神香草的组织培养及植株再生

1植物名称神香草(HyssopusofficinalisLinn.)。2材料类别嫩茎。3培养条件培养基:(1)MS+6-BA0.2mg·L-1(单位下同)+NAA0.2+La(NO3)31.0;(2)MS+6-BA0.4+NAA0.4+La(NO3)31.2;(3)MS+6-BA0.6+NAA0.6+La(NO3)31.4;(4)MS+6-BA0.8+NAA0.8+La(NO3)31.6;(5)MS+6-BA0.8+NAA0.8+La(NO3)31.8;(6)MS+6-BA0.2+IAA0.2;(7)MS+6-BA0.4+IAA0.4;(8)MS+6-BA0.6+IAA0.6;(9)MS+6-BA0.8+IAA0.8;(10)MS+6-BA1+NAA1;(11)MS+6-BA1.2+NAA1.2;(12)MS+6-BA0.1+IAA0.6;(13)1/3MS+IAA0.5;(14)1/3MS+IAA1.2。上述MS培养基中加3…     

Aggressive organ penetration and high vector transmissibility of epidemic dengue virus-2 Cosmopolitan genotype in a transmission mouse model

Dengue virus (DENV) causes dengue fever and severe hemorrhagic fever in humans and is primarily transmitted by Aedes aegypti and A. albopictus mosquitoes. The incidence of DENV infection has been gradually increasing in recent years due to global urbanization and international travel. Understanding the virulence determinants in host and vector transmissibility of emerging epidemic DENV will be critical to combat potential outbreaks. The DENV serotype 2 (DENV-2), which caused a widespread outbreak in Taiwan in 2015 (TW2015), is of the Cosmopolitan genotype and is phylogenetically related to the virus strain linked to another large outbreak in Indonesia in 2015. We found that the TW2015 virus was highly virulent in type I and type II interferon-deficient mice, with robust replication in spleen, lung, and intestine. The TW2015 virus also had high transmissibility to Aedes mosquitoes and could be effectively spread in a continuous mosquitoes-mouse-mosquitoes-mouse transmission cycle. By making 16681-based mutants carrying different segments of the TW2015 virus, we identified the structural pre-membrane (prM) and envelope (E) genes as key virulence determinants in the host, with involvement in the high transmissibility of the TW2015 virus in mosquitoes. The transmission mouse model will make a useful platform for evaluation of DENV with high epidemic potential and development of new strategies against dengue outbreaks.     

CRMP/UNC-33 organizes microtubule bundles for KIF5-mediated mitochondrial distribution to axon

Neurons are highly specialized cells with polarized cellular processes and subcellular domains. As vital organelles for neuronal functions, mitochondria are distributed by microtubule-based transport systems. Although the essential components of mitochondrial transport including motors and cargo adaptors are identified, it is less clear how mitochondrial distribution among somato-dendritic and axonal compartment is regulated. Here, we systematically study mitochondrial motors, including four kinesins, KIF5, KIF17, KIF1, KLP-6, and dynein, and transport regulators in C. elegans PVD neurons. Among all these motors, we found that mitochondrial export from soma to neurites is mainly mediated by KIF5/UNC-116. Interestingly, UNC-116 is especially important for axonal mitochondria, while dynein removes mitochondria from all plus-end dendrites and the axon. We surprisingly found one mitochondrial transport regulator for minus-end dendritic compartment, TRAK-1, and two mitochondrial transport regulators for axonal compartment, CRMP/UNC-33 and JIP3/UNC-16. While JIP3/UNC-16 suppresses axonal mitochondria, CRMP/UNC-33 is critical for axonal mitochondria; nearly no axonal mitochondria present in unc-33 mutants. We showed that UNC-33 is essential for organizing the population of UNC-116-associated microtubule bundles, which are tracks for mitochondrial trafficking. Disarrangement of these tracks impedes mitochondrial transport to the axon. In summary, we identified a compartment-specific transport regulation of mitochondria by UNC-33 through organizing microtubule tracks for different kinesin motors other than microtubule polarity.     

Spotlight: Assembly of protein complexes by integrating graph clustering methods

As is generally assumed, clusters in protein–protein interaction (PPI) networks perform specific, crucial functions in biological systems. Various network community detection methods have been developed to exploit PPI networks in order to identify protein complexes and functional modules. Due to the potential role of various regulatory modes in biological networks, a single method may just apply a single graph property and neglect communities highlighted by other network properties.     

陌上菜的组织培养与植株再生

1植物名称陌上菜[Lindernia procumbens(Krock.)Philcox.],又称母草。2材料类别嫩茎节间。3培养条件愈伤组织诱导培养基:(1)MS 6-BA 0.5mg·L-1(单位下同);(2)MS 6     

绵马鳞毛蕨的组织培养与植株再生

1植物名称绵马鳞毛蕨(Dryopteris crassirhizoma Nakai),又称粗茎鳞毛蕨、野鸡翅膀子。2材料类别嫩叶。3培养条件愈伤组织诱导培养基:(1)1/2MS 6-BA0.3mg·L-1(单位下同) IBA0.3 NH4H2PO3200,(2)     

An enhanced association of RACK1 with Abl in cells transfected with oncogenic ras

The cellular RACK1 was shown in association with Abl in BALB/3T3 cells transfected with S-ras(Q(61)K) by immunoprecipitation. An identical finding was demonstrated with cells transfected with the embryonic E-ras, but not in cells without transformation. The Abl-RACK1 of transformed cells as resolvable with Triton X-114 was found with little affinity for FAK, PY(397)-FAK and integrin. Of interests, PY(397)-FAK in the membrane skeleton of transformed cells was shown in significant quantities on the Western blot. However the PY(397)-FAK of transformed cells was not functionally able to react with RACK1 and recruit cytokeratin-1, a substrate of Src, indicating that PY(397)-FAK is not operative to transmit integrin signals. In other words, the Abl-RACK1 of transformed cells cannot replace the Src-RACK1 of cells without transformation to bridge PY(397)-FAK and cytokeratin-1 for integrin signals, and the formation of Abl-RACK1 in transformed cells may block the association of PY(397)-FAK-RACK1. We characterized Abl and RACK1 from transformed cells by chromatography on a HiTrap-PEP(Taxol) affinity column, constructed from a beta-tubulin peptide specific for Taxol binding (PEP(Taxol)). However, the Triton X-100 cannot achieve the same resolution of Abl-RACK1 from plasma membrane as is shown with Triton X-114. A significant fraction of Abl was deposited at the membrane skeleton and was therefore not accessible with Triton X-100. Half of Abl resolved with Triton X-100 was demonstrated to have catalytic activity as shown with positive phosphotyrosine staining on the Western blot and competitive elution with a specific phosphate, such as sodium beta-glycerophosphate, from HiTrap-PEP(Taxol), but this was not associated with RACK1. No significant difference of RACK1 was found in Triton X-100 resolvable membrane preparations from cells with and without transformations. Future studies are planned to differentiate the mechanism operative for RACK1 associated and RACK1 freed Abl in cells transformed with oncogenic ras.     

Modeling spinal muscular atrophy in Drosophila

Spinal Muscular Atrophy (SMA), a recessive hereditary neurodegenerative disease in humans, has been linked to mutations in the survival motor neuron (SMN) gene. SMA patients display early onset lethality coupled with motor neuron loss and skeletal muscle atrophy. We used Drosophila, which encodes a single SMN ortholog, survival motor neuron (Smn), to model SMA, since reduction of Smn function leads to defects that mimic the SMA pathology in humans. Here we show that a normal neuromuscular junction (NMJ) structure depends on SMN expression and that SMN concentrates in the post-synaptic NMJ regions. We conducted a screen for genetic modifiers of an Smn phenotype using the Exelixis collection of transposon-induced mutations, which affects approximately 50% of the Drosophila genome. This screen resulted in the recovery of 27 modifiers, thereby expanding the genetic circuitry of Smn to include several genes not previously known to be associated with this locus. Among the identified modifiers was wishful thinking (wit), a type II BMP receptor, which was shown to alter the Smn NMJ phenotype. Further characterization of two additional members of the BMP signaling pathway, Mothers against dpp (Mad) and Daughters against dpp (Dad), also modify the Smn NMJ phenotype. The NMJ defects caused by loss of Smn function can be ameliorated by increasing BMP signals, suggesting that increased BMP activity in SMA patients may help to alleviate symptoms of the disease. These results confirm that our genetic approach is likely to identify bona fide modulators of SMN activity, especially regarding its role at the neuromuscular junction, and as a consequence, may identify putative SMA therapeutic targets.