Microtubule plus-ends reveal essential links between intracellular polarization and localized modulation of endocytosis during division-plane establishment in plant cells

Background  

A key event in plant morphogenesis is the establishment of a division plane. A plant-specific microtubular preprophase band (PPB) accurately predicts the line of cell division, whereas the phragmoplast, another plant-specific array, executes cell division by maintaining this predicted line. Although establishment of these specific arrays apparently involves intracellular repolarization events that focus cellular resources to a division site, it still remains unclear how microtubules position the cell division planes. Here we study GFP-AtEB1 decorated microtubule plus-ends to dissect events at the division plane.     

Genome-wide study identifies two loci associated with lung function decline in mild to moderate COPD

Accelerated lung function decline is a key COPD phenotype; however, its genetic control remains largely unknown. We performed a genome-wide association study using the Illumina Human660W-Quad v.1_A BeadChip. Generalized estimation equations were used to assess genetic contributions to lung function decline over a 5-year period in 4,048 European American Lung Health Study participants with largely mild COPD. Genotype imputation was performed using reference HapMap II data. To validate regions meeting genome-wide significance, replication of top SNPs was attempted in independent cohorts. Three genes (TMEM26, ANK3 and FOXA1) within the regions of interest were selected for tissue expression studies using immunohistochemistry. Two intergenic SNPs (rs10761570, rs7911302) on chromosome 10 and one SNP on chromosome 14 (rs177852) met genome-wide significance after Bonferroni. Further support for the chromosome 10 region was obtained by imputation, the most significantly associated imputed SNPs (rs10761571, rs7896712) being flanked by observed markers rs10761570 and rs7911302. Results were not replicated in four general population cohorts or a smaller cohort of subjects with moderate to severe COPD; however, we show novel expression of genes near regions of significantly associated SNPS, including TMEM26 and FOXA1 in airway epithelium and lung parenchyma, and ANK3 in alveolar macrophages. Levels of expression were associated with lung function and COPD status. We identified two novel regions associated with lung function decline in mild COPD. Genes within these regions were expressed in relevant lung cells and their expression related to airflow limitation suggesting they may represent novel candidate genes for COPD susceptibility.     

Variants in the 15q24/25 Locus Associate with Lung Function Decline in Active Smokers

Genetic variation in nicotinic acetylcholine receptor subunit genes (nAChRs) is associated with lung function level and chronic obstructive pulmonary disease (COPD). It is unknown whether these variants also predispose to an accelerated lung function decline. We investigated the association of nAChR susceptibility variants with lung function decline and COPD severity. The rs1051730 and rs8034191 variants were genotyped in a population-based cohort of 1,226 heavy smokers (COPACETIC) and in an independent cohort of 883 heavy smokers, of which 653 with COPD of varying severity (LEUVEN). Participants underwent pulmonary function tests at baseline. Lung function decline was assessed over a median follow-up of 3 years in COPACETIC. Current smokers homozygous for the rs1051730 A-allele or rs8034191 G-allele had significantly greater FEV₁/FVC decline than homozygous carriers of wild-type alleles (3.3% and 4.3%, p = 0.026 and p = 0.009, respectively). In the LEUVEN cohort, rs1051730 AA-carriers and rs8034191 GG-carriers had a two-fold increased risk to suffer from COPD GOLD IV (OR 2.29, 95% confidence interval [CI] = 1.11–4.75; p = 0.025 and OR = 2.42, 95% [CI] = 1.18–4.95; p = 0.016, respectively). The same risk alleles conferred, respectively, a five- and four-fold increased risk to be referred for lung transplantation because of end-stage COPD (OR = 5.0, 95% [CI] = 1.68–14.89; p = 0.004 and OR = 4.06, 95% [CI] = 1.39–11.88; p = 0.010). In Europeans, variants in nAChRs associate with an accelerated lung function decline in current smokers and with clinically relevant COPD.     

Isolation and multiplex genotyping of polymorphic microsatellite DNA markers in the snakehead murrel, Channa striata

Seven polymorphic microsatellite loci were isolated and characterized for the snakehead murrel, Channa striata (Channidae), a valuable tropical freshwater fish species. Among 25 specimens collected from Kedah state in Malaysia, the number of alleles per locus ranged from 2 to 7. Observed and expected heterozygosities ranged from 0.120 to 0.880 and 0.117 to 0.698, respectively. A single locus (CS1-C07) was significantly deviated from Hardy-Weinberg equilibrium after Bonferroni correction. These novel markers would be useful for population genetic studies of the C. striata.     

Generating social network data using partially described networks: an example informing avian influenza control in the British poultry industry

Background

The United Kingdom (UK) government has been recording the births, deaths, and movements of cattle for the last decade. Despite reservations about the accuracy of these data, they represent a large and valuable body of information about the demographics of the UK cattle herd and its contact structure. In this article, a range of demographic data about UK cattle, and particularly their movements, are presented, as well as yearly trends in the patterns of movements.

Results

A clear seasonal pattern is evident in the number of movements of cattle, as are the reductions in movement volume due to foot and mouth disease outbreaks in 2001 and 2007. The distribution of ages of cattle at their time of death is multimodal, and the impact of the over thirty months rule is marked. Most movements occur between agricultural holdings, markets, and slaughterhouses, and there is a non-random pattern to the types of holdings movements occur between. Most animals move only a short distance and a few times in their life. Most movements between any given pair of holdings only occurred once in the last 10 years, but about a third occurred between 2 and 10 times in that period. There is no clear trend to movement patterns in the UK since 2002.

Conclusions

Despite a substantial number of regulatory interventions during the last decade, movement patterns show no clear trend since 2002. The observed patterns in the repeatability of movements, the types of holdings involved in movements, the distances and frequencies of cattle movements, and the batch sizes involved give an insight into the structure of the UK cattle industry, and could act as the basis for a predictive model of livestock movements in the UK.     

Phylogeographic Pattern of the Striped Snakehead,Channa striata in Sundaland: Ancient River Connectivity,Geographical and Anthropogenic Singnatures

A phylogeographic study of an economically important freshwater fish, the striped snakehead, Channa striata in Sundaland was carried out using data from mtDNA ND5 gene target to elucidate genetic patterning. Templates obtained from a total of 280 individuals representing 24 sampling sites revealed 27 putative haplotypes. Three distinct genetic lineages were apparent; 1)northwest Peninsular Malaysia, 2)southern Peninsular, east Peninsular, Sumatra and SW (western Sarawak) and 3) central west Peninsular and Malaysian Borneo (except SW). Genetic structuring between lineages showed a significant signature of natural geographical barriers that have been acting as effective dividers between these populations. However, genetic propinquity between the SW and southern Peninsular and east Peninsular Malaysia populations was taken as evidence of ancient river connectivity between these regions during the Pleistocene epoch. Alternatively, close genetic relationship between central west Peninsular Malaysia and Malaysian Borneo populations implied anthropogenic activities. Further, haplotype sharing between the east Peninsular Malaysia and Sumatra populations revealed extraordinary migration ability of C. striata (>500 km) through ancient connectivity. These results provide interesting insights into the historical and contemporary landscape arrangement in shaping genetic patterns of freshwater species in Sundaland.     

Polymorphisms in the glucocorticoid receptor gene that modulate glucocorticoid sensitivity are associated with rheumatoid arthritis

Introduction  

The glucocorticoid receptor (GR) plays an important regulatory role in the immune system. Four polymorphisms in the GR gene are associated with differences in glucocorticoid (GC) sensitivity; the minor alleles of the polymorphisms N363 S and BclI are associated with relative hypersensitivity to GCs, while those of the polymorphisms ER22/23EK and 9β are associated with relative GC resistance. Because differences in GC sensitivity may influence immune effector functions, we examined whether these polymorphisms are associated with the susceptibility to develop Rheumatoid Arthritis (RA) and RA disease severity.     

Ellagic acid mitigates arsenic‐trioxide‐induced mitochondrial dysfunction and cytotoxicity in SH‐SY5Y cells

In the current study, neuroprotective significance of ellagic acid (EA, a polyohenol) was explored by primarily studying its antioxidant and antiapoptotic potential against arsenic trioxide (As₂O₃)‐induced toxicity in SH‐SY5Y human neuroblastoma cell lines. The mitigatory effects of EA with particular reference to cell viability and cytotoxicity, the generation of reactive oxygen species, DNA damage, and mitochondrial dynamics were studied. Pretreatment of SH‐SY5Y cells with EA (10 and 20 μM) for 60 min followed by exposure to 2 μM As₂O₃ protected the SH‐SY5Y cells against the harmful effects of the second. Also, EA pre‐treated groups expressed improved viability, repaired DNA, reduced free radical generation, and maintained altered mitochondrial membrane potential than those exposed to As₂O₃ alone. EA supplementation also inhibited As₂O₃‐induced cytochrome c expression that is an important hallmark for determining mitochondrial dynamics. Thus, the current investigations are more convinced for EA as a promising candidate in modulating As₂O₃‐induced mitochondria‐mediated neuronal toxicity under in vitro system.     

An intragenic distribution bias of DNA uptake sequences in <Emphasis Type="Italic">Pasteurellaceae</Emphasis> and <Emphasis Type="Italic">Neisseriae</Emphasis>

   

Most sequenced strains from Pasteurellaceae and Neisseriae contain hundreds to thousands of uptake sequence (US) motifs in their genome, which are associated with natural competence for DNA uptake. The mechanism of their recognition is still unclear, and I searched for intragenic location patterns of these motifs for clues about their distribution. In all cases, one orientation of the US has a higher occurrence in the reading frame, and in all Pasteurellaceae, the US and the reverse complement motifs are biased towards the gene termini. These findings could help design experimental set-ups to study preferential DNA uptake, thereby further unravelling the phenomenon of natural competence.