Data-Driven Modeling of Intracellular Auxin Fluxes Indicates a Dominant Role of the ER in Controlling Nuclear Auxin Uptake

1. Download high-res image (289KB)
2. Download full-size image

     

Single step recombinant human growth hormone (rhGH) purification from milk by peptide affinity chromatography

Recombinant human growth hormone (rhGH) is used for the treatment of several pathologies, most of them related to growth. Although different expression systems can be used for its production, the milk from transgenic cows is one of the most interesting due to the high rhGH level achieved (5 g/L). We have designed and synthesized short peptides (9 or 10 amino acid long) using Fmoc chemistry and studied their ability to purify rhGH from milk once immobilized on an agarose support. Using spiked milk with the hormone as a sample, rhGH was purified with 88% yield and 92% purity in a single step with a fold purification of 4.5. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:999–1005, 2018     

Universal and group-specific real-time PCR diagnosis of flavescence dorée (16Sr-V), bois noir (16Sr-XII) and apple proliferation (16Sr-X) phytoplasmas from field-collected plant hosts and insect vectors

Three real‐time PCR–based assays for the specific diagnosis of flavescence dorée (FD), bois noir (BN) and apple proliferation (AP) phytoplasmas and a universal one for the detection of phytoplasmas belonging to groups 16Sr‐V, 16Sr‐X and 16Sr‐XII have been developed. Ribosomal‐based primers CYS2Fw/Rv and TaqMan probe CYS2 were used for universal diagnosis in real‐time PCR. For group‐specific detection of FD phytoplasma, ribosomal‐based primers fAY/rEY, specific for 16Sr‐V phytoplasmas, were chosen. For diagnosis of BN and AP phytoplasmas, specific primers were designed on non‐ribosomal and nitroreductase DNA sequences, respectively. SYBR^® Green I detection coupled with melting curve analysis was used in each group‐specific protocol. Field‐collected grapevines infected with FD and BN phytoplasmas and apple trees infected with AP phytoplasma, together with Scaphoideus titanus, Hyalesthes obsoletus and Cacopsylla melanoneura adults, captured in the same vineyards and orchards, were used as templates in real‐time PCR assays. The diagnostic efficiency of each group‐specific protocol was compared with well‐established detection procedures, based on conventional nested PCR. Universal amplification was obtained in real‐time PCR from DNAs of European aster yellows (16Sr‐I), elm yellows (16Sr‐V), stolbur (16Sr‐XII) and AP phytoplasma reference isolates maintained in periwinkles. The same assay detected phytoplasma DNA in all test plants and test insect vectors infected with FD, BN and AP phytoplasmas. Our group‐specific assays detected FD, BN, and AP phytoplasmas with high efficiencies, similar to those obtained with nested PCR and did not amplify phytoplasma DNA of other taxonomic groups. Melting curve analysis was necessary for the correct identification of the specific amplicons generated in the presence of very low target concentrations. Our work shows that real‐time PCR methods can sensitively and rapidly detect phytoplasmas at the universal or group‐specific level. This should be useful in developing defence strategies and for quantitative studies of phytoplasma–plant–vector interactions.     

Different Arginine Transfer Ribonucleic Acid Species Prevalent in Shaken and Unshaken Cultures of Neurospora

When the arginyl-transfer ribonucleic acid (tRNA) species isolated from unshaken and from shaken cultures of Neurospora were compared by co-chromatography, a marked change in the relative abundance of the two main tRNA(arg) species was found. The two arginine tRNA species had different codon responses in ribosome binding assays. The tRNA(arg) eluting first (prevalent in shaken cultures) bound strongly to polyadenylic-guanylic acid [poly(A,G)] and to a lesser extent to polycytidylic-guanylic-adenylic acid [poly(C,G,A)]. The second tRNA(arg) species (prevalent in unshaken cultures) bound to poly(C,G,A) but not to poly(A, G). The possible significance of these observations is briefly discussed. Several modifications that improve the yield of tRNA from Neurospora were introduced in a standard isolation procedure.     

Rediscovery of the sun bear (Helarctos malayanus)in Yingjiang County,Yunnan Province,China

DEAR EDITOR, The sun bear,Helarctos malayanus (Raffles,1821),is a forestdependent bear species distributed in tropical Southeast Asia.The species was previously reported from scattered localities in southwestern China,which is at the northeastern edge of its global range.Due to the scarcity of reliable recent records,some authorities cast doubt on the continued existence of sun bear in China.Here we present the rediscovery of this species in Yingjiang County,western Yunnan Province,China,near the international border with Myanmar's Kachin State.