Rice Crinkly4 receptor-like kinase positively regulates culm elongation and amino acid K532 is not essential for its kinase activity

Receptor-like kinases (RLKs) play important roles in multiple aspects of plant growth and development. As a member of the TNFR-like RLK subfamily, rice Crinkly4 (OsCR4) functions mainly in epidermal cell differentiation in many organs. Here we show that in addition to its essential role in epidermal cell differentiation in the palea and lemma, OsCR4 positively regulates rice culm elongation, similar to maize CR4. Although OsCR4 is an active kinase, like CR4 in maize and ACR4 in Arabidopsis, the conserved amino acid K532 in OsCR4 is not essential for its kinase activity in vitro. Whether other conserved amino acids are required for its kinase activity and the relationship between its activity and function in plant development remain to be investigated.     

Synchronized oviposition triggered by migratory flight intensifies larval outbreaks of beet webworm

Identifying the reproductive consequences of insect migration is critical to understanding its ecological and evolutionary significance. However, many empirical studies are seemingly contradictory, making recognition of unifying themes elusive and controversial. The beet webworm, Loxostege sticticalis L. is a long-range migratory pest of many crops in the northern temperate zone from 36 °N to 55 °N, with larval populations often exploding in regions receiving immigrants. In laboratory experiments, we examined (i) the reproductive costs of migratory flight by tethered flight, and (ii) the reproductive traits contributing to larval outbreaks of immigrant populations. Our results suggest that the beet webworm does not initiate migratory flight until the 2nd or 3rd night after emergence. Preoviposition period, lifetime fecundity, mating capacity, and egg hatch rate for adults that experienced prolonged flight after the 2nd night did not differ significantly from unflown moths, suggesting these traits are irrelevant to the severity of beet webworm outbreaks after migration. However, the period of first oviposition, a novel parameter developed in this paper measuring synchrony of first egg-laying by cohorts of post-migratory females, for moths flown on d 3 and 5 of adulthood was shorter than that of unflown moths, indicating a tightened time-window for onset of oviposition after migration. The resulting synchrony of egg-laying will serve to increase egg and subsequent larval densities. A dense population offers potential selective advantages to the individual larvae comprising it, whereas the effect from the human standpoint is intensification of damage by an outbreak population. The strategy of synchronized oviposition may be common in other migratory insect pests, such as locust and armyworm species, and warrants further study.     

Intentionally introduced species: more easily invited than removed

Alien species are brought into countries world wide on a massive scale for agricultural production, ex situ conservation, landscape aesthetics, gardens, and ecosystem restoration. Unfortunately, some of these species have escaped and adversely impacted on regional as well as global biodiversity conservation and agricultural production. To reduce such risks, it is necessary to implement specific and effective measures. Since various government departments and institutions are involved in the management of alien species, it is difficult to prevent native and agroecosystems from being invaded by invited species. We propose the establishment of a supervision and inspection continuum over intentional species introduction, similar to that which exists in some countries over unintentional species introductions. Namely, a justification of the necessity to import, a risk assessment, assurances as to provision of an adequate containment facility assessment, and a damage-limitation protocol should that need to be invoked. These requirements should be satisfied before an alien species is knowingly imported, and the necessary follow-up supervision is important post- importation.     

A recombinant mimetics of the HIV-1 gp41 prehairpin fusion intermediate fused with human IgG Fc fragment elicits neutralizing antibody response in the vaccinated mice

HIV-1 gp41 prehairpin fusion intermediate (PFI) composed of three N-terminal heptad repeats (NHR) plays a crucial role in viral fusion and entry and represents an attractive target for anti-HIV therapeutics (e.g., enfuvirtide) and vaccines. In present study, we constructed and expressed two recombinant gp41 PFI mimetics, designated N46Fd and N46FdFc. N46Fd consists of N46 (residues 536-581) in gp41 NHR and foldon (Fd), a trimerization motif. N46FdFc is composed of N46Fd fused with human IgG Fc fragment as an immunoenhancer. We immunized mice with N46 peptide, N46Fd and N46FdFc, respectively, and found that only N46FdFc elicited neutralizing antibody response in mice against infection by HIV-1 strains IIIB (clade B, X4), 92US657 (clade B, R5), and 94UG103 (clade A, X4R5). Anti-N46FdFc antibodies inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines.     

Survey of simple sequence repeats in completed fungal genomes

The use of simple sequence repeats or microsatellites as genetic markers has become very popular because of their abundance and length variation between different individuals. SSRs are tandem repeat units of 1 to 6 base pairs that are found abundantly in many prokaryotic and eukaryotic genomes. This is the first study examining and comparing SSRs in completely sequenced fungal genomes. We analyzed and compared the occurrences, relative abundance, relative density, most common, and longest SSRs in nine taxonomically different fungal species: Aspergillus nidulans, Cryptococcus neoformans, Encephalitozoon cuniculi, Fusarium graminearum, Magnaporthe grisea, Neurospora crassa, Saccharomyces cerevisiae, Schizosaccharomyces pombe, and Ustilago maydis. Our analysis revealed that, in all of the genomes studied, the occurrence, abundance, and relative density of SSRs varied and was not influenced by the genome sizes. No correlation between relative abundance and the genome sizes was observed, but it was shown that N. crassa, the largest genome analyzed had the highest relative abundance of SSRs. In most genomes, mononucleotide, dinucleotide, and trinucleotide repeats were more abundant than the longer repeated SSRs. Generally, in each organism, the occurrence, relative abundance, and relative density of SSRs decreased as the repeat unit increased. Furthermore, each organism had its own common and longest SSRs. Our analysis showed that the relative abundance of SSRs in fungi is low compared with the human genome and that longer SSRs in fungi are rare. In addition to providing new information concerning the abundance of SSRs for each of these fungi, the results provide a general source of molecular markers that could be useful for a variety of applications such as population genetics and strain identification of fungal organisms.     

Aldosterone induction of hepatic stellate cell contraction through activation of RhoA/ROCK-2 signaling pathway

The RhoA/ROCK-2 signaling pathway is necessary for activated hepatic stellate cell (HSC) contraction. HSC contraction plays an important role in the pathogenesis of cirrhosis and portal hypertension. This study investigated whether aldosterone contributes to HSC contraction by activation of the RhoA/ROCK-2 signaling pathway. Primary HSCs were isolated from Sprague-Dawley rats via in situ pronase/collagenase perfusion. We found that aldosterone enhanced the contraction of a collagen lattice seeded with HSCs. This induced contraction was suppressed by the mineralcorticoid receptor (MR) inhibitor spironolactone, the ROCK-2 inhibitor Y27632, and the angiotensin II type 1 receptor (AT(1)R) inhibitor irbesartan. Moreover, actin fiber staining showed that aldosterone significantly increased actin fiber formation in HSCs. Pre-incubating with spironolactone, Y27632, or irbesartan inhibited the aldosterone-induced actin fiber reorganization. Molecularly, the effect of aldosterone on activation of HSC contraction was mediated by phosphorylated myosin light chain (P-MLC) through the RhoA/ROCK-2 signaling pathway. All these inhibitors had the ability to block aldosterone-induced protein expressions in the RhoA/ROCK-2/P-MLC cascade in HSCs. Taken together, our current study suggests that aldosterone induces contraction of activated HSCs through the activation of the RhoA/ROCK-2 signaling pathway. This finding may provide a potential therapeutic target for control of cirrhosis and portal hypertension.     

^137Cs,^134Cs在人工海洋小生境中的行为

在自行建立的人工海洋小生境中,采用示踪法综合地研究~(137)Cs、~(134)Cs在人工小生境中的行为。结果表明,~(137)Cs和~(134)Cs具有共同的生理生态行为,并表现出相似的规律、沉积物对~(137)Cs、~(134)Cs的吸附能力甚低,~(137)Cs、~(134)Cs在海洋动物体内趋于全身性的分布。各主要生化物质均能检出~(137)Cs、~(134)Cs。排泄实验后,海洋动物的胃肠、肝(消化腺)~(137)Cs、~(134)Cs损失显著。沉积物表现为解吸-重吸附的过程。