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PLoS Pathogens Jul 2023Microsporidia are a large phylum of intracellular parasites that can infect most types of animals. Species in the Nematocida genus can infect nematodes including...
Microsporidia are a large phylum of intracellular parasites that can infect most types of animals. Species in the Nematocida genus can infect nematodes including Caenorhabditis elegans, which has become an important model to study mechanisms of microsporidia infection. To understand the genomic properties and evolution of nematode-infecting microsporidia, we sequenced the genomes of nine species of microsporidia, including two genera, Enteropsectra and Pancytospora, without any previously sequenced genomes. Core cellular processes, including metabolic pathways, are mostly conserved across genera of nematode-infecting microsporidia. Each species encodes unique proteins belonging to large gene families that are likely used to interact with host cells. Most strikingly, we observed one such family, NemLGF1, is present in both Nematocida and Pancytospora species, but not any other microsporidia. To understand how Nematocida phenotypic traits evolved, we measured the host range, tissue specificity, spore size, and polar tube length of several species in the genus. Our phylogenetic analysis shows that Nematocida is composed of two groups of species with distinct traits and that species with longer polar tubes infect multiple tissues. Together, our work details both genomic and trait evolution between related microsporidia species and provides a useful resource for further understanding microsporidia evolution and infection mechanisms.
Topics: Animals; Microsporidia; Phylogeny; Nematoda; Caenorhabditis elegans; Genomics
PubMed: 37471459
DOI: 10.1371/journal.ppat.1011510 -
Microbiology Spectrum Feb 2024Microsporidia are obligate intracellular eukaryotic parasites with an extremely broad host range. They have both economic and public health importance. Ploidy in...
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.
Topics: Humans; Microsporidia; Phylogeny; Evolution, Molecular; Genome, Fungal; Polyploidy
PubMed: 38214524
DOI: 10.1128/spectrum.03669-23 -
EMBO Reports Dec 2023Disrupting the small RNA pathway and chromatin-modifying enzymes in C. elegans often leads to a mortal germline (Mrt) phenotype, characterized by progressive sterility...
Disrupting the small RNA pathway and chromatin-modifying enzymes in C. elegans often leads to a mortal germline (Mrt) phenotype, characterized by progressive sterility observed over multiple generations at elevated temperature. This phenotype arises from the inheritance of aberrant epigenetic memory across generations. In this issue of EMBO Reports, Frézal and colleagues reported that, while in standard laboratory environment C. elegans wild isolates exhibit the Mrt phenotype, sterility does not occur when the worms are exposed to naturally associated bacteria and microsporidia. Excitingly, diet-induced epigenetic memory may persist for multiple generations. This suggests intriguing diet-gene interactions in modulating nongenetic inheritance, potentially shaping the evolutionary trajectory of the animals.
Topics: Animals; Caenorhabditis elegans; Epigenesis, Genetic; Caenorhabditis elegans Proteins; Phenotype; Infertility
PubMed: 37983676
DOI: 10.15252/embr.202358318 -
Journal of Fungi (Basel, Switzerland) Jul 2023Microsporidia are a large group of mysterious obligate intracellular eukaryotic parasites. The microsporidian spore can survive in the absence of nutrients for years... (Review)
Review
Microsporidia are a large group of mysterious obligate intracellular eukaryotic parasites. The microsporidian spore can survive in the absence of nutrients for years under harsh conditions and germinate within seconds under the stimulation of environmental changes like pH and ions. During germination, microsporidia experience an increase in intrasporal osmotic pressure, which leads to an influx of water into the spore, followed by swelling of the polaroplasts and posterior vacuole, which eventually fires the polar filament (PF). Infectious sporoplasm was transported through the extruded polar tube (PT) and delivered into the host cell. Despite much that has been learned about the germination of microsporidia, there are still several major questions that remain unanswered, including: (i) There is still a lack of knowledge about the signaling pathways involved in spore germination. (ii) The germination of spores is not well understood in terms of its specific energetics. (iii) Limited understanding of how spores germinate and how the nucleus and membranes are rearranged during germination. (iv) Only a few proteins in the invasion organelles have been identified; many more are likely undiscovered. This review summarizes the major resolved and unresolved issues concerning the process of microsporidian spore germination.
PubMed: 37504762
DOI: 10.3390/jof9070774 -
Frontiers in Microbiology 2023
PubMed: 37485513
DOI: 10.3389/fmicb.2023.1248661 -
Microorganisms Jul 2023Parasites are a significant component of biodiversity. They negatively affect fish appearance, growth, and reproduction. In this study, the prevalence of infection,...
Parasites are a significant component of biodiversity. They negatively affect fish appearance, growth, and reproduction. In this study, the prevalence of infection, diversity, and mean intensity of parasites were examined in 9 freshwater fish species (45 samples per fish species). Ecto-parasites were examined on the skin, gills, and fins with a hand lens. Wet mounts were prepared using mucosal scrapings from all the external and internal organs of the sampled fish. Microscopy, muscle compression, and the pepsin-HCL artificial digestion technique were also performed. In this study, 26 species of parasites were identified including three taxa belonging to 9 species of protozoan parasites, 11 treamtodes, and 6 monogenean parasites. The identified protozoan parasites were , sp., sp., sp., sp., , , sp., and . The identified trematode parasites were , , , , , , sp., sp., , , and The identified monogenean parasites were , , , , and . The diversity of parasites was maximum at the Okara site. The host's organs that were targeted for parasitic infection included the intestine, liver, gills, fins, skin, and kidneys. The majority of the parasites were identified in followed by , , , , and . Two species appeared to be resistant species because none of the parasites were observed in or . This study also concluded that the prevalence of parasites increased with increasing length, size, and age of fish.
PubMed: 37630500
DOI: 10.3390/microorganisms11081940 -
BMC Genomics Jul 2023The interaction networks between coding and non-coding RNAs (ncRNAs) including long non-coding RNA (lncRNA), covalently closed circular RNA (circRNA) and miRNA are...
BACKGROUND
The interaction networks between coding and non-coding RNAs (ncRNAs) including long non-coding RNA (lncRNA), covalently closed circular RNA (circRNA) and miRNA are significant to elucidate molecular processes of biological activities and interactions between host and pathogen. Congenital infection caused by vertical transmission of microsporidia N. bombycis can result in severe economic losses in the silkworm-feeding industry. However, little is known about ncRNAs that take place in the microsporidia congenital infection. Here we conducted whole-transcriptome RNA-Seq analyses to identify ncRNAs and regulatory networks for both N. bombycis and host including silkworm embryos and larvae during the microsporidia congenital infection.
RESULTS
A total of 4,171 mRNAs, 403 lncRNA, 62 circRNAs, and 284 miRNAs encoded by N. bombycis were identified, among which some differentially expressed genes formed cross-talk and are involved in N. bombycis proliferation and infection. For instance, a lncRNA/circRNA competing endogenous RNA (ceRNA) network including 18 lncRNAs, one circRNA, and 20 miRNAs was constructed to describe 14 key parasites genes regulation, such as polar tube protein 3 (PTP3), ricin-B-lectin, spore wall protein 4 (SWP4), and heat shock protein 90 (HSP90). Regarding host silkworm upon N. bombycis congenital infection, a total of 14,889 mRNAs, 3,038 lncRNAs, 19,039 circRNAs, and 3,413 miRNAs were predicted based on silkworm genome with many differentially expressed coding and non-coding genes during distinct developmental stages. Different species of RNAs form interacting network to modulate silkworm biological processes, such as growth, metamorphosis and immune responses. Furthermore, a lncRNA/circRNA ceRNA network consisting of 140 lncRNAs, five circRNA, and seven miRNAs are constructed hypothetically to describe eight key host genes regulation, such as Toll-6, Serpin-6, inducible nitric oxide synthase (iNOS) and Caspase-8. Notably, cross-species analyses indicate that parasite and host miRNAs play a vital role in pathogen-host interaction in the microsporidia congenital infection.
CONCLUSION
This is the first comprehensive pan-transcriptome study inclusive of both N. bombycis and its host silkworm with a specific focus on the microsporidia congenital infection, and show that ncRNA-mediated regulation plays a vital role in the microsporidia congenital infection, which provides a new insight into understanding the basic biology of microsporidia and pathogen-host interaction.
Topics: RNA, Long Noncoding; RNA, Circular; Nosema; Microsporidiosis; Host-Pathogen Interactions; MicroRNAs; RNA, Messenger; Gene Regulatory Networks
PubMed: 37495972
DOI: 10.1186/s12864-023-09490-3 -
Microorganisms Apr 2024spp. and Microsporidia are opportunistic microorganisms with remarkable zoonotic transmission potential due to their capacity to infect humans and animals. The aim of...
spp. and Microsporidia are opportunistic microorganisms with remarkable zoonotic transmission potential due to their capacity to infect humans and animals. The aim of this study was to evaluate the prevalence of these microorganisms in stool samples of animal and human origin. In total, 369 stool samples (205 from human patients with diarrhea and 164 of animal origin) were included in the study. spp. and Microsporidia presence were determined by using multiplex nested PCR. Positive results were analyzed by using Sanger sequencing of the amplicon, utilizing BLASTN and ClustalX software to confirm identification. spp. were found in 0.97% and 4.26% of human and animal samples, respectively. was detected in human and animal stools in 6.82% and 3.05% of the samples, respectively. No associations were found when analyzing the presence of spp. and and the demographic and clinical variables of patients and animals. This study demonstrates the presence of these microorganisms in human and animal samples from different species, and the most interesting findings are the detection of spp. in pets (e.g., rodents) that are not usually included in this type of study, and the identification of in patients with diarrhea without underlying disease.
PubMed: 38792745
DOI: 10.3390/microorganisms12050918