Localization of a novel RNA-binding protein, SKIV2L2, to the nucleus in the round spermatids of mice

In our previous study (Kawashima et al., Biol Reprod 2009; 80: 1293-1304), we suggested that the first cycle of spermatogenesis recovered from busulfan-induced temporary arrest was a good model system to analyze the proteins expressed at the specific stages of spermatogenesis in the mouse, and this has been confirmed in the present paper. Namely, six-week-old mice were injected with busulfan at 20 mg/kg body weight. The germ cells except for the undifferentiated spermatogonia disappeared by 32 days after injection. The surviving spermatogonia started to proliferate, and spermatogenesis was entirely recovered about 77 days after injection. By proteome analysis of the busulfan-treated testis during the process of recovery of spermatogenesis, we identified a protein that was expected to be expressed in the spermatogenic cells as Superkiller viralicidic activity-2-like-2 (SKIV2L2). Skiv2l2 mRNA was found in the kidney, epididymis and heart as well as the testis. In the testis, Skiv2l2 mRNA was shown to be highly expressed in the spermatocytes at stages I to VI. On the other hand, SKIV2L2 protein was found to be predominantly localized in the nuclei of round spermatids. In accordance with the fact that SKIV2L2 belongs to the Ski2 family within the superfamily 2 of RNA helicases, it has been shown that SKIV2L2 has both the RNA-binding and ATPase activities.     

Derivatives of erythropoietin that are tissue protective but not erythropoietic

Erythropoietin (EPO) is both hematopoietic and tissue protective, putatively through interaction with different receptors. We generated receptor subtype-selective ligands allowing the separation of EPO's bioactivities at the cellular level and in animals. Carbamylated EPO (CEPO) or certain EPO mutants did not bind to the classical EPO receptor (EPOR) and did not show any hematopoietic activity in human cell signaling assays or upon chronic dosing in different animal species. Nevertheless, CEPO and various nonhematopoietic mutants were cytoprotective in vitro and conferred neuroprotection against stroke, spinal cord compression, diabetic neuropathy, and experimental autoimmune encephalomyelitis at a potency and efficacy comparable to EPO.     

Persistence of memory in drop breakup: the breakdown of universality

A low-viscosity drop breaking apart inside a viscous fluid is encountered when air bubbles, entrained in thick syrup or honey, rise and break apart. Experiments, simulations, and theory show that the breakup under conditions in which the interior viscosity can be neglected produces an exceptional form of singularity. In contrast to previous studies of drop breakup, universality is violated so that the final shape at breakup retains an imprint of the initial and boundary conditions. A finite interior viscosity, no matter how small, cuts off this form of singularity and produces an unexpectedly long and slender thread. If exterior viscosity is large enough, however, the cutoff does not occur because the minimum drop radius reaches subatomic dimensions first.     

RESPONSE OF CHICKPEA TO NITROGEN SOURCES UNDER SALINITY STRESS

Abstract

In vitro‐grown Chrysanthemum morifolium Ramat. cultivars Bright Golden Anne, Deep Luv, and Lucido were exposed to elevated mannitol, sucrose, or sorbitol concentrations to see if their response to this osmotic stress mimics that of in vivo plants enduring water deficit. The relative efficacy of the three osmotic agents at manifesting a response was also evaluated. Tissue osmolarity paralleled media mannitol and sorbitol concentration for all three cultivars. Shoot growth correspondingly decreased with increased osmolarity applied during the rooting phase. These responses generally resembled those of water‐stressed greenhouse plants. The degree of response varied with cultivar; ‘Lucido’ was the most sensitive and ‘Bright Golden Anne’ the least. Sucrose (metabolized by the plants) failed to elicit consistent osmotic stress symptoms; instead it enhanced both shoot and root growth. In vitro stress‐induced symptoms were produced in both proliferation and rooting stages, but consistent shoot growth reduction with increasing levels of incorporated osmotic agent was only observed during rooting. Plants did not retain the osmotic adjustment when they were subsequently subcultured from the stress treatments back to the control medium.     

Heavy metal pollution of soil from industrial and municipal wastes in Chittagong,Bangladesh

Heavy metal pollution was assessed in soils collected from 0–15, 15–30 and 30–45-cm depths of three industrial (FMC, PMC and CMC), and two municipal (BSD and MLF) waste disposal sites around Chittagong city in 2008. Soils were analysed for pH, organic carbon, total nitrogen, available P, exchangeable Ca, Mg, K and Na, and total Cd, Pb, Cu, Mn and Zn. The pH, organic C, total N, available P, total Cd, Pb, Cu and Mn, and contamination indices for Cd and Pb varied significantly among sites. Mean Cd, Pb, Cu, Mn and Zn were in the range 0.5–1.9, 54–86, 25–50, 261–624 and 204–330 mg kg^?1, respectively. Contamination indinces for Cd, Pb, Zn and Cu were estimated by comparison with respective threshold values. Contamination indices showed that the sites MLF and FMC had low Cu contamination. Other sites were not contaminated with thisheavy metal. All sites except PMC were highly contaminated with Cd, FMC was moderately contaminated and the others had low Pb contamination. FMC was highly contaminated, but the others were moderately contaminated with Zn. The integrated contamination index revealed that PMC had low contamination and the other sites were highly contaminated with heavy metals.