Genomics of phytopathogenic fungi and the development of bioinformatic resources

Genomic resources available to researchers studying phytopathogenic fungi are limited. Here, we briefly review the genomic and bioinformatic resources available and the current status of fungal genomics. We also describe a relational database containing sequences of expressed sequence tags (ESTs) from three phytopathogenic fungi, Blumeria graminis, Magnaporthe grisea, and Mycosphaerella graminicola, and the methods and underlying principles required for its construction. The database contains significant annotation for each EST sequence and is accessible at http://cogeme.ex.ac.uk. An easy-to-use interface allows the user to identify gene sequences by using simple text queries or homology searches. New querying functions and large sequence sets from a variety of phytopathogenic species will be incorporated in due course.     

A hybrid bovine ß-casein/bGH gene directs transgene expression to the lung and mammary gland of transgenic mice

We investigated spatial and temporal expression of bGH controlled by two different sizes (1.8kb and 15kb) of 5-flanking sequences of the bovine ß-casein in transgenic mice. In the 1.8-kb promoter-containing mice, bGH expression was specifically confined to lung and mammary gland at lactation. While mammary gland expression was highly variable depending on the lines, lung expression was relatively constant with a high level in most lines. Moreover, this dual-tissue specificity of bGH expression was consistently retained in all of the 15kb-promoter-containing mice, although a low ectopic expression was sometimes detected in salivary gland or brain. During mammary gland development in the 1.8-kb promoter-containing mice was mammary gland expression first detected at lactation, following the bovine rather than murine pattern of ß-casein expression. In contrast, lung expression was almost constant regardless of mammary gland developmental state or sex. Therefore, it can be concluded that a combination of the bovine ß-casein promoter and bGH gene directs a distinct dual-tissue specific bGH expression with different regulatory mechanisms between mammary gland and lung and as little as 1.8-kb promoter is sufficient for the proper regulation of the bovine ß-casein gene in mammary gland.     

Effects of algal food quality on sexual reproduction of Daphnia magna

The objective of our study was to investigate sexual reproduction of Daphnia magna associated with mating behaviors and hatching rates, according to different algal food sources. Since a diatom is known to contain more abundant long‐chain poly unsaturated fatty acids (PUFAs), we hypothesized that the diatom‐consuming D. magna would exhibit more successful reproduction rates. Upon the hypothesis, we designed three experiments using two algal species, a green alga (Chlorella vulgaris) and a diatom (Stephanodiscus hantzschii). From the results, we found that the mating frequency and copulation duration increased in the treatment with S. hantzschii, resulting in a significant increase of hatching rates of resting eggs. In the other two repetitive mating strategies (e.g., one female vs. multiple males, and one male vs. multiple females), we found that the hatching rates of resting eggs were greater in the S. hantzschii treatment. In addition to the mating strategy, male body size significantly increased in the diatom treatment, hence average diameter of penis was also statistically different among the treatments (greater diameter in the S. hantzschii treatment). To examine the effect of algal food quality, we estimated quantity of fatty acids in the two algal species. Our result showed that S. hantzschii had a higher proportion of long‐chain PUFAs than C. vulgaris. Furthermore, a stable isotope analysis revealed that carbon and nitrogen originated from S. hantzschii were more assimilated to D. magna. In summary, our study manifested that diatom consumption of D. magna leads to more successful sexual reproduction. We then discussed how the diatom consumption of zooplankton influences food web dynamics in a freshwater ecosystem.     

A Comparison of the Reaction Sites Associated with the Resistance of Coleoptiles of Barley, Oats and Wheat to Infection by Septoria nodorum

A novel technique has been developed to inoculate the outer epidermal cells of coleoptiles of barley, oats and wheat with S. nodorum. Using this technique, which results in a large number of attempted penetrations, the composition of the material deposited at unsuccessful penetration sites in these cereals have been compared. Although the deposits reacted in a similar manner with some histochemical reagents (ammoniacal silver solution, Coppick-Fowler reaction, p-nitrobenzene tetrafluoroborate and Coomassie brilliant blue R250) marked differences occurred between the reactions sites formed by barley and wheat and by oats with other stains (bromophenol blue, nile blue sulphate and Toluidine blue). Chemical treatments used to delignify tissue also revealed differences in these reaction sites. It is concluded that although the reaction sites share some similar components there are significant differences in their chemical structure.     

The ACC1 gene, encoding acetyl-CoA carboxylase, is essential for growth in Ustilago maydis

Acetyl-CoA carboxylase [ACCase; acetylCoA: carbon dioxide ligase (ADP forming), EC 6.4.1.2] catalyses the ATP-dependent carboxylation of acetylCoA to form malonyl-CoA. We have amplified a fragment of the biotin carboxylase (BC) domain of the Ustilago maydis acetyl-CoA carboxylase (ACC1) gene from genomic DNA and used this amplified DNA fragment as a probe to recover the complete gene from a EMBL3 genomic library. The ACC1 gene has a reading frame of 6555 nucleotides, which is interrupted by a single intron of 80 bb in length. The gene encodes a protein containing 2185 amino acids, with a calculated M_r of 242 530; this is in good agreement with the size of ACCases from other sources. Further identification was based on the position of putative binding sites for acetyl-CoA, ATP, biotin and carboxybiotin found in other ACCases. A single ACC1 allele was disrupted in a diploid wild-type strain. After sporulation of diploid disruptants, no haploid progeny containing a disrupted acc1 allele were recovered, even though an exogenous source of fatty acids was provided. The data indicate that, in U. maydis, ACCase is required for essential cellular processes other than de novo fatty acid biosynthesis.The EMBL accession number for the sequence reported in this paper is Z46886     

Emergency aorto-coronary venous bypass graft in cardiogenic shock

The mortality rate of shock complicating myocardial infarction is extremely high (80-100%) despite intensive medical management. Five patients with acute myocardial infarction and cardiogenic shock received an emergency aorto-coronary bypass graft, from three hours to five days after the onset of infarction and three to nine hours after the onset of shock. Selective coronary angiography was performed in all cases prior to operation. Four of the five patients survived and were discharged from hospital. Two cases with A-V dissociation and complete heart block reverted to normal sinus rhythm after the operation. This limited experience indicates that emergency aortocoronary bypass graft surgery can reduce mortality significantly in properly selected cases of cardiogenic shock.     

Process development of oxalic acid production in submerged culture of Aspergillus niger F22 and its biocontrol efficacy against the root-knot nematode Meloidogyne incognita

Bioprocess and Biosystems Engineering - Oxalic acid has potent nematicidal activity against the root-knot nematode Meloidogyne incognita. In this study, fermentation parameters for oxalic acid...     

Continuous production of D-β-hydroxyisobutyric acid from methacrylic acid by Candida rugosa

Summary Continuous production of D- -hydroxyisobutyric acid (D-HIBA) from methacrylic acid (MA) using Candida rugosa IFO 0750 was most efficient under ammonium-limited conditions, whereas D-HIBA was not detected under glucose-limited conditions. As high as 21.5 g D-HIBA/l with 55% molar conversion yield from MA was obtained at a dilution rate of 0.04 h^-1.