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Peyretaillade E, Akossi RF, Tournayre J, Delbac F, Wawrzyniak I. How to overcome constraints imposed by microsporidian genome features to ensure gene prediction? J Eukaryot Microbiol 2024:e13038. [PMID: 38934348 DOI: 10.1111/jeu.13038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 06/03/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024]
Abstract
Since the advent of sequencing techniques and due to their continuous evolution, it has become easier and less expensive to obtain the complete genome sequence of any organism. Nevertheless, to elucidate all biological processes governing organism development, quality annotation is essential. In genome annotation, predicting gene structure is one of the most important and captivating challenges for computational biology. This aspect of annotation requires continual optimization, particularly for genomes as unusual as those of microsporidia. Indeed, this group of fungal-related parasites exhibits specific features (highly reduced gene sizes, sequences with high rate of evolution) linked to their evolution as intracellular parasites, requiring the implementation of specific annotation approaches to consider all these features. This review aimed to outline these characteristics and to assess the increasingly efficient approaches and tools that have enhanced the accuracy of gene prediction for microsporidia, both in terms of sensitivity and specificity. Subsequently, a final part will be dedicated to postgenomic approaches aimed at reinforcing the annotation data generated by prediction software. These approaches include the characterization of other understudied genes, such as those encoding regulatory noncoding RNAs or very small proteins, which also play crucial roles in the life cycle of these microorganisms.
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Affiliation(s)
| | - Reginal F Akossi
- LMGE, CNRS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Jérémy Tournayre
- INRAE, UMR Herbivores, Université Clermont Auvergne, VetAgro Sup, Saint-Genès-Champanelle, France
| | - Frédéric Delbac
- LMGE, CNRS, Université Clermont Auvergne, Clermont-Ferrand, France
| | - Ivan Wawrzyniak
- LMGE, CNRS, Université Clermont Auvergne, Clermont-Ferrand, France
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Khalaf A, Lawniczak MKN, Blaxter ML, Jaron KS. Polyploidy is widespread in Microsporidia. Microbiol Spectr 2024; 12:e0366923. [PMID: 38214524 PMCID: PMC10845963 DOI: 10.1128/spectrum.03669-23] [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: 10/13/2023] [Accepted: 12/15/2023] [Indexed: 01/13/2024] Open
Abstract
Microsporidia are obligate intracellular eukaryotic parasites with an extremely broad host range. They have both economic and public health importance. Ploidy in microsporidia is variable, with a few species formally identified as diploid and one as polyploid. Given the increase in the number of studies sequencing microsporidian genomes, it is now possible to assess ploidy levels across all currently explored microsporidian diversity. We estimate ploidy for all microsporidian data sets available on the Sequence Read Archive using k-mer-based analyses, indicating that polyploidy is widespread in Microsporidia and that ploidy change is dynamic in the group. Using genome-wide heterozygosity estimates, we also show that polyploid microsporidian genomes are relatively homozygous, and we discuss the implications of these findings on the timing of polyploidization events and their origin.IMPORTANCEMicrosporidia are single-celled intracellular parasites, distantly related to fungi, that can infect a broad range of hosts, from humans all the way to protozoans. Exploiting the wealth of microsporidian genomic data available, we use k-mer-based analyses to assess ploidy status across the group. Understanding a genome's ploidy is crucial in order to assemble it effectively and may also be relevant for better understanding a parasite's behavior and life cycle. We show that tetraploidy is present in at least six species in Microsporidia and that these polyploidization events are likely to have occurred independently. We discuss why these findings may be paradoxical, given that Microsporidia, like other intracellular parasites, have extremely small, reduced genomes.
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Affiliation(s)
- Amjad Khalaf
- Tree of Life, Wellcome Sanger Institute, Cambridge, United Kingdom
| | | | - Mark L. Blaxter
- Tree of Life, Wellcome Sanger Institute, Cambridge, United Kingdom
| | - Kamil S. Jaron
- Tree of Life, Wellcome Sanger Institute, Cambridge, United Kingdom
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Tournayre J, Polonais V, Wawrzyniak I, Akossi RF, Parisot N, Lerat E, Delbac F, Souvignet P, Reichstadt M, Peyretaillade E. MicroAnnot: A Dedicated Workflow for Accurate Microsporidian Genome Annotation. Int J Mol Sci 2024; 25:880. [PMID: 38255958 PMCID: PMC10815200 DOI: 10.3390/ijms25020880] [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] [Received: 10/27/2023] [Revised: 12/29/2023] [Accepted: 01/04/2024] [Indexed: 01/24/2024] Open
Abstract
With nearly 1700 species, Microsporidia represent a group of obligate intracellular eukaryotes with veterinary, economic and medical impacts. To help understand the biological functions of these microorganisms, complete genome sequencing is routinely used. Nevertheless, the proper prediction of their gene catalogue is challenging due to their taxon-specific evolutionary features. As innovative genome annotation strategies are needed to obtain a representative snapshot of the overall lifestyle of these parasites, the MicroAnnot tool, a dedicated workflow for microsporidian sequence annotation using data from curated databases of accurately annotated microsporidian genes, has been developed. Furthermore, specific modules have been implemented to perform small gene (<300 bp) and transposable element identification. Finally, functional annotation was performed using the signature-based InterProScan software. MicroAnnot's accuracy has been verified by the re-annotation of four microsporidian genomes for which structural annotation had previously been validated. With its comparative approach and transcriptional signal identification method, MicroAnnot provides an accurate prediction of translation initiation sites, an efficient identification of transposable elements, as well as high specificity and sensitivity for microsporidian genes, including those under 300 bp.
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Affiliation(s)
- Jérémy Tournayre
- INRAE, UMR Herbivores, Université Clermont Auvergne, VetAgro Sup, 63122 Saint-Genès-Champanelle, France; (J.T.); (P.S.); (M.R.)
| | - Valérie Polonais
- LMGE, CNRS, Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (V.P.); (I.W.); (R.F.A.); (F.D.)
| | - Ivan Wawrzyniak
- LMGE, CNRS, Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (V.P.); (I.W.); (R.F.A.); (F.D.)
| | - Reginald Florian Akossi
- LMGE, CNRS, Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (V.P.); (I.W.); (R.F.A.); (F.D.)
| | - Nicolas Parisot
- UMR 203, BF2I, INRAE, INSA Lyon, Université de Lyon, 69621 Villeurbanne, France
| | - Emmanuelle Lerat
- VAS, CNRS, UMR5558, LBBE, Université Claude Bernard Lyon 1, 69622 Villeurbanne, France;
| | - Frédéric Delbac
- LMGE, CNRS, Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (V.P.); (I.W.); (R.F.A.); (F.D.)
| | - Pierre Souvignet
- INRAE, UMR Herbivores, Université Clermont Auvergne, VetAgro Sup, 63122 Saint-Genès-Champanelle, France; (J.T.); (P.S.); (M.R.)
| | - Matthieu Reichstadt
- INRAE, UMR Herbivores, Université Clermont Auvergne, VetAgro Sup, 63122 Saint-Genès-Champanelle, France; (J.T.); (P.S.); (M.R.)
| | - Eric Peyretaillade
- LMGE, CNRS, Université Clermont Auvergne, 63000 Clermont-Ferrand, France; (V.P.); (I.W.); (R.F.A.); (F.D.)
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Angst P, Pombert JF, Ebert D, Fields PD. Near chromosome-level genome assembly of the microsporidium Hamiltosporidium tvaerminnensis. G3 (BETHESDA, MD.) 2023; 13:jkad185. [PMID: 37565496 PMCID: PMC10542269 DOI: 10.1093/g3journal/jkad185] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/05/2023] [Indexed: 08/12/2023]
Abstract
Microsporidia are intracellular parasitic fungi whose genomes rank among the smallest of all known eukaryotes. A number of outstanding questions remain concerning the evolution of their large-scale variation in genome architecture, responsible for genome size variation of more than an order of magnitude. This genome report presents the first near-chromosomal assembly of a large-genome microsporidium, Hamiltosporidium tvaerminnensis. Combined Oxford Nanopore, Pacific Biosciences (PacBio), and Illumina sequencing led to a genome assembly of 17 contigs, 11 of which represent complete chromosomes. Our assembly is 21.64 Mb in length, has an N50 of 1.44 Mb, and consists of 39.56% interspersed repeats. We introduce a novel approach in microsporidia, PacBio Iso-Seq, as part of a larger annotation pipeline for obtaining high-quality annotations of 3,573 protein-coding genes. Based on direct evidence from the full-length Iso-Seq transcripts, we present evidence for alternative polyadenylation and variation in splicing efficiency, which are potential regulation mechanisms for gene expression in microsporidia. The generated high-quality genome assembly is a necessary resource for comparative genomics that will help elucidate the evolution of genome architecture in response to intracellular parasitism.
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Affiliation(s)
- Pascal Angst
- Department of Environmental Sciences, Zoology, University of Basel, Basel 4051, Switzerland
| | | | - Dieter Ebert
- Department of Environmental Sciences, Zoology, University of Basel, Basel 4051, Switzerland
| | - Peter D Fields
- Department of Environmental Sciences, Zoology, University of Basel, Basel 4051, Switzerland
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Huang Q, Mirjalali H, Zhou Z. Editorial: Genomic and evolutionary analysis of microsporidian parasites. Front Microbiol 2023; 14:1248661. [PMID: 37485513 PMCID: PMC10361567 DOI: 10.3389/fmicb.2023.1248661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/25/2023] Open
Affiliation(s)
- Qiang Huang
- Honeybee Research Institute, Jiangxi Agricultural University, Nanchang, China
| | - Hamed Mirjalali
- Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zeyang Zhou
- State Key Laboratory of Resource Insects, Southwest University, Chongqing, China
- Key Laboratory of Conservation and Utilization of Pollinator Insect of the Upper Reaches of the Yangtze River (Co-construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Chongqing Normal University, Chongqing, China
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Ran M, Shi Y, Li B, Xiang H, Tao M, Meng X, Li T, Li C, Bao J, Pan G, Zhou Z. Genome-Wide Characterization and Comparative Genomic Analysis of the Serpin Gene Family in Microsporidian Nosema bombycis. Int J Mol Sci 2022; 24:ijms24010550. [PMID: 36613990 PMCID: PMC9820262 DOI: 10.3390/ijms24010550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/10/2022] [Accepted: 12/24/2022] [Indexed: 12/30/2022] Open
Abstract
Microsporidia are ubiquitous in the environment, infecting almost all invertebrates, vertebrates, and some protists. The microsporidian Nosema bombycis causes silkworms pébrine disease and leads to huge economic losses. Parasite secreted proteins play vital roles in pathogen-host interactions. Serine protease inhibitors (serpins), belonging to the largest and most broadly distributed protease inhibitor superfamily, are also found in Microsporidia. In this study, we characterized 19 serpins (NbSPNs) in N. bombycis; eight of them were predicted with signal peptides. All NbSPN proteins contain a typical conserved serpin (PF00079) domain. The comparative genomic analysis revealed that microsporidia serpins were only found in the genus Nosema. In addition to N. bombycis, a total of 34 serpins were identified in another six species of Nosema including N. antheraeae (11), N. granulosis (8), Nosema sp. YNPr (3), Nosema sp. PM-1 (3), N. apis (4), and N. ceranae (5). Serpin gene duplications in tandem obviously occurred in Nosema antheranae. Notably, the NbSPNs were phylogenetically clustered with serpins from the Chordopoxvirinae, the subfamily of Poxvirus. All 19 NbSPN transcripts were detected in the infected midgut and fat body, while 19 NbSPN genes except for NbSPN12 were found in the transcriptome of the infected silkworm embryonic cell line BmE-SWU1. Our work paves the way for further study of serpin function in microsporidia.
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Affiliation(s)
- Maoshuang Ran
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Yulian Shi
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Boning Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Heng Xiang
- College of Animal Science and Technology, Southwest University, Chongqing 400715, China
| | - Meilin Tao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
| | - Xianzhi Meng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Tian Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Chunfeng Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Jialing Bao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
| | - Guoqing Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
- Correspondence: (G.P.); (Z.Z.)
| | - Zeyang Zhou
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing 400715, China
- College of Animal Science and Technology, Southwest University, Chongqing 400715, China
- Correspondence: (G.P.); (Z.Z.)
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Heterologous Expressed NbSWP12 from Microsporidia Nosema bombycis Can Bind with Phosphatidylinositol 3-phosphate and Affect Vesicle Genesis. J Fungi (Basel) 2022; 8:jof8080764. [PMID: 35893133 PMCID: PMC9332396 DOI: 10.3390/jof8080764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/15/2022] [Accepted: 07/21/2022] [Indexed: 02/01/2023] Open
Abstract
Microsporidia are a big group of single-celled obligate intracellular organisms infecting most animals and some protozoans. These minimalist eukaryotes lack numerous genes in metabolism and vesicle trafficking. Here, we demonstrated that the spore wall protein NbSWP12 of microsporidium Nosema bombycis belongs to Bin/Amphiphysin/Rvs (BAR) protein family and can specifically bind with phosphatidylinositol 3-phosphate [Ptdlns(3)P]. Since Ptdlns(3)P is involved in endosomal vesicle biogenesis and trafficking, we heterologous expressed NbSWP12 in yeast Saccharomyces cerevisiae and proved that NbSWP12 can target the cell membrane and endocytic vesicles. Nbswp12 transformed into Gvp36 (a BAR protein of S. cerevisiae) deletion mutant rescued the defect phenotype of vesicular traffic. This study identified a BAR protein function in vesicle genesis and sorting and provided clues for further understanding of how microsporidia internalize nutrients and metabolites during proliferation.
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