Occurrence and genetics of black‐eyed migratory locusts,Locusta migratoria (Orthoptera: Acrididae)

Black‐eyed Locusta migratoria appeared in albino locusts as a result of crossing between a short‐winged strain originating from Tsushima Island, Japan, and an albino strain originating from Okinawa Island. The black eye trait was recessive to the white eye trait because the crosses between black‐ and white‐eyed albino locusts produced only individuals with white eyes in the F₁ generation. In the F₂ generation, black‐ and white‐eyed individuals appeared in a ratio of 1:3, indicating that the black eye trait was controlled by a simple Mendelian unit. The black eye trait showed no genetic association with other traits including wing morph, adult body dimensions and classical morphometric ratios such as hind femur length / head width and forewing length / hind femur length.     

Multigeneration exposure test of Drosophila melanogaster to ELF magnetic fields

Mutations, other than dominant lethals, were accumulated on wild type second chromosomes (+) of Drosophila melanogaster during exposure to 50 Hz sinusoidal alternating magnetic fields of 0.5 or 5 mT (rms) for 40 generations by the Curly/Plum(Cy/Pm) accumulation method. We maintained, for 40 generations under continuous exposure, each (+) chromosome as a heterozygote with (Cy) chromosome. Viability of the (+) chromosome was tested by sib-mating of (Cy/+) male and (Cy/+) female in a culture every 10th generation to obtain the homozygote. Viability indices, defined as twice the ratio of number of (+/+) flies to that of (Cy/+) flies plus 1 in the progeny of the test mating, also were calculated, which equaled 1.00 at the starting point. For the control and 0.5 and 5 mT exposed groups, percent frequencies of recessive lethal lines, defined as a line with (+/+) flies less than 0.3% in the test mating, were, respectively, 1.9, 0.9, and 2.9% (10th), 9.0, 4.9, and 9.5% (20th), 30.3, 22.9, and 30.4% (30th), and 39.9, 32.4, and 43.3% (40th generation). For the control and 0.5 and 5 mT groups, average viability indices, excluding lethals and markedly deleterious, were, respectively, 0.778, 0.796, and 0.752 (20th), 0.704, 0.698, and 0.694 (30th), and 0.669, 0.678, and 0.595 (40th generation). Their decreasing rates were 0.0054, 0.0059, and 0.0078 per generation. No significant difference was detected among the exposure levels in either the recessive lethal mutation frequency or the viability index. Bioelectromagnetics 19:335–340, 1998. © 1998 Wiley-Liss, Inc.     

Rab35 GTPase recruits NDP52 to autophagy targets

Autophagy targets intracellular molecules, damaged organelles, and invading pathogens for degradation in lysosomes. Recent studies have identified autophagy receptors that facilitate this process by binding to ubiquitinated targets, including NDP52. Here, we demonstrate that the small guanosine triphosphatase Rab35 directs NDP52 to the corresponding targets of multiple forms of autophagy. The active GTP‐bound form of Rab35 accumulates on bacteria‐containing endosomes, and Rab35 directly binds and recruits NDP52 to internalized bacteria. Additionally, Rab35 promotes interaction of NDP52 with ubiquitin. This process is inhibited by TBC1D10A, a GAP that inactivates Rab35, but stimulated by autophagic activation via TBK1 kinase, which associates with NDP52. Rab35, TBC1D10A, and TBK1 regulate NDP52 recruitment to damaged mitochondria and to autophagosomes to promote mitophagy and maturation of autophagosomes, respectively. We propose that Rab35‐GTP is a critical regulator of autophagy through recruiting autophagy receptor NDP52.     

Glutamine supplementation increases Th1-cytokine responses in murine intestinal intraepithelial lymphocytes

Intestinal intraepithelial lymphocytes (IELs) are major effector cells in the gut mucosal immune system, and are phenotypically distinct from thymic and peripheral T cells. Although nutritional supplementation with glutamine affects the intestinal immune response, it remains unclear whether this is a direct effect via the IEL-derived cytokines. This study examined changes in IEL-derived cytokine production following treatment with glutamine in vitro. Murine IELs were purified and activated with PMA plus ionomycin, and then cultured in the presence of various glutamine concentrations. IEL-derived cytokines were measured using a cytometric bead array (CBA) system, and IEL subsets were analyzed by flow cytometry. Treatment with glutamine increased the production of IL-2 and IFN-gamma from IELs in the presence of PMA plus ionomycin, but had no effect on TNFalpha, IL-4, or IL-5 production. Treatment with alanine or glucose had no regulatory effect on IEL-derived cytokines. Glutamine therefore had a direct effect on the production of selected IEL-derived Th1-cytokines, and enteral supplementation with glutamine may influence the intestinal immune responses mediated by IELs.     

Minus-end-directed motor Ncd exhibits processive movement that is enhanced by microtubule bundling in vitro

Drosophila Ncd, a kinesin-14A family member, is essential for meiosis and mitosis. Ncd is a minus-end-directed motor protein that has an ATP-independent microtubule binding site in the tail region, which enables it to act as a dynamic crosslinker of microtubules to assemble and maintain the spindle. Although a tailless Ncd has been shown to be nonprocessive, the role of the Ncd tail in single-molecule motility is unknown. Here, we show that individual Ncd dimers containing the tail region can move processively along microtubules at very low ionic strength, which provides the first evidence of processivity for minus-end-directed kinesins. The movement of GFP-Ncd consists of both a unidirectional and a diffusive element, and it was sensitive to ionic strength. Motility of a truncation series of Ncd and removal of the tubulin tail suggested that the Ncd tail serves as an electrostatic tether to microtubules. Under higher ionic conditions, Ncd showed only a small bias in diffusion along "single" microtubules, whereas it exhibited processive movement along "bundled" microtubules. This property may allow Ncd to accumulate preferentially in the vicinity of focused microtubules and then to crosslink and slide microtubules, possibly contributing to dynamic spindle self-organization.     

Regioselective synthesis of methylated epigallocatechin gallate via nitrobenzenesulfonyl (Ns) protecting group

Regioselective synthesis of methylated epigallocatechin gallate from epigallocatechin was accomplished using a 2-nitrobenzenesulfonyl (Ns) group as a protecting group for phenols. This methodology provided several methylated catechins, which are naturally scarce catechin derivatives.     

Synthesis and protonation behavior of a water-soluble N-fused porphyrin: Conjugation with an oligoarginine by click chemistry

A water-soluble derivative of N-fused porphyrin (NFP) possessing a nona-arginine (R9) peptide tail was synthesized for the first time by a Cu(I)-catalyzed azide-alkyne ‘click’ reaction. In aqueous solution, at pH 8, the conjugated molecule (NFP-R9) exists as free base and protonated below pH < 6.5 to form monoprotonated species dominantly, and diprotonated one below pH < 2.3, while such clear two-step protonation behavior was not observed in the DMF solution.     

Functional dissection of LIS1 and NDEL1 towards understanding the molecular mechanisms of cytoplasmic dynein regulation

LIS1 and NDEL1 are known to be essential for the activity of cytoplasmic dynein in living cells. We previously reported that LIS1 and NDEL1 directly regulated the motility of cytoplasmic dynein in an in vitro motility assay. LIS1 suppressed dynein motility and inhibited the translocation of microtubules (MTs), while NDEL1 dissociated dynein from MTs and restored dynein motility following suppression by LIS1. However, the molecular mechanisms and detailed interactions of dynein, LIS1, and NDEL1 remain unknown. In this study, we dissected the regulatory effects of LIS1 and NDEL1 on dynein motility using full-length or truncated recombinant fragments of LIS1 or NDEL1. The C-terminal fragment of NDEL1 dissociated dynein from MTs, whereas its N-terminal fragment restored dynein motility following suppression by LIS1, demonstrating that the two functions of NDEL1 localize to different parts of the NDEL1 molecule, and that restoration from LIS1 suppression is caused by the binding of NDEL1 to LIS1, rather than to dynein. The truncated monomeric form of LIS1 had little effect on dynein motility, but an artificial dimer of truncated LIS1 suppressed dynein motility, which was restored by the N-terminal fragment of NDEL1. This suggests that LIS1 dimerization is essential for its regulatory function. These results shed light on the molecular interactions between dynein, LIS1, and NDEL1, and the mechanisms of cytoplasmic dynein regulation.     

Structural characteristics of hydration sites in lysozyme

A new method is presented for determining the hydration site of proteins, where the effect of structural fluctuations in both protein and hydration water is explicitly considered by using molecular dynamics simulation (MDS). The whole hydration sites (HS) of lysozyme are composed of 195 single HSs and 38 clustered ones (CHS), and divided into 231 external HSs (EHS) and 2 internal ones (IHS). The largest CHSs, ‘Hg’ and ‘Lβ’, are the IHSs having 2.54 and 1.35 mean internal hydration waters respectively. The largest EHS, ‘Clft’, is located in the cleft region. The real hydration structure of a CHS is an ensemble of multiple structures. The transition between two structures occurs through recombinations of some H-bonds. The number of the experimental X-ray crystal waters is nearly the same as that of the estimated MDS hydration waters for 70% of the HSs, but significantly different for the rest of HSs.