Genome Engineering by RNA-Guided Transposition for sp. PCC 7120.

In genome engineering, the integration of incoming DNA has been dependent on enzymes produced by dividing cells, which has been a bottleneck toward increasing DNA insertion frequencies and accuracy. Recently, RNA-guided transposition with CRISPR-associated transposase (CAST) was reported as highly effective and specific in . Here, we developed Golden Gate vectors to test CAST in filamentous cyanobacteria and to show that it is effective in sp.

Spatio-temporal coherence of circadian clocks and temporal control of differentiation in filaments.

Circadian clock arrays in multicellular filaments of the heterocyst-forming cyanobacterium sp. strain PCC 7120 display remarkable spatio-temporal coherence under nitrogen-replete conditions. To shed light on the interplay between circadian clocks and the formation of developmental patterns, we followed the expression of a clock-controlled gene under nitrogen deprivation, at the level of individual cells.

Systematic mapping review of orthognathic surgery.

Study Design: Systematic mapping review AIM AND SCOPE: The objective of this mapping review was to identify, describe, and organize clinical research currently available from systematic reviews and primary studies regarding co-interventions and different surgical modalities used in orthognathic surgery (OS) and their outcomes.

Methods: Systematic reviews (SRs), randomized controlled trials, and observational studies that evaluated perioperative OS co-interventions and surgical modalities were identified in an exhaustive search of MEDLINE, EMBASE, Epistemonikos, Lilacs, Web of Science, and CENTRAL. Grey literature was also screened.

Adaptation to an Intracellular Lifestyle by a Nitrogen-Fixing, Heterocyst-Forming Cyanobacterial Endosymbiont of a Diatom.

The symbiosis between the diatom and the heterocyst-forming cyanobacterium makes an important contribution to new production in the world's oceans, but its study is limited by short-term survival in the laboratory. In this symbiosis, fixes atmospheric dinitrogen in the heterocyst and provides with fixed nitrogen. Here, we conducted an electron microscopy study of and found that the filaments of the symbiont, typically composed of one terminal heterocyst and three or four vegetative cells, are located in the diatom's cytoplasm not enclosed by a host membrane.

Developing Academic Engagement Through a Virtual Week of Research, Scholarly, and Creative Activity: Rethinking Collaboration.

The goal of having a Week of Research, Scholarly, and Creative Activity (RSCA) virtual event was to highlight and acknowledge the valuable array of research, scholarly, and creative activities that are currently being done across the entire campus at California State University Long Beach (CSULB). There's no doubt that in 2020 and 2021, our lives have been impacted in a multitude of ways. The COVID-19 global pandemic placed restrictions on in-person gatherings that forced many to rely on virtual meetings.

Genetic and lipidomic analyses suggest that , a plant-symbiotic cyanobacterium, does not produce sphingolipids.

Sphingolipids, a class of amino-alcohol-based lipids, are well characterized in eukaryotes and in some anaerobic bacteria. However, the only sphingolipids so far identified in cyanobacteria are two ceramides (i.e.

Functional Diversity of TonB-Like Proteins in the Heterocyst-Forming Cyanobacterium sp. PCC 7120.

The TonB-dependent transport of scarcely available substrates across the outer membrane is a conserved feature in Gram-negative bacteria. The plasma membrane-embedded TonB-ExbB-ExbD accomplishes complex functions as an energy transducer by physically interacting with TonB-dependent outer membrane transporters (TBDTs). TonB mediates structural rearrangements in the substrate-loaded TBDTs that are required for substrate translocation into the periplasm.

Single-Cell Measurements of Fixation and Intercellular Exchange of C and N in the Filaments of the Heterocyst-Forming Cyanobacterium sp. Strain PCC 7120.

Under diazotrophic conditions, the model filamentous, heterocyst-forming cyanobacterium sp. strain PCC 7120 develops a metabolic strategy based on the physical separation of the processes of oxygenic photosynthesis, in vegetative cells, and N fixation, in heterocysts. This strategy requires the exchange of carbon and nitrogen metabolites and their distribution along the filaments, which takes place through molecular diffusion via septal junctions involving FraCD proteins.

A TonB-Like Protein, SjdR, Is Involved in the Structural Definition of the Intercellular Septa in the Heterocyst-Forming Cyanobacterium .

Cyanobacteria are photosynthetic organisms with a Gram-negative envelope structure. Certain filamentous species such as sp. strain PCC 7120 can fix dinitrogen upon depletion of combined nitrogen.

Heterocyst Septa Contain Large Nanopores That Are Influenced by the Fra Proteins in the Filamentous Cyanobacterium sp. Strain PCC 7120.

Multicellular heterocyst-forming cyanobacteria, such as , grow as chains of cells forming filaments that, under diazotrophic conditions, contain two cell types: vegetative cells that perform oxygenic photosynthesis and N-fixing heterocysts. Along the filament, the intercellular septa contain a thick peptidoglycan layer that forms septal disks. Proteinaceous septal junctions connect the cells in the filament traversing the septal disks through nanopores.

Robust, coherent, and synchronized circadian clock-controlled oscillations along filaments.

Circadian clocks display remarkable reliability despite significant stochasticity in biomolecular reactions. We study the dynamics of a circadian clock-controlled gene at the individual cell level in sp. PCC 7120, a multicellular filamentous cyanobacterium.

Impaired cell-cell communication in the multicellular cyanobacterium affects carbon uptake, photosynthesis, and the cell wall.

Cell-cell communication is an essential attribute of multicellular organisms. The effects of perturbed communication were studied in septal protein mutants of the heterocyst-forming filamentous cyanobacterium sp. PCC 7120 model organism.

Coexistence of Communicating and Noncommunicating Cells in the Filamentous Cyanobacterium .

In filamentous heterocyst-forming (N-fixing) cyanobacteria, septal junctions join adjacent cells, mediating intercellular communication, and are thought to traverse the septal peptidoglycan through nanopores. Fluorescence recovery after photobleaching (FRAP) analysis with the fluorescent marker calcein showed that cultures of sp. strain PCC 7120 grown in the presence of combined nitrogen contained a substantial fraction of noncommunicating cells (58% and 80% of the tested vegetative cells in nitrate- and ammonium-grown cultures, respectively), whereas cultures induced for nitrogen fixation contained far fewer noncommunicating cells (16%).

Predicting substrate exchange in marine diatom-heterocystous cyanobacteria symbioses.

In the open ocean, some phytoplankton establish symbiosis with cyanobacteria. Some partnerships involve diatoms as hosts and heterocystous cyanobacteria as symbionts. Heterocysts are specialized cells for nitrogen fixation, and a function of the symbiotic cyanobacteria is to provide the host with nitrogen.

A novel septal protein of multicellular heterocystous cyanobacteria is associated with the divisome.

Cyanobacteria are unique among the eubacteria as they possess a hybrid Gram phenotype, having an outer membrane but also a comparably thick peptidoglycan sheet. Furthermore, the cyanobacterial divisome includes proteins specific for both the Gram types as well as cyanobacteria-specific proteins. Cells in multicellular cyanobacteria share a continuous periplasm and their cytoplasms are connected by septal junctions that enable communication between cells in the filament.

Pentapeptide-repeat, cytoplasmic-membrane protein HglK influences the septal junctions in the heterocystous cyanobacterium Anabaena.

N -fixing heterocystous cyanobacteria grow as chains of cells that are connected by proteinaceous septal junctions, which traverse the septal peptidoglycan through nanopores and mediate intercellular molecular transfer. In the model organism Anabaena sp. strain PCC 7120, proteins SepJ, FraC and FraD, which are localized at the cell poles in the intercellular septa, are needed to produce septal junctions.

Developmental Biology in Cyanobacteria.

Filamentous, heterocyst-forming cyanobacteria are phototrophic multicellular organisms in which N-fixing heterocysts and CO-fixing vegetative cells exchange regulators and nutrients [...

Catabolic pathway of arginine in Anabaena involves a novel bifunctional enzyme that produces proline from arginine.

Arginine participates widely in metabolic processes. The heterocyst-forming cyanobacterium Anabaena catabolizes arginine to produce proline and glutamate, with concomitant release of ammonium, as major products. Analysis of mutant Anabaena strains showed that this catabolic pathway is the product of two genes, agrE (alr4995) and putA (alr0540).

Cyanobacterial Septal Junctions: Properties and Regulation.

Heterocyst-forming cyanobacteria are multicellular organisms that grow as chains of cells (filaments or trichomes) in which the cells exchange regulators and nutrients. In this article, we review the morphological, physiological and genetic data that have led to our current understanding of intercellular communication in these organisms. Intercellular molecular exchange appears to take place by simple diffusion through proteinaceous structures, known as septal junctions, which connect the adjacent cells in the filament and traverse the septal peptidoglycan through perforations known as nanopores.

Specific mutations in the permease domain of septal protein SepJ differentially affect functions related to multicellularity in the filamentous cyanobacterium .

Filamentous, heterocyst-forming cyanobacteria are multicellular organisms in which growth requires the activity of two interdependent cell types that exchange nutrients and regulators. Vegetative cells provide heterocysts with reduced carbon, and heterocysts provide vegetative cells with fixed nitrogen. Additionally, heterocyst differentiation from vegetative cells is regulated by inhibitors of differentiation produced by prospective heterocysts and heterocysts.

Genetic responses to carbon and nitrogen availability in Anabaena.

Heterocyst-forming cyanobacteria are filamentous organisms that perform oxygenic photosynthesis and CO fixation in vegetative cells and nitrogen fixation in heterocysts, which are formed under deprivation of combined nitrogen. These organisms can acclimate to use different sources of nitrogen and respond to different levels of CO . Following work mainly done with the best studied heterocyst-forming cyanobacterium, Anabaena, here we summarize the mechanisms of assimilation of ammonium, nitrate, urea and N , the latter involving heterocyst differentiation, and describe aspects of CO assimilation that involves a carbon concentration mechanism.

Homospermidine biosynthesis in the cyanobacterium Anabaena requires a deoxyhypusine synthase homologue and is essential for normal diazotrophic growth.

Polyamines are primordial, small organic polycations present in almost all cells, but their roles in bacteria are poorly understood. sym-Homospermidine is the dominant polyamine in the filamentous, N -fixing, heterocyst-forming cyanobacterium Anabaena sp. PCC 7120.