Toxic and non-toxic Nodularia strains can be distinguished from each other and from eukaryotic algae with chlorophyll fluorescence fingerprinting

Chlorophyll fluorescence induction curves of toxic and non-toxic strains of the cyanobacterium Nodularia were measured and compared with fluorescence curves measured from four species of eukaryotic algae. Both cyanobacteria and algae were isolated from the Baltic Sea. The results show that Nodularia strains can be distinguished from the eukaryotes by applying a pattern recognition procedure to the fluorescence induction curves, suggesting that the fluorescence fingerprinting technique might be useful in environmental monitoring of marine algae. The six studied Nodularia strains could not be distinguished from each other from their fluorescence induction kinetics. However, their fluorescence curves fell into two clear categories, the toxic and the non-toxic Nodularia. Emission spectroscopy and differences in the fluorescence induction curves showed that the ratio of the intensity of the Photosystem I emission peak to the Photosystem II peak is higher in non-toxic Nodularia than in the toxic strains, suggesting that the toxicity affects the structure of the photosynthesis machinery. The effect on photosynthesis may be related to the ability of the microcystins to chelate iron.     

Optimization of novel monobactams with activity against carbapenem-resistant Enterobacteriaceae – Identification of LYS228

Metallo-β-lactamases (MBLs), such as New Delhi metallo-β-lactamase (NDM-1) have spread world-wide and present a serious threat. Expression of MBLs confers resistance in Gram-negative bacteria to all classes of β-lactam antibiotics, with the exception of monobactams, which are intrinsically stable to MBLs. However, existing first generation monobactam drugs like aztreonam have limited clinical utility against MBL-expressing strains because they are impacted by serine β-lactamases (SBLs), which are often co-expressed in clinical isolates. Here, we optimized novel monobactams for stability against SBLs, which led to the identification of LYS228 (compound 31). LYS228 is potent in the presence of all classes of β-lactamases and shows potent activity against carbapenem-resistant isolates of Enterobacteriaceae (CRE).     

Organization of cortical processing for facial movements during licking in cats

We proposed that cortical organization for the execution of adequate licking in cats was processed under the control of two kinds of affiliated groups for face and jaw & tongue movements (Hiraba H, Sato T. 2005A. Cerebral control of face, jaw, and tongue movements in awake cats: Changes in regional cerebral blood flow during lateral feeding Somatosens Mot Res 22:307–317). We assumed the cortical organization for face movements from changes in MRN (mastication-related neuron) activities recorded at area M (motor cortex) and orofacial behaviors after the lesion in the facial SI (facial region in the primary somatosensory cortex). Although we showed the relationship between facial SI (area 3b) and area M (area 4δ), the property of area C (area 3a) was not fully described. The aim of this present study is to investigate the functional role of area C (the anterior part of the coronal sulcus) that transfers somatosensory information in facial SI to area M, as shown in a previous paper (Hiraba H. 2004. The function of sensory information from the first somatosensory cortex for facial movements during ingestion in cats Somatosens Mot Res 21:87--97). We examined the properties of MRNs in area C and changes in orofacial behaviors after the area C or area M lesion. MRNs in area C had in common RFs in the lingual, perioral, and mandibular parts, and activity patterns of MRNs showed both post- and pre-movement types. Furthermore, cats with the area C lesion showed similar disorders to cats with the area M lesion, such as the dropping of food from the contralateral mouth, prolongation of the period of ingestion and mastication, and so on. From these results, we believe firmly the organization of unilateral cortical processing in facial SI, area C, and area M for face movements during licking.     

Nitrogen resorption in senescing leaf blades of rice exposed to free-air CO<Subscript>2</Subscript> enrichment (FACE) under different N fertilization levels

Background and Aims

The effects of Sb(V), alone or combined with Se, on the growth and root development of plants are unknown. The aim of this study is to investigate the interaction between selenite and different forms of Sb and the effects on their uptake in rice and on rice root morphology.

Methods

A hydroponic experiment was conducted that contained fourteen treatments. The treatment levels for Se were 0.5 and 1 mg L^?1, and the treatment levels for Sb(III) and Sb(V) were 5 and 15 mg L^?1.

Results

Sb(V) alone significantly reduced the surface area, mean diameter and volume of the roots, whereas Sb(III) alone reduced the values of most parameters of root morphology. The addition of 1 mg L^?1 Se significantly enhanced the surface area, number of medium roots, and Sb concentration in the roots subjected to 15 mg L^?1 Sb(V), but it decreased the number of root forks, the number and proportion of fine roots, and the shoot Sb concentration under exposure to 15 mg L^?1 Sb(III). When the plants were subjected to 1 mg L^?1 Se, the addition of 15 mg L^?1 Sb(III) markedly reduced the shoot and root Se concentrations and the number of root tips, root forks, and fine roots and increased the mean root diameter. However, the addition of Sb(V) did not significantly affect the root and shoot Se concentrations but significantly decreased the number of root forks and fine roots and increased the proportion of medium roots.

Conclusions

Se and Sb(III) showed antagonistic effects on uptake in the shoots, but not in the roots, of paddy rice. A range of Se concentrations could stimulate the uptake of Sb in both the shoots and roots of paddy rice exposed to Sb(V).

     

Concerted Evolution of a Highly Repetitive DNA Family in Eptatretidae (Cyclostomata, Agnatha) Implies Specifically Differential Homogenization and Amplification Events in Their Germ Cells

In eight hagfish species, it is known that chromosome elimination occurs during early embryogenesis, and some highly repetitive DNA families, restricted to germ cells, have been isolated. One of these families, ``EEEo2,' has been isolated as DNA fragments by restriction enzyme analyses from Eptatretus okinoseanus and E. cirrhatus. In this study, EEEo2 sequences were isolated from germline DNA in E. burgeri, Paramyxine sheni, and P. atami using PCR methods. Sequence analysis revealed that these sequences are intraspecifically homogeneous, except in E. burgeri, and are interspecifically conserved with heterogeneity. The intraspecific sequence variability tends to decrease as the copy number increases. These results indicate that EEEo2 has evolved in a concerted manner. Moreover, an ancestral repeating motif consisting of triplicate subrepeats was deduced. These results suggest that EEEo2 arose as an initial amplification of this subrepeat and has evolved by saltatory replication. Phylogenetic analyses suggested the possibility that EEEo2 in E. okinoseanus and E. cirrhatus has been subjected to strong homogenizing forces for concerted evolution, whereas the force is weak in E. burgeri. In addition, EEEo2 in P. sheni and P. atami appear to have been incompletely subjected to these forces. Chromosomal in situ hybridization experiments revealed that EEEo2 sequences were located along almost their entire length of several heterochromatic chromosomes that are restricted to germ cells. These chromosomes are disposed to form a secondary association during the first meiotic metaphases, except in P. sheni. This chromosomal distribution may promote a concerted mode of sequence evolution in both nonhomologous chromosomes and homologous chromosomes and reflect the differential driving forces between species. Received: 17 April 1999 / Accepted: 10 September 1999     

Changes in flower coloration and sepal anthocyanins of Cyanic delphinium cultivars during flowering

The changes in flower color related to sepal pigmentation of cyanic Delphinium cultivars were investigated during anthesis. The sepal hues of the purple and blue flowered varieties observed on the initial day of unfurling had changed with a decrease in hue angle three days after anthesis. In both the purple and blue cultivars, violdelphin (3) was the major component on day one of anthesis, and the chromaticity improved with increasing sepal concentrations of violdelphin (3) and cyanodelphin (4) after three days of unfurling. The flower hue was dominated by the constitution of acylated anthocyanins, and the chromaticity was ordered by the sepal concentration. The biosynthesis of cyanodelphin (4) from violdelphin (3) was postulated since an increase in the sepal concentration of cyanodelphin (4) was accompanied by a decrease in violdelphin (3). Acylation of the anthocyanins was initiated by an increase in the respective possible precursors, tulipanin (2) and violdelphin (3), to subsequently synthesize violdelphin (3) and cyanodelphin (4) during flowering.     

Androgen receptor CAG polymorphism and prostate cancer risk

Recent studies have suggested that polymorphisms of the androgen receptor gene ( AR) may influence the risk of prostate cancer (PC) development and progression. Here, we analyzed the length of the CAG repeat of the AR gene in 1363 individuals, including patients with PC, benign prostate hyperplasia (BPH), and population controls. There was a tendency for short CAG repeats to be associated with PC. The Odds Ratio (OR) for PC was 1.47 ( P=0.05) when individuals with short CAG repeats (18). CAG repeat length was not significantly associated with family history, disease stage, grade, age at diagnosis, prostate-specific antigen (PSA) level at diagnosis, or prognosis of the patients. Unexpectedly, short CAG repeats were significantly less common in patients with BPH compared with controls (OR=0.47, P=0.03). Our results suggest that the CAG polymorphism of the AR gene is unlikely to have a major role in the development or progression of PC in the Finnish population. The association of CAG repeats with the risk of BPH warrants further study.     

JSNP: a database of common gene variations in the Japanese population

JSNP is a repository of Japanese Single Nucleotide Polymorphism (SNP) data, begun in 2000 and developed through the Prime Minister’s Millennium Project. The aim of this undertaking is to identify and collate up to 150 000 SNPs from the Japanese population, located in genes or in adjacent regions that might influence the coding sequence of the genes. The project has been carried out by a collaboration between the Human Genome Center (HGC) in the Institute of Medical Science (IMS) at the University of Tokyo and the Japan Science and Technology Corporation (JST). JSNP serves as both a storage site for the Japanese SNPs obtained from the ongoing project and as a facility for public dissemination to allow researchers access to high quality SNP data. A primary motivation of the project is the construction of a basic data set to identify relationships between polymorphisms and common diseases or the reaction to drugs. As such, emphasis has been placed on the identification of SNPs that lie in candidate regions which may affect phenotype but which would not necessarily directly cause disease. Unrestricted access to JSNP and any associated files is available at http://snp.ims.u-tokyo.ac.jp/.     

Male mate choice in a sexually cannibalistic species: male escapes from hungry females in the praying mantid <Emphasis Type="Italic">Tenodera angustipennis</Emphasis>

While competing males and choosy females may be common in animal mating systems, male choice can evolve under certain conditions. Sexual cannibalism is such a condition because of the high mortality risk for males. In mantids, female body condition is associated with male mate preference, with fat females preferred, due to at least two reasons: females in poor nutritional condition are likely to attack and predate males, and fat females can potentially increase the number of offspring. Thus, the risk of cannibalism and female fecundity can influence male mating behavior. In this study, we attempted to separate these factors by using the praying mantid Tenodera angustipennis to examine whether male preference for fat female mantids was based on avoiding sexual cannibalism (cannibalism avoidance hypothesis) or preference for female fecundity (fecundity preference hypothesis). The feeding regimes were experimentally manipulated to discriminate between the effects of female fecundity and female hunger status on male and female mating behaviors. We found that recently starved females more frequently locomoted toward the male, and that male abdominal bending was less intensive and escape was sooner from recently starved females. These female and male behavioral responses to female hunger condition may reveal male avoidance of dangerous females in this mantid.