Absence of genetic polymorphism of human plasma fibronectin studied by immunoelectrophoresis

Plasma fibronectin from 500 blood donors was studied by immunoelectrophoresis. No variants were found. Plasma fibronectin does not appear to be electrophoretically polymorphic in humans.     

Joint effects of porcine leptin and leptin receptor polymorphisms on productivity and quality traits

Leptin signalling plays a fundamental role in growth, fatness and body composition. The aim of this study was to investigate the porcine LEP gene sequence in an Iberian × Landrace experimental cross to identify polymorphisms associated with productivity and quality traits. Because of the documented effects on these traits of the LEPR c.1987C>T polymorphism, the LEP and LEPR c.1987C>T polymorphisms and their interactions have been jointly investigated. The LEP gene sequencing has allowed the identification of 39 polymorphisms, eight of which are novel. Three intronic SNPs, LEP g.1382C>T, LEP g.1387C>T and LEP g.1723A>G, have been genotyped, and association analyses have been carried out. Analyses of LEP g.1387C>T, fully linked to LEP g.1382C>T, have revealed additive effects on live and carcass weights and dominant effects on several backfat thickness measurements. Novel effects of both LEP and LEPR polymorphisms on fatty acid composition in subcutaneous fat have been detected, probably mediated through the effects on fatness. The results reported here suggest that the T alleles of both LEP g.1387C>T and LEPR c.1987C>T, which are fixed in the Iberian pigs, would lead to an increase in growth, fatness and saturated fatty acid content in fat, which could be explained by an increased feed intake.     

A new technique for the visualization of the cytoskeleton in cultured fibroblasts with Coomassie blue R250

Staining of fibroblast monolayers with Coomassie brilliant blue R250 provides a relatively easy and fast method for visualization of cytoskeletal elements. Staining of detergent-extracted monolayers improves resolution and provides preparations comparable in definition to those obtained by specific immunofluorescence.     

Endophytic Penicillium species secretes mycophenolic acid that inhibits the growth of phytopathogenic fungi

The worldwide demand for reduced and restricted use of pesticides in agriculture due to serious environmental effects, health risks and the development of pathogen resistance calls for the discovery of new bioactive compounds. In the medical field, antibiotic-resistant microorganisms have become a major threat to man, increasing mortality. Endophytes are endosymbiotic microorganisms that inhabit plant tissues without causing any visible damage to their host. Many endophytes secrete secondary metabolites with biological activity against a broad range of pathogens, making them potential candidates for novel drugs and alternative pesticides of natural origin. We isolated endophytes from wild plants in Israel, focusing on endophytes that secrete secondary metabolites with biological activity. We isolated 302 different endophytes from 30 different wild plants; 70 of them exhibited biological activity against phytopathogens. One biologically active fungal endophyte from the genus Penicillium, isolated from a squill (Urginea maritima) leaf, was further examined. Chloroform-based extraction of its growth medium was similarly active against phytopathogens. High-performance liquid chromatography separation followed by gas chromatography/mass spectrometry analysis revealed a single compound—mycophenolic acid—as the main contributor to the biological activity of the organic extract.     

Allelopathic actions in the Florida scrub community

The hypothesis that allelochemicals released from members of the Florida scrub community deter the invasion of fire-prone sandhill grasses was investigated. Constituents of the endemic scrub members, Ceratiola ericoides, Conradina canescens and Calamintha ashei, were examined for their phytotoxic activity. Effects of the plant natural products on the germination and radicle growth of lettuce (Lactuca sativa), as well as little bluestem (Schizachyrium scoparium) and green sprangletop (Leptochloa dubia), two native grasses of the Florida sandhill community, were tested. The data suggest that ursolic acid and other natural detergents which are released from a source plant enhance the solubilization of allelopathic lipids via micellization. In general, natural surfactants seem to play a significant role in the water transport of lipophilic phytotoxins to target seeds or seedlings.