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Hass JK, Henriquez MC, Churcher J, Hamou H, Morales SR, Melin AD. Assessing morphological preservation of gastrointestinal parasites from fecal samples of wild capuchin monkeys (Cebus imitator) stored in ethanol versus formalin. Sci Rep 2024; 14:3623. [PMID: 38351262 PMCID: PMC10864282 DOI: 10.1038/s41598-024-53915-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 02/06/2024] [Indexed: 02/16/2024] Open
Abstract
The copromicroscopic identification of gastrointestinal parasites is a common, cost-effective method vital to understanding host-parasite interactions. However, its efficacy depends on effective preservation of the samples. In this study, we compare the preservation of ethanol and formalin preserved gastrointestinal parasites collected from a wild population of Costa Rican capuchin monkeys (Cebus imitator). Fecal samples were collected, halved, and stored in either 10% formalin or 96% ethanol at ambient temperature, then microscopically screened for the presence of parasites. Parasites were morphologically identified and rated based on their preservation using a newly developed rubric. We identified more parasitic morphotypes in formalin-preserved samples but found no difference in the number of parasites per fecal gram (PFG) between mediums. There was no difference in the PFG of two most prevalent parasite morphotypes, Filariopsis barretoi larvae and Strongyle-type eggs, and while Filariopsis larvae were better preserved in formalin, strongyle eggs showed no preservation difference between mediums. Our results support the suitability of both ethanol and formalin for morphological parasite identification in samples stored over 1 year, describe the morphological changes and challenges associated with parasite degradation, and highlight the potential for future studies to use both morphological and molecular methods in non-invasively collected samples.
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Affiliation(s)
- Joelle K Hass
- Department of Anthropology and Archaeology, University of Calgary, Calgary, AB, Canada.
- Host Parasite Interactions Network, University of Calgary, Calgary, AB, Canada.
| | - Megan C Henriquez
- Department of Anthropology and Archaeology, University of Calgary, Calgary, AB, Canada.
- Host Parasite Interactions Network, University of Calgary, Calgary, AB, Canada.
- Department of Anthropology, The Graduate Center, City University of New York, New York, NY, USA.
- The New York Consortium in Evolutionary Primatology (NYCEP), New York, NY, USA.
| | - Jessica Churcher
- Department of Anthropology and Archaeology, University of Calgary, Calgary, AB, Canada
- Host Parasite Interactions Network, University of Calgary, Calgary, AB, Canada
| | - Hadjira Hamou
- Department of Anthropology and Archaeology, University of Calgary, Calgary, AB, Canada
- Host Parasite Interactions Network, University of Calgary, Calgary, AB, Canada
| | | | - Amanda D Melin
- Department of Anthropology and Archaeology, University of Calgary, Calgary, AB, Canada.
- Host Parasite Interactions Network, University of Calgary, Calgary, AB, Canada.
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada.
- Department of Medical Genetics, University of Calgary, Calgary, AB, Canada.
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2
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Guiglielmoni N, Villegas LI, Kirangwa J, Schiffer PH. Revisiting genomes of non-model species with long reads yields new insights into their biology and evolution. Front Genet 2024; 15:1308527. [PMID: 38384712 PMCID: PMC10879605 DOI: 10.3389/fgene.2024.1308527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 01/04/2024] [Indexed: 02/23/2024] Open
Abstract
High-quality genomes obtained using long-read data allow not only for a better understanding of heterozygosity levels, repeat content, and more accurate gene annotation and prediction when compared to those obtained with short-read technologies, but also allow to understand haplotype divergence. Advances in long-read sequencing technologies in the last years have made it possible to produce such high-quality assemblies for non-model organisms. This allows us to revisit genomes, which have been problematic to scaffold to chromosome-scale with previous generations of data and assembly software. Nematoda, one of the most diverse and speciose animal phyla within metazoans, remains poorly studied, and many previously assembled genomes are fragmented. Using long reads obtained with Nanopore R10.4.1 and PacBio HiFi, we generated highly contiguous assemblies of a diploid nematode of the Mermithidae family, for which no closely related genomes are available to date, as well as a collapsed assembly and a phased assembly for a triploid nematode from the Panagrolaimidae family. Both genomes had been analysed before, but the fragmented assemblies had scaffold sizes comparable to the length of long reads prior to assembly. Our new assemblies illustrate how long-read technologies allow for a much better representation of species genomes. We are now able to conduct more accurate downstream assays based on more complete gene and transposable element predictions.
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3
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Pu W, Xiao K, Luo S, Zhu H, Yuan Z, Gao C, Hu J. Characterization of Five Meloidogyne incognita Effectors Associated with PsoRPM3. Int J Mol Sci 2022; 23:ijms23031498. [PMID: 35163425 PMCID: PMC8836280 DOI: 10.3390/ijms23031498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 01/17/2022] [Accepted: 01/22/2022] [Indexed: 12/04/2022] Open
Abstract
Root-knot nematodes (RKNs) are devastating parasites that invade thousands of plants. In this study, five RKN effectors, which might interact with Prunussogdiana resistance protein PsoRPM3, were screened and identified. In situ hybridisation results showed that MiCal, MiGST_N_4, MiEFh and MiACPS are expressed in the subventral oesophageal glands (SvG), and MiTSPc hybridization signals are found in the dorsal esophageal gland (DG) of Meloidogyne incognita in the pre-J2. RT-qPCR data indicated that the expression of MiCal, MiGST_N_4, MiEFh, and MiACPS genes are highly expressed in M. incognita of pra-J2 and J3/J4 stages. The expression of MiTSPc increased significantly in the female stage of M. incognita. Moreover, all effectors found in this study localize in the cytoplasm and nucleus when transiently expressed in plant cells. In addition, MiGST_N_4, MiEFh, MiACPS and MiTSPc can elicit the ROS burst and strong hypersensitive response (HR), as well as significant ion leakage. Our data suggest that MiGST_N_4, MiEFh, MiACPS and MiTSPc effectors may be involved in triggering the immune response of the host plant.
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4
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Ma X, Agudelo P, Richards VP, Baeza JA. Genome survey sequencing of the phyto-parasitic nematode Hoplolaimus galeatus. PeerJ 2022; 10:e12749. [PMID: 35111396 PMCID: PMC8781444 DOI: 10.7717/peerj.12749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 12/15/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Hoplolaimus galeatus is a plant-parasite nematode with a broad range of hosts. This nematode is known to damage cotton, corn, and soybean crops. Hoplolaimus galeatus is also an economically important pest of turfgrasses. Despite its economical importance, no genomic resources exist for this parasite. METHODS Using 300 bp paired-end short read sequencing, this study estimated genome size, analyzed a nearly complete mitochondrial chromosome, and explored nuclear repetitive elements, including microsatellites, in H. galeatus for the first time. The phylogenetic placement of H. galeatus in the superfamily Tylenchoidea was also examined. RESULTS The average haploid genome size estimated using a k-mer approach was 517.69 Mbp. The partially assembled mitochondrial genome of H. galeatus is 16,578 bp in length and comprised of 11 protein-coding genes, two ribosomal RNA genes, and 16 transfer RNA genes. A maximum likelihood phylogenetic analysis confirmed the monophyly of the genus Hoplolaimus and the superfamily Tylenchoidea. Repetitive elements constituted 50% of the nuclear genome while half of the genome represented single- or low-copy sequences. A large portion of repetitive sequences could not be assigned to known repeat element families. Considering only annotated repetitive elements, the most ubiquitous belonged to Class II- Subclass 2-Maverick elements, Class I-LTR-Ty-3/Bel-Pao elements, and satellites. 45S ribosomal DNA was also abundant and a total of 36 SSRs were identified.This study developed genomic resources for the plant-parasitic nematode Hoplolaimus galeatus that will contribute to the better understanding of meta-population connectivity and putative genomic mechanisms involved in the exploitation of the broad range of host plants used by H. galeatus.
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Affiliation(s)
- Xinyuan Ma
- Department of Biological Sciences, Clemson University, Clemson, SC, United States of America
| | - Paula Agudelo
- Plant and Environmental Sciences Department, Clemson University, Clemson, SC, United States of America
| | - Vincent P. Richards
- Plant and Environmental Sciences Department, Clemson University, Clemson, SC, United States of America
| | - J. Antonio Baeza
- Department of Biological Sciences, Clemson University, Clemson, SC, United States of America,Smithsonian Marine Station at Fort Pierce, Smithsonian Institution, Fort Pierce, FL, United States of America,Departamento de Biologia Marina, Universidad Catolica del Norte, Coquimbo, IV Region, Chile
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5
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Mining nematode protein secretomes to explain lifestyle and host specificity. PLoS Negl Trop Dis 2021; 15:e0009828. [PMID: 34587193 PMCID: PMC8504978 DOI: 10.1371/journal.pntd.0009828] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/11/2021] [Accepted: 09/21/2021] [Indexed: 12/15/2022] Open
Abstract
Parasitic nematodes are highly successful pathogens, inflicting disease on humans, animals and plants. Despite great differences in their life cycles, host preference and transmission modes, these parasites share a common capacity to manipulate their host's immune system. This is at least partly achieved through the release of excretory/secretory proteins, the most well-characterized component of nematode secretomes, that are comprised of functionally diverse molecules. In this work, we analyzed published protein secretomes of parasitic nematodes to identify common patterns as well as species-specific traits. The 20 selected organisms span 4 nematode clades, including plant pathogens, animal parasites, and the free-living species Caenorhabditis elegans. Transthyretin-like proteins were the only component common to all adult secretomes; many other protein classes overlapped across multiple datasets. The glycolytic enzymes aldolase and enolase were present in all parasitic species, but missing from C. elegans. Secretomes from larval stages showed less overlap between species. Although comparison of secretome composition across species and life-cycle stages is challenged by the use of different methods and depths of sequencing among studies, our workflow enabled the identification of conserved protein families and pinpointed elements that may have evolved as to enable parasitism. This strategy, extended to more secretomes, may be exploited to prioritize therapeutic targets in the future.
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6
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Van Goor J, Shakes DC, Haag ES. Fisher vs. the Worms: Extraordinary Sex Ratios in Nematodes and the Mechanisms that Produce Them. Cells 2021; 10:1793. [PMID: 34359962 PMCID: PMC8303164 DOI: 10.3390/cells10071793] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/08/2021] [Accepted: 07/13/2021] [Indexed: 01/20/2023] Open
Abstract
Parker, Baker, and Smith provided the first robust theory explaining why anisogamy evolves in parallel in multicellular organisms. Anisogamy sets the stage for the emergence of separate sexes, and for another phenomenon with which Parker is associated: sperm competition. In outcrossing taxa with separate sexes, Fisher proposed that the sex ratio will tend towards unity in large, randomly mating populations due to a fitness advantage that accrues in individuals of the rarer sex. This creates a vast excess of sperm over that required to fertilize all available eggs, and intense competition as a result. However, small, inbred populations can experience selection for skewed sex ratios. This is widely appreciated in haplodiploid organisms, in which females can control the sex ratio behaviorally. In this review, we discuss recent research in nematodes that has characterized the mechanisms underlying highly skewed sex ratios in fully diploid systems. These include self-fertile hermaphroditism and the adaptive elimination of sperm competition factors, facultative parthenogenesis, non-Mendelian meiotic oddities involving the sex chromosomes, and environmental sex determination. By connecting sex ratio evolution and sperm biology in surprising ways, these phenomena link two "seminal" contributions of G. A. Parker.
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Affiliation(s)
- Justin Van Goor
- Department of Biology, University of Maryland, College Park, MD 20742, USA;
| | - Diane C. Shakes
- Department of Biology, William and Mary, Williamsburg, VA 23187, USA;
| | - Eric S. Haag
- Department of Biology, University of Maryland, College Park, MD 20742, USA;
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7
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Stretton AOW. My life with Sydney, 1961-1971. J Neurogenet 2021; 34:225-237. [PMID: 33446021 DOI: 10.1080/01677063.2020.1834544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
During the 1961-1971 decade, Sydney Brenner made several significant contributions to molecular biology-showing that the genetic code is a triplet code; discovery of messenger RNA; colinearity of gene and protein; decoding of chain terminating codons; and then an important transition: the development of the nematode Caenorhabditis elegans into the model eucaryote genetic system that has permeated the whole of recent biology.
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8
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9
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Knot IE, Zouganelis GD, Weedall GD, Wich SA, Rae R. DNA Barcoding of Nematodes Using the MinION. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00100] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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10
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Sepúlveda-Crespo D, Reguera RM, Rojo-Vázquez F, Balaña-Fouce R, Martínez-Valladares M. Drug discovery technologies: Caenorhabditis elegans as a model for anthelmintic therapeutics. Med Res Rev 2020; 40:1715-1753. [PMID: 32166776 DOI: 10.1002/med.21668] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/10/2019] [Accepted: 02/26/2020] [Indexed: 12/16/2022]
Abstract
Helminthiasis is one of the gravest problems worldwide. There is a growing concern on less available anthelmintics and the emergence of resistance creating a major threat to human and livestock health resources. Novel and broad-spectrum anthelmintics are urgently needed. The free-living nematode Caenorhabditis elegans could address this issue through automated high-throughput technologies for the screening of large chemical libraries. This review discusses the strong advantages and limitations for using C elegans as a screening method for anthelmintic drug discovery. C elegans is the best model available for the validation of novel effective drugs in treating most, if not all, helminth infections, and for the elucidation the mode of action of anthelmintic candidates. This review also focuses on available technologies in the discovery of anthelmintics published over the last 15 years with particular attention to high-throughput technologies over conventional screens. On the other hand, this review highlights how combinatorial and nanomedicine strategies could prolong the use of anthelmintics and control resistance problems.
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Affiliation(s)
- Daniel Sepúlveda-Crespo
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, León, Spain
| | - Rosa M Reguera
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, León, Spain
| | - Francisco Rojo-Vázquez
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), León, Spain.,Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, León, Spain
| | - Rafael Balaña-Fouce
- Departamento de Ciencias Biomédicas, Facultad de Veterinaria, Universidad de León, León, Spain
| | - María Martínez-Valladares
- Instituto de Ganadería de Montaña (CSIC-Universidad de León), León, Spain.,Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de León, León, Spain
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11
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Chen D, Yang C, Liu S, Hang W, Wang X, Chen J, Shi A. SAC-1 ensures epithelial endocytic recycling by restricting ARF-6 activity. J Cell Biol 2018; 217:2121-2139. [PMID: 29563216 PMCID: PMC5987724 DOI: 10.1083/jcb.201711065] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 02/06/2018] [Accepted: 02/28/2018] [Indexed: 11/22/2022] Open
Abstract
Arf6/ARF-6 is a crucial regulator of the endosomal phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) pool in endocytic recycling. To further characterize ARF-6 regulation, we performed an ARF-6 interactor screen in Caenorhabditis elegans and identified SAC-1, the homologue of the phosphoinositide phosphatase Sac1p in yeast, as a novel ARF-6 partner. In the absence of ARF-6, basolateral endosomes show a loss of SAC-1 staining in epithelial cells. Steady-state cargo distribution assays revealed that loss of SAC-1 specifically affected apical secretory delivery and basolateral recycling. PI(4,5)P2 levels and the endosomal labeling of the ARF-6 effector UNC-16 were significantly elevated in sac-1 mutants, suggesting that SAC-1 functions as a negative regulator of ARF-6. Further analyses revealed an interaction between SAC-1 and the ARF-6-GEF BRIS-1. This interaction outcompeted ARF-6(guanosine diphosphate [GDP]) for binding to BRIS-1 in a concentration-dependent manner. Consequently, loss of SAC-1 promotes the intracellular overlap between ARF-6 and BRIS-1. BRIS-1 knockdown resulted in a significant reduction in PI(4,5)P2 levels in SAC-1-depleted cells. Interestingly, the action of SAC-1 in sequestering BRIS-1 is independent of SAC-1's catalytic activity. Our results suggest that the interaction of SAC-1 with ARF-6 curbs ARF-6 activity by limiting the access of ARF-6(GDP) to its guanine nucleotide exchange factor, BRIS-1.
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Affiliation(s)
- Dan Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Chao Yang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Sha Liu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Weijian Hang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xianghong Wang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Juan Chen
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Anbing Shi
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China .,Institute for Brain Research, Huazhong University of Science and Technology, Wuhan, Hubei, China.,Key Laboratory of Neurological Disease of National Education Ministry, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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12
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Chen J, Hu L, Sun L, Lin B, Huang K, Zhuo K, Liao J. A novel Meloidogyne graminicola effector, MgMO237, interacts with multiple host defence-related proteins to manipulate plant basal immunity and promote parasitism. MOLECULAR PLANT PATHOLOGY 2018; 19:1942-1955. [PMID: 29485753 PMCID: PMC6638000 DOI: 10.1111/mpp.12671] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/25/2018] [Accepted: 02/26/2018] [Indexed: 05/04/2023]
Abstract
Plant-parasitic nematodes can secrete effector proteins into the host tissue to facilitate their parasitism. In this study, we report a novel effector protein, MgMO237, from Meloidogyne graminicola, which is exclusively expressed within the dorsal oesophageal gland cell and markedly up-regulated in parasitic third-/fourth-stage juveniles of M. graminicola. Transient expression of MgMO237 in protoplasts from rice roots showed that MgMO237 was localized in the cytoplasm and nucleus of the host cells. Rice plants overexpressing MgMO237 showed an increased susceptibility to M. graminicola. In contrast, rice plants expressing RNA interference vectors targeting MgMO237 showed an increased resistance to M. graminicola. In addition, yeast two-hybrid and co-immunoprecipitation assays showed that MgMO237 interacted specifically with three rice endogenous proteins, i.e. 1,3-β-glucan synthase component (OsGSC), cysteine-rich repeat secretory protein 55 (OsCRRSP55) and pathogenesis-related BetvI family protein (OsBetvI), which are all related to host defences. Moreover, MgMO237 can suppress host defence responses, including the expression of host defence-related genes, cell wall callose deposition and the burst of reactive oxygen species. These results demonstrate that the effector MgMO237 probably promotes the parasitism of M. graminicola by interacting with multiple host defence-related proteins and suppressing plant basal immunity in the later parasitic stages of nematodes.
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Affiliation(s)
- Jiansong Chen
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Lili Hu
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Longhua Sun
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Borong Lin
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Kun Huang
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
| | - Kan Zhuo
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
| | - Jinling Liao
- Laboratory of Plant NematologySouth China Agricultural UniversityGuangzhou510642China
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlSouth China Agricultural UniversityGuangzhou510642China
- Department of Eco‐engineering, Guangdong Eco‐Engineering PolytechnicGuangzhou510520China
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13
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Ren X, Li R, Wei X, Bi Y, Ho V, Ding Q, Xu Z, Zhang Z, Hsieh CL, Young A, Zeng J, Liu X, Zhao Z. Genomic basis of recombination suppression in the hybrid between Caenorhabditis briggsae and C. nigoni. Nucleic Acids Res 2018; 46:1295-1307. [PMID: 29325078 PMCID: PMC5814819 DOI: 10.1093/nar/gkx1277] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 12/07/2017] [Accepted: 12/19/2017] [Indexed: 02/06/2023] Open
Abstract
DNA recombination is required for effective segregation and diversification of genomes and for the successful completion of meiosis. Recent studies in various species hybrids have demonstrated a genetic link between DNA recombination and speciation. Consistent with this, we observed a striking suppression of recombination in the hybrids between two nematodes, the hermaphroditic Caenorhabditis briggsae and the gonochoristic C. nigoni. To unravel the molecular basis underlying the recombination suppression in their hybrids, we generated a C. nigoni genome with chromosome-level contiguity and produced an improved C. briggsae genome with resolved gaps up to 2.8 Mb. The genome alignment reveals not only high sequence divergences but also pervasive intra- and inter-chromosomal sequence re-arrangements between the two species, which are plausible culprits for the observed suppression. Comparison of recombination boundary sequences suggests that recombination in the hybrid requires extensive sequence homology, which is rarely seen between the two genomes. The new genomes and genomic libraries form invaluable resources for studying genome evolution, hybrid incompatibilities and sex evolution for this pair of model species.
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Affiliation(s)
- Xiaoliang Ren
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Runsheng Li
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Xiaolin Wei
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- PTN (Peking University-Tsinghua University-National Institute of Biological Sciences) Joint Graduate Program, Beijing 100084, China
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Yu Bi
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Vincy Wing Sze Ho
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Qiutao Ding
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Zhichao Xu
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhihong Zhang
- Illumina Inc., 5200 Illumina Way, San Diego 92122, USA
| | | | - Amanda Young
- Illumina Inc., 5200 Illumina Way, San Diego 92122, USA
| | - Jianyang Zeng
- Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Xiao Liu
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Zhongying Zhao
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
- State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong, China
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14
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Kollmar M, Simm D. Identifying Sequenced Eukaryotic Genomes and Transcriptomes with diArk. Methods Mol Biol 2018; 1757:1-19. [PMID: 29761453 DOI: 10.1007/978-1-4939-7737-6_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The diArk Eukaryotic Genome Database is a manually curated and updated repository of available eukaryotic genome and transcriptome assemblies. diArk is a key resource for researchers interested in comparative eukaryotic genomics, and the entry point to browsing sequenced eukaryotes in general and to find the most closely related species to the own organism of interest in particular. The exponentially increasing number of sequenced species demands sophisticated search and data presentation tools. In this chapter we describe how to navigate the diArk database keeping a first-time user in mind.
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Affiliation(s)
- Martin Kollmar
- Group Systems Biology of Motor Proteins, Department of NMR-Based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.
| | - Dominic Simm
- Group Systems Biology of Motor Proteins, Department of NMR-Based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
- Theoretical Computer Science and Algorithmic Methods, Institute of Computer Science, Georg-August-University, Göttingen, Germany
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15
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Besnard F, Koutsovoulos G, Dieudonné S, Blaxter M, Félix MA. Toward Universal Forward Genetics: Using a Draft Genome Sequence of the Nematode Oscheius tipulae To Identify Mutations Affecting Vulva Development. Genetics 2017; 206:1747-1761. [PMID: 28630114 PMCID: PMC5560785 DOI: 10.1534/genetics.117.203521] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 06/15/2017] [Indexed: 12/30/2022] Open
Abstract
Mapping-by-sequencing has become a standard method to map and identify phenotype-causing mutations in model species. Here, we show that a fragmented draft assembly is sufficient to perform mapping-by-sequencing in nonmodel species. We generated a draft assembly and annotation of the genome of the free-living nematode Oscheius tipulae, a distant relative of the model Caenorhabditis elegans We used this draft to identify the likely causative mutations at the O. tipulae cov-3 locus, which affect vulval development. The cov-3 locus encodes the O. tipulae ortholog of C. elegans mig-13, and we further show that Cel-mig-13 mutants also have an unsuspected vulval-development phenotype. In a virtuous circle, we were able to use the linkage information collected during mutant mapping to improve the genome assembly. These results showcase the promise of genome-enabled forward genetics in nonmodel species.
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Affiliation(s)
- Fabrice Besnard
- École Normale Supérieure, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institut de Biologie de l'École Normale Supérieure, Paris Sciences et Lettres Research University, 75005, France
| | | | - Sana Dieudonné
- École Normale Supérieure, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institut de Biologie de l'École Normale Supérieure, Paris Sciences et Lettres Research University, 75005, France
| | - Mark Blaxter
- Institute of Evolutionary Biology, University of Edinburgh, EH8 9YL, United Kingdom
| | - Marie-Anne Félix
- École Normale Supérieure, Centre National de la Recherche Scientifique, Institut National de la Santé et de la Recherche Médicale, Institut de Biologie de l'École Normale Supérieure, Paris Sciences et Lettres Research University, 75005, France
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16
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Jovelin R, Krizus A, Taghizada B, Gray JC, Phillips PC, Claycomb JM, Cutter AD. Comparative genomic analysis of upstream miRNA regulatory motifs in Caenorhabditis. RNA (NEW YORK, N.Y.) 2016; 22:968-978. [PMID: 27140965 PMCID: PMC4911920 DOI: 10.1261/rna.055392.115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 02/18/2016] [Indexed: 06/05/2023]
Abstract
MicroRNAs (miRNAs) comprise a class of short noncoding RNA molecules that play diverse developmental and physiological roles by controlling mRNA abundance and protein output of the vast majority of transcripts. Despite the importance of miRNAs in regulating gene function, we still lack a complete understanding of how miRNAs themselves are transcriptionally regulated. To fill this gap, we predicted regulatory sequences by searching for abundant short motifs located upstream of miRNAs in eight species of Caenorhabditis nematodes. We identified three conserved motifs across the Caenorhabditis phylogeny that show clear signatures of purifying selection from comparative genomics, patterns of nucleotide changes in motifs of orthologous miRNAs, and correlation between motif incidence and miRNA expression. We then validated our predictions with transgenic green fluorescent protein reporters and site-directed mutagenesis for a subset of motifs located in an enhancer region upstream of let-7 We demonstrate that a CT-dinucleotide motif is sufficient for proper expression of GFP in the seam cells of adult C. elegans, and that two other motifs play incremental roles in combination with the CT-rich motif. Thus, functional tests of sequence motifs identified through analysis of molecular evolutionary signatures provide a powerful path for efficiently characterizing the transcriptional regulation of miRNA genes.
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Affiliation(s)
- Richard Jovelin
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada Informatics and Bio-Computing Program, Ontario Institute for Cancer Research, Toronto, Ontario M5G 0A3, Canada
| | - Aldis Krizus
- Department of Molecular Genetics, University of Toronto, Ontario M5S 1A8, Canada
| | - Bakhtiyar Taghizada
- Department of Molecular Genetics, University of Toronto, Ontario M5S 1A8, Canada
| | - Jeremy C Gray
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada
| | - Patrick C Phillips
- Institute of Ecology and Evolution, University of Oregon, Oregon 97403, USA
| | - Julie M Claycomb
- Department of Molecular Genetics, University of Toronto, Ontario M5S 1A8, Canada
| | - Asher D Cutter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada
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17
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A review of methods for nematode identification. J Microbiol Methods 2016; 138:37-49. [PMID: 27262374 DOI: 10.1016/j.mimet.2016.05.030] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 05/23/2016] [Accepted: 05/31/2016] [Indexed: 12/15/2022]
Abstract
Nematodes are non-segmented roundworms found in soil, aquatic environment, plants, or animals. Either useful or pathogenic, they greatly influence environmental equilibrium, human and animal health, as well as plant production. Knowledge on their taxonomy and biology are key issues to answer the different challenges associated to these organisms. Nowadays, most of the nematode taxonomy remains unknown or unclear. Several approaches are available for parasite identification, from the traditional morphology-based techniques to the sophisticated high-throughput sequencing technologies. All these techniques have advantages or drawbacks depending on the sample origin and the number of nematodes to be processed. This review proposes an overview of all newly available methods available to identify known and/or unknown nematodes with a specific focus on emerging high-throughput molecular techniques.
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18
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Li R, Ren X, Bi Y, Ho VWS, Hsieh CL, Young A, Zhang Z, Lin T, Zhao Y, Miao L, Sarkies P, Zhao Z. Specific down-regulation of spermatogenesis genes targeted by 22G RNAs in hybrid sterile males associated with an X-Chromosome introgression. Genome Res 2016; 26:1219-32. [PMID: 27197225 PMCID: PMC5052035 DOI: 10.1101/gr.204479.116] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/16/2016] [Indexed: 12/23/2022]
Abstract
Hybrid incompatibility (HI) prevents gene flow between species, thus lying at the heart of speciation genetics. One of the most common HIs is male sterility. Two superficially contradictory observations exist for hybrid male sterility. First, an introgression on the X Chromosome is more likely to produce male sterility than on autosome (so-called large-X theory); second, spermatogenesis genes are enriched on the autosomes but depleted on the X Chromosome (demasculinization of X Chromosome). Analysis of gene expression in Drosophila hybrids suggests a genetic interaction between the X Chromosome and autosomes that is essential for male fertility. However, the prevalence of such an interaction and its underlying mechanism remain largely unknown. Here we examine the interaction in nematode species by contrasting the expression of both coding genes and transposable elements (TEs) between hybrid sterile males and its parental nematode males. We use two lines of hybrid sterile males, each carrying an independent introgression fragment from Caenorhabditis briggsae X Chromosome in an otherwise Caenorhabditis nigoni background, which demonstrate similar defects in spermatogenesis. We observe a similar pattern of down-regulated genes that are specific for spermatogenesis between the two hybrids. Importantly, the down-regulated genes caused by the X Chromosome introgressions show a significant enrichment on the autosomes, supporting an epistatic interaction between the X Chromosome and autosomes. We investigate the underlying mechanism of the interaction by measuring small RNAs and find that a subset of 22G RNAs specifically targeting the down-regulated spermatogenesis genes is significantly up-regulated in hybrids, suggesting that perturbation of small RNA-mediated regulation may contribute to the X-autosome interaction.
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Affiliation(s)
- Runsheng Li
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Xiaoliang Ren
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Yu Bi
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Vincy Wing Sze Ho
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | | | - Amanda Young
- Illumina Incorporated, San Diego, California 92122, USA
| | - Zhihong Zhang
- Illumina Incorporated, San Diego, California 92122, USA
| | - Tingting Lin
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yanmei Zhao
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100190, China
| | - Long Miao
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100190, China
| | - Peter Sarkies
- MRC Clinical Sciences Centre, London W12 0NN, United Kingdom; Institute of Clinical Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Zhongying Zhao
- Department of Biology, Hong Kong Baptist University, Hong Kong, China; State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong, China
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19
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Haemonchus contortus: Genome Structure, Organization and Comparative Genomics. ADVANCES IN PARASITOLOGY 2016; 93:569-98. [PMID: 27238013 DOI: 10.1016/bs.apar.2016.02.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
One of the first genome sequencing projects for a parasitic nematode was that for Haemonchus contortus. The open access data from the Wellcome Trust Sanger Institute provided a valuable early resource for the research community, particularly for the identification of specific genes and genetic markers. Later, a second sequencing project was initiated by the University of Melbourne, and the two draft genome sequences for H. contortus were published back-to-back in 2013. There is a pressing need for long-range genomic information for genetic mapping, population genetics and functional genomic studies, so we are continuing to improve the Wellcome Trust Sanger Institute assembly to provide a finished reference genome for H. contortus. This review describes this process, compares the H. contortus genome assemblies with draft genomes from other members of the strongylid group and discusses future directions for parasite genomics using the H. contortus model.
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Abstract
Be it their pervasiveness, experimental tractability or their impact on human health and agriculture, nematode–bacterium associations are far-reaching research subjects. Although the omics hype did not spare them and helped reveal mechanisms of communication and exchange between the associated partners, a huge amount of knowledge still awaits to be harvested from their study. Here, I summarize and compare the kind of research that has been already performed on the model nematode Caenorhabditis elegans and on symbiotic nematodes, both marine and entomopathogenic ones. The emerging picture highlights how complementing genetic studies with ecological ones (in the case of well-established genetic model systems such as C. elegans) and vice versa (in the case of the yet uncultured Stilbonematinae) will deepen our understanding of how microbial symbioses evolved and how they impact our environment. Nematode–bacterium associations are major research subjects. Complementing genetic studies with ecological ones is necessary to boost our understanding of how microbial symbioses evolved and how they impact the environment.
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Affiliation(s)
- Silvia Bulgheresi
- Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria
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21
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Ward JD. Rendering the Intractable More Tractable: Tools from Caenorhabditis elegans Ripe for Import into Parasitic Nematodes. Genetics 2015; 201:1279-94. [PMID: 26644478 PMCID: PMC4676526 DOI: 10.1534/genetics.115.182717] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 10/20/2015] [Indexed: 12/14/2022] Open
Abstract
Recent and rapid advances in genetic and molecular tools have brought spectacular tractability to Caenorhabditis elegans, a model that was initially prized because of its simple design and ease of imaging. C. elegans has long been a powerful model in biomedical research, and tools such as RNAi and the CRISPR/Cas9 system allow facile knockdown of genes and genome editing, respectively. These developments have created an additional opportunity to tackle one of the most debilitating burdens on global health and food security: parasitic nematodes. I review how development of nonparasitic nematodes as genetic models informs efforts to import tools into parasitic nematodes. Current tools in three commonly studied parasites (Strongyloides spp., Brugia malayi, and Ascaris suum) are described, as are tools from C. elegans that are ripe for adaptation and the benefits and barriers to doing so. These tools will enable dissection of a huge array of questions that have been all but completely impenetrable to date, allowing investigation into host-parasite and parasite-vector interactions, and the genetic basis of parasitism.
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Affiliation(s)
- Jordan D Ward
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94158
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22
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Tzika AC, Ullate-Agote A, Grbic D, Milinkovitch MC. Reptilian Transcriptomes v2.0: An Extensive Resource for Sauropsida Genomics and Transcriptomics. Genome Biol Evol 2015; 7:1827-41. [PMID: 26133641 PMCID: PMC4494049 DOI: 10.1093/gbe/evv106] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Despite the availability of deep-sequencing techniques, genomic and transcriptomic data remain unevenly distributed across phylogenetic groups. For example, reptiles are poorly represented in sequence databases, hindering functional evolutionary and developmental studies in these lineages substantially more diverse than mammals. In addition, different studies use different assembly and annotation protocols, inhibiting meaningful comparisons. Here, we present the “Reptilian Transcriptomes Database 2.0,” which provides extensive annotation of transcriptomes and genomes from species covering the major reptilian lineages. To this end, we sequenced normalized complementary DNA libraries of multiple adult tissues and various embryonic stages of the leopard gecko and the corn snake and gathered published reptilian sequence data sets from representatives of the four extant orders of reptiles: Squamata (snakes and lizards), the tuatara, crocodiles, and turtles. The LANE runner 2.0 software was implemented to annotate all assemblies within a single integrated pipeline. We show that this approach increases the annotation completeness of the assembled transcriptomes/genomes. We then built large concatenated protein alignments of single-copy genes and inferred phylogenetic trees that support the positions of turtles and the tuatara as sister groups of Archosauria and Squamata, respectively. The Reptilian Transcriptomes Database 2.0 resource will be updated to include selected new data sets as they become available, thus making it a reference for differential expression studies, comparative genomics and transcriptomics, linkage mapping, molecular ecology, and phylogenomic analyses involving reptiles. The database is available at www.reptilian-transcriptomes.org and can be enquired using a wwwblast server installed at the University of Geneva.
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Affiliation(s)
- Athanasia C Tzika
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, Switzerland SIB Swiss Institute of Bioinformatics, Switzerland Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Switzerland
| | - Asier Ullate-Agote
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, Switzerland SIB Swiss Institute of Bioinformatics, Switzerland Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Switzerland
| | - Djordje Grbic
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, Switzerland SIB Swiss Institute of Bioinformatics, Switzerland Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Switzerland
| | - Michel C Milinkovitch
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, Switzerland SIB Swiss Institute of Bioinformatics, Switzerland Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Switzerland
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23
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Giribet G. Morphology should not be forgotten in the era of genomics–a phylogenetic perspective. ZOOL ANZ 2015. [DOI: 10.1016/j.jcz.2015.01.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Thomas CG, Wang W, Jovelin R, Ghosh R, Lomasko T, Trinh Q, Kruglyak L, Stein LD, Cutter AD. Full-genome evolutionary histories of selfing, splitting, and selection in Caenorhabditis. Genome Res 2015; 25:667-78. [PMID: 25783854 PMCID: PMC4417115 DOI: 10.1101/gr.187237.114] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 03/12/2015] [Indexed: 12/19/2022]
Abstract
The nematode Caenorhabditis briggsae is a model for comparative developmental evolution with C. elegans. Worldwide collections of C. briggsae have implicated an intriguing history of divergence among genetic groups separated by latitude, or by restricted geography, that is being exploited to dissect the genetic basis to adaptive evolution and reproductive incompatibility; yet, the genomic scope and timing of population divergence is unclear. We performed high-coverage whole-genome sequencing of 37 wild isolates of the nematode C. briggsae and applied a pairwise sequentially Markovian coalescent (PSMC) model to 703 combinations of genomic haplotypes to draw inferences about population history, the genomic scope of natural selection, and to compare with 40 wild isolates of C. elegans. We estimate that a diaspora of at least six distinct C. briggsae lineages separated from one another approximately 200,000 generations ago, including the “Temperate” and “Tropical” phylogeographic groups that dominate most samples worldwide. Moreover, an ancient population split in its history approximately 2 million generations ago, coupled with only rare gene flow among lineage groups, validates this system as a model for incipient speciation. Low versus high recombination regions of the genome give distinct signatures of population size change through time, indicative of widespread effects of selection on highly linked portions of the genome owing to extreme inbreeding by self-fertilization. Analysis of functional mutations indicates that genomic context, owing to selection that acts on long linkage blocks, is a more important driver of population variation than are the functional attributes of the individually encoded genes.
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Affiliation(s)
- Cristel G Thomas
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3B2
| | - Wei Wang
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3B2
| | - Richard Jovelin
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3B2
| | - Rajarshi Ghosh
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA; Department of Pediatrics-Oncology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Tatiana Lomasko
- Informatics and Bio-Computing, Ontario Institute for Cancer Research, Toronto, Ontario, Canada, M5G 0A3
| | - Quang Trinh
- Informatics and Bio-Computing, Ontario Institute for Cancer Research, Toronto, Ontario, Canada, M5G 0A3
| | - Leonid Kruglyak
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544, USA; Departments of Human Genetics and Biological Chemistry, David Geffen School of Medicine, UCLA, Los Angeles, California 90095, USA; Howard Hughes Medical Institute, UCLA, Los Angeles, California 90095, USA
| | - Lincoln D Stein
- Informatics and Bio-Computing, Ontario Institute for Cancer Research, Toronto, Ontario, Canada, M5G 0A3; Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada, M5S 3B2; Bioinformatics and Genomics, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Asher D Cutter
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3B2; Center for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, Ontario, Canada, M5S 3B2
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25
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Kulke D, von Samson-Himmelstjerna G, Miltsch SM, Wolstenholme AJ, Jex AR, Gasser RB, Ballesteros C, Geary TG, Keiser J, Townson S, Harder A, Krücken J. Characterization of the Ca2+-gated and voltage-dependent K+-channel Slo-1 of nematodes and its interaction with emodepside. PLoS Negl Trop Dis 2014; 8:e3401. [PMID: 25521608 PMCID: PMC4270693 DOI: 10.1371/journal.pntd.0003401] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 11/07/2014] [Indexed: 11/18/2022] Open
Abstract
The cyclooctadepsipeptide emodepside and its parent compound PF1022A are broad-spectrum nematicidal drugs which are able to eliminate nematodes resistant to other anthelmintics. The mode of action of cyclooctadepsipeptides is only partially understood, but involves the latrophilin Lat-1 receptor and the voltage- and calcium-activated potassium channel Slo-1. Genetic evidence suggests that emodepside exerts its anthelmintic activity predominantly through Slo-1. Indeed, slo-1 deficient Caenorhabditis elegans strains are completely emodepside resistant. However, direct effects of emodepside on Slo-1 have not been reported and these channels have only been characterized for C. elegans and related Strongylida. Molecular and bioinformatic analyses identified full-length Slo-1 cDNAs of Ascaris suum, Parascaris equorum, Toxocara canis, Dirofilaria immitis, Brugia malayi, Onchocerca gutturosa and Strongyloides ratti. Two paralogs were identified in the trichocephalids Trichuris muris, Trichuris suis and Trichinella spiralis. Several splice variants encoding truncated channels were identified in Trichuris spp. Slo-1 channels of trichocephalids form a monophyletic group, showing that duplication occurred after the divergence of Enoplea and Chromadorea. To explore the function of a representative protein, C. elegans Slo-1a was expressed in Xenopus laevis oocytes and studied in electrophysiological (voltage-clamp) experiments. Incubation of oocytes with 1-10 µM emodepside caused significantly increased currents over a wide range of step potentials in the absence of experimentally increased intracellular Ca2+, suggesting that emodepside directly opens C. elegans Slo-1a. Emodepside wash-out did not reverse the effect and the Slo-1 inhibitor verruculogen was only effective when applied before, but not after, emodepside. The identification of several splice variants and paralogs in some parasitic nematodes suggests that there are substantial differences in channel properties among species. Most importantly, this study showed for the first time that emodepside directly opens a Slo-1 channel, significantly improving the understanding of the mode of action of this drug class.
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Affiliation(s)
- Daniel Kulke
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- Global Drug Discovery, Animal Health, Parasiticides, Bayer HealthCare, Leverkusen, Germany
| | | | - Sandra M. Miltsch
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Adrian J. Wolstenholme
- Department of Infectious Diseases, College of Veterinary Medicine, The University of Georgia, Athens, Georgia, United States of America
| | - Aaron R. Jex
- Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria, Australia
| | - Robin B. Gasser
- Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria, Australia
| | - Cristina Ballesteros
- Institute of Parasitology, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Timothy G. Geary
- Institute of Parasitology, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Simon Townson
- Tropical Parasitic Diseases Unit, Northwick Park Institute for Medical Research, Harrow, Middlesex, United Kingdom
| | - Achim Harder
- WE Biology, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Jürgen Krücken
- Institute for Parasitology and Tropical Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
- * E-mail:
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26
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Abstract
The genomes of more than 20 helminths have now been sequenced. Here we perform a meta-analysis of all sequenced genomes of nematodes and Platyhelminthes, and attempt to address the question of what are the defining characteristics of helminth genomes. We find that parasitic worms lack systems for surface antigenic variation, instead maintaining infections using their surfaces as the first line of defence against the host immune system, with several expanded gene families of genes associated with the surface and tegument. Parasite excretory/secretory products evolve rapidly, and proteases even more so, with each parasite exhibiting unique modifications of its protease repertoire. Endoparasitic flatworms show striking losses of metabolic capabilities, not matched by nematodes. All helminths do however exhibit an overall reduction in auxiliary metabolism (biogenesis of co-factors and vitamins). Overall, the prevailing pattern is that there are few commonalities between the genomes of independently evolved parasitic worms, with each parasite having undergone specific adaptations for their particular niche.
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27
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Abstract
Nematodes are abundant and diverse, and include many parasitic species. Molecular phylogenetic analyses have shown that parasitism of plants and animals has arisen at least 15 times independently. Extant nematode species also display lifestyles that are proposed to be on the evolutionary trajectory to parasitism. Recent advances have permitted the determination of the genomes and transcriptomes of many nematode species. These new data can be used to further resolve the phylogeny of Nematoda, and identify possible genetic patterns associated with parasitism. Plant-parasitic nematode genomes show evidence of horizontal gene transfer from other members of the rhizosphere, and these genes play important roles in the parasite-host interface. Similar horizontal transfer is not evident in animal parasitic groups. Many nematodes have bacterial symbionts that can be essential for survival. Horizontal transfer from symbionts to the nematode is also common, but its biological importance is unclear. Over 100 nematode species are currently targeted for sequencing, and these data will yield important insights into the biology and evolutionary history of parasitism. It is important that these new technologies are also applied to free-living taxa, so that the pre-parasitic ground state can be inferred, and the novelties associated with parasitism isolated.
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28
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Koutsovoulos G, Makepeace B, Tanya VN, Blaxter M. Palaeosymbiosis revealed by genomic fossils of Wolbachia in a strongyloidean nematode. PLoS Genet 2014; 10:e1004397. [PMID: 24901418 PMCID: PMC4046930 DOI: 10.1371/journal.pgen.1004397] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 04/06/2014] [Indexed: 12/19/2022] Open
Abstract
Wolbachia are common endosymbionts of terrestrial arthropods, and are also found in nematodes: the animal-parasitic filaria, and the plant-parasite Radopholus similis. Lateral transfer of Wolbachia DNA to the host genome is common. We generated a draft genome sequence for the strongyloidean nematode parasite Dictyocaulus viviparus, the cattle lungworm. In the assembly, we identified nearly 1 Mb of sequence with similarity to Wolbachia. The fragments were unlikely to derive from a live Wolbachia infection: most were short, and the genes were disabled through inactivating mutations. Many fragments were co-assembled with definitively nematode-derived sequence. We found limited evidence of expression of the Wolbachia-derived genes. The D. viviparus Wolbachia genes were most similar to filarial strains and strains from the host-promiscuous clade F. We conclude that D. viviparus was infected by Wolbachia in the past, and that clade F-like symbionts may have been the source of filarial Wolbachia infections. Bovine lungworms are economically important nematode parasites of cattle. We have sequenced the genome of the bovine lungworm to provide information for drug and vaccine discovery. Within the lungworm genome we found extensive evidence of an ancient association between the lungworm and a bacterium called Wolbachia. The lungworm Wolbachia is now a “fossil” in the genome, but tells of an ancient infection. Association between lungworms, and related nematode worms, and Wolbachia was not known previously. We have used the lungworm Wolbachia sequence to explore the history of nematode-Wolbachia interactions, particularly the jumping of these symbionts between arthropods and nematodes.
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Affiliation(s)
- Georgios Koutsovoulos
- Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
| | - Benjamin Makepeace
- Institute of Infection and Global Health, The University of Liverpool, Liverpool, United Kingdom
| | - Vincent N. Tanya
- Institut de Recherche Agricole pour le Développement, Regional Centre of Wakwa, Ngaoundéré, Adamawa Region, Cameroon
| | - Mark Blaxter
- Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
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Peymen K, Watteyne J, Frooninckx L, Schoofs L, Beets I. The FMRFamide-Like Peptide Family in Nematodes. Front Endocrinol (Lausanne) 2014; 5:90. [PMID: 24982652 PMCID: PMC4058706 DOI: 10.3389/fendo.2014.00090] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 05/31/2014] [Indexed: 12/31/2022] Open
Abstract
In the three decades since the FMRFamide peptide was isolated from the mollusk Macrocallista nimbosa, structurally similar peptides sharing a C-terminal RFamide motif have been identified across the animal kingdom. FMRFamide-like peptides (FLPs) represent the largest known family of neuropeptides in invertebrates. In the phylum Nematoda, at least 32 flp-genes are classified, making the FLP system of nematodes unusually complex. The diversity of the nematode FLP complement is most extensively mapped in Caenorhabditis elegans, where over 70 FLPs have been predicted. FLPs have shown to be expressed in the majority of the 302 C. elegans neurons including interneurons, sensory neurons, and motor neurons. The vast expression of FLPs is reflected in the broad functional repertoire of nematode FLP signaling, including neuroendocrine and neuromodulatory effects on locomotory activity, reproduction, feeding, and behavior. In contrast to the many identified nematode FLPs, only few peptides have been assigned a receptor and there is the need to clarify the pathway components and working mechanisms of the FLP signaling network. Here, we review the diversity, distribution, and functions of FLPs in nematodes.
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Affiliation(s)
- Katleen Peymen
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Jan Watteyne
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Lotte Frooninckx
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Liliane Schoofs
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
| | - Isabel Beets
- Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Leuven, Belgium
- *Correspondence: Isabel Beets, Functional Genomics and Proteomics Group, Department of Biology, KU Leuven, Naamsestraat 59, Leuven 3000, Belgium e-mail:
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Kumar S, Jones M, Koutsovoulos G, Clarke M, Blaxter M. Blobology: exploring raw genome data for contaminants, symbionts and parasites using taxon-annotated GC-coverage plots. Front Genet 2013; 4:237. [PMID: 24348509 PMCID: PMC3843372 DOI: 10.3389/fgene.2013.00237] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 10/23/2013] [Indexed: 12/16/2022] Open
Abstract
Generating the raw data for a de novo genome assembly project for a target eukaryotic species is relatively easy. This democratization of access to large-scale data has allowed many research teams to plan to assemble the genomes of non-model organisms. These new genome targets are very different from the traditional, inbred, laboratory-reared model organisms. They are often small, and cannot be isolated free of their environment – whether ingested food, the surrounding host organism of parasites, or commensal and symbiotic organisms attached to or within the individuals sampled. Preparation of pure DNA originating from a single species can be technically impossible, but assembly of mixed-organism DNA can be difficult, as most genome assemblers perform poorly when faced with multiple genomes in different stoichiometries. This class of problem is common in metagenomic datasets that deliberately try to capture all the genomes present in an environment, but replicon assembly is not often the goal of such programs. Here we present an approach to extracting, from mixed DNA sequence data, subsets that correspond to single species’ genomes and thus improving genome assembly. We use both numerical (proportion of GC bases and read coverage) and biological (best-matching sequence in annotated databases) indicators to aid partitioning of draft assembly contigs, and the reads that contribute to those contigs, into distinct bins that can then be subjected to rigorous, optimized assembly, through the use of taxon-annotated GC-coverage plots (TAGC plots). We also present Blobsplorer, a tool that aids exploration and selection of subsets from TAGC-annotated data. Partitioning the data in this way can rescue poorly assembled genomes, and reveal unexpected symbionts and commensals in eukaryotic genome projects. The TAGC plot pipeline script is available from https://github.com/blaxterlab/blobology, and the Blobsplorer tool from https://github.com/mojones/Blobsplorer.
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Affiliation(s)
- Sujai Kumar
- Institute of Evolutionary Biology, Ashworth Laboratories, University of Edinburgh Edinburgh, UK
| | - Martin Jones
- Institute of Evolutionary Biology, Ashworth Laboratories, University of Edinburgh Edinburgh, UK
| | - Georgios Koutsovoulos
- Institute of Evolutionary Biology, Ashworth Laboratories, University of Edinburgh Edinburgh, UK
| | - Michael Clarke
- Institute of Evolutionary Biology, Ashworth Laboratories, University of Edinburgh Edinburgh, UK
| | - Mark Blaxter
- Institute of Evolutionary Biology, Ashworth Laboratories, University of Edinburgh Edinburgh, UK ; Edinburgh Genomics, University of Edinburgh Edinburgh, UK
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Cantacessi C, Hofmann A, Pickering D, Navarro S, Mitreva M, Loukas A. TIMPs of parasitic helminths - a large-scale analysis of high-throughput sequence datasets. Parasit Vectors 2013; 6:156. [PMID: 23721526 PMCID: PMC3679795 DOI: 10.1186/1756-3305-6-156] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 05/28/2013] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Tissue inhibitors of metalloproteases (TIMPs) are a multifunctional family of proteins that orchestrate extracellular matrix turnover, tissue remodelling and other cellular processes. In parasitic helminths, such as hookworms, TIMPs have been proposed to play key roles in the host-parasite interplay, including invasion of and establishment in the vertebrate animal hosts. Currently, knowledge of helminth TIMPs is limited to a small number of studies on canine hookworms, whereas no information is available on the occurrence of TIMPs in other parasitic helminths causing neglected diseases. METHODS In the present study, we conducted a large-scale investigation of TIMP proteins of a range of neglected human parasites including the hookworm Necator americanus, the roundworm Ascaris suum, the liver flukes Clonorchis sinensis and Opisthorchis viverrini, as well as the schistosome blood flukes. This entailed mining available transcriptomic and/or genomic sequence datasets for the presence of homologues of known TIMPs, predicting secondary structures of defined protein sequences, systematic phylogenetic analyses and assessment of differential expression of genes encoding putative TIMPs in the developmental stages of A. suum, N. americanus and Schistosoma haematobium which infect the mammalian hosts. RESULTS A total of 15 protein sequences with high homology to known eukaryotic TIMPs were predicted from the complement of sequence data available for parasitic helminths and subjected to in-depth bioinformatic analyses. CONCLUSIONS Supported by the availability of gene manipulation technologies such as RNA interference and/or transgenesis, this work provides a basis for future functional explorations of helminth TIMPs and, in particular, of their role/s in fundamental biological pathways linked to long-term establishment in the vertebrate hosts, with a view towards the development of novel approaches for the control of neglected helminthiases.
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Affiliation(s)
- Cinzia Cantacessi
- Center for Biodiscovery and Molecular Development of Therapeutics, Queensland Tropical Health Alliance, James Cook University, Cairns, Queensland, Australia
| | - Andreas Hofmann
- Structural Chemistry Program, Eskitis Institute, Griffith University, Brisbane, Queensland, Australia
| | - Darren Pickering
- Center for Biodiscovery and Molecular Development of Therapeutics, Queensland Tropical Health Alliance, James Cook University, Cairns, Queensland, Australia
| | - Severine Navarro
- Center for Biodiscovery and Molecular Development of Therapeutics, Queensland Tropical Health Alliance, James Cook University, Cairns, Queensland, Australia
| | - Makedonka Mitreva
- The Genome Institute, Washington University School of Medicine, St. Louis, MO, USA
| | - Alex Loukas
- Center for Biodiscovery and Molecular Development of Therapeutics, Queensland Tropical Health Alliance, James Cook University, Cairns, Queensland, Australia
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