Correction: Expression from DIF1-motif promoters of hetR and patS is dependent on HetZ and modulated by PatU3 during heterocyst differentiation.

[This corrects the article DOI: 10.1371/journal.pone.

Expression from DIF1-motif promoters of hetR and patS is dependent on HetZ and modulated by PatU3 during heterocyst differentiation.

HetR and PatS/PatX-derived peptides are the activator and diffusible inhibitor for cell differentiation and patterning in heterocyst-forming cyanobacteria. HetR regulates target genes via HetR-recognition sites. However, some genes (such as patS/patX) upregulated at the early stage of heterocyst differentiation possess DIF1 (or DIF+) motif (TCCGGA) promoters rather than HetR-recognition sites; hetR possesses both predicted regulatory elements.

pH-dependent gas vesicle formation in Microcystis.

In lakes with seasonal cyanobacterial blooms, the pH fluctuates from slightly above 7 to around 10. In this study, we found that the abundance of gas vesicles in Microcystis species, in parallel to the buoyancy of cells, increased in response to elevation of the extracellular pH. Within 48 h after pH upshift, gas vesicle protein genes (gvp) were upregulated at both mRNA and protein levels due to reduced decay of gvp transcripts.

Molecular separation of two long taxonomically debated cyanobacterial genera Cylindrospermopsis and Raphidiopsis (Nostocales) based on the ITS-L phylogeny.

The cyanobacterial genera Raphidiopsis and Cylindrospermopsis morphologically resembled each other and are difficult to distinguish, especially when heterocytes do not form in Cylindrospermopsis species. The phylogeny based on multiple gene loci sequences in previous studies cannot divide the strains of these two genera into separate clusters. In the present study, four gene loci 16S rRNA, ITS-L, cpcBA-IGS and rpoC1, sequenced from many Chinese strains (44 Cylindrospermopsis strains and 16 Raphidiopsis strains), were analyzed to infer the phylogenetic relationship between the two genera.

Preparation of protoplasts from Chlorella protothecoides.

This paper describes an enzymatic method for yielding protoplasts from the microalga Chlorella protothecoides. Four kinds of commercially available enzymes were tested. The enzymatic digestion was optimal with 2% cellulase R-10 and 1% snailase prepared in 25 mM Tris buffer (pH 6.

Expression profiles of carp IRF-3/-7 correlate with the up-regulation of RIG-I/MAVS/TRAF3/TBK1, four pivotal molecules in RIG-I signaling pathway.

The cytoplasmic helicase protein RIG-I (retinoic acid-inducible gene I) and downstream signaling molecules, MAVS (mitochondrial antiviral signaling protein), TRAF3 (TNF-receptor-associated factor 3) and TBK1 (TANK-binding kinase 1), have significant roles in the recognition of cytoplasmic 5'-triphosphate ssRNA and short dsRNA, and phosphorylation of IRF-3 (interferon regulatory factor 3) and IRF-7 which is responsible for the induction of type I interferons (IFN). In the present study, the full-length cDNAs of RIG-I, MAVS, TRAF3 and TBK1 were cloned and identified in common carp (Cyprinus carpio L.).

Identification and characterization of common carp (Cyprinus carpio L.) granzyme A/K, a cytotoxic cell granule-associated serine protease.

Granzyme (Gzm) is an important member of serine protease family, and key component in the specific and non-specific cell-mediated cytotoxicity. Partial GzmA/K cDNA sequence of common carp (Cyprinus carpio L.) was isolated from thymus cDNA library by the method of suppression subtractive hybridization (SSH).

The N-acetylmuramic acid 6-phosphate etherase gene promotes growth and cell differentiation of cyanobacteria under light-limiting conditions.

Inactivation of sll0861 in Synechocystis sp. strain PCC 6803 or the homologous gene alr2432 in Anabaena sp. strain PCC 7120 had no effect on the growth of these organisms at a light intensity of 30 micromol photons m(-2) s(-1) but reduced their growth at a light intensity of 5 or 10 micromol photons m(-2) s(-1).

Identification of a gene, ccr-1 (sll1242), required for chill-light tolerance and growth at 15 degrees C in Synechocystis sp. PCC 6803.

Synechocystis sp. PCC 6803 exposed to chill (5 degrees C)-light (100 mumol photons m(-2) s(-1)) stress loses its ability to reinitiate growth. From a random insertion mutant library of Synechocystis sp.

A TPR-family membrane protein gene is required for light-activated heterotrophic growth of the cyanobacterium Synechocystis sp. PCC 6803.

The unicellular cyanobacterium Synechocystis sp. PCC6803 can grow heterotrophically in complete darkness, given that a brief period of illumination is supplemented every day (light-activated heterotrophic growth, LAHG), or under very weak (<0.5 micromol m(-2) s(-1)) but continuous light.

Three-piece-ligation PCR and application in disruption of chlorophyll synthesis genes in Synechocystis sp. PCC 6803.

Linear DNA, consisting of a drug-resistance marker and long flanking sequences, was synthesized by one-step polymerase chain reaction after a three-piece ligating reaction. Chlorophyll synthesis genes, chlH and chlL in Synechocystis sp. PCC 6803, were replaced by a kanamycin-resistance marker through double recombinations with flanking homology regions.

DNA sequence and genetic characterization of plasmid pFQ11 from Frankia alni strain CpI1.

An 8551-bp plasmid, pFQ11, from Frankia alni strain CpI1 was sequenced. Its sequence was found to be very similar to that presented for pFQ31 from strain ArI3. Six potential protein-encoding open reading frames (ORFs) were identified, and transcriptional activity was shown within four of those regions of the plasmid by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis.

Genetic suppression analysis of non-antibiotic-producing mutants of the Streptomyces coelicolor absA locus.

The absA locus in Streptomyces coelicolor A3(2) was identified because mutations in it uncoupled sporulation from antibiotic synthesis: absA mutants failed to produce any of the four antibiotics characteristic of S. coelicolor. These mutants are now shown to contain point mutations in the absA1 gene which encodes the histidine kinase sensor-transmitter protein of a two-component signalling system.