The effect of visual density on the fecundity of the guppy,Poecilia reticulata

Synopsis This paper examines the effect of visual density on the brood size of female guppies,Poecilia reticulata. Previous laboratory studies of guppies showed that the fecundity of females decreases as density increases. In the present study, the effect of visual density was examined under conditions where detrimental factors such as interaction of individuals, waste substances, and dissolved oxygen were constant. The brood size of females at visual densities of 4 or more individuals was significantly larger than at zero visual density. There was a significant positive correlation between brood size and visual density. Sex ratio did not significantly affect brood size. Guppies can recognize surrounding densities and change their own fecundity in response to changes in density.     

Alcohol and Smoking Affect Risk of Uncomplicated Colonic Diverticulosis in Japan

Colonic diverticula are located predominantly on the right side in Asia and on the left side in Europe and the United States. Factors associated with uncomplicated colonic diverticulosis and its distribution pattern have been unknown. Our aims are to investigate the prevalence and risk factors for uncomplicated colonic diverticulosis. We conducted a prospective cross-sectional study in adults who underwent colonoscopy. Alcohol, alcohol related flushing, smoking, medications, and comorbidities were assessed by interview on the colonoscopy day. Alcohol consumption was categorized as nondrinker, light (1–180 g/week), moderate (181–360 g/week), and heavy (≥361 g/week). Smoking index was defined as the number of cigarettes per day multiplied by the number of smoking years and categorized as nonsmoker, <400, 400–799, and ≥800. A total of 2,164 consecutive patients were enrolled. Overall, 542 patients (25.1%) had uncomplicated colonic diverticulosis located on the right side (50%), bilaterally (29%), and on the left side (21%). Univariate analysis revealed age, male, smoking index, alcohol consumption, aspirin use, anticoagulants use, corticosteroid use, hypertension, and atherosclerotic disease as factors significantly associated with diverticulosis. Alcohol related flushing was not associated with the disease. Multivariate analysis showed increasing age (P<0.01), increasing alcohol consumption (P<0.01) and smoking (P<0.01), and atherosclerotic disease (P<0.01) as significantly associated factors. Alcohol and smoking were associated with right-sided and bilateral diverticula. In conclusion, one in four Japanese adults have colonic diverticulosis (50% right-sided). Age, alcohol consumption, and smoking were found to be significant risk factors for uncomplicated colonic diverticulosis, particularly right-sided and bilateral.     

SGS3 and RDR6 interact and colocalize in cytoplasmic SGS3/RDR6-bodies

Suppressor of gene silencing 3 (SGS3) is involved in RNA-dependent RNA polymerase 6 (RDR6)-dependent small-interfering RNA (siRNA) pathways in Arabidopsis. However, the roles of SGS3 in those pathways are unclear. Here, we show that SGS3 interacts and colocalizes with RDR6 in cytoplasmic granules. Interestingly, the granules containing SGS3 and RDR6 (named SGS3/RDR6-bodies) were distinct from the processing bodies where mRNAs are decayed and/or stored. Microscopic analyses and complementation experiments using SGS3-deletion mutants suggested that proper localization of SGS3 is important for its function. These results provide novel insights into RDR6-dependent siRNA formation in plants.

Structured summary

MINT-7014710: SGS3 (uniprotkb:Q9LDX1) and RDR6 (uniprotkb:Q9SG02) physically interact (MI:0218) by bimolecular fluorescence complementation (MI:0809)MINT-7014697: RDR6 (uniprotkb:Q9SG02) and SGS3 (uniprotkb:Q9LDX1) colocalize (MI:0403) by fluorescence microscopy (MI:0416)     

Genetic relationships between Japanese native and commercial breeds using 70 chicken autosomal SNP genotypes by the DigiTag2 assay

Recently, single nucleotide polymorphisms (SNPs) have been used to identify genes or genomic regions responsible for economic traits, including genetic diseases in domestic animals, and to examine genetic diversity of populations. In this study, we genotyped 70 chicken autosomal SNPs using DigiTag2 assay to understand the genetic structure of the Japanese native chicken breeds Satsumadori and Ingie, and the relationship of these breeds with other established breeds, Rhode Island Red (RIR), commercial broiler and layer. Five breeds, each consisting of approximately 20 chickens, were subjected to the assay, revealing the following: Average expected heterozygosities of broiler, Satsumadori, RIR, layer and Ingie were 0.265, 0.254, 0.244, 0.179 and 0.176, respectively. Phylogenetic analysis using the concatenated 70 autosomal SNP genotypes distinguished all chickens and formed clusters of chickens belonging to the respective breeds. In addition, the 2-D scatter plot of the first two principal components was consistent with the phylogenic tree. Taken together with the pairwise F(st) distances, broiler and RIR were closely positioned near each other, while Ingie was positioned far from the other breeds. Structure analysis revealed that the probable number of genetic clusters (K) was six and four with maximum likelihood and ΔK values, respectively. The clustering with maximum likelihood revealed that, in addition to the clustering of the other five breeds, the Satsumadori was subdivided into two genetic clusters. The clustering with ΔK value indicated that the broiler and Rhode Island Red were assigned to the same genetic cluster.     

Cloning of a putative monogalactosyldiacylglycerol synthase gene from rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) plants and its expression in response to submergence and other stresses

Suppression subtractive hybridization was used to construct a subtractive cDNA library from plants of non-submerged and 7-day-submerged rice (Oryza sativa L., FR13A, a submergence-tolerant cultivar). One clone of the subtractive cDNA library, S23, was expressed abundantly during submergence. The full length of S23 was amplified using 5- and 3-rapid amplification of cDNA ends, and found to consist of 1,671 bp with an open reading frame of 1,077 bp (181–1257) encoding 358 amino acids. Its deduced amino acid sequence showed a high homology with monogalactosyldiacylglycerol synthase (UDPgalactose: 1,2-diacylglycerol 3--d-galactosyl transferase; EC 2.4.1.46, MGDG synthase) from Arabidopsis thaliana; therefore, we named the gene OsMGD. Time-course studies showed that the expression of OsMGD in the rice cultivars FR13A and IR42 (submergence-susceptive cultivar) during submergence was gradually increased and that expression in FR13A was higher than in IR42. The expression of OsMGD in FR13A was influenced by benzyladenine and illumination. The accumulation of OsMGD mRNA in both FR13A and IR42 was also increased by ethephon, gibberellin, drought and salt treatment, but cold stress had no effect on the expression of the gene. These results suggest that the expression of OsMGD mRNA requires benzyladenine or illumination, and that the process is also mediated by ethephon and gibberellin. Salt and drought stress have an effect similar to that of submergence. Furthermore, the enhanced expression of OsMGD may relate to photosynthesis, and play an important role during submergence.Abbreviations BA N⁶-Benzyladenine - GA Gibberellin - MGD Monogalactosyldiacylglycerol synthase - RACE Rapid amplification of cDNA ends     

Immunology

It has been known for the past 85 years that mucosal responses can be stimulated by local presentation of antigen and that the gut immune system is capable of mounting both primary and secondary responses to potentially harmful antigens while avoiding the expression of damaging responses to harmless dietary proteins. How these types of responses are induced and regulated remains unclear. In the gut attention has for some time been focused on Peyer's patches (PP) due to evidence that they play a vital role in the induction of humoral and cellular responses. Moreover, it has been established that MHC class II molecules are found in the gut mucosa on a variety of cell types outside PP, namely the lamina propria (LP). Fed antigens have also been detected in the LP and studies have shown that LP cells can stimulate allogeneic mixed lymphocyte responses and are capable of presenting soluble protein antigen to naïve T cells. This article reviews the present understanding of the possible roles of PP and LP in intestinal immunity in terms of induction, regulation, surveillance of immune responses and the antigen presenting cell types involved.     

Cutting edge: role of STAT1, STAT3, and STAT5 in IFN-alpha beta responses in T lymphocytes

Engagement of the IFN-alphabeta receptor initiates multiple signaling cascades, including activation of the STAT. In this study, we demonstrate that IFN-alphabeta, although antiproliferative in wild-type CD4(+) or CD8(+) T cells, act as strong mitogens on their STAT1(-/-) counterparts. Furthermore, IFN-alphabeta exert little effect on apoptosis in wild-type cells, but are potent survival factors in the absence of STAT1. The antiapoptotic response in the absence of STAT1 is predominantly mediated by STAT3, and to a lesser extent by STAT5A/B. In contrast, the mitogenic IFN-alphabeta response gained through the absence of STAT1 is only marginally affected when STAT5A/B expression is also abrogated, but is completely dependent on STAT3 activation. These findings provide the first evidence for a function of STAT3 and STAT5A/B in the IFN-alphabeta response, and support a model in which the IFN-alphabeta receptor initiates both pro- and antiapoptotic responses through STAT1, and STAT3 and STAT5A/B, respectively.     

Phosphatidylethanolamine domains and localization of phospholipid synthases in Bacillus subtilis membranes

Application of the cardiolipin (CL)-specific fluorescent dye 10-N-nonyl-acridine orange has recently revealed CL-rich domains in the septal regions and at the poles of the Bacillus subtilis membrane (F. Kawai, M. Shoda, R. Harashima, Y. Sadaie, H. Hara, and K. Matsumoto, J. Bacteriol. 186:1475-1483, 2004). This finding prompted us to examine the localization of another phospholipid, phosphatidylethanolamine (PE), with the cyclic peptide probe, Ro09-0198 (Ro), that binds specifically to PE. Treatment with biotinylated Ro followed by tetramethyl rhodamine-conjugated streptavidin revealed that PE is localized in the septal membranes of vegetative cells and in the membranes of the polar septum and the engulfment membranes of sporulating cells. When the mutant cells of the strains SDB01 (psd1::neo) and SDB02 (pssA10::spc), which both lack PE, were examined under the same conditions, no fluorescence was observed. The localization of the fluorescence thus evidently reflected the localization of PE-rich domains in the septal membranes. Similar PE-rich domains were observed in the septal regions of the cells of many Bacillus species. In Escherichia coli cells, however, no PE-rich domains were found. Green fluorescent protein fusions to the enzymes that catalyze the committed steps in PE synthesis, phosphatidylserine synthase, and in CL synthesis, CL synthase and phosphatidylglycerophosphate synthase, were localized mainly in the septal membranes in B. subtilis cells. The majority of the lipid synthases were also localized in the septal membranes; this includes 1-acyl-glycerol-3-phosphate acyltransferase, CDP-diacylglycerol synthase, phosphatidylserine decarboxylase, diacylglycerol kinase, glucolipid synthase, and lysylphosphatidylglycerol synthase. These results suggest that phospholipids are produced mostly in the septal membranes and that CL and PE are kept from diffusing out to lateral ones.     

Molecular evidence for hybridization of species in the genus Gallus except for Gallus varius

A phylogenetic tree for fowl including chicken in the genus Gallus and based on mitochondrial D-loop analysis further supports the hypothesis developed from morphology and progeny production that red junglefowl (RJF) is the direct ancestor of the chicken. The phylogenetic positions of the chicken and the other fowl species in the genus Gallus are of great importance when considering maintenance and improvement of chicken breeds through introgression of genetic variation from wild-type genomes. However, because the phylogenetic analysis based on the DNA sequences is not sufficient to conclude the phylogenetic positions of the fowls in the genus, in the present study, we have determined sequences of whole mitochondrial DNA (mtDNA) and two segments of the nuclear genome (intron 9 of ornithine carbamoyltransferase, and four chicken repeat 1 elements) for the species in the genus Gallus. The phylogenetic analyses based on mtDNA sequences revealed that two grey junglefowls (GyJF) were clustered in a clade with RJFs and chicken, and that one GyJF was located in a remote position close to Ceylon junglefowl (CJF). The analyses based on the nuclear sequences revealed that alleles of GyJFs were alternatively clustered with those of CJF and with those of RJFs and chicken. Alternative clustering of RJF and chicken alleles were also observed. These findings taken together strongly indicate that inter-species hybridizations have occurred between GyJF and RJF/chicken and between GyJF and CJF.     

Purification and characterization of a trypsin-like serine proteinase from rat brain slices that degrades laminin and type IV collagen and stimulates protease-activated receptor-2

A trypsin-like serine proteinase was purified from the incubation medium of rat brain slices by gelatin zymography. The purification consisted of ammonium sulfate precipitation, benzamidine-Sepharose 6B affinity chromatography, and carboxymethyl-cellulose and gel filtration chromatographies. The gelatinolytic activity, identified at 22 kDa (P22) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions, was eluted as one active peak throughout the purification, and the final preparation gave a single protein peak on reverse-phase HPLC. Diisopropyl fluorophosphate, benzamidine, p-toluenesulfonyl-L-lysine chloromethyl ketone, and aprotinin completely inhibited the activity of P22, whereas phenanthroline, p-toluene-sulfonyl-L-phenylalanine chloromethyl ketone, and elastinal did not. P22 efficiently digested the extracellular matrix proteins laminin and type IV collagen. P22 produced an increase in intracellular Ca2+ concentration in A172 glioblastoma, which was desensitized through prior stimulation with protease-activated receptor-2 agonist peptide SLIGKV, indicating that P22 can stimulate protease-activated receptor-2. Rat brain penetration injury induced gelatinolytic activity in the lesioned area whose molecular size was consistent with that of P22. These results indicated that on incubation of rat brain slices, a trypsin-like serine proteinase was secreted into the medium that was capable of digesting extracellular matrix and stimulating protease-activated receptor-2. It is suggested that the gelatinolytic activity induced by brain injury might be that of P22.