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Spore Wall (spore + wall)

Distribution by Scientific Domains
Life Sciences80%

Selected Abstracts

Meu10 is required for spore wall maturation in Schizosaccharomyces pombe

GENES TO CELLS, Issue 2 2002
Takahiro Tougan
Background: Many genes are meiosis and/or sporulation-specifically transcribed during this process. Isolation and analysis of these genes might help us to understand how meiosis and sporulation are regulated. For this purpose, we have isolated a large number of cDNA clones from Schizosaccharomyces pombe whose expression is up-regulated during meiosis. Results: We have isolated meu10+ gene, which encodes 416 amino acids and bears homology to SPS2 of Saccharomyces cerevisiae. A strain whose meu10+ gene has been deleted forms no viable spores. Thin-section electron micrographs showed that the meu10, strain has abnormally formed spore walls, and then they disrupt, allowing cytoplasmic material to escape. The Meu10-GFP fusion protein is localized to the spore periphery, thereafter returned to the cytoplasm after sporulation. Meu10-GFP localization to the spore wall was almost normal in the bgs2, or chs1, mutants that lack 1,3-,-glucan or chitin, respectively. In contrast, 1,3-,-glucan is abnormally localized in meu10, cells. Meu10 has an N-terminal domain with homology to the mammalian insulin receptor and a C-terminal domain with a transmembrane motif. Mutants whose N-terminal or C-terminal domain was truncated were severely defective for sporulation. Conclusions: Meu10 is a spore wall component and plays a pivotal role in the formation of the mature spore wall structure. [source]

Puccinia romagnoliana Marie & Sacc.

JOURNAL OF PHYTOPATHOLOGY, Issue 4-5 2002
a Potential Bioherbicide Agent for Biocontrol of Purple Nutsedge (Cyperus rotundus L.) in Mulberry
Abstract The ingress, infection process and disease development of Puccinia romagnoliana Marie & Sacc. on purple nutsedge (Cyperus rotundus L.) and its cross-infectivity to an economically important sericultural crop, mulberry (Morus alba L.) were investigated under a scanning electron microscope. The potential of P. romagnoliana as a biocontrol agent was also evaluated for the control of purple nutsedge under greenhouse conditions. Uredinia of P. romagnoliana were paraphysate that bore numerous pedicellate urediniospores, having echinulate spore wall. Urediniospores had 2,3 subequatorial germpores, which gave rise to germtubes. Germtubes were observed to orientate toward stomata and terminated in appressoria, through which infection pegs were formed that penetrated the leaf. Symptoms developed on leaves 10 days after inoculation. P. romagnoliana was highly pathogenic to purple nutsedge, which, when disease was severe, caused death of the shoots and reduced both number and vigour of the tubers. P. romagnoliana did not infect the main commercial crop, mulberry. Thus, the present study demonstrated the potential ofP. romagnoliana as a bioherbicide to control the purple nutsedge in mulberry fields. [source]

Proteomic analysis of spore wall proteins and identification of two spore wall proteins from Nosema bombycis (Microsporidia)

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 12 2008
Zhengli Wu
Abstract Microsporidia are fungal-like unicellular eukaryotes which develop as obligate intracellular parasites. They differentiate into resistant spores that are protected by a thick spore wall composed of a glycoprotein-rich outer layer or exospore and a chitin-rich inner layer or endospore. In this study performed on the silkworm pathogen Nosema bombycis, we analyzed the spore wall proteins (SWPs) by proteomic-based approaches, MALDI-TOF MS and LC-MS/MS, and 14 hypothetical spore wall proteins (HSWPs) or peptides were obtained in total. Furthermore, we have examined the SWPs by SDS-PAGE and three main spore wall peptides were detected with molecular weights of 32.7,kDa (SWP32), 30.4,kDa (SWP30), and 25.3,kDa (SWP25), respectively. By N-terminal amino acid residue sequencing, and searching the genomic DNA shotgun database of N. bombycis, the complete ORFs of SWP30 and SWP32 were obtained, which encode for a 278- and a 316-amino acid peptide, respectively. Mouse polyclonal antibodies were raised against SWP30 and SWP32 recombinant proteins produced in Escherichia coli, and the results of indirect immunofluorescence assay (IFA) and immunoelectron microscopy (IEM) analyses indicated SWP30 to be an endosporal protein while SWP32 was shown to be an exosporal protein. Both SWP30 and SWP32 are included in the 14 HSWPs identified by MS, confirming the results of the proteomic-based approaches. (GenBankÔ, EMBL and DDBJ accession numbers: NbHSWP1,NbHSWP12, accession no. EF683101,EF683112. NbHSWP13 and NbHSWP14, accession no. EU179719 and EU179720). [source]

Transfer of Nosema locustae (Microsporidia) to Antonospora locustae n. comb.

THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2004
Based on Molecular, Ultrastructural Data
ABSTRACT. Nosema locustae is a microsporidian parasite of grasshopper pesthd that is used as a biological control agent, and is one of the emerging model systems for microsporidia. Due largely to its diplokaryotic nuclei, N. locustae has been classified in the genus Nosema, a large genus with members that infect a wide variety of insects. However, some molecular studies have cast doubt on the validity of certain Nosema species, and on the taxonomic position of N. locustae. To clarify the affinities of this important insect parasite we sequenced part of the rRNA operon of N. locustae and conducted a phylogenetic analysis using the complete small subunit rRNA gene. Nosema locustae is only distantly related to the nominotypic N. bombycis, and is instead closely related to Antonospora scoticae, a recently described parasite of bees. We examined the ultrastructure of mature N. locustae spores, and found the spore wall to differ from true Nosema species in having a multi-layered exospore resembling that of Antonospora (one of the distinguishing features of that genus). Based on both molecular and morphological evidence, therefore, we propose transferring N. locustae to the genus Antonospora, as Antonospora locustae n. comb. [source]

Meu10 is required for spore wall maturation in Schizosaccharomyces pombe

GENES TO CELLS, Issue 2 2002
Takahiro Tougan
Background: Many genes are meiosis and/or sporulation-specifically transcribed during this process. Isolation and analysis of these genes might help us to understand how meiosis and sporulation are regulated. For this purpose, we have isolated a large number of cDNA clones from Schizosaccharomyces pombe whose expression is up-regulated during meiosis. Results: We have isolated meu10+ gene, which encodes 416 amino acids and bears homology to SPS2 of Saccharomyces cerevisiae. A strain whose meu10+ gene has been deleted forms no viable spores. Thin-section electron micrographs showed that the meu10, strain has abnormally formed spore walls, and then they disrupt, allowing cytoplasmic material to escape. The Meu10-GFP fusion protein is localized to the spore periphery, thereafter returned to the cytoplasm after sporulation. Meu10-GFP localization to the spore wall was almost normal in the bgs2, or chs1, mutants that lack 1,3-,-glucan or chitin, respectively. In contrast, 1,3-,-glucan is abnormally localized in meu10, cells. Meu10 has an N-terminal domain with homology to the mammalian insulin receptor and a C-terminal domain with a transmembrane motif. Mutants whose N-terminal or C-terminal domain was truncated were severely defective for sporulation. Conclusions: Meu10 is a spore wall component and plays a pivotal role in the formation of the mature spore wall structure. [source]