Indole-3-acetic Acid Levels and the Role of Indole-3-acetic Acid Oxidase in the Normal Root and Club-root of Cabbage

The auxin content of club-root (Plasmodiophora brassicae Wor.) is 50–100 times higher than that of normal cabbage root. The importance of this difference in the disease development is discussed. Both normal root and club-root of cabbage contain allosteric IAA oxidase and IAA oxidase with ordinary kinetic properties. In normal cabbage root the allosteric one is associated with cell fractions sedimenting at 20,000 × g and 105,000 × g, in club-root it remains in the supernatant after 105,000 × g centrifugation. IAA oxidase with conventional kinetic properties is present in both these tissues in the cell fraction sedimenting at 10,000 × g, which contains mainly cell wall fragments. It is concluded that IAA oxidase is not primarily involved in regulation of the endogenous IAA level.     

SOME ORDOVICIAN AND SILURIAN BRACHIOPOD ASSEMBLAGES

Finds of brachiopod assemblages in graptolitic shales give support to Ruedemann's theory of an epiplanktic life of certain Palaeozoic brachiopods. The possibly epiplanktic brachiopods observed in the present study belong to the families Obolidae ('Obolus') and Sowerbyellidae (Sericoidea). Other assemblages might have been benthic, and a representative of Chonetidae (Shagamella) is thought to yield an example of this kind of biocoenosis.     

Bioactive factors secreted from mesenchymal stromal cells protect the intestines from experimental colitis in a three-dimensional culture

Background aims

Although mesenchymal stromal cells (MSCs) have shown therapeutic potential in intestinal tissue repair, controversy concerning their short survival and poor biodistribution in recipient tissues still remains. Therefore, we investigated the paracrine role of MSC in three-dimensional culture of colon with experimental colitis.

X-ray Microanalysis of Phosphorus in Scenedesmus obtusiusculus

Results from energy dispersive x-ray microanalysis indicate considerable variation in phosphorus as well as in other elements found in polyphosphate granules in cells of Scenedesmus obtusiusculus starved of phosphorus for 24, 36 and 48 h. Comparison is made with cells at a 3-h stage of synchronization and after 48 h cultivation in a phosphorus-containing medium. After 48 h with a very limited external source of phosphorus, phosphorus was not detectable in‘polyphosphate granules’ in Epon-Araldite sections unless the resin and other organic molecules were removed by plasma microincineration. In spite of the low amounts of elements (Mg. Al, Si, P and Ca) detected in these granules they are still dense to electrons in unstained sections, like the granules in cells cultivated in the presence of phosphorus. That suggests that the localized differences in the structural packing of elements or radicals in the polyphosphale polymer is more important For visualization of unstained polyphosphate granules than the absolute concentration of phosphorus or other elements. In contrast to previous assumptions, the abundance of morphologically-observable‘polyphosphate’ granules can no longer be taken as an index of mobilizable phosphate reserves.     

A treat of Cambrian arthropods

Walossek, D. 1993: The Upper Cambrian Rehbachiella and the phylogeny of Branchiopoda and Crustacea. Fossils and Strata 32 .     

Whole Genome Amplification for Sequencing and Applications in Conservation Genetics

Abstract: We describe a method for rapidly amplifying whole genomes via a Phi29 DNA polymerase-mediated strand displacement reaction (SDR). Genomic amplification products derived from the SDR reaction resulted in high quantities of DNA suitable for polymerase chain reaction (PCR) amplification and sequencing of mitochondrial genomes. Control region sequences of DNA derived directly from PCR amplicons of extracted DNA were identical to those derived from PCR amplification of SDR genomic DNA. Effective SDR amplification and subsequent sequencing was successful across tissues sources ranging in age from 1 year to 19 years. Strand replacement reaction genomic amplification offers a means of obtaining large quantities of DNA from small amounts of tissue.