Cancer-upregulated gene 2 (CUG2), a new component of centromere complex,is required for kinetochore function

We previously identified cancer-upregulated gene 2 (CUG2) as a commonly up-regulated gene in various human cancer tissues, especially in ovary, liver, and lung (Lee et al., 2007a). CUG2 was determined to be a nuclear protein that exhibited high proto-oncogenic activities when overexpressed in NIH3T3 mouse fibroblast cells. To identify other cellular functions of CUG2, we performed yeast two-hybrid screening and identified CENP-T, a component of CENP-A nucleosome complex in the centromere, as an interacting partner of CUG2. Moreover, CENP-A, the principle centromeric determinant, was also found in complex with CENP-T/CUG2. Immunofluorescent staining revealed the co-localization of CUG2 with human centromeric markers. Inhibition of CUG2 expression drastically affected cell viability by inducing aberrant cell division. We propose that CUG2 is a new component of the human centromeric complex that is required for proper chromosome segregation during mitosis.     

Fine mapping of the rice Bph1 gene, which confers resistance to the brown planthopper (Nilaparvata lugens stal), and development of STS markers for marker-assisted selection

The brown planthopper (BPH) is a major insect pest in rice, and damages these plants by sucking phloem-sap and transmitting viral diseases. Many BPH resistance genes have been identified in indica varieties and wild rice accessions, but none has yet been cloned. In the present study we report fine mapping of the region containing the Bph1 locus, which enabled us to perform marker-aided selection (MAS). We used 273 F8 recombinant inbred lines (RILs) derived from a cross between Cheongcheongbyeo, an indica type variety harboring Bph1 from Mudgo, and Hwayeongbyeo, a BPH susceptible japonica variety. By random amplification of polymorphic DNA (RAPD) analysis using 656 random 10-mer primers, three RAPD markers (OPH09, OPA10 and OPA15) linked to Bph1 were identified and converted to SCAR (sequence characterized amplified region) markers. These markers were found to be contained in two BAC clones derived from chromosome 12: OPH09 on OSJNBa0011B18, and both OPA10 and OPA15 on OSJNBa0040E10. By sequence analysis of ten additional BAC clones evenly distributed between OSJNBa0011B18 and OSJNBa0040E10, we developed 15 STS markers. Of these, pBPH4 and pBPH14 flanked Bph1 at distances of 0.2 cM and 0.8 cM, respectively. The STS markers pBPH9, pBPH19, pBPH20, and pBPH21 co-segregated with Bph1. These markers were shown to be very useful for marker-assisted selection (MAS) in breeding populations of 32 F6 RILs from a cross between Andabyeo and IR71190, and 32 F5 RILs from a cross between Andabyeo and Suwon452.     

Efficient and high-throughput vector construction and Agrobacterium-mediated transformation of Arabidopsis thaliana suspension-cultured cells for functional genomics

We established a large-scale, high-throughput protocol to construct Arabidopsis thaliana suspension-cultured cell lines, each of which carries a single transgene, using Agrobacterium-mediated transformation. We took advantage of RIKEN Arabidopsis full-length (RAFL) cDNA clones and the Gateway cloning system for high-throughput preparation of binary vectors carrying individual full-length cDNA sequences. Throughout all cloning steps, multiple-well plates were used to treat 96 samples simultaneously in a high-throughput manner. The optimal conditions for Agrobacterium-mediated transformation of 96 independent binary vector constructs were established to obtain transgenic cell lines efficiently. We evaluated the protocol by generating transgenic Arabidopsis T87 cell lines carrying individual 96 metabolism-related RAFL cDNA fragments, and showed that the protocol was useful for high-throughput and large-scale production of gain-of-function lines for functional genomics.     

Statins activate GATA-6 and induce differentiated vascular smooth muscle cells

The beneficial effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) beyond cholesterol lowering involve their direct actions on vascular smooth muscle cells (VSMCs). However, the effects of statins on phenotypic modulation of VSMCs are unknown. We herein show that simvastatin (Sm) and atorvastatin (At) inhibited DNA synthesis in human aortic VSMCs dose-dependently, while cell toxicity was not observed below the concentration of 1 μM of Sm or 100 nM of At. Stimulating proliferative VSMCs with Sm or At induced the expression of SM-α-actin and SM-MHC, highly specific markers of differentiated phenotype. Sm up-regulated the binding activity of GATA-6 to SM-MHC GATA site and activated the transfected SM-MHC promoter in proliferative VSMCs, while mutating the GATA-6 binding site abolished this activation. Geranylgeranylpyrophosphate (10 μM), an inhibitor of Rho family proteins, abolished the statin-mediated induction of the differentiated phenotype in VSMCs. These findings suggest that statins activate GATA-6 and induce differentiated VSMCs.     

Unique set of copulatory organs in mantises: Concealed female genital opening and extremely asymmetric male genitalia

Several insects exhibit strong asymmetry in male genital shape, but the functions of this asymmetry is unknown. In the four species of the family Mantidae belonging to the genera Tenodera, Statilia and Hierodula, male genitalia consist of a more complex left‐side lobe, with two well‐pointed sclerotized processes, the apical process (paa) and the distal process (pda). Female genitalia are symmetric, and the genital opening (gonopore) is concealed by placement of the ovipositor (ovi) into the subgenital plate (sgp). Mating with experimental males, in which either paa or pda was cut, demonstrated that paa is essential for successful copulation. By fluorescence detection of the surface of females mated with males in which the paa was coated with fine fluorescent beads, the paa attachment site was determined to be the left edge of the female sgp. This finding suggests that copulation begins with exposure of the female gonopore by the male hooking the paa to the sgp and unfastening the ovi from the sgp, as associated with other parts of the male genitalia. The extremely asymmetric male genitalia also determine their mating posture. The male, mounting the female, bends his abdomen from the right side of his mate to attach his paa to her sgp. We found no antisymmetry in male genitalia, and never observed reversal (leftward) abdominal bending by the males. This was the fixed mating posture, even in virgin males, suggesting its innateness.     

Effects of CO2 on growth and photosynthesis of Pyrrosia piloselloides (L.) Price gametophytes

The effects of CO2 concentration on spore germination, growth, and net photosynthetic rate (PN) of gametophytes of a tropical epiphytic fern, Pyrrosia piloselloides, were investigated over a 100-d period. Increasing CO2 concentration stimulated spore germination and enhanced gametophytic growth. The appearance of sexual organs and formation of sporophytes were accelerated with higher CO2 during growth. Radiant energy saturated PN and dark respiration rate also increased with increasing CO2 concentrations during growth.