Flávia de Faria Siqueira

Characterization of polymorphisms and isoforms of the Clostridium perfringens phospholipase C gene (plc) reveals high genetic diversity

Clostridium perfringens phospholipase C (Cp-PLC), also called alpha-toxin, is encoded by the plc gene and has been implicated in several diseases; however, only a few studies have described polymorphisms in this gene. The aim of this study was to analyze polymorphisms in the Cp-PLC nucleotide and amino acid sequences obtained from isolates from different regions and to compare them to Clostridium phospholipase C sequences deposited in the NCBI database. Environmental samples (sediment, poultry feed, sawdust) and stool samples (from poultry, bovine, swine, horse, caprine, bird, dog, rabbit, toucan) were collected from healthy and sick animals. A total of 73 isolates were analyzed with the majority of samples belonging to the toxin type A subtype and possessing the gene encoding for the beta-2 toxin. Comparison of plc gene sequences from respective isolates revealed a high genetic diversity in the nucleotide sequences of mature Cp-PLC. Sequence comparisons identified 30 amino acid substitutions and 34 isoforms including some isoforms with substitutions in amino acids critical to toxin function. Comparison of sequences obtained in this study to Cp-PLC sequences obtained from the NCBI database resulted in the identification of 11 common haplotypes and 22 new isoforms. Phylogenetic analysis of phospholipase C sequences obtained from other Clostridium species identified relationships previously described. This report describes a broad characterization of the genetic diversity in the C. perfringens plc gene resulting in the identification of various isoforms. A better understanding of sequences encoding phospholipase C isoforms may reveal changes associated with protein function and C. perfringens virulence.

Lysophosphatidic Acid Mediates the Release of Cytokines and Chemokines by Human Fibroblasts Treated with Loxosceles Spider Venom

represent separate translocation events or aneusomy of a previously translocated chromosome. The latter possibility is favored, given that: (1) the partner status (7q32.3 or other) was identical in the allele pairs from each case; (2) two of the three cases demonstrated aneuploidy; and (3) 6p25.3 translocations appear to be an early event during lymphomagenesis, based on our constant finding of this translocation in initial biopsies from patients with multiple tumor specimens over time (AL Feldman, unpublished observation). In addition to the lack of a normal copy of the 6p25.3 allele, multiple copies of the translocations could have implications on the partner locus. For example, we previously reported overexpression of microRNAs (especially MIR29B1) that reside near the 7q32.3 breakpoint in ALKnegative ALCLs with t(6;7)(p25.3;q32.3) (Feldman et al., 2009). In summary, we present three cases of pcALCL with biallelic rearrangements of 6p25.3 and no intact copies of the DUSP22–IRF4 locus. These cases indicate one mechanism by which both copies of the DUSP22 gene can be disrupted or deleted in T-cell lymphomas, and provide further evidence that DUSP22 may represent a tumorsuppressor gene. CONFLICT OF INTEREST The authors state no conflict of interest.

Complete mitochondrial genome sequence of Piaractus mesopotamicus (Holmberg, 1887).

Abstract The migratory species Piaractus Mesopotamicus, popularly known as the pacu, was determined to have a complete mitochondrial genome of 16,722 bp with 45% GC content. The genome contained 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and a 1048 bp Control Region (D-loop). Almost all the PCGs used the standard ATG start codon, except for Cox1 that used a GTG start codon. Five of the 13 PCGs had a TAA stop codon, two had the incomplete stop codon TA- (Atp6 and Cox3), and five had the incomplete stop codon T–– (Nd2, Cox2, Nd3, Nd4, and Cytb). AGG was the stop codon of Cox1.

Survey of Microbial Enzymes in Soil, Water, and Plant Microenvironments

Detection of microbial enzymes in natural environments is important to understand biochemical activities and to verify the biotechnological potential of the microorganisms. In the present report, 346 isolates from soil, water, and plants were screened for enzyme production (caseinase, gelatinase, amylase, carboxymethyl cellulase, and esterase). Our results showed that 89.6% of isolates produced at least one tested enzyme. A predominance of amylase in soil samples, carboxymethyl cellulase in plants, as well as esterase and gelatinase in water was observed. Interesting enzymatic profiles were found in some microenvironments, suggesting specificity of available nutrients and/or natural selection. This study revealed the potential of microorganisms present in water, soil, and plant to produce important enzymes for biotechnological exploration. A predominance of certain enzymes was found, depending on the type of environmental sample. The distribution of microbial enzymes in soil, water and plants has been little exploited in previous reports.

Complete mitochondrial genome sequence of Brycon orbignyanus (Characiformes, Bryconidae)

Abstract We report the whole mitochondrial genome of the Brycon orbignyanus, commonly known as the piracanjuba. The mitogenome was determined to be a circular, 16,800 bp DNA molecule, containing 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes and one 1160 bp noncoding control region. Twelve of the PCGs were located on the heavy strand, and one PCG (Nd6) was located on the light strand. The most common start codon was ATG; however, the Cox1 gene displayed the GTG start codon. Seven PCGs had incomplete stop codons: specifically, Cox2, Cox3, Nd3, Nd4, and Cytb contained the T– – codon, and Nd2 and Atp6 contained the TA– codon. The Cox1 gene contained the AGG stop codon.