Internode length in Pisum. I. The effect of the Le/le gene difference on endogenous gibberellin-like substances

The allelopathic potential of the dry fruits of Washingtonia filifera (L. Linden) H. Wendl. was investigated. Leachates from fruits inhibited the germination of lettuce, wheat, red cabbage and cucumber seeds. The inhibitory effect was partly neutralized by kinetin (20 mg 1⁻¹) and gibberellic acid (50 mg 1⁻¹). The effect of kinetin was more pronounced at 25°C than at 20°C. Substances inhibiting germination were localized in the pericarp of the fruit and were resistant to high temperature.     

Cardiac myoglobin deficit has evolved repeatedly in teleost fishes

Myoglobin (Mb) is the classic vertebrate oxygen-binding protein present in aerobic striated muscles. It functions principally in oxygen delivery and provides muscle with its characteristic red colour. Members of the Antarctic icefish family (Channichthyidae) are widely thought to be extraordinary for lacking cardiac Mb expression, a fact that has been attributed to their low metabolic rate and unusual evolutionary history. Here, we report that cardiac Mb deficit, associated with pale heart colour, has evolved repeatedly during teleost evolution. This trait affects both gill- and air-breathing species from temperate to tropical habitats across a full range of salinities. Cardiac Mb deficit results from total pseudogenization in three-spined stickleback and is associated with a massive reduction in mRNA level in two species that evidently retain functional Mb. The results suggest that near or complete absence of Mb-assisted oxygen delivery to heart muscle is a common facet of teleost biodiversity, even affecting lineages with notable oxygen demands. We suggest that Mb deficit may affect how different teleost species deal with increased tissue oxygen demands arising under climate change.     

Increase of sialyltransferase activity in the serum and liver of inflamed rates

Induction of inflammation by turpentine injection caused 1.5–2-fold increase of both sialy- and galactosyltransferase activity in liver homogenates. The effect was apparent after 12 h turpentine treatment. Serum sialytransferase activity started to increase in the inflamed rats after 18 h, reaching a maximum of 4-fold at 48 h. In contrast, galactosyltransferase activity in serum showed no significant increase. The coordinated and temporal increase of sialytransferase activity in liver and serum suggest involvement of a specific mechanism for the preferential release of this enzyme into serum.     

Insulin-like growth factor-binding protein from human plasma. Purification and characterization

Insulin-like growth factor (IGF)-binding protein (BP) has been purified from Cohn fraction IV of human plasma by acidification, ion exchange to remove endogenous ligands, and affinity chromatography on agarose-IGF-II. The pure protein appeared as a single peak by high performance reverse-phase and gel permeation chromatography (molecular mass, 45-50 kDa), but on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gave a major band at 53 kDa and a minor band at 47 kDa, unreduced, or 43 and 40 kDa, respectively, reduced. The two bands stained for both protein and carbohydrate. After storage at 2 degrees C for 5 months at pH 3, two additional bands, at 26 and 22 kDa on unreduced gels, were also present. Autoradiography after affinity labeling with IGF-I or IGF-II tracer revealed a single labeled band of 61 kDa. BP, quantitated using a specific radioimmunoassay, was retained by agarose-immobilized IGF-I, IGF-II, concanavalin A, and wheat germ lectin, but not Helix pomatia lectin. Competitive binding curves using pure BP and human IGF-I and IGF-II as both labeled and unlabeled ligands indicated association constants of 2-3 X 10(10) liters/mol for both peptides, with a slightly higher affinity for IGF-II than IGF-I, and 0.9 binding sites for either peptide per 53-kDa protein. The exact relationship of this acid-stable IGF BP to the 150-kDa complex from which it is derived remains to be determined.