Teaching an old pET new tricks: tuning of inclusion body formation and properties by a mixed feed system in E. coli

Applied Microbiology and Biotechnology - Against the outdated belief that inclusion bodies (IBs) in Escherichia coli are only inactive aggregates of misfolded protein, and thus should be avoided...     

Increasing Biomass Production on Limited Land Area Through an Optimal Planting Arrangement

Planting density is a primary consideration in silviculture; however, planting arrangement is often ignored. Most, if not all, forest plantations are arranged in rectangular or square lattices (i.e., grids). Using a simple mathematical model, we investigate the potential influence of planting arrangement on planting density, biomass yield, and rotation period by assuming that efficiently arranging trees is similar to packing congruent circles on a plane. The hexagonal lattice achieves the densest circle packing on a plane; therefore, a hexagonal or triangular lattice arrangement of stems provides the highest planting density for a given spacing. Using packing density to quantify arrangement efficiency, tree crowns in a hexagonal lattice fill approximately 90.7% of available area at initial canopy contact, while tree crowns in a square lattice fill approximately 78.5% of available area at initial canopy contact. The hexagonal lattice permits about a 15% higher density than the square lattice, which allows canopy closure to occur earlier without any change in individual tree growth. Short rotation woody crop (SRWC) systems are excellent candidates under the model’s assumptions of level stand with even-age monoculture. If belowground resources are non-limiting, a hexagonal lattice arrangement shortens rotation period and thus optimizes the biomass yield per land area over time. Higher productivity over time is central to sustainable and efficient use of limited area for bioenergy and biomass products.     

The function of the lampbrush loops formed by the Y chromosome of Drosophila hydei in spermatocyte nuclei

Summary The function of pairs of translocated fragments of the Y chromosome of Drosophila hydei was tested. As the pairs of fragments together had a complete set of Y chromosomal sites, complementation of their function could be predicted according to results of earlier experiments. In contrast to the earlier experiments the development of lampbrush loops during the spermatocyte stage was blocked in one partner of each combined pair. As a consequence, no complementary effect on spermiogenesis is detectable. The results indicate that the formation of lampbrush loops by seven sites in the Y chromosome is a necessary prerequisite for the normal progress of spermiogenesis. This can be considered as further support of the view that the lampbrush loops in spermatocyte nuclei of Drosophila are phenotypic manifestations of the activity of male fertility factors.Supported by the Deutsche Forschungsgemeinschaft.     

Ikarugamycin: A Natural Product Inhibitor of Clathrin‐Mediated Endocytosis

Ikarugamycin (IKA) is a previously discovered antibiotic, which has been shown to inhibit the uptake of oxidized low‐density lipoproteins in macrophages. Furthermore, several groups have previously used IKA to inhibit clathrin‐mediated endocytosis (CME) in plant cell lines. However, detailed characterization of IKA has yet to be performed. Consequently, we performed biochemistry and microscopy experiments to further characterize the effects of IKA on CME. We show that IKA has an IC₅₀ of 2.7 μm in H1299 cells and acutely inhibits CME, but not other endocytic pathways, in a panel of cell lines. Although long‐term incubation with IKA has cytotoxic effects, the short‐term inhibitory effects on CME are reversible. Thus, IKA can be a useful tool for probing routes of endocytic trafficking.