Bt rice expressing Cry1Ab does not stimulate an outbreak of its non-target herbivore, Nilaparvata lugens

In this study, the non-target effects of Bt rice “KMD2” expressing a Cry1Ab protein on the performance of the brown planthopper (BPH), Nilaparvata lugens, over multiple generations were evaluated under laboratory and field conditions. In the laboratory, BPH was reared to observe the impact of the Bt rice as compared to its parental non-Bt cultivar Xiushui 11, while the population dynamics and oviposition performance of BPH were investigated in the field. The survival of BPH nymphs fed Bt and non-Bt rice did not differ significantly. The nymph developmental duration of BPH was significantly delayed by the Bt rice by comparison with the non-Bt rice for the 1st and 2nd but not the 4th generation. Most importantly, the fecundity of BPH on the Bt rice was significantly decreased in every generation when compared with the non-Bt rice. In the field investigations, the population density of BPH nymphs was significantly lower in the Bt rice field. However, the temporal pattern of population dynamics of BPH adults was similar between the Bt and non-Bt rice, presumably due to migratory interference of the adults. In the Bt rice field, the percentage of tillers with eggs and the number of eggs per tiller were also significantly lower from tillering to mature stage. Additionally, Cry1Ab protein could not be detected in guts from single BPH adults. In general, our results suggest that the Bt rice “KMD2” could not stimulate an outbreak of BPH.     

中国奥甲螨科3新种（甲螨亚目：奥甲螨科）

记述采自我国南方的奥甲螨科3新种:鞭毛奧甲螨Oppia flagellifera sp.nov.、雕纹大奥甲螨Lasiobelba sculpta sp.nov.和闽越奥甲螨Vietoppia fujianensis sp.nov,。     

Genome analysis of Elytrigia caespitosa, Lophopyrum nodosum, Pseudoroegneria geniculata ssp. scythica, and Thinopyrum intermedium (Triticeae: Gramineae).

To elucidate the genome constitutions of the tetraploid (2n = 4x = 28) species Elytrigia caespitosa, Lophopyrum nodosum, and Pseudoroegneria geniculata ssp. scythica and the hexaploid (2n = 6x = 42) Thinopyrum intermedium, meiotic pairing was studied in these species as well as 10 hybrids. Karyotype analysis with aceto-orcein stained root-tip cells was performed for the four species and the hybrids of T. bessarabicum with E. caespitosa, P. geniculata ssp. scythica, and T. intermedium. Karyotype analysis by Giemsa C-banding was carried out with the three tetraploid species and the two triploid hybrids involving T. bessarabicum. The species behaved as strict allopolyploids. All hybrids were male sterile with few stainable pollen grains. It is concluded from the results that the three tetraploid species have the genome formula JeJeSS and T. intermedium has the formula JeJeJeJeSS. The chromosomes of the Je and S genomes in these species had C-banding patterns differing from each other and from those of the extant diploid species. Based on these findings, the four species investigated should be placed in the same genus or the same section of a genus. However, new combinations are not proposed at this time pending future taxonomic investigation of the genome constitution of Elytrigia repens (L.) Nevski.     

Genome constitutions of Thinopyrum curvifolium, T. scirpeum, T. distichum, and T. junceum (Triticeae: Gramineae).

The objective of this study is to elucidate genome constitutions of Thinopyrum curvifolium (Lange) D.R. Dewey, T. scirpeum (K. Presl) D.R. Dewey, T. distichum (Thunb.) A. L?ve, and T. junceum (L.) A. L?ve. Hybrids of T. sartorii (Boiss. &Heidr.) A. L?ve with T. scirpeum and T. junceum, as well as the hybrid between T. curvifolium and Pseudoroegneria geniculata ssp. scythica (Nevski) A. L?ve, were made and chromosome pairing at metaphase I was studied. The karyotype analyses of mitotic cells stained by aceto-orcein were conducted for both hybrids and the four target species. The Giemsa C-banding following acetocarmine staining was carried out for the above species and the triploid hybrid T. curvifolium x T. bessarabicum (Savul &Rayss) A. L?ve. Meiotic data indicate that all target species have two sets of the basic genome J, but they behave like true allopolyploids because of bivalentization. Karyotypes of T. curvifolium and its triploid hybrid with T. bessarabicum indicate that T. curvifolium contains two different versions of the Jb genome, designated as Jb3 and Jb4, rather than two Je genomes as previously believed. Thinopyrum scirpeum and T. elongatum (4x) have similar karyotypes. Both are segmental allotetraploids carrying two forms of the Je genome. Their genome formulae are Je2 Je3 and Je1 Je3, respectively. Thinopyrum distichum has a karyotype similar to T. junceiforme, which has the Jb2 Je2 genome formula. However, the two species differ in C-banding patterns, reflecting their geographical separation. Thinopyrum junceum is a hexaploid with two pairs of Jb2 genomes and one pair of the Je2 genome, and it has a C-banding pattern similar to that of T. junceiforme, which has one pair each of the Jb2 and Je2 genomes.     

Can mobile sandy land be vegetated in the cold and dry Tibetan Plateau in China?

Desertification has taken place in the overgrazed grassland of the Tibetan Plateau,China,and the area of mobile sandy land has increased in recent decades.The challenging problem about desertification control is how to restore the vegetation of mobile sandy lands caused by severe desertification.Sand drifting is now regarded as the limiting factor of vegetation restoration in such lands.The initial phase of vegetation restoration is plant colonization,but it is often aborted due to sand drifting,and then vegetation restoration fails to proceed.For the sake of revegetation,the first step is to stop sand drifting to ensure plant colonization.In the northeastern Tibetan Plateau,China,feasible approaches have been found through long-term experiments,and the vegetation is being restored satisfactorily with these approaches in experimental sandy lands.The approaches comprise three types:enclosure,mechanical barriers and biological barriers.Different sandy lands require dissimilar combinations of these approaches.Enclosures may be adequate to revegetate inter-dunes or degraded grassland even in cold regions like the Tibetan Plateau,China,but it is deficient for revegetation of the shifting sand dunes unless mechanical and biological barriers are established simultaneously.     

Assessing indica-japonica differentiation of improved rice varieties using microsatellite markers

To assess the indica-japonica differentiation of improved rice varieties, a total of 512 modem varieties including 301 indica and 211 japonica accessions were analyzed using 36 microsatellites. The Fst coefficients ranged from 0.002 to 0.730 among the loci with an average of 0.315. Significant differentiation was detected at 94.4% of the loci studied （P 〈 0.05, pairwise Fst tests）, indicating that there was a high level of indica-japonica differentiation within the improved varieties. At 18 loci, about 74%-98% of the alleles of indica and japonica accessions were distributed in two ranges of amplicon length. Linkage disequilibrium analysis showed that the distribution trends were significantly nonrandomly associated. Using the differentiation trends at the 18 loci, microsatellite index （MI） was proposed for discrimination of the two subspecies. When rice accessions with MI value greater than zero were classified as indica, and those with MI value smaller than zero were classified as japonica, about 96.1% of the accessions could be classified. This result agrees with the classification based on morphological-physiological characters, indicating that this method is feasible and effective.     

α-actinin-4 is essential for maintaining the spreading, motility and contractility of fibroblasts

Background

α-Actinins cross-link actin filaments, with this cross-linking activity regulating the formation of focal adhesions, intracellular tension, and cell migration. Most non-muscle cells such as fibroblasts express two isoforms, α-actinin-1 (ACTN1) and α-actinin-4 (ACTN4). The high homology between these two isoforms would suggest redundancy of their function, but recent studies have suggested different regulatory roles. Interestingly, ACTN4 is phosphorylated upon growth factor stimulation, and this loosens its interaction with actin.

Methodology/Principal Findings

Using molecular, biochemical and cellular techniques, we probed the cellular functions of ACTN4 in fibroblasts. Knockdown of ACTN4 expression in murine lung fibroblasts significantly impaired cell migration, spreading, adhesion, and proliferation. Surprisingly, knockdown of ACTN4 enhanced cellular compaction and contraction force, and increased cellular and nuclear cross-sectional area. These results, except the increased contractility, are consistent with a putative role of ACTN4 in cytokinesis. For the transcellular tension, knockdown of ACTN4 significantly increased the expression of myosin light chain 2, a element of the contractility machinery. Re-expression of wild type human ACTN4 in ACTN4 knockdown murine lung fibroblasts reverted cell spreading, cellular and nuclear cross-sectional area, and contractility back towards baseline, demonstrating that the defect was due to absence of ACTN4.

Significance

These results suggest that ACTN4 is essential for maintaining normal spreading, motility, cellular and nuclear cross-sectional area, and contractility of murine lung fibroblasts by maintaining the balance between transcellular contractility and cell-substratum adhesion.     

Morphological bases of suppressive and facilitative spatial summation in the striate cortex of the cat

In V1 of cats and monkeys, activity of neurons evoked by stimuli within the receptive field can be modulated by stimuli in the extra-receptive field (ERF). This modulating effect can be suppressive (S-ERF) or facilitatory (F-ERF) and plays different roles in visual information processing. Little is known about the cellular bases underlying the different types of ERF modulating effects. Here, we focus on the morphological differences between the S-ERF and F-ERF neurons. Single unit activities were recorded from V1 of the cat. The ERF properties of each neuron were assessed by area-response functions using sinusoidal grating stimuli. On completion of the functional tests, the cells were injected intracellularly with biocytin. The labeled cells were reconstructed and morphologically characterized in terms of the ERF modulation effects. We show that the vast majority of S-ERF neurons and F-ERF neurons are pyramidal cells and that the two types of cells clearly differ in the size of the soma, in complexity of dendrite branching, in spine size and density, and in the range of innervations of the axon collaterals. We propose that different pyramidal cell phenotypes reflect a high degree of specificity of neuronal connections associated with different types of spatial modulation.     

黑木耳多糖对急性脑缺血/再灌注损伤影响的研究

目的:观察黑木耳多糖(APP)对急性脑缺血大鼠的保护作用并探讨其相关机制。方法:成年雄性SD大鼠给予不同浓度的AAP灌胃20d,每天1次,腹腔注射银杏叶提取物(ginkgo biloba extract,EGb671)作为阳性对照,20d后实施右侧大脑中动脉栓塞(MCAO)建立局灶性脑缺血模型。MCAO60min后复灌,复灌24h后进行Longa神经功能损伤评分,并用2,3,5-氯化三苯基四氮唑(TTC)染色法测定脑梗死面积。复灌48h后用TUNEL免疫组化检测神经元凋亡,测定脑组织线粒体内活性氧簇(ROS)的生成量判断氧化应激水平。结果:黑木耳多糖能降低神经功能损伤评分,减小脑梗死面积,减少神经元凋亡,并且能够使缺血复灌脑组织线粒体ROS生成显著减少。高剂量AAP组的凋亡神经元数量、ROS生成量和阳性对照组相比有显著性差异。结论:黑木耳多糖能够对抗大鼠的局灶性脑缺血损伤,其保护作用和减轻氧化应激水平有关,并优于银杏叶提取物。     

The Origin of the White Roman Goose

In order to avoid interference from nuclear copies of mitochondrial DNA (numts), mtDNA of the white Roman goose (domestic goose) was extracted from liver mitochondria. The mtDNA control region was amplified using a long PCR strategy and then sequenced. Neighbor-joining, maximum parsimony, and maximum-likelihood approaches were implemented using the 1,177 bp mtDNA control region sequences to compute the phylogenetic relationships of the domestic goose with other geese. The resulting identity values for the white Roman geese were 99.1% (1,166/1,177) with western graylag geese and 98.8% (1,163/1,177) with eastern graylag geese. In molecular phylogenetic trees, the white Roman goose was grouped in the graylag lineage, indicating that the white Roman goose came from the graylag goose (Anser anser). Thus, the scientific name of the white Roman goose should be Anser anser ‘White Roman.’