Project description:Whole-genome sequencing of Acanthamoeba polyphaga Linc Ap-1 resulted in a draft assembly of the chromosomal DNA and a complete sequence of the mitochondrial DNA (mtDNA). Despite very high sequence similarity with the mtDNA of Acanthamoeba castellanii Neff, in contrast to Acanthamoeba polyphaga Linc Ap-1, the determined DNA sequence revealed a complete absence of introns.
Project description:A culture of Acanthamoeba castellanii cells was infected with mimivirus. At specified times after infection, infected cells aliquots were subjected to total RNA extraction. Cy3 labeled cDNA was hybridized on custom designed Agilent oligonucleotide tiling microarrays covering both strands of the mimivirus genome.
Project description:Long non-coding RNAs are important regulators of diverse biological prosesses. Here, we report on functional identification and characterization of a novel long intergenic noncoding RNA with MyoD-regulated and skeletal muscle-restricted expression that promotes the activation of the myogenic program, and is therefore termed Linc-RAM (Linc-RNA Activator of Myogenesis). Linc-RAM is transcribed from an intergenic region of myogenic cells and its expression is upregulated during myogenesis. Notably, in vivo functional studies show that Linc-RAM knockout mice display impaired muscle regeneration due to differentiation defect of satellite cells. Mechanistically, Linc-RAM regulates expression of myogenic genes by directly binding MyoD, which in turn promotes the assembly of the MyoD-Baf60c-Brg1 complex on the regulatory elements of target genes. Collectively, our findings reveal the functional role and molecular mechanism of a lineage-specific Linc-RAM as a regulatory lncRNA required for tissues-specific chromatin remodeling and gene expression.
Project description:Proteomics, lipidomics, and metabolomics analysis of extracellular vesicles secreted by an environmental strain and a clinical strain of Acanthamoeba castellanii.
Project description:BackgroundMycobacterium smegmatis is a rapidly-growing mycobacterium causing rare opportunistic infections in human patients. It is present in soil and water environments where free-living amoeba also reside, but data regarding M. smegmatis-amoeba relationships have been contradictory from mycobacteria destruction to mycobacteria survival.Methodology/principal findingsUsing optic and electron microscopy and culture-based microbial enumeration we investigated the ability of M. smegmatis mc(2) 155, M. smegmatis ATCC 19420(T) and M. smegmatis ATCC 27204 organisms to survive into Acanthamoeba polyphaga trophozoites and cysts. We observed that M. smegmatis mycobacteria penetrated and survived in A. polyphaga trophozoites over five-day co-culture resulting in amoeba lysis and the release of viable M. smegmatis mycobacteria without amoebal cyst formation. We further observed that amoeba-co-culture, and lysed amoeba and supernatant and pellet, significantly increased five-day growth of the three tested M. smegmatis strains, including a four-fold increase in intra-amoebal growth.Conclusions/significanceAmoebal co-culture increases the growth of M. smegmatis resulting in amoeba killing by replicating M. smegmatis mycobacteria. This amoeba-M. smegmatis co-culture system illustrates an unusual paradigm in the mycobacteria-amoeba interactions as mycobacteria have been mainly regarded as amoeba-resistant organisms. Using these model organisms, this co-culture system could be used as a simple and rapid model to probe mycobacterial factors implicated in the intracellular growth of mycobacteria.