Reducing the tetraploid non-nodulating alfalfa (Medicago sativa) MnNC-1008(NN) germ plasm to the diploid level

MnNC-1008(NN) (referred to as MN-1008) is a tetraploid alfalfa mutant with two recessive genes (nn ₁ and nn ₂ )conditioning the non-nodulating trait. The tetraploid level (2n=4x=32) of this Medicago sativa germ plasm was reduced to the diploid (2n=2x=16) level using the 4x-2x genetic cross originally described as a workable method for the induction of haploidy in alfalfa by T. E. Bingham. In our experiments more than 7000 emasculated flowers of a single non-nodulating MN-1008 mutant alfalfa plant with purple petals were cross-pollinated with pollen from a single, diploid, yellow-flowered alfalfa plant. Mature seeds from these crosses were collected and germinated, after which the plants were subjected to morphological and cytogenetic analyses as well as to DNA fingerprinting. Out of 26 viable progeny, 6 were hybrid plants, 19 proved to be self-mated derivatives of MN-1008, while one descendant turned out to be a diploid (2n=2x=16), purple flowered, non-nodulating plant denoted as M. sativa DN-1008. This diploid, non-nodulating alfalfa plant can serve as starting material to facilitate the comprehensive morphological, physiological and genetic analysis (gene mapping and cloning) of nodulation in order to learn more about the biology of the symbiotic root nodule development. To produce diploid, nodulating hybrid F₁ plants, DN-1008 was crossed with a diploid, yellow-flowered M. sativa ssp. quasifalcata plant. An F₂ population segregating the nn ₁ and nn ₂ genes in a diploid manner, in which the genetic analysis is more simple than in a tetraploid population, can be established by self-mating of the F₁ plants.     

青海湖裸鲤mtDNA遗传多样性的初步研究

本文用BclⅠ、AvaⅠ、BamHⅠ、PstⅠ、KpnⅠ、PvuⅡ共6种限制性内切核酸酶,分析了15尾青海湖裸鲤mtDNA的限制性片段长度多态性,共检测出20个酶切位点,发现BclⅠ、BamHⅠ和PvuⅡ三种酶切类型具有多态性.根据不同个体mtDNA的酶切类型,青海湖裸鲤存在4种mtDNA单倍型,计算mtDNA多态度π值为0.0043,初步认为青海湖裸鲤在线粒体DNA上存在较丰富的群体内变异、 Abstract:An analysis of patterns of cleavage of mtDNA by restriction endonucleases was performed for 15 Gymnocypris przewalskii przewalskii.Mitochondrial DNA polymorphisms were detected in the restriction patterns generated by the following 5 enzymes,BclI,AvaI,BamH],PstI,KpnI,PvuII.Only 3 of them (BclI,BantHI,PvuII) were found to be polymorphisms.Our results shorted that there were 4 mtDNA haplotypes in Gyrnnocypris przewalskii przewalskii and the genetic divergenec(π)was 0.0043,which indicated that mtDNA genetic diversity in Gymnocypris przewalskii przewalskii is higher.     

A new species of Chiroptella Vercammen-Grandjean, 1960 (Acari: Trombiculidae) from diadem leaf-nosed bat Hipposideros diadema (Geoffroy) (Chiroptera: Hipposideridae) in Bali Island (Indonesia) with distribution records,hosts, and a key to the species of the genus

A new chigger mite Chiroptella baliensis n. sp. is described based on material from the diadem leaf-nosed bat Hipposideros diadema (Geoffroy) (Hipposideridae) in Bali Island (Lesser Sunda Islands, East Indonesia). With this newly described species, the genus Chiroptella includes 22 species, 13 in the subgenus Chiroptella Vercammen-Grandjean, 1960 (sensu stricto), and 9 in the subgenus Neosomia Vercammen-Grandjean, 1968. Species of Chiroptella are distributed throughout the Ethiopian region, the Oriental region, and the Australian region (and only marginally throughout the Palaearctic region) and are all associated with several families of bats. The paper also provides a key to all members of the genus and the new combinations for two species originally described as Chiroptella.

     

Rudnicula goffi n. sp. (Acariformes: Trombiculidae) from the diadem leaf-nosed bat Hipposideros diadema (Geoffroy) (Chiroptera: Hipposideridae) on Bali,Indonesia

Systematic Parasitology - A new species of chigger mite, Rudnicula goffi n. sp., is described from the diadem leaf-nosed bat Hipposideros diadema (Geoffroy) (Hipposideridae) caught in the Goa...     

Digital Microfluidics for Automated Proteomic Processing

Clinical proteomics has emerged as an important new discipline, promising the discovery of biomarkers that will be useful for early diagnosis and prognosis of disease. While clinical proteomic methods vary widely, a common characteristic is the need for (i) extraction of proteins from extremely heterogeneous fluids (i.e. serum, whole blood, etc.) and (ii) extensive biochemical processing prior to analysis. Here, we report a new digital microfluidics (DMF) based method integrating several processing steps used in clinical proteomics. This includes protein extraction, resolubilization, reduction, alkylation and enzymatic digestion. Digital microfluidics is a microscale fluid-handling technique in which nanoliter-microliter sized droplets are manipulated on an open surface. Droplets are positioned on top of an array of electrodes that are coated by a dielectric layer - when an electrical potential is applied to the droplet, charges accumulate on either side of the dielectric. The charges serve as electrostatic handles that can be used to control droplet position, and by biasing a sequence of electrodes in series, droplets can be made to dispense, move, merge, mix, and split on the surface. Therefore, DMF is a natural fit for carrying rapid, sequential, multistep, miniaturized automated biochemical assays. This represents a significant advance over conventional methods (relying on manual pipetting or robots), and has the potential to be a useful new tool in clinical proteomics.Mais J. Jebrail, Vivienne N. Luk, and Steve C. C. Shih contributed equally to this work.Sergio L. S. Freire''s current address is at the University of the Sciences in Philadelphia located at 600 South 43rd Street, Philadelphia, PA 19104.Download video file.^{(130M, mp4)}     

Chemical properties of forest soils as affected by nests of <Emphasis Type="Italic">Myrmica ruginodis</Emphasis> (Formicidae)

Chemical properties (total and available P concentration; oxidizable C concentration; available K, Na, and Ca concentration; and pH) were quantified for 33 nests of the ant Myrmica ruginodis and in surrounding soil in young spruce forest stands. All properties, except total P, were significantly higher in the nests than in the surrounding soil. Total P was not higher in nests than in surrounding soil across all nests because nests had higher total P than surrounding soil if the soil contained low concentrations of total P but nests had lower total P than surrounding soil if the soil contained high concentrations of total P. The effect of nests on total P in the surrounding soil corresponded with effects of nests on oxidizable carbon (an indicator of organic matter) in the surrounding soil (concentrations of oxidizable carbon and total P were closely correlated). Available P concentrations were much higher in nests than in surrounding soil. Overall, the results indicated that two main processes explain the chemical changes of soil in the ant nests: (i) mixing due to excavation of deeper soil layers and (ii) deposition of excreta and food residues. The effect of soil mixing (whereby ants transport mineral soil from deeper layers to layers near the surface) is more pronounced in soils with high organic content near the surface because mixing increases the proportion of mineral soil in the nest while decreasing the proportion of organic matter and the concentration of total P.     

Gamma-secretase inhibitor treatment promotes VEGF-A-driven blood vessel growth and vascular leakage but disrupts neovascular perfusion

The Notch signaling pathway is essential for normal development due to its role in control of cell differentiation, proliferation and survival. It is also critically involved in tumorigenesis and cancer progression. A key enzyme in the activation of Notch signaling is the gamma-secretase protein complex and therefore, gamma-secretase inhibitors (GSIs)--originally developed for Alzheimer's disease--are now being evaluated in clinical trials for human malignancies. It is also clear that Notch plays an important role in angiogenesis driven by Vascular Endothelial Growth Factor A (VEGF-A)--a process instrumental for tumor growth and metastasis. The effect of GSIs on tumor vasculature has not been conclusively determined. Here we report that Compound X (CX), a GSI previously reported to potently inhibit Notch signaling in vitro and in vivo, promotes angiogenic sprouting in vitro and during developmental angiogenesis in mice. Furthermore, CX treatment suppresses tumor growth in a mouse model of renal carcinoma, leads to the formation of abnormal vessels and an increased tumor vascular density. Using a rabbit model of VEGF-A-driven angiogenesis in skeletal muscle, we demonstrate that CX treatment promotes abnormal blood vessel growth characterized by vessel occlusion, disrupted blood flow, and increased vascular leakage. Based on these findings, we propose a model for how GSIs and other Notch inhibitors disrupt tumor blood vessel perfusion, which might be useful for understanding this new class of anti-cancer agents.     

Long-Lasting Insecticidal Nets Are Synergistic with Mass Drug Administration for Interruption of Lymphatic Filariasis Transmission in Nigeria

In central Nigeria Anopheles mosquitoes transmit malaria and lymphatic filariasis (LF). The strategy used for interrupting LF transmission in this area is annual mass drug administration (MDA) with albendazole and ivermectin, but after 8 years of MDA, entomological evaluations in sentinel villages showed continued low-grade mosquito infection rates of 0.32%. After long-lasting insecticidal net (LLIN) distribution by the national malaria program in late 2010, however, we were no longer able to detect infected vectors over a 24-month period. This is evidence that LLINs are synergistic with MDA in interrupting LF transmission.