Correlation Index-Based Responsible-Enzyme Gene Screening (CIRES), a Novel DNA Microarray-Based Method for Enzyme Gene Involved in Glycan Biosynthesis

BACKGROUND: Glycan biosynthesis occurs though a multi-step process that requires a variety of enzymes ranging from glycosyltransferases to those involved in cytosolic sugar metabolism. In many cases, glycan biosynthesis follows a glycan-specific, linear pathway. As glycosyltransferases are generally regulated at the level of transcription, assessing the overall transcriptional profile for glycan biosynthesis genes seems warranted. However, a systematic approach for assessing the correlation between glycan expression and glycan-related gene expression has not been reported previously. METHODOLOGY: To facilitate genetic analysis of glycan biosynthesis, we sought to correlate the expression of genes involved in cell-surface glycan formation with the expression of the glycans, as detected by glycan-recognizing probes. We performed cross-sample comparisons of gene expression profiles using a newly developed, glycan-focused cDNA microarray. Cell-surface glycan expression profiles were obtained using flow cytometry of cells stained with plant lectins. Pearson's correlation coefficients were calculated for these profiles and were used to identify enzyme genes correlated with glycan biosynthesis. CONCLUSIONS: This method, designated correlation index-based responsible-enzyme gene screening (CIRES), successfully identified genes already known to be involved in the biosynthesis of certain glycans. Our evaluation of CIRES indicates that it is useful for identifying genes involved in the biosynthesis of glycan chains that can be probed with lectins using flow cytometry

PI3K Signaling in Normal B Cells and Chronic Lymphocytic Leukemia (CLL).

B cells provide immunity to extracellular pathogens by secreting a diverse repertoire of antibodies with high affinity and specificity for exposed antigens. The B cell receptor (BCR) is a transmembrane antibody, which facilitates the clonal selection of B cells producing secreted antibodies of the same specificity. The diverse antibody repertoire is generated by V(D)J recombination of heavy and light chain genes, whereas affinity maturation is mediated by activation-induced cytidine deaminase (AID)-mediated mutagenesis. These processes, which are essential for the generation of adaptive humoral immunity, also render B cells susceptible to chromosomal rearrangements and point mutations that in some cases lead to cancer. In this chapter, we will review the central role of PI3K s in mediating signals from the B cell receptor that not only facilitate the development of functional B cell repertoire, but also support the growth and survival of neoplastic B cells, focusing on chronic lymphocytic leukemia (CLL) B cells. Perhaps because of the central role played by PI3K in BCR signaling, B cell leukemia and lymphomas are the first diseases for which a PI3K inhibitor has been approved for clinical use

Ecological and life history traits of Hemiodus orthonops in the invasion process: looking for clues at home

The understanding of the environmental preferences and life history of a species in its native range provides insights for assessing its potential success in a novel area. Hemiodus orthonops is a migratory fish from the Paraguay and Middle Paraná rivers that invaded the Upper Paraná River through a fish pass, constructed in 2002. The invasion of this fish was analyzed based on habitat attributes and its life history in the native range and in the novel habitats. The native and novel habitats presented similar features. The population showed exponential growth in the years following the invasion, with relevant alterations in somatic growth, proportions of items in the diet, and in reproductive investment. The successful invasion appears to be related to similarities in water chemistry and habitat types between the native and novel range and the species' high dispersion ability. The species also showed earlier maturation and use of poor quality, but highly available feeding resources. Comparing life histories there was indication of a trade-off between investment in reproduction and somatic growth, with an increase in the latter in the novel habitats. In addition, the reproductive investment was more associated with offspring survival (oocyte size) than fecundity.Fil: Agostinho, Angelo A.. Universidade Estadual de Maringá; BrasilFil: Suzuki, Harumi I.. Universidade Estadual de Maringá; BrasilFil: Fugi, Rosemara. Universidade Estadual de Maringá; BrasilFil: Alves, Diego C.. Universidade Estadual de Maringá; BrasilFil: Tonella, Livia H.. Universidade Estadual de Maringá; BrasilFil: Espínola, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentin