An Improved GA for Combinational Logic Expressions

This paper discusses complete binary trees as chromosomes of Genetic Algorithm (GA), and proposes the concept of dominant and recessive genes. On the base of it, a new crossover operator with the selective ability was designed. Finally experimental results are presented.

Time-series Analysis in Imatinib-resistant Chronic Myeloid Leukemia K562-cells under Different Drug Treatments

Chronic myeloid leukemia（CML） is characterized by the accumulation of active BCR-ABL protein. Imatinib is the first-line treatment of CML; however, many patients are resistant to this drug. In this study, we aimed to compare the differences in expression patterns and functions of time-series genes in imatinib-resistant CML cells under different drug treatments. GSE24946 was downloaded from the GEO database, which included 17 samples of K562-r cells with（n=12） or without drug administration（n=5）. Three drug treatment groups were considered for this study： arsenic trioxide（ATO）, AMN107, and ATO＋AMN107. Each group had one sample at each time point（3, 12, 24, and 48 h）. Time-series genes with a ratio of standard deviation/average（coefficient of variation） 〉0.15 were screened, and their expression patterns were revealed based on Short Time-series Expression Miner（STEM）. Then, the functional enrichment analysis of time-series genes in each group was performed using DAVID, and the genes enriched in the top ten functional categories were extracted to detect their expression patterns. Different time-series genes were identified in the three groups, and most of them were enriched in the ribosome and oxidative phosphorylation pathways. Time-series genes in the three treatment groups had different expression patterns and functions. Time-series genes in the ATO group（e.g. CCNA2 and DAB2） were significantly associated with cell adhesion, those in the AMN107 group were related to cellular carbohydrate metabolic process, while those in the ATO＋AMN107 group（e.g. AP2M1） were significantly related to cell proliferation and antigen processing. In imatinib-resistant CML cells, ATO could influence genes related to cell adhesion, AMN107 might affect genes involved in cellular carbohydrate metabolism, and the combination therapy might regulate genes involved in cell proliferation.

Flexible manipulation of Omb levels in the endogenous expression region of Drosophila wing by combinational overexpression and suppression strategy

Manipulating an exogenous or endogenous gene of interest at a defined level is critical for a wide variety of experiments.The Gal4/UAS system has been widely used to direct gene expression for studying complex genetic and biological problems in Drosophila melanogaster and other model organisms.Driven by a given tissue-specific Gal4,expressing UAS-transgene or UAS-RNAi(RNA interference)could be used to up-or down-regulate target gene expression,respectively.However,the efficiency of the Gal4/UAS system is roughly predefined by properties of transposon vector constructs and the insertion site in the transgenic stock.Here,we describe a simple way to modulate optomotor blind(omb)expression levels in its endogenous expression region of the wing disc.We co-expressed UAS-omb and UAS-omb-RNAi together under the control of dpp-Gal4 driver which is expressed in the omb expression region of the wing pouch.The repression effect is more sensitive to temperature than that of overexpression.At low temperature,overexpression plays a dominant role but the efficiency is attenuated by UAS-omb-RNAi.In contrast,at high temperature RNAi predominates in gene expression regulation.By this strategy,we could manipulate omb expression levels at a moderate level.It allows us to manipulate omb expression levels in the same tissue between overexpression and repression at different stages by temperature control.