Marinobacter persicus sp. nov., a moderately halophilic bacterium from a saline lake in Iran

A Gram-negative, non-endospore-forming, rod shaped, strictly aerobic, moderately halophilic bacterium, designated strain M9B^T, was isolated from the hypersaline lake Aran-Bidgol in Iran. Cells of strain M9B^T were found to be motile and produce colonies with an orange-yellow pigment. Growth was determined to occur between 5 and 20 % (w/v) NaCl and the isolate grew optimally at 7.5–10 % (v/w) NaCl. The optimum pH and temperature for growth of the strain were determined to be pH 7.0 and 35 °C, respectively, while it was able to grow over pH and temperature ranges of 6–8 and 25–45 °C, respectively. Phylogenetic analysis based on the comparison of 16S rRNA gene sequences revealed that strain M9B^T is a member of the genus Marinobacter. The closest relative to this strain was found to be Marinobacter hydrocarbonoclasticus MBIC 1303^T with a similarity level of 97.7 %. DNA–DNA hybridization between the novel isolate and this phylogenetically related species was 13 ± 2 %. The major cellular fatty acids of the isolate were identified as C_16:0, C_19:1 ω6c, C_18:1 ω9c and C_16:1 ω9c. The polar lipid pattern of strain M9B^T was determined to consist of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine and three phospholipids. Ubiquinone 9 (Q-9) was the only lipoquinone detected. The G+C content of the genomic DNA of this strain was determined to be 58.6 mol%. Phenotypic characteristics, phylogenetic analysis and DNA–DNA relatedness data suggest that this strain represents a novel species of the genus Marinobacter, for which the name Marinobacter persicus sp. nov. is proposed. The type strain of Marinobacter persicus is strain M9B^T (=IBRC-M 10445^T = CCM 7970^T = CECT 7991^T = KCTC 23561^T).     

Initial verification of the resistance management strategy for Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) in Australia

Shortly after the initial detection of western flower thrips (WFT), Frankiniella occidentalis (Pergande), in Australia during 1993 a resistance management strategy based on the alternation of chemical groups was implemented. This study aimed to verify this strategy by field testing α-cypermethrin against WFT with and without chemical alternation. Up to 114 times α-cypermethrin resistance (at LC50) was detected and resistance increased with and without chemical alternation; however, chemical alternation did significantly reduce numbers of thrips compared with a nonalternation strategy. Resistance has the potential to undermine the sustainable use of those chemicals to which there is no current detectable resistance. Consequently, chemicals with a high frequency and level of resistance against WFT need to be identified through monitoring and quickly eliminated from WFT chemical control recommendations.     

Enhancement of CRISPR/Cas12a trans-cleavage activity using hairpin DNA reporters

The RNA programmed non-specific (trans) nuclease activity of CRISPR-Cas Type V and VI systems has opened a new era in the field of nucleic acid-based detection. Here, we report on the enhancement of trans-cleavage activity of Cas12a enzymes using hairpin DNA sequences as FRET-based reporters. We discover faster rate of trans-cleavage activity of Cas12a due to its improved affinity (K_m) for hairpin DNA structures, and provide mechanistic insights of our findings through Molecular Dynamics simulations. Using hairpin DNA probes we significantly enhance FRET-based signal transduction compared to the widely used linear single stranded DNA reporters. Our signal transduction enables faster detection of clinically relevant double stranded DNA targets with improved sensitivity and specificity either in the presence or in the absence of an upstream pre-amplification step.     

长江中下游湿地大型水鸟种群动态和幼鸟比例研究

迁徙水鸟保护对生物多样性保护具有重要意义。开展水鸟种群数量和幼鸟比例监测,对科学评估其种群变化趋势、制定长期保护策略具有重要价值。长江中下游湿地是东亚-澳大利西亚迁徙路线上重要的水鸟越冬区之一。本研究采用野外同步调查等方法对该区域87个湿地的亟需保护和具有代表性的10种大型越冬水鸟,其中雁形目6种,分别是鸿雁Anser cygnoides、豆雁A.fabalis、灰雁A.grus、白额雁A.albifrons、小白额雁A.erythropus和小天鹅Cygnus columbianus;鹤形目4种,分别是白鹤Leucogeranus leucogeranus、白枕鹤Antigone vipio、灰鹤Grus grus和白头鹤G.monacha,进行了长期监测(2003—2019年冬季),并结合相关文献,评估其种群变化趋势、幼鸟比例和死亡率。研究结果如下：(1)2005—2019年3种水鸟(豆雁、灰雁和灰鹤)的种群数量呈上升趋势,7种水鸟(鸿雁、白额雁、小白额雁、小天鹅、白鹤、白枕鹤和白头鹤)种群数量呈下降趋势;(2)种群趋势下降组(N=7)和上升组(N=3)的幼鸟比例均值在2016—2...     

焕镛木花部数量变异和腋生花现象

对广西环江木论的焕镛木[Woonyoungia septentrionalis(Dandy)Law]自然居群花朵着生方式和性别比例作了随机抽样调查,首次发现其花的着生方式除多数为顶生花外,还有少量的腋生花,自然居群中雄株与雌株的性别比例为1.21:1,对中国科学院华南植物园栽培居群和广西环江木论自然居群20株600朵花进行的解剖统计揭示,雌、雄花各部分的数量是变化的,雄花的花被片一轮或两轮,2－6片,雄蕊81－152枚,雌花的花被片两轮,外轮2－4片,内轮4－13片,心皮3－8枚,只有雄花花药2室及雌花每心皮具2个胚珠是稳定的。花部表型性状的大幅度变异表明焕镛木具有较丰富的遗传多样性。讨论了生花与顶生花在木兰科系统发育中的意义、表型性状的异步进化现象以及建立焕镛木属Woonyoungia Law的依据。     

Amyloid Beta1-40-Induced Astrogliosis and the Effect of Genistein Treatment in Rat: A Three-Dimensional Confocal Morphometric and Proteomic Study

Astrocytes are highly involved in regulation and homeostasis of the extracellular environment in the healthy brain. In pathological conditions, these cells play a major role in the inflammatory response seen in CNS tissues, which is called reactive astrogliosis and includes hypertrophy and proliferation of astrocytes. Here, we performed 3D confocal microscopy to evaluate the morphological response of reactive astrocytes positive for glial fibrillary acidic protein (GFAP) in rats, to the presence of Aβ_1–40 in the rat brain before and after treatment with genistein. In 50 astrocytes per animal, we measured the volume and surface area for the nucleus, cell body, the entire cell, the tissue covered by single astrocytes and quantified the number and length of branches, the density of the astrocytes and the intensity of GFAP immunoreactivity. Injecting Aβ_1–40 into the brain of rats caused astrogliosis indicated by increased values for all measured parameters. Mass spectrometric analysis of hippocampal tissue in Aβ_1–40-injected brain showed decreased amounts of tubulins, enolases and myelin basic protein, and increased amounts of dihydropyrimidinase-related protein 2. In Aβ_1–40-injected rats pretreated with genistein, GFAP intensity was decreased to the sham-operated group level, and Aβ_1–40-induced astrogliosis was significantly ameliorated.     

Kappa-chain constant-region gene sequences in genus Rattus: coding regions are diverging more rapidly than noncoding regions

We have determined the nucleotide sequence of a 1,200-base pair (bp) genomic fragment that includes the kappa-chain constant-region gene (C kappa) from two species of native Australian rodents, Rattus leucopus cooktownensis and Rattus colletti. Comparison of these sequences with each other and with other rodent C kappa genes shows three surprising features. First, the coding regions are diverging at a rate severalfold higher than that of the nearby noncoding regions. Second, replacement changes within the coding region are accumulating at a rate at least as great as that of silent changes. Third, most of the amino acid replacements are localized in one region of the C kappa domain--namely, the carboxy-terminal "bends" in the alpha-carbon backbone. These three features have previously been described from comparisons of the two allelic forms of C kappa genes in R. norvegicus. These data imply the existence of considerable evolutionary constraints on the noncoding regions (based on as yet undetermined functions) or powerful positive selection to diversify a portion of the constant-region domain (whose physiological significance is not known). These surprising features of C kappa evolution appear to be characteristic only of closely related C kappa genes, since comparison of rodent with human sequences shows the expected greater conservation of coding regions, as well as a predominance of silent nucleotide substitutions within the coding regions.      

Genetic variation in the response of pea (Pisum sativum L.) to high soil concentrations of boron

In a greenhouse experiment nine current Australian cultivars of pea were grown to flowering time under five levels of soil boron (0, 10, 20, 30 and 40 mg kg^–1) applied to the soil. This study was conducted to identify the genetic range in tolerance to boron within the group and to identify specific responses which may be utilised as selection criteria in a breeding program. Significant differences in response to increasing levels of boron were found between cultivars for dry-weight yield, and boron concentrations were lowest in shoots of the most tolerant cultivars. Of the other parameters measured, emergence was not affected but plant height and the number of nodes were reduced and the severity of symptom expression increased at the higher boron treatments. Symptom expression was the most efficient observation for predicting the response of cultivars, as determined by dry-weight yield and concentration of boron in shoots, and it was found that the correlation coefficients between symptoms and the latter two measurements were r=–0.78 (p<0.01) and r=0.81 (p<0.01), respectively. Early Dun, Dundale, Alma and Maitland were the more tolerant of the cultivars and these happen to be the most widely grown cultivars in southern Australia.     

Breast myeloma: a report of 3 cases with fine needle aspiration cytologic findings

BACKGROUND: Multiple myeloma of the breast is very rare, and the fine needle aspiration (FNA) findings have not been reported before. CASES: Two cases of multiple myeloma presented with bilateral breast nodules during treatment with chemotherapy. One case of multiple myeloma presented initially with a left breast mass. FNA smears of all 3 cases revealed numerous plasma cells, plasmablasts and multinucleated giant plasma cells. The smears were diagnosed as plasma cell tumors. Serum immunoelectrophoresis revealed IgG myeloma in 2 cases and IgA myeloma in 1. Marrow aspirates revealed > 30% plasma cells. Two patients died, and 1 was alive at this writing. CONCLUSION: The aspiration cytology findings of myeloma can be confuse, with primary and secondary tumors of the breast. The previous clinical history and ancillary studies, such as bone marrow study and serum immunoelectrophoresis, are essential to the correct diagnosis.