[en] Highlights: • Three stereoisomers of a pentamine showed distinct effects on a group I ribozyme. Among cationic molecules that can modulate ribozyme activities, polyamines act as both activator and inhibitor of ribozyme reactions partly due to their structural flexibility. Restriction of structural flexibility of polyamines may allow them to emphasize particular modulation effects. We examined eight stereoisomers of a synthetic pentamine bearing three cyclopentane rings. In the reaction of a structurally unstable group I ribozyme, three stereoisomers exhibited distinct effects as inhibitor, an additive with a neutral effect, and also as an activator.

[en] Highlights: • PEG rescued mutations in the bimolecular group I ribozyme more effectively than those in the oligomeric form. In the RNA world, enrichment of self-replicating RNAs would have been beneficial to their survival, amplification, and evolution. Self-assembly of RNAs may be a strategy by which they enrich themselves. We examined the effects of molecular crowding on the activity of a bimolecular group I ribozyme and its derivative that self-assembles to form ribozyme oligomers. In a comparative activity assay using PEG as a molecular crowder, PEG rescued mutations in the parent bimolecular ribozyme more effectively than those in the oligomeric form.

[en] Short communication

[en] Short communication

No abstract available

[en] A recent genome wide case-control association study identified NuMA region on 11q13 as a candidate locus for breast cancer susceptibility. Specifically, the variant Ala794Gly was suggested to be associated with increased risk of breast cancer. In order to evaluate the NuMa gene for breast cancer susceptibility, we have here screened the entire coding region and exon-intron boundaries of NuMa in 92 familial breast cancer patients and constructed haplotypes of the identified variants. Five missense variants were further screened in 341 breast cancer cases with a positive family history and 368 controls. We examined the frequency of Ala794Gly in an extensive series of familial (n = 910) and unselected (n = 884) breast cancer cases and controls (n = 906), with a high power to detect the suggested breast cancer risk. We also tested if the variant is associated with histopathologic features of breast tumors. Screening of NuMA resulted in identification of 11 exonic variants and 12 variants in introns or untranslated regions. Five missense variants that were further screened in breast cancer cases with a positive family history and controls, were each carried on a unique haplotype. None of the variants, or the haplotypes represented by them, was associated with breast cancer risk although due to low power in this analysis, very low risk alleles may go unrecognized. The NuMA Ala794Gly showed no difference in frequency in the unselected breast cancer case series or familial case series compared to control cases. Furthermore, Ala794Gly did not show any significant association with histopathologic characteristics of the tumors, though Ala794Gly was slightly more frequent among unselected cases with lymph node involvement. Our results do not support the role of NuMA variants as breast cancer susceptibility alleles

[en] Phytoene synthase (psy) gene is responsible for the synthesis of carotenoids in plants. In this study complimentary deoxyribonucleic acid (cDNA) and genomic sequences of psy were isolated by rapid amplification of cDNA ends and polymerase chain reaction (PCR) using ribonucleic acid (RNA) and DNA isolated from the mesocarp tissues of oil palm (Elaeis guineensis). The size of the full-length cDNA was 2233 bp. The open reading frame (ORF) was 1299 bp and encoded 433 deduced amino acid (AA) residues. The transcript profile revealed that psy was expressed at a maximum level at 12 weeks after anthesis (WAA). The lowest expression of psy was at 13 WAA, which was speculated as the transition of the leaf-like carotenoid to the formation of storage carotenoids. The AA sequence deduced from the cDNA was 70%- 78% identical to PSY from other higher plants. The genomic sequence analysis revealed that the psy gene contains six exons and five introns. Southern blot analysis indicated that oil palm has only one copy of the psy gene in its genome. (author)

No abstract available

[en] The product of the pleiotropic vestigial (vg) gene of Drosophila melanogaster is responsible for 4 traits in adult fly: wings and halters development, normal position of postscutellar bristles, and female fertility. Radiation-induced vg mutations lead to variation in these traits in different degree. Classical spontaneous vestigial no wing (vg^nw) null-mutation displays a deep reduction of the wings and halters, the erected postscutellar bristles, and female sterility and it results from 3 kb-long deletion at the 3'-end of the gene. This indicates that different gene domains may be responsible for different traits. Our large collection of radiation-induced vg mutations (about of 170 mutants) consists of 50% of the vg^nw mutants. It was interesting to analyze the nature of our mutations and find out if the 3'-end of the gene really is a “hot region” for intragenic mutagenesis. To study this issue, the analysis of 7 vg^nw mutants was performed using PCR and sequencing methods. As the results showed, different DNA changes (base substitutions, small deletions and insertions) in exons 3, 4, 5, as well as in the intron 4 were found. It is important to note, that one mutant with changes in only 2 traits from 4 had a large deletion of intron 2. This data indicate that different regions of the vg gene may be responsible for vg^nw phenotype. In the light of the data obtained, the functional importance of introns is discussed.

[en] DNA sequences of different species and different portion of the DNA of the same species may have completely different correlation properties, but the origin of these correlations is still not very clear and is currently being investigated, especially in different particular cases. We report here a study of the DNA sequence of human beta globin region (HUMHBB) which has strong linear and nonlinear correlations. We studied the roles of two of the typical elements of DNA sequence, genes and Alu repeats, in the nonlinear correlations of HUMHBB. We find that there exist strong nonlinear correlations between the exons or introns in different genes and between the Alu repeats. They may be one of the major sources of the nonlinear correlations in HUMBHB