Eucalyptus has a functional equivalent of the Arabidopsis floral meristem identity gene LEAFY

Two genes cloned from Eucalyptus globulus, Eucalyptus LeaFy (ELF1 and ELF2), have sequence homology to the floral meristem identity genes LEAFY from Arabidopsis and FLORICAULA from Antirrhinum. ELF1 is expressed in the developing eucalypt floral organs in a pattern similar to LEAFY while ELF2 appears to be a pseudo gene. ELF1 is expressed strongly in the early floral primordium and then successively in the primordia of sepals, petals, stamens and carpels. It is also expressed in the leaf primordia and young leaves and adult and juvenile trees.The ELF1 promoter coupled to a GUS reporter gene directs expression in transgenic Arabidopsis in a temporal and tissue-specific pattern similar to an equivalent Arabidopsis LEAFY promoter construct. Strong expression is seen in young flower buds and then later in sepals and petals. No expression was seen in rosette leaves or roots of flowering plants or in any non-flowering plants grown under long days. Furthermore, ectopic expression of the ELF1 gene in transgenic Arabidopsis causes the premature conversion of shoots into flowers, as does an equivalent 35S-LFY construct. These data suggest that ELF1 plays a similar role to LFY in flower development and that the basic mechanisms involved in flower initiation and development in Eucalyptus are similar to those in Arabidopsis.     

The sequence of a pea vicilin gene and its expression in transgenic tobacco plants

A 5.5 kb Eco RI fragment containing a vicilin gene was selected from a Pisum sativum genomic library, and the protein-coding region and adjacent 5 and 3 regions were sequenced. A DNA construction comprising this 5.5 kb fragment together with a gene for neomycin phosphotransferase II was stably introduced into tobacco using an Agrobacterium tumefaciens binary vector, and the fidelity of expression of the pea vicilin gene in its new host was studied. The seeds of eight transgenic tobacco plants showed a sixteen-fold range in the level of accumulated pea vicilin. The level of accumulation of vicilin protein and mRNA correlated with the number of integrated copies of the vicilin gene. Pea vicilin was confined to the seeds of transgenic tobacco. Using immunogold labelling, vicilin was detected in protein bodies of eight out of ten embryos (axes plus cotyledons) and, at a much lower level, in two out of eleven endosperms. Pea vicilin was synthesized early in tobacco seed development; some molecules were cleaved as is the case in pea seeds, yielding a major parental component of M _r50000 together with a range of smaller polypeptides.     

Risk Factors for Blood Transfusions in Primary Anatomic and Reverse Total Shoulder Arthroplasty for Osteoarthritis

BackgroundThe purpose of this study was to determine risk factors for blood transfusion in primary anatomic and reverse total shoulder arthroplasty (TSA) performed for osteoarthritis.MethodsPatients who underwent anatomic or reverse TSA for a diagnosis of primary osteoarthritis were identified in a national surgical database from 2005 to 2018 by utilizing both CPT and ICD-9/ICD-10 codes. Univariate analysis was performed on the two transfused versus non-transfused cohorts to compare for differences in comorbidities and demographics. Independent risk factors for perioperative blood transfusions were identified via multivariate regression models.Results305 transfused and 18,124 nontransfused patients were identified. Female sex (p<0.001), age >85 years (p=0.001), insulin-dependent diabetes mellitus (p=0.001), dialysis dependence (p=0.001), acute renal failure (p=0.012), hematologic disorders (p=0.010), disseminated cancer (p<0.001), ASA ≥ 3 (p<0.001), and functional dependence (p=0.001) were shown to be independent risk factors for blood transfusions on multivariate logistic regression analysis.ConclusionSeveral independent risk factors for blood transfusion following anatomic/reverse TSA for osteoarthritis were identified. Awareness of these risk factors can help surgeons and perioperative care teams to both identify and optimize high-risk patients to decrease both transfusion requirements and its associated complications in this patient population. Level of Evidence: III     

Tracking Mutant Huntingtin Aggregation Kinetics in Cells Reveals Three Major Populations That Include an Invariant Oligomer Pool

Huntington disease is caused by expanded polyglutamine sequences in huntingtin, which procures its aggregation into intracellular inclusion bodies (IBs). Aggregate intermediates, such as soluble oligomers, are predicted to be toxic to cells, yet because of a lack of quantitative methods, the kinetics of aggregation in cells remains poorly understood. We used sedimentation velocity analysis to define and compare the heterogeneity and flux of purified huntingtin with huntingtin expressed in mammalian cells under non-denaturing conditions. Non-pathogenic huntingtin remained as hydrodynamically elongated monomers in vitro and in cells. Purified polyglutamine-expanded pathogenic huntingtin formed elongated monomers (2.4 S) that evolved into a heterogeneous aggregate population of increasing size over time (100–6,000 S). However, in cells, mutant huntingtin formed three major populations: monomers (2.3 S), oligomers (mode s_20,w = 140 S) and IBs (mode s_20,w = 320,000 S). Strikingly, the oligomers did not change in size heterogeneity or in their proportion of total huntingtin over 3 days despite continued monomer conversion to IBs, suggesting that oligomers are rate-limiting intermediates to IB formation. We also determined how a chaperone known to modulate huntingtin toxicity, Hsc70, influences in-cell huntingtin partitioning. Hsc70 decreased the pool of 140 S oligomers but increased the overall flux of monomers to IBs, suggesting that Hsc70 reduces toxicity by facilitating transfer of oligomers into IBs. Together, our data suggest that huntingtin aggregation is streamlined in cells and is consistent with the 140 S oligomers, which remain invariant over time, as a constant source of toxicity to cells irrespective of total load of insoluble aggregates.     

Restoration of mutationally suppressed characters in Drosophila melanogaster

We examined three strains of Drosophila melanogaster made wingless for periods of up to 40 years by homozygosity for the recessive mutant, vestigial. The intent was to quantify the degeneration of genes for wing structure and function that were not expressed during these periods. No increase in abnormality of wing morphology or use was found in the oldest strains despite up to 1000 generations of winglessness. We propose that these genes have remained intact because of important pleiotropic effects not connected with wing formation.     

The effect of inhibitors of DNA repair on the genetic instability of Streptomyces cattleya

Various streptomycetes show well defined instabilities that do not appear to be attributable to plasmid loss. The unstable phenotype, in many cases, arises at frequencies too high to be explained by point mutations. The frequency of instability can be enhanced by UV irradiation. Two major repair systems have been found in Escherichia coli: the 'error-free' system which is inhibited by caffeine and the 'error-prone' system which is inhibited by arsenite. Using spores of Streptomyces cattleya NRRL 8057 and the virulent actinophage VC11 we have shown that a caffeine inhibitable, host mediated UV repair system is active in spores during early development. Some evidence was also found for the presence of an arsenite inhibitable UV repair system. The caffeine inhibitable UV repair system was found to be involved in the induction of genetic instability in S. cattleya. The arsenite system may be implicated in the repair of such events. Genetic instability was also induced by single strand breaks in DNA caused by 32P.