ELAV links paused Pol II to alternative polyadenylation in the Drosophila nervious system

Alternative polyadenylation (APA) has been implicated in a variety of developmental and disease processes. A particularly dramatic form of APA occurs in the developing nervous system of flies and mammals, whereby various developmental genes undergo coordinate 3' UTR extension. In Drosophila, the RNA-binding protein ELAV inhibits RNA processing at proximal polyadenylation sites, thereby fostering the formation of exceptionally long 3' UTRs. Here, we present evidence that paused Pol II promotes recruitment of ELAV to extended genes. Replacing promoters of extended genes with heterologous promoters blocks normal 3' extension in the nervous system, while extension-associated promoters can induce 3' extension in ectopic tissues expressing ELAV. Computational analyses suggest that promoter regions of extended genes tend to contain paused Pol II and associated cis-regulatory elements such as GAGA. ChIP-seq assays identify ELAV in the promoter regions of extended genes. Our study provides evidence for a regulatory link between promoter-proximal pausing and APA

Antagonistic Roles of SEPALLATA3, FT and FLC Genes as Targets of the Polycomb Group Gene CURLY LEAF

In Arabidopsis, mutations in the Pc-G gene CURLY LEAF (CLF) give early flowering plants with curled leaves. This phenotype is caused by mis-expression of the floral homeotic gene AGAMOUS (AG) in leaves, so that ag mutations largely suppress the clf phenotype. Here, we identify three mutations that suppress clf despite maintaining high AG expression. We show that the suppressors correspond to mutations in FPA and FT, two genes promoting flowering, and in SEPALLATA3 (SEP3) which encodes a co-factor for AG protein. The suppression of the clf phenotype is correlated with low SEP3 expression in all case and reveals that SEP3 has a role in promoting flowering in addition to its role in controlling floral organ identity. Genetic analysis of clf ft mutants indicates that CLF promotes flowering by reducing expression of FLC, a repressor of flowering. We conclude that SEP3 is the key target mediating the clf phenotype, and that the antagonistic effects of CLF target genes masks a role for CLF in promoting flowering

SOFTWARE PROCESS IMPROVEMENT: AWARENESS, USE, AND BENEFITS IN CANADIAN SOFTWARE DEVELOPMENT FIRMS

Since 1982, the software development community has been concerned with the delivery of quality systems. Software process improvement (SPI) is an initiative to avoid the delivery of low quality systems. However, the awareness and adoption of SPI is low. Thus, this study examines the rate of awareness, use, and benefits of SPI initiatives in Canadian software development firms. Using SPSS as the analytical tool, this study found that 59% of Canadian software development firms are aware of SPI programs and 43% of employees use a form of SPI programs to develop software products. Although the sample size is small and the results cannot be generalized, the sample firms that use SPI programs reported an improvement in software product quality as the greatest benefit. These findings confirm the importance of SPI programs as a means of producing higher-quality software products, which can increase the likelihood of software companies winning global contracts

Matrix relations in the analysis of variance

Artykuł nie zawiera streszczeniaFor balanced classifications and for unbalanced nested classifications, we give a simple rule which establishes a one-to-one correspondence between numbers of degrees of freedom and projection operators in the analysis of variance. The rule enables us to determine explicitly the matrix representations of appropriate sums of squares

Przegląd niektórych prac Katedry Zastosowań Matematyki Akademii Rolniczej w Lublinie

For balanced classifications and for unbalanced nested classifications, we give a simple rule which establishes a one-to-one correspondence between numbers of degrees of freedom and projection operators in the analysis of variance. The rule enables us to determine explicitly the matrix representations of appropriate sums of squares