scholarly journals Shaping an Endospore: Architectural Transformations During Bacillus subtilis Sporulation

2020 ◽  
Vol 74 (1) ◽  
pp. 361-386 ◽  
Author(s):  
Kanika Khanna ◽  
Javier Lopez-Garrido ◽  
Kit Pogliano
Keyword(s):  
Bacillus Subtilis ◽  
Protein Localization ◽  
Cell Structure ◽  
Chromosome Translocation ◽  
Specific Gene ◽  
Bacterial Cells ◽  
Biological Phenomena ◽  
A Cell ◽  
Ideal Model System ◽  
Unique Cell

Endospore formation in Bacillus subtilis provides an ideal model system for studying development in bacteria. Sporulation studies have contributed a wealth of information about the mechanisms of cell-specific gene expression, chromosome dynamics, protein localization, and membrane remodeling, while helping to dispel the early view that bacteria lack internal organization and interesting cell biological phenomena. In this review, we focus on the architectural transformations that lead to a profound reorganization of the cellular landscape during sporulation, from two cells that lie side by side to the endospore, the unique cell within a cell structure that is a hallmark of sporulation in B. subtilis and other spore-forming Firmicutes. We discuss new insights into the mechanisms that drive morphogenesis, with special emphasis on polar septation, chromosome translocation, and the phagocytosis-like process of engulfment, and also the key experimental advances that have proven valuable in revealing the inner workings of bacterial cells.

scholarly journals Multicopy Plasmids Affect Replisome Positioning in Bacillus subtilis

2004 ◽  
Vol 186 (21) ◽  
pp. 7084-7090 ◽  
Author(s):  
Jue D. Wang ◽  
Megan E. Rokop ◽  
Melanie M. Barker ◽  
Nathaniel R. Hanson ◽  
Alan D. Grossman
Keyword(s):  
Bacillus Subtilis ◽  
Dna Polymerase ◽  
Fluorescent Protein ◽  
Subcellular Location ◽  
Multicopy Plasmid ◽  
Bacterial Cells ◽  
Initiation Of Replication ◽  
A Cell ◽  
A Subunit ◽  
Green Fluorescent

ABSTRACT The DNA replication machinery, various regions of the chromosome, and some plasmids occupy characteristic subcellular positions in bacterial cells. We visualized the location of a multicopy plasmid, pHP13, in living cells of Bacillus subtilis using an array of lac operators and LacI-green fluorescent protein (GFP). In the majority of cells, plasmids appeared to be highly mobile and randomly distributed. In a small fraction of cells, there appeared to be clusters of plasmids located predominantly at or near a cell pole. We also monitored the effects of the presence of multicopy plasmids on the position of DNA polymerase using a fusion of a subunit of DNA polymerase to GFP. Many of the plasmid-containing cells had extra foci of the replisome, and these were often found at uncharacteristic locations in the cell. Some of the replisome foci were dynamic and highly mobile, similar to what was observed for the plasmid. In contrast, replisome foci in plasmid-free cells were relatively stationary. Our results indicate that in B. subtilis, plasmid-associated replisomes are recruited to the subcellular position of the plasmid. Extending this notion to the chromosome, we postulated that the subcellular position of the chromosomally associated replisome is established by the subcellular location of oriC at the time of initiation of replication.

scholarly journals Milestones in Bacillus subtilis sporulation research

2021 ◽  
Vol 8 (1) ◽  
pp. 1-16
Author(s):  
Eammon P. Riley ◽  
Corinna Schwarz ◽  
Alan I. Derman ◽  
Javier Lopez-Garrido
Keyword(s):  
Gene Expression ◽  
Bacillus Subtilis ◽  
Cell Biology ◽  
Chromosome Translocation ◽  
Future Research ◽  
Specific Gene ◽  
Rapid Progress ◽  
Specific Gene Expression ◽  
General Aspects ◽  
And Function

Endospore formation has been a rich field of research for more than a century, and has benefited from the powerful genetic tools available in Bacillus subtilis. In this review, we highlight foundational discoveries that shaped the sporulation field, from its origins to the present day, tracing a chronology that spans more than one hundred eighty years. We detail how cell-specific gene expression has been harnessed to investigate the existence and function of intercellular proteinaceous channels in sporulating cells, and we illustrate the rapid progress in our understanding of the cell biology of sporulation in recent years using the process of chromosome translocation as a storyline. Finally, we sketch general aspects of sporulation that remain largely unexplored, and that we envision will be fruitful areas of future research.

scholarly journals Blocking Chromosome Translocation during Sporulation of Bacillus subtilis Can Result in Prespore-Specific Activation of σG That Is Independent of σE and of Engulfment

2006 ◽  
Vol 188 (20) ◽  
pp. 7267-7273 ◽  
Author(s):  
Vasant K. Chary ◽  
Panagiotis Xenopoulos ◽  
Patrick J. Piggot
Keyword(s):  
Bacillus Subtilis ◽  
Rna Polymerase ◽  
Mother Cell ◽  
Chromosome Translocation ◽  
Specific Gene ◽  
Main Function ◽  
Cell Compartment ◽  
Gene Encoding ◽  
Direct Activator

ABSTRACT Formation of spores by Bacillus subtilis is characterized by cell compartment-specific gene expression directed by four RNA polymerase σ factors, which are activated in the order σF-σE-σG-σK. Of these, σG becomes active in the prespore upon completion of engulfment of the prespore by the mother cell. Transcription of the gene encoding σG, spoIIIG, is directed in the prespore by RNA polymerase containing σF but also requires the activity of σE in the mother cell. When first formed, σG is not active. Its activation requires expression of additional σE-directed genes, including the genes required for completion of engulfment. Here we report conditions in which σG becomes active in the prespore in the absence of σE activity and of completion of engulfment. The conditions are (i) having an spoIIIE mutation, so that only the origin-proximal 30% of the chromosome is translocated into the prespore, and (ii) placing spoIIIG in an origin-proximal location on the chromosome. The main function of the σE-directed regulation appears to be to coordinate σG activation with the completion of engulfment, not to control the level of σG activity. It seems plausible that the role of σE in σG activation is to reverse some inhibitory signal (or signals) in the engulfed prespore, a signal that is not present in the spoIIIE mutant background. It is not clear what the direct activator of σG in the prespore is. Competition for core RNA polymerase between σF and σG is unlikely to be of major importance.

Chromosome Translocation Inflates Bacillus subtilis Forespores and Impacts Cellular Morphology

2018 ◽  
Author(s):  
Javier Lopez-Garrido ◽  
Nikola Ojkic ◽  
Kanika Khanna ◽  
Felix R. Wagner ◽  
Elizabeth Villa ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Chromosome Translocation ◽  
Cellular Morphology

scholarly journals CdSe QD Biosynthesis in Yeast Using Tryptone-Enriched Media and Their Conjugation with a Peptide Hecate for Bacterial Detection and Killing

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1463 ◽  
Author(s):  
Vishma Pratap Sur ◽  
Marketa Kominkova ◽  
Zaneta Buchtova ◽  
Kristyna Dolezelikova ◽  
Ondrej Zitka ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Synthesis Process ◽  
Synthesis Methods ◽  
Bacterial Cells ◽  
Cdse Qds ◽  
Yeast Saccharomyces Cerevisiae ◽  
Shape Distribution ◽  
Transmission Electron ◽  
A Cell ◽  
Physical And Chemical

The physical and chemical synthesis methods of quantum dots (QDs) are generally unfavorable for biological applications. To overcome this limitation, the development of a novel “green” route to produce highly-fluorescent CdSe QDs constitutes a promising substitute approach. In the present work, CdSe QDs were biosynthesized in yeast Saccharomyces cerevisiae using a novel method, where we showed for the first time that the concentration of tryptone highly affects the synthesis process. The optimum concentration of tryptone was found to be 25 g/L for the highest yield. Different methods were used to optimize the QD extraction from yeast, and the best method was found to be by denaturation at 80 °C along with an ultrasound needle. Multiple physical characterizations including transmission electron microscopy (TEM), dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy (EDX), and spectrophotometry confirmed the optical features size and shape distribution of the QDs. We showed that the novel conjugate of the CdSe QDs and a cell-penetrating peptide (hecate) can detect bacterial cells very efficiently under a fluorescent microscope. The conjugate also showed strong antibacterial activity against vancomycin-resistant Staphylococcus aureus (VRSA), methicillin-resistant Staphylococcus aureus (MRSA), and Escherichia coli, which may help us to cope with the problem of rising antibiotic resistance.

scholarly journals Analysis of the transcriptome of bovine endometrial cells isolated by laser micro-dissection (1): specific signatures of stromal, glandular and luminal epithelial cells

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Wiruntita Chankeaw ◽  
Sandra Lignier ◽  
Christophe Richard ◽  
Theodoros Ntallaris ◽  
Mariam Raliou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Localization ◽  
Expression Profiles ◽  
Cell Types ◽  
Molecular Signature ◽  
Receptor Protein ◽  
Specific Gene ◽  
Specific Cell ◽  
Biological Processes ◽  
Endometrial Cells

Abstract Background A number of studies have examined mRNA expression profiles of bovine endometrium at estrus and around the peri-implantation period of pregnancy. However, to date, these studies have been performed on the whole endometrium which is a complex tissue. Consequently, the knowledge of cell-specific gene expression, when analysis performed with whole endometrium, is still weak and obviously limits the relevance of the results of gene expression studies. Thus, the aim of this study was to characterize specific transcriptome of the three main cell-types of the bovine endometrium at day-15 of the estrus cycle. Results In the RNA-Seq analysis, the number of expressed genes detected over 10 transcripts per million was 6622, 7814 and 8242 for LE, GE and ST respectively. ST expressed exclusively 1236 genes while only 551 transcripts were specific to the GE and 330 specific to LE. For ST, over-represented biological processes included many regulation processes and response to stimulus, cell communication and cell adhesion, extracellular matrix organization as well as developmental process. For GE, cilium organization, cilium movement, protein localization to cilium and microtubule-based process were the only four main biological processes enriched. For LE, over-represented biological processes were enzyme linked receptor protein signaling pathway, cell-substrate adhesion and circulatory system process. Conclusion The data show that each endometrial cell-type has a distinct molecular signature and provide a significantly improved overview on the biological process supported by specific cell-types. The most interesting result is that stromal cells express more genes than the two epithelial types and are associated with a greater number of pathways and ontology terms.

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