Small Subunit Ribosomal DNA Phylogeny of Various Microsporidia with Emphasis on AIDS Related Forms

Baker, Michael D.; Vossbrinck, Charles R.; Didier, Elizabeth S.; Maddox, Joseph V.; Shadduck, John A.

doi:10.1111/j.1550-7408.1995.tb05906.x

Cited by 190 publications

(120 citation statements)

References 25 publications

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“…After germination, the emptied content of the spores was used for DNA extraction by standard phenol-chloroform method. The 16S small subunit (SSU) rRNA gene was amplified using the primers 18f 5k-CACCAG-GTTGATTCTGCC-3k and 1537r 5k-TTATGA-TCCTGCTAATGGTTC-3k designed by Baker et al (1995). PCR amplification was carried out in 200 ml microfuge tubes, using 10 ng DNA, 5 pmol of each primer, 0 .…”

Section: Isolation Of Dna Pcr Amplification and Sequencing Of 16s Ssmentioning

confidence: 99%

Morphological and molecular characterization of a new microsporidian (Protozoa: Microsporidia) isolated fromSpodoptera litura(Fabricius) (Lepidoptera: Noctuidae)

et al. 2006

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A microsporidium was isolated from larvae of Spodoptera litura (Fabricius) collected from Tamil Nadu, India. This microsporidian species is monomorphic, disporous and develops in direct contact with the cytoplasm of the host cell. The nuclear configuration of merogonic and sporogonic stages was diplokaryotic. The merogonic proliferative stage was unusual that normal development with 1, 2 and 4 binucleated forms were common, while large multinucleate meronts containing 8 and 12 small compact horseshoe-like diplokaryotic nuclei were also observed. The fresh spores were typically ovocylindrical in shape, with a mean size of 3 . 91r1 . 91 mm and the polar filament length was y90 mm. Infection was systemic with mature spores produced in the midgut, nervous tissue, muscles, labial glands, gonads, tracheae, epidermis, Malpighian tubules and, most extensively, fat body tissues. The new isolate was highly pathogenic to S. litura larvae. Host specificity tests performed on 37 non-target hosts of 5 different insect orders revealed that the new isolate is pathogenic only to lepidopteran insects. We sequenced the 16S small subunit rRNA (SSU rRNA) gene of the isolate and compared it with 72 non-redundant microsporidian sequences from the GenBank. Based on the light microscopic studies and phylogenetic analyses, the new isolate is assigned to the genus Nosema. Significant differences in the SSU rRNA sequence were identified when compared with the type species Nosema bombycis and other closely related species viz., Nosema spodopterae. Structural differences were also observed in the 16S SSU rRNA between the new isolate and the two above-mentioned microsporidian pathogens. We conclude that the microsporidian isolate reported here is distinctly different from the other known species and is likely to be a new species.

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Section: Isolation Of Dna Pcr Amplification and Sequencing Of 16s Ssmentioning

confidence: 99%

Morphological and molecular characterization of a new microsporidian (Protozoa: Microsporidia) isolated fromSpodoptera litura(Fabricius) (Lepidoptera: Noctuidae)

et al. 2006

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“…It was first recognized in 1857 by Nägeli (2). Recently, phylogenetic analyses based on conserved proteins (3)(4)(5), ribosomal DNA (rDNA) sequences (6,7), and complete sequencing of the Encephalitozoon cuniculi genome (8) have suggested that microsporidia, which undergo a highly reductive evolution, are closely related to fungi (9). However, the N. bombycis genome has greatly expanded due to transposable elements and gene duplications (10).…”

mentioning

confidence: 99%

Interaction and Assembly of Two Novel Proteins in the Spore Wall of the Microsporidian Species Nosema bombycis and Their Roles in Adherence to and Infection of Host Cells

et al. 2015

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Microsporidia are obligate intracellular parasites with rigid spore walls that protect against various environmental pressures. Despite an extensive description of the spore wall, little is known regarding the mechanism by which it is deposited or the role it plays in cell adhesion and infection. In this study, we report the identification and characterization of two novel spore wall proteins, SWP7 and SWP9, in the microsporidian species Nosema bombycis. SWP7 and SWP9 are mainly localized to the exospore and endospore of mature spores and the cytoplasm of sporonts, respectively. In addition, a portion of SWP9 is targeted to the spore wall of sporoblasts earlier than SWP7 is. Both SWP7 and SWP9 are specifically colocalized to the spore wall in mature spores. Furthermore, immunoprecipitation, far-Western blotting, unreduced SDS-PAGE, and yeast two-hybrid data demonstrated that SWP7 interacted with SWP9. The chitin binding assay showed that, within the total spore protein, SWP9 and SWP7 can bind to the deproteinated chitin spore coats (DCSCs) of N. bombycis. However, binding of the recombinant protein rSWP7-His to the DCSCs is dependent on the combination of rSWP9 -glutathione S-transferase (GST) with the DCSCs. Finally, rSWP9-GST, anti-SWP9, and anti-SWP7 antibodies decreased spore adhesion and infection of the host cell. In conclusion, SWP7 and SWP9 may have important structural capacities and play significant roles in modulating host cell adherence and infection in vitro. A possible major function of SWP9 is as a scaffolding protein that supports other proteins (such as SWP7) that form the integrated spore wall of N. bombycis.M icrosporidia, which infect numerous vertebrate and invertebrate species, are a specific group of obligate spore-forming, intracellular, and unicellular eukaryotic protists (1). The microsporidian species Nosema bombycis causes pebrine, a disease that was common in Europe, America, and Asia during the mid19th century and still causes heavy losses in silk-producing countries, such as China and India (1). It was first recognized in 1857 by Nägeli (2). Recently, phylogenetic analyses based on conserved proteins (3-5), ribosomal DNA (rDNA) sequences (6, 7), and complete sequencing of the Encephalitozoon cuniculi genome (8) have suggested that microsporidia, which undergo a highly reductive evolution, are closely related to fungi (9). However, the N. bombycis genome has greatly expanded due to transposable elements and gene duplications (10).The microsporidian spore wall, which is usually comprised of an electron-dense proteinaceous outer layer (exospore) of 25 to 30 nm and an electron-transparent chitinous inner layer (endospore) of 30 to 35 nm, maintains the spore's morphology and helps the mature spore resist the outer environment (11-13). Although chitin is the major component of the spore wall, only one chitin-associated protein has been identified. The chitin deacetylase activity of E. cuniculi (EcCDA) has been confirmed to be expressed during sporogonic stages (14). Currently, the deprot...

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“…intestinalis (formerly Septata intestinalis) -this pathogen was first described by Cali et al (1991b) found in patients with chronic diarrhea, by Orenstein et al (1992) in a case of disseminated microsporidiosis and from humans infecting enterocytes, macrophages and associated with diarrhea in an Aids patient. This result was underlined by the analysis of Baker et al (1995) who suggest that S. intestinalis should be designated as E. intestinalis on the basis of the phylogenetic analysis of the small subunit ribosomal DNA. This parasite was found associated with chronic diarrhea and dissemination in Aids patients (Cali et al 1993), small intestinal microsporidiosis (Field et al 1993).…”

Section: Encephalitozoonmentioning

confidence: 93%

Microsporidia and acquired immunodeficiency syndrome

Schottelius

Costa²

2000

Mem. Inst. Oswaldo Cruz

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Small Subunit Ribosomal DNA Phylogeny of Various Microsporidia with Emphasis on AIDS Related Forms

Cited by 190 publications

References 25 publications

Morphological and molecular characterization of a new microsporidian (Protozoa: Microsporidia) isolated fromSpodoptera litura(Fabricius) (Lepidoptera: Noctuidae)

Morphological and molecular characterization of a new microsporidian (Protozoa: Microsporidia) isolated fromSpodoptera litura(Fabricius) (Lepidoptera: Noctuidae)

Interaction and Assembly of Two Novel Proteins in the Spore Wall of the Microsporidian Species Nosema bombycis and Their Roles in Adherence to and Infection of Host Cells

Microsporidia and acquired immunodeficiency syndrome

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