an 710062, China
| | - Fumin Lei
- 1] Co-Innovation Center for Qinba regions' sustainable development, College of Life Sciences, Shaanxi Normal University, No. 199, South Chang'an Road, Xi'an 710062, China [2] Key Laboratory of the Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China
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Pause-melting misalignment: a novel model for the birth and motif indel of tandem repeats in the mitochondrial genome. BMC Genomics 2013; 14:103. [PMID: 23414101 PMCID: PMC3599147 DOI: 10.1186/1471-2164-14-103] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2012] [Accepted: 02/11/2013] [Indexed: 01/11/2023] Open
Abstract
Background Tandem repeats (TRs) in the mitochondrial (mt) genome control region have been documented in a wide variety of vertebrate species. The mechanism by which repeated tracts originate and undergo duplication and deletion, however, remains unclear. Results We analyzed DNA sequences of mt genome TRs (mtTRs) in the ridged-eye flounder (Pleuronichthys cornutus), and characterized DNA sequences of mtTRs from other vertebrates using the data available in GenBank. Tandem repeats are concentrated in the control regions; however, we found approximately 16.6% of the TRs elsewhere in the mt genome. The flounder mtTRs possess three motif types with hypervariable characteristics at the 3′ end of the control region (CR). Conclusion Based on our analysis of this larger dataset of mtTR sequences, we propose a novel model of Pause Melting Misalignment (PMM) to describe the birth and motif indel of tandem repeats. PMM is activated during a pause event in mitochondrial replication in which a dynamic competition between the nascent (N) heavy strand and the displaced (D) heavy strand may lead to the melting of the N-strand from the template (T) light strand. When mispairing occurs during rebinding of the N-strand, one or several motifs can be inserted or deleted in both strands during the next round of mt-replication or repair. This model can explain the characteristics of TRs in available vertebrate mt genomes.
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Transposable elements are a significant contributor to tandem repeats in the human genome. Comp Funct Genomics 2012; 2012:947089. [PMID: 22792041 PMCID: PMC3389668 DOI: 10.1155/2012/947089] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Revised: 04/10/2012] [Accepted: 04/11/2012] [Indexed: 11/17/2022] Open
Abstract
Sequence repeats are an important phenomenon in the human genome, playing important roles in genomic alteration often with phenotypic consequences. The two major types of repeat elements in the human genome are tandem repeats (TRs) including microsatellites, minisatellites, and satellites and transposable elements (TEs). So far, very little has been known about the relationship between these two types of repeats. In this study, we identified TRs that are derived from TEs either based on sequence similarity or overlapping genomic positions. We then analyzed the distribution of these TRs among TE families/subfamilies. Our study shows that at least 7,276 TRs or 23% of all minisatellites/satellites is derived from TEs, contributing ∼0.32% of the human genome. TRs seem to be generated more likely from younger/more active TEs, and once initiated they are expanded with time via local duplication of the repeat units. The currently postulated mechanisms for origin of TRs can explain only 6% of all TE-derived TRs, indicating the presence of one or more yet to be identified mechanisms for the initiation of such repeats. Our result suggests that TEs are contributing to genome expansion and alteration not only by transposition but also by generating tandem repeats.
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Collin MA, Edgerly JS, Hayashi CY. Comparison of fibroin cDNAs from webspinning insects: insight into silk formation and function. ZOOLOGY 2011; 114:239-46. [PMID: 21741226 DOI: 10.1016/j.zool.2011.01.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 01/20/2011] [Accepted: 01/23/2011] [Indexed: 10/18/2022]
Abstract
Embiopterans (webspinning insects) are renowned for their prolific use of silk. These organisms spin silk to construct elaborate networks of tubes in which they live, forage, and reproduce. The silken galleries are essential for protecting these soft-bodied insects from predators and other environmental hazards. Despite the ecological importance of embiopteran silk, very little is known about its constituent proteins. Here, we characterize the silk protein cDNAs from four embiopteran species to better understand the function and evolution of these adaptive molecules. We show that webspinner fibroins (silk proteins) are highly repetitive in sequence and possess several conserved characteristics, despite differences in habitat preferences across species. The most striking similarities are in the codon usage biases of the fibroin genes, particularly in the repetitive regions, as well as sequence conservation of the carboxyl-terminal regions of the fibroins. Based on analyses of the silk genes, we propose hypotheses regarding codon bias and its effect on the translation and replication of these unusual genes. Furthermore, we discuss the significance of specific fibroin motifs to the mechanical and structural characteristics of silk fibers. Lastly, we report that the conservation of webspinner fibroin carboxyl-terminal regions suggests that fiber formation may occur through a mechanism analogous to that found in Lepidoptera. From these results, insight is gained into the tempo and mode of evolution that has shaped embiopteran fibroins.
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Affiliation(s)
- Matthew A Collin
- Department of Biology, University of California, Riverside, CA 92521, USA.
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Kaur T, Ong AHK. Heteroplasmy, Length, and Sequence Characterization of the Mitochondrial Control Region in Tomistoma schlegelii. Biochem Genet 2011; 49:562-75. [DOI: 10.1007/s10528-011-9431-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 10/28/2010] [Indexed: 11/28/2022]
Affiliation(s)
- Taranjeet Kaur
- Universiti Tunku Abdul Rahman, Kuala Lumpur, Wilayah Persekutuan, Malaysia
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Iziga R, Ponce M, Infante C, Rebordinos L, Cañavate JP, Manchado M. Molecular characterization and gene expression of thyrotropin-releasing hormone in Senegalese sole (Solea senegalensis). Comp Biochem Physiol B Biochem Mol Biol 2010; 157:167-74. [DOI: 10.1016/j.cbpb.2010.05.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 05/31/2010] [Accepted: 05/31/2010] [Indexed: 10/19/2022]
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Zakrzewski F, Wenke T, Holtgräwe D, Weisshaar B, Schmidt T. Analysis of a c0t-1 library enables the targeted identification of minisatellite and satellite families in Beta vulgaris. BMC PLANT BIOLOGY 2010; 10:8. [PMID: 20064260 PMCID: PMC2820488 DOI: 10.1186/1471-2229-10-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 01/11/2010] [Indexed: 05/03/2023]
Abstract
BACKGROUND Repetitive DNA is a major fraction of eukaryotic genomes and occurs particularly often in plants. Currently, the sequencing of the sugar beet (Beta vulgaris) genome is under way and knowledge of repetitive DNA sequences is critical for the genome annotation. We generated a c0t-1 library, representing highly to moderately repetitive sequences, for the characterization of the major B. vulgaris repeat families. While highly abundant satellites are well-described, minisatellites are only poorly investigated in plants. Therefore, we focused on the identification and characterization of these tandemly repeated sequences. RESULTS Analysis of 1763 c0t-1 DNA fragments, providing 442 kb sequence data, shows that the satellites pBV and pEV are the most abundant repeat families in the B. vulgaris genome while other previously described repeats show lower copy numbers. We isolated 517 novel repetitive sequences and used this fraction for the identification of minisatellite and novel satellite families. Bioinformatic analysis and Southern hybridization revealed that minisatellites are moderately to highly amplified in B. vulgaris. FISH showed a dispersed localization along most chromosomes clustering in arrays of variable size and number with exclusion and depletion in distinct regions. CONCLUSION The c0t-1 library represents major repeat families of the B. vulgaris genome, and analysis of the c0t-1 DNA was proven to be an efficient method for identification of minisatellites. We established, so far, the broadest analysis of minisatellites in plants and observed their chromosomal localization providing a background for the annotation of the sugar beet genome and for the understanding of the evolution of minisatellites in plant genomes.
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Affiliation(s)
- Falk Zakrzewski
- Institute of Botany, Dresden University of Technology, D-01062 Dresden, Germany
| | - Torsten Wenke
- Institute of Botany, Dresden University of Technology, D-01062 Dresden, Germany
| | - Daniela Holtgräwe
- Institute of Genome Research, University of Bielefeld, D-33594 Bielefeld, Germany
| | - Bernd Weisshaar
- Institute of Genome Research, University of Bielefeld, D-33594 Bielefeld, Germany
| | - Thomas Schmidt
- Institute of Botany, Dresden University of Technology, D-01062 Dresden, Germany
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Tang Z, Fu S, Ren Z, Zou Y. Rapid Evolution of Simple Sequence Repeat Induced by Allopolyploidization. J Mol Evol 2009; 69:217-28. [DOI: 10.1007/s00239-009-9261-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 05/21/2009] [Accepted: 06/29/2009] [Indexed: 01/24/2023]
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Collin MA, Garb JE, Edgerly JS, Hayashi CY. Characterization of silk spun by the embiopteran, Antipaluria urichi. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2009; 39:75-82. [PMID: 18996196 DOI: 10.1016/j.ibmb.2008.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Revised: 10/04/2008] [Accepted: 10/06/2008] [Indexed: 05/27/2023]
Abstract
Silks are renowned for being lightweight materials with impressive mechanical properties. Though moth and spider silks have received the most study, silk production has evolved in many other arthropods. One insect group that has been little investigated is Embioptera (webspinners). Embiopterans produce silk from unique tarsal spinning structures during all life stages. We characterize the molecular and mechanical properties of Antipaluria urichi (Embioptera) silk through multiple approaches. First, we quantify the number of silk secretory structures on their forelimbs and the tensile properties of Antipaluria silk. Second, we present silk protein (fibroin) transcripts from an embiopteran forelimb protarsomere cDNA library. We describe a fibroin that shares several features with other arthropod silks, including a subrepetitive core region, a non-repetitive carboxyl-terminal sequence, and a composition rich in glycine, alanine, and serine. Despite these shared attributes, embiopteran silk has several different tensile properties compared to previously measured silks. For example, the tensile strength of Antipaluria silk is much lower than that of Bombyx mori silk. We discuss the observed mechanical properties in relation to the fibroin sequence, spinning system, and embiopteran silk use.
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Affiliation(s)
- Matthew A Collin
- Department of Biology, University of California, Riverside, CA 92521, USA.
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Call DR, Orfe L, Davis MA, Lafrentz S, Kang MS. Impact of compounding error on strategies for subtyping pathogenic bacteria. Foodborne Pathog Dis 2008; 5:505-16. [PMID: 18713065 DOI: 10.1089/fpd.2008.0097] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Comparative-omics will identify a multitude of markers that can be used for intraspecific discrimination between strains of bacteria. It seems intuitive that with this plethora of markers we can construct higher resolution subtyping assays using discrete markers to define strain "barcodes." Unfortunately, with each new marker added to an assay, overall assay robustness declines because errors are compounded exponentially. For example, the difference in accuracy of strain classification for an assay with 60 markers will change from 99.9% to 54.7% when average probe accuracy declines from 99.999% to 99.0%. To illustrate this effect empirically, we constructed a 19 probe bead-array for subtyping Listeria monocytogenes and showed that despite seemingly reliable individual probe accuracy (>97%), our best classification results at the strain level were <75%. A more robust strategy would use as few markers as possible to achieve strain discrimination. Consequently, we developed two variable number of tandem repeat (VNTR) assays (Vibrio parahaemolyticus and L. monocytogenes) and demonstrate that these assays along with a published assay (Salmonella enterica) produce robust results when products were machine scored. The discriminatory ability with four to seven VNTR loci was comparable to pulsed-field gel electrophoresis. Passage experiments showed some instability with ca. 5% of passaged lines showing evidence for new alleles within 30 days (V. parahaemolyticus and S. enterica). Changes were limited to a single locus and allele so conservative rules can be used to determine strain matching. Most importantly, VNTRs appear robust and portable and can clearly discriminate between strains with relatively few loci thereby limiting effects of compounding error.
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Affiliation(s)
- Douglas R Call
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington 99164-7040, USA.
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Barros P, Blanco MG, Boán F, Gómez-Márquez J. Evolution of a complex minisatellite DNA sequence. Mol Phylogenet Evol 2008; 49:488-94. [PMID: 18723095 DOI: 10.1016/j.ympev.2008.07.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 07/07/2008] [Accepted: 07/29/2008] [Indexed: 11/17/2022]
Abstract
Minisatellites are tandem repeats of short DNA units widely distributed in genomes. However, the information on their dynamics in a phylogenetic context is very limited. Here we have studied the organization of the MsH43 locus in several species of primates and from these data we have reconstructed the evolutionary history of this complex minisatellite. Overall, with the exception of gibbon, MsH43 has an organization that is asymmetric, since the distribution of repeats is distinct between the 5' and 3' halves, and heterogeneous since there are many different repeats, some of them characteristic of each species. Inspection of the MsH43 arrays showed the existence of many duplications and deletions, suggesting the implication of slippage processes in the generation of polymorphism. Concerning the evolutionary history of this minisatellite, we propose that the birth of MsH43 may be situated before the divergence of Old World Monkeys since we found the existence of some MsH43 repeat motifs in prosimians and New World Monkeys. The analysis of MsH43 in apes revealed the existence of an evolutionary breakpoint in the pathway that originated African great apes and humans. Remarkably, human MsH43 is more homologous to orang-utan than to the corresponding sequence in gorilla and chimpanzee. This finding does not comply with the evolutionary paradigm that continuous alterations occur during the course of genome evolution. To adjust our results to the standard phylogeny of primates, we propose the existence of a wandering allele that was maintained almost unaltered during the period that extends between orang-utan and humans.
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Affiliation(s)
- Paula Barros
- Departamento de Bioquímica e Bioloxía Molecular, Facultade de Bioloxía-CIBUS, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
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Jurka J, Gentles AJ. Origin and diversification of minisatellites derived from human Alu sequences. Gene 2005; 365:21-6. [PMID: 16343813 DOI: 10.1016/j.gene.2005.09.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2005] [Revised: 08/02/2005] [Accepted: 09/07/2005] [Indexed: 11/25/2022]
Abstract
We analyze minisatellites derived from Alu fragments corresponding approximately to the first 44 bases of human Alu consensus sequences from different subfamilies. The origin of Alu-derived minisatellites appears to have been mediated by short flanking repeats, as first proposed by Haber and Louis [Haber, J.E., Louis, E.J., 1998. Minisatellite origins in yeast and humans. Genomics 48, 132-135.]. We also present evidence for base substitutions and deletions introduced to minisatellites by gene conversion with partially similar but unrelated flanking regions. Segments flanked by short direct repeats are relatively common in different regions of Alu and other repetitive sequences. Our analysis shows that they can be effectively used in comparative studies of the overall sequence context which may contribute to instability of DNA segments flanked by short direct repeats.
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Affiliation(s)
- Jerzy Jurka
- Genetic Information Research Institute, 1925 Landings Drive, Mountain View, CA 94043, USA.
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Lindholm AK, Breden F, Alexander HJ, Chan WK, Thakurta SG, Brooks R. Invasion success and genetic diversity of introduced populations of guppies Poecilia reticulata in Australia. Mol Ecol 2005; 14:3671-82. [PMID: 16202088 DOI: 10.1111/j.1365-294x.2005.02697.x] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
High genetic diversity is thought to characterize successful invasive species, as the potential to adapt to new environments is enhanced and inbreeding is reduced. In the last century, guppies, Poecilia reticulata, repeatedly invaded streams in Australia and elsewhere. Quantitative genetic studies of one Australian guppy population have demonstrated high additive genetic variation for autosomal and Y-linked morphological traits. The combination of colonization success, high heritability of morphological traits, and the possibility of multiple introductions to Australia raised the prediction that neutral genetic diversity is high in introduced populations of guppies. In this study we examine genetic diversity at nine microsatellite and one mitochondrial locus for seven Australian populations. We used mtDNA haplotypes from the natural range of guppies and from domesticated varieties to identify source populations. There were a minimum of two introductions, but there was no haplotype diversity within Australian populations, suggesting a founder effect. This was supported by microsatellite markers, as allelic diversity and heterozygosity were severely reduced compared to one wild source population, and evidence of recent bottlenecks was found. Between Australian populations little differentiation of microsatellite allele frequencies was detected, suggesting that population admixture has occurred historically, perhaps due to male-biased gene flow followed by bottlenecks. Thus success of invasion of Australia and high additive genetic variance in Australian guppies are not associated with high levels of diversity at molecular loci. This finding is consistent with the release of additive genetic variation by dominance and epistasis following inbreeding, and with disruptive and negative frequency-dependent selection on fitness traits.
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Affiliation(s)
- Anna K Lindholm
- School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney 2052, Australia.
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Eckert M, Gout L, Rouxel T, Blaise F, Jedryczka M, Fitt B, Balesdent MH. Identification and characterization of polymorphic minisatellites in the phytopathogenic ascomycete Leptosphaeria maculans. Curr Genet 2004; 47:37-48. [PMID: 15614492 DOI: 10.1007/s00294-004-0539-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Revised: 09/14/2004] [Accepted: 09/28/2004] [Indexed: 10/26/2022]
Abstract
Leptosphaeria maculans causes phoma stem canker, the most serious disease of oilseed rape world-wide. Sexual recombination is important in the pathogen life cycle and increases the risk of plant resistance genes being overcome rapidly. Thus, there is a need to develop easy-to-use molecular markers suitable for large-scale population genetic studies. The minisatellite MinLm1, showing six alleles in natural populations, has previously been used as a marker to survey populations. Here, we report the characterization of five new minisatellites (MinLm2-MinLm6), of which four were identified by a systematic search for tandemly repeated polymorphic regions in BAC-end sequencing data from L. maculans. Of 782 BAC-end sequences analysed, 43 possessed putative minisatellite-type repeats and four of these (MinLm3-MinLm6) displayed both consistent PCR amplification and size polymorphism in a collection of L. maculans isolates of diverse origins. Cloning and sequencing of each allele confirmed that polymorphism was due to variation in the repeat number of a core motif ranging from 11 bp (MinLm3) to 51 bp (MinLm4). The number of alleles found for each minisatellite ranged from three (MinLm4) to nine (MinLm2), with eight, five and six for MinLm3, MinLm5 and MinLm6, respectively. MinLm2-MinLm6 are all single locus markers specific to L. maculans and share some common features, such as conservation of core motifs and incomplete direct repeats in the flanking regions. To our knowledge, L. maculans is the first fungal species for which six polymorphic single locus minisatellite markers have been reported.
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Cozzolino S, Cafasso D, Pellegrino G, Musacchio A, Widmer A. Molecular evolution of a plastid tandem repeat locus in an orchid lineage. J Mol Evol 2004; 57 Suppl 1:S41-9. [PMID: 15008402 DOI: 10.1007/s00239-003-0006-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The molecular evolution of a chloroplast minisatellite locus in the Anacamptis palustris (Orchidaceae) lineage and haplotype variation in two Italian A. palustris populations were investigated. A phylogenetic analyses of the chloroplast tRNA(LEU) intron, where the minisatellite locus is located, revealed that a deletion in the ancestor of the A. palustris lineage led to the formation of two noncontiguous, complementary sequence motifs. We propose a model to explain the initial formation of the minisatellite repeat motif, starting with the two noncontiguous, complementary sequence motifs. A survey of minisatellite variation in four species of the A. palustris lineage revealed several haplotypes that differed not only in repeat number, but also in repeat organization. A haplotype network suggests that three different minisatellite loci evolved independently at the same position in the tRNA(LEU) intron. A secondary structure model revealed that the A. palustris minisatellite repeat forms a stem region of the tRNA(LEU) intron, which allows its notable expansion without negatively affecting splicing. Minisatellite variation was high in the two examined A. palustris populations where 20 haplotypes were detected, whereas no length variation was detected in a neighboring poly (A) microsatellite locus. We estimated a chloroplast minisatellite mutation rate of 3.2 x 10(-3) mutations per generation. Southern blot analyses did not find evidence for chloroplast heteroplasmy. Based on the analysis of the largest known, extant A. palustris population, a stepwise mutation model (SMM) was inferred.
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Affiliation(s)
- Salvatore Cozzolino
- Dipartimento di Biologia Vegetale, Università degli Studi di Napoli Federico II, via Foria 223, 1-80139 Naples, Italy.
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Inukai T, Sano Y. Sequence rearrangement in the AT-rich minisatellite of the novel rice transposable element Basho. Genome 2002; 45:493-502. [PMID: 12033618 DOI: 10.1139/g02-010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In the process of characterizing a rice wx deletion mutant, an AT-rich minisatellite sequence that consisted of units of approximately 80 bp was detected about 2.3 kb downstream of the wx gene. This AT-rich minisatellite was a multiple-copy element (1 x 10(3) to 2 x 10(3) copies per haploid genome) and interspersed in the rice genome. By BLAST homology search it was indicated that not only the tandem repeat but also both flanking sequences were conserved among copies. According to the characteristics of the termini (5'-CHH ... CTAG-3') and a target site preference for T, this AT-rich minisatellite accompanying the flanking sequences was classified into a novel transposon, Basho. The results of direct amplification of Basho showed that relatively large variation in size existed in the Basho family. We estimate the variation to be generated by not only alteration of the number of units in the minisatellite but also by duplications of larger blocks including the conserved flanking sequences caused by single-strand mispairing (SSM) at noncontiguous repeats. Because the AT-rich minisatellite contained in Basho possessed several motifs of the matrix attachment region (MAR) in its repeat unit, the functional role as MAR in the rice genome was discussed.
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Affiliation(s)
- Tsuyoshi Inukai
- Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
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