Expression patterns of <Emphasis Type="Italic">engrailed</Emphasis> and <Emphasis Type="Italic">dpp</Emphasis> in the gastropod <Emphasis Type="Italic">Lymnaea stagnalis</Emphasis>

We isolated the full-length cDNAs of engrailed and dpp-BMP2/4 orthologues from the pond snail Lymnaea stagnalis and examined their expression patterns during development by the whole mount in situ hybridization. At the gastrula and trochophore stages, engrailed is expressed in the peripheral ectoderm of the presumptive and invaginating shell gland, corroborating its role in the shell formation that is widely conserved among molluscs. At the same stages, dpp-BMP2/4 is expressed in the right-hand side ectoderm of the shell gland and in the invaginating stomodaeum. Unlike in the gastropod Patella vulgata, our results suggested that dpp-BMP2/4 has a role in the shell formation, rather than in the regional specification and that it could be involved in the specification pathway of the left–right asymmetry of the developing shell in L. stagnalis.     

Stress-induced environmental changes in a single cell as revealed by fluorescence lifetime imaging.

The fluorescence lifetime image of HeLa cells expressing an enhanced green fluorescent protein (EGFP)-fusion protein changes under stress, which allows noninvasive determination of the status of individual cells.     

Hot springs and cool natural products

Natural products have played a unique role in providing new tools and insights in chemical biology. The tremendous value of natural products was highlighted by scientists from Korea and Japan at the 4(th) Korea-Japan Chemical Biology symposium.     

WDR55 is a nucleolar modulator of ribosomal RNA synthesis, cell cycle progression, and teleost organ development

The thymus is a vertebrate-specific organ where T lymphocytes are generated. Genetic programs that lead to thymus development are incompletely understood. We previously screened ethylnitrosourea-induced medaka mutants for recessive defects in thymus development. Here we report that one of those mutants is caused by a missense mutation in a gene encoding the previously uncharacterized protein WDR55 carrying the tryptophan-aspartate-repeat motif. We find that WDR55 is a novel nucleolar protein involved in the production of ribosomal RNA (rRNA). Defects in WDR55 cause aberrant accumulation of rRNA intermediates and cell cycle arrest. A mutation in WDR55 in zebrafish also leads to analogous defects in thymus development, whereas WDR55-null mice are lethal before implantation. These results indicate that WDR55 is a nuclear modulator of rRNA synthesis, cell cycle progression, and embryonic organogenesis including teleost thymus development.     

Terminal proteomics: N- and C-terminal analyses for high-fidelity identification of proteins using MS

In proteomics, MS plays an essential role in identifying and quantifying proteins. To characterize mature target proteins from living cells, candidate proteins are often analyzed with PMF and MS/MS ion search methods in combination with computational search routines based on bioinformatics. In contrast to shotgun proteomics, which is widely used to identify proteins, proteomics based on the analysis of N- and C-terminal amino acid sequences (terminal proteomics) should render higher fidelity results because of the high information content of terminal sequence and potentially high throughput of the method not requiring very high sequence coverage to be achieved by extensive sequencing. In line with this expectation, we review recent advances in methods for N- and C-terminal amino acid sequencing of proteins. This review focuses mainly on the methods of N- and C-terminal analyses based on MALDI-TOF MS for its easy accessibility, with several complementary approaches using LC/MS/MS. We also describe problems associated with MS and possible remedies, including chemical and enzymatic procedures to enhance the fidelity of these methods.     

Effects on genome constitution and novel cell wall formation caused by the addition of 5RS rye chromosome to common wheat

The cytological instability of common wheat-rye addition lines was investigated in the present study. The chromosome numbers of almost all addition lines were considerably stable, but those of CS 5R were very variable. The rye chromosome added in this line was found to be much shorter than expected. Fluorescent in situ hybridization with 5S rDNA and the centromere-specific probes clearly revealed that the short rye chromosome contains only a short arm of chromosome 5R (5RS). In this line, chromosome numbers of both 5RS and common wheat were changeable. The chromosome numbers ranged from 2n = 36 to 2n = 44 in the cells carrying two 5RS, and ranged from 2n = 31 to 2n = 44 in one 5RS cells. In addition to the chromosome instability, the multicells wrapped in a sac-like structure were frequently observed in the root meristematic tissues of CS 5RS after the enzyme treatment for chromosome preparation. Genomic in situ hybridization with rye DNA as a probe showed that all cells in sacs investigated were at the interphase stage and contained one or two 5RS chromosomes. An electron microscopic analysis revealed that the cells of CS 5RS, particularly in sacs, have abnormal (irregular and curved) cell walls. These results indicate that 5RS has (a) specific factor(s) influencing the cell wall development as well as the genome stability.     

Toll-like receptor 2 (TLR2) and dectin-1 contribute to the production of IL-12p40 by bone marrow-derived dendritic cells infected with Penicillium marneffei

The present study was designed to elucidate the role of TLR2, TLR4 and dectin-1 in the production of IL-12p40 by bone marrow-derived dendritic cells (BM-DCs) infected with Penicillium marneffei. IL-12p40 production was almost completely abrogated in BM-DCs from TLR2 gene-knockout (KO) and MyD88KO mice, but not from TLR4-defective C3H/HeJ mice compared to those from control mice. Furthermore, BM-DCs from dectin-1KO mice faintly produced IL-12p40 upon stimulation with this fungus. Using a luciferase reporter assay, P. marneffei activated NF-kappaB in HEK293 cells transfected with the TLR2 gene, but not with the dectin-1 gene, and their co-transfection did not lead to further increase in this response. These results indicate that TLR2 and dectin-1 are essential in sensing P. marneffei for the activation of BM-DCs.