This is an addendum to our recent paper published in The Plant Journal (52:352–61). The major findings were: (1) trichomes on the leaves of gl3-sst sim double mutants developed as large multi-cellular clusters whereas wild type trichomes are composed of single cells; (2) ectopic CYCD3;1 expression in gl3-sst trichomes also resulted in trichome cluster formation; and (3) that GL1 expression is prolonged in the gl3-sst sim trichome clusters. This addendum shows that ectopic CYCD3;1 expression in gl3-sst also enhanced GL1 expression. An analysis of the GL1 promoter found two overlapping potential E2F binding sites in a region of the promoter known to be essential for GL1 function. This finding indicates that GL1 may be directly regulated by the activity of a CYCD3/CDKA complex that phosphorylates E2F-RB bound to the GL1 promoter.
plant cell cycle; endoreduplication; glabra1; plant development
The environmental sequencing of the Sargasso Sea has introduced a huge new resource of genomic information. Unlike the protein sequences held in the current searchable databases, the Sargasso Sea sequences originate from a single marine environment and have been sequenced from species that are not easily obtainable by laboratory cultivation. The resource also contains very many fragments of whole protein sequences, a side effect of the shotgun sequencing method.
These sequences form a significant addendum to the current searchable databases but also present us with some intrinsic difficulties. While it is important to know whether it is possible to assign function to these sequences with the current methods and whether they will increase our capacity to explore sequence space, it is also interesting to know how current bioinformatics techniques will deal with the new sequences in the resource.
The Sargasso Sea sequences seem to introduce a bias that decreases the potential of current methods to propose structure and function for new proteins. In particular the high proportion of sequence fragments in the resource seems to result in poor quality multiple alignments.
These observations suggest that the new sequences should be used with care, especially if the information is to be used in large scale analyses. On a positive note, the results may just spark improvements in computational and experimental methods to take into account the fragments generated by environmental sequencing techniques.
The genetics of complex disease is entering a new and exciting era. The exponentially growing knowledge and technological capabilities emerging from the human genome project have finally reached the point where relevant genes can be readily and affordably identified. As a result, the last 12 months has seen a virtual explosion in new knowledge with reports of unequivocal association to relevant genes appearing almost weekly. The impact of these new discoveries in Neuroscience is incalculable at this stage but potentially revolutionary. In this review, an attempt is made to illuminate some of the mysteries surrounding complex genetics. Although focused almost exclusively on multiple sclerosis all the points made are essentially generic and apply equally well, with relatively minor addendums, to any other complex trait, neurological or otherwise.
multiple sclerosis; genetics; association; linkage
On routine electrophoretic analyses on filter paper and starch gel in an alkaline or neutral medium, no abnormal hemoglobin fractions were found in the blood of 600 newborn infants or their mothers. Trace amounts of hemoglobin Barts were noted in many of the blood samples from newborns when the starch gels (phosphate buffer pH 7.0) were stained with a benzidine/H2O2 reagent. In one infant, precocious cessation of synthesis of hemoglobin F was postulated to account for the small amounts of this hemoglobin found in a cord-blood specimen. Analysis of 15,000 blood samples from adults revealed two instances in which the hemoglobin F level was 20 and 35%, respectively. The former was attributed to a hereditary persistence of hemoglobin F, while the latter was associated with acute leukemia.
In an addendum, the finding of an infant with an abnormal hemoglobin variant, resembling in many of its properties hemoglobin F Texas, is reported.
The use of Cephalosporium eichhorniae 152 (ATCC 38255) (reclassified as Acremonium alabamense; see Addendum in Proof), a thermophilic, acidophilic, amylolytic fungus, for the conversion of potato processing wastes into microbial protein for use as animal feed was studied. The fungus was not inhibited by α-solanine or β-2-chaconine, antimicrobial compounds in potatoes, or by morpholine or cyclohexylamine (additives to steam used in the peeling process) at levels likely to be encountered in this substrate. Mixed effluent from holding tanks at a potato-processing plant contained about 109 bacteria per ml and inhibited fungal growth. The fungus grew well on fresh potato wastes containing up to 5% total carbohydrate and utilized both starch and protein at 45°C and pH 3.75. On potato homogenate medium containing 2% carbohydrate (about 14% fresh potato) supplemented with monoammonium phosphate (0.506 g/liter) and ferric iron (0.1 g/liter), with pH control (at 3.75) and additional nitrogen supplied by the automatic addition of ammonium hydroxide, typical yields were 0.61 g (dry weight) of product and 0.3 g of crude protein per g of carbohydrate supplied. An aerobic, spore-forming bacterium, related to Bacillus brevis, commonly contaminated nonsterilized batch cultures but was destroyed by heating for 15 min at 100°C.
Objective: To document the prevalence and pattern of stereotypic behaviour in patients with Alzheimer's dementia and frontal and temporal variants of frontotemporal dementia. Secondly, to examine the relationship between stereotypic and other neuropsychiatric behaviours.
Methods: Patients with the following were studied; Alzheimer's disease (n=28), frontal variant frontotemporal dementia (fvFTD, n=18), and semantic dementia—the temporal lobe variant of FTD (n=13). All patients were assessed using the Neuropsychiatric Inventory (NPI), the Mini-Mental State Examination, Addenbrooke's Cognitive Examination, and the Clinical Dementia Rating scale. Patients were also rated on the newly devised Stereotypic and Ritualistic Behaviour (SRB) subscale, which was designed as an addendum to the NPI.
Results: There was no significant difference across diagnostic groups in terms of age, sex, or severity of cognitive deficits. The overall NPI was significantly higher in patients with fvFTD compared with the other two groups, but fvFTD and semantic dementia showed a similar, and significantly increased, prevalence of stereotypic behaviours on the SRB subscale. Within the FTD group as a whole these behaviours were more likely to be complex, whereas in Alzheimer's disease, when present, such behaviours tended to be more simple stereotypies or stimulus bound repetitive behaviours. Stereotypic behaviours were not correlated with either disease severity or the extent of cognitive impairment in the fvFTD group, but were in the other two diagnostic groups.
Conclusion: Complex stereotypic behaviours are a core feature of the dementing syndrome in FTD and may reflect early and specific deficits in orbitofrontal circuitry and basal ganglia involvement.
Six children, with severe deficiency of some or all of the immunoglobulins and minor somatic abnormalities, had chromosomal abnormalities: (1) 45,XY,t(13q/18q), (2) 46,XY,21ps +, (3) two brothers 46,XY (inv. 7) (4) 45,X,t(11p/10p)/46X,iXq,t(11p/10p) and, (5) in addendum, 45,XX,-18;46,XX, r18. The chromosome abnormalities were detected in B- as well as T-lymphocytes (as evidenced by using both PHA- and PWM-stimulated cultures) in all probands, but one was mosaic in PHA culture, although all his PWM-stimulated cells were abnormal. Chromosomal variants were also detected in relatives of three and immunodeficiency in relatives of two.
Herewith is printed for the second time in California Medicine, the proposed C.M.A. Constitution introduced in the 1950 House of Delegates by Reference Committee No. 3 of that body.
Included in this document is an additional proposed section introduced by Reference Committee No. 3 as an addendum to its original introduction of the proposed Constitution.
Members of the Association, and especially members of the House of Delegates, are urged to give this proposed Constitution a thorough study. It contains various provisions which are different from existing constitutional provisions and which have been under discussion in the House of Delegates in the past.
Five families (three English, one Irish, one West Indian) contained eleven members with sarcoidosis, nine of whom have been investigated and followed. Their multisystem involvement and course was similar to that of other patients attending the Sarcoidosis Clinic at the Royal Northern Hospital. There were three brother-sister and two mother-offspring relations; it was not observed in a father-offspring relationship. It is noted that the course of one sister was considerably worse than that of her brother. The evidence suggests a recessive mode of inheritance for sarcoidosis susceptibility. Four other families are reported on in an Addendum.
Two orientation devices are described which are currently in use at the J. Hillis Miller Health Center Library.
One is a taped tour which requires a portable recorder with earphones attached. Tapes are now available for nursing students, physical therapy students, and Health Center staff. The tour includes location information and description of the card catalog and certain basic index and abstract services.
The second orientation device is a short instruction tape on the use of Index Medicus which is attached to the Index Medicus table. This is heard through a telephone apparatus.
It is anticipated that the tape technique will be expanded to apply to other students and other library tools. It is also believed that this technique may be used in other libraries.
Information about the supplies and equipment used is given as an addendum.
A network of shared intermediates/components and/or common molecular outputs in biotic and abiotic stress signaling has long been known, but the possibility of effective influence between differently triggered stresses (co-protection) is less studied. Recent observations show that wounding induces transient protection in tomato (Solanum lycopersicum L.) to four pathogens with a range of lifestyles, locally and systemically. The contribution of ethylene (ET) in basal but also in wound-induced resistance to each pathogen, although dispensable, is demonstrated to be positive (Botrytis cinerea, Phytophthora capsici) or negative (Fusarium oxysporum, Pseudomonas syringae pv. tomato). Furthermore, the expression of several defense markers is influenced locally and/or systemically by wounding and ET, and might be part of that core of conserved molecular responses whereby an abiotic stress such as wounding imparts co-resistance to biotic stress. In this addendum, we speculate on some of the physiological responses to wounding that might contribute to the modulation of resistance in a more pathogen-specific manner.
tomato; phytophthora; fusarium; wounding; ethylene; defense mechanisms; electric fields; zoospores; tylosis
Antisense oligodeoxynucleotide (ODN) inhibition emerges as an effective means for probing gene function in plant cells. Employing this method we have established the importance of the SUSIBA2 transcription factor for regulation of starch synthesis in barley endosperm, and arrived at a model for the role of the SUSIBAs in sugar signaling and source-sink commutation during cereal endosperm development. In this addendum we provide additional data demonstrating the suitability of the antisense ODN technology in studies on starch branching enzyme activities in barley leaves. We also comment on the mechanism for ODN uptake in plant cells.
antisense ODN; barley; SBE; SUSIBA2
Glucose functions in plants both as a metabolic resource as well as a hormone that regulates expression of many genes. Arabidopsis hexokinase1 (HXK1) is the best understood plant glucose sensor/transducer, yet we are only now appreciating the cellular complexity of its signaling functions. We have recently shown that one of the earliest detectable responses to plant glucose treatments are extensive alterations of cellular F-actin. Interestingly, AtHXK1 is predominantly located on mitochondria, yet also can interact with actin. A normal functioning actin cytoskeleton is required for HXK1 to act as an effector in glucose signaling assays. We have suggested that HXK1 might alter F-actin dynamics and thereby influence the formation and/or stabilization of cytoskeleton-bound polysomes. In this Addendum, we have extended our initial observations on the subcellular targeting of HXK1 and its interaction with F-actin. We then further consider the cellular context in which HXK1 might regulate gene expression.
Arabidopsis; F-actin; glucose signaling; hexokinase; hTalin; mitochondria; polysomes; protoplasts; transient expression assay; fluorescence microscopy
In animal cells, nitric oxide and NO-derived molecules have been shown to mediate post-translational modifications such as S-nitrosylation and protein tyrosine nitration which are associated with cell signalling and pathological processes, respectively. In plant cells, knowledge of the function of these post-translational modifications under physiological and stress conditions is still very rudimentary. In this addendum, we briefly examine how reactive nitrogen species (RNS) can exert important effects on proteins that could mediate signalling processes in plants.
nitrosative stress; nitric oxide synthase; S-nitrosoglutathione; nitro-tyrosine; post-translational modifications; S-nitrosylation
The formation of neuronal synapses is a finely organized process that involves the presynaptic assembly of the machinery responsible for neurotransmitter release and the postsynaptic recruitment of neurotransmitter receptors and scaffold proteins to the postsynaptic density (PSD). The molecular cues guiding the establishment of synaptic connections are now beginning to be identified. Recent studies indicate that cell adhesion molecules (CAMs) participate prominently in the key steps of synapse formation, inducing trans-synaptic adhesion and promoting a precise alignment of pre- and postsynaptic terminals. This addendum describes a new mechanism of cell-cell interaction that combines features of both diffusible and membrane-bound synaptogenic factors. It particularly points out the key role played by GDNF triggering trans-homophilic binding between GFRα1 molecules and cell adhesion between GFRα1-expressing cells. In this model GFRα1 functions as a ligand-induced cell adhesion molecule (LICAM) to establish precise synaptic contacts and promote the assembly of presynaptic terminals. In this overview, I summarize the current concepts of synapse formation in the limelight of this new mechanism of ligand-induced cell adhesion.
GDNF; GFRα1; LICAM; cell adhesion; synapse formation
Remodeling of joints is a key feature of inflammatory and degenerative joint disease. Bone erosion, cartilage degeneration and growth of bony spurs termed osteophytes are key features of structural joint pathology in the course of arthritis, which lead to impairment of joint function. Understanding their molecular mechanisms is essential to tailor targeted therapeutic approaches to protect joint architecture from inflammatory and mechanical stress. This addendum summarizes the new insights in the molecular regulation of bone formation in the joint and its relation to bone resorption. It describes how inflammatory cytokines impair bone formation and block the repair response of joints towards inflammatory stimuli. It particularly points out the key role of Dickkopf-1 protein, a regulator of the Wingless signaling and inhibitor of bone formation. This new link between inflammation and bone formation is also crucial for explaining the generation of osteophytes, bony spurs along joints, which are characterized by new bone and cartilage formation. This mechanism is largely dependent on an activation of wingless protein signaling and can lead to complete joint fusion. This addendum summarized the current concepts of joint remodeling in the limelight of these new findings.
joint remodeling; arthritis; bone formation; bone erosion; osteoblasts; osteoclasts; Dickkopf; wingless proteins
For a long time it has been believed that lignification has an important role in host defense against pathogen invasion. Recently, by using an RNAi gene-silencing assay we showed that monolignol biosynthesis plays a critical role in cell wall apposition (CWA)-mediated defense against powdery mildew fungus penetration into diploid wheat. Silencing monolignol genes led to super-susceptibility of wheat leaf tissues to an appropriate pathogen, Blumeria graminis f. sp. tritici (Bgt), and compromised penetration resistance to a non-appropriate pathogen, B. graminis f. sp. hordei. Autofluorescence of CWA regions was reduced significantly at the fungal penetration sites in silenced cells. Our work indicates an important role for monolignol biosynthetic genes in effective CWA formation against pathogen penetration. In this addendum, we show that silencing of monolignol genes also compromised penetration resistant to Bgt in a resistant wheat line. In addition, we discuss possible insights into how lignin biosynthesis contributes to host defense.
monolignol; papilla autofluorescence; methylated lignin; defense lignin; cereal
Hormonal regulation of root development is a long known phenomenon. In the past decades, the molecular mechanisms of individual hormonal pathways and their impact on root development have been studied. Recent genetic and molecular studies suggest importance of interactions of the individual hormonal pathways and their components. In our paper1 we show impact of endogenous cytokinin on the root architecture and its interaction with auxin in Arabidopsis thaliana. In this addendum we discuss our results in the light of significant recent papers that deal with cytokinin-auxin interactions and we point out spatiotemporal specificity of these interactions in the root development.
root meristem; hormonal regulation; cytokinin-auxin interaction; spatiotemporal specificity; Arabidopsis thaliana
Regulation of mRNA decay rates appears to be an important control point in determining the abundance of gene transcripts. Rapid change in decay rates of mRNAs could provide prompt responses of the plants to environmental fluctuations. SOS1 is a plasma-membrane Na+/H+ antiporter crucial for salt tolerance in Arabidopsis. In our recent paper in The Plant Journal, we have shown that SOS1 mRNA is inherently instable at normal growth conditions, but its stability is substantially elevated by salt and oxidative stress treatments. Salt stress-induced SOS1 mRNA stability is mediated by reactive oxygen species (ROS) produced, at least in part, through NADPH oxidases. We proposed a hypothetical model for the signaling pathway controlling SOS1 mRNA stability. In this addendum, we discuss the possible involvement of other components in conferring inherent instability and stress-induced stability of SOS1 mRNA.
mRNA stability; salt stress; signaling transduction; SOS1
After germination, seedlings follow one of two developmental programs, photo- and skotomorphogenesis, and the choice is determined by the interplay between environmental signals (light) and endogenous cues (the plant hormones gibberellins among others). In the December issue of Plant Journal we describe a molecular mechanism that allows the integration of light and gibberellin signaling to tightly control the switch between skoto- and photomorphogenesis. On one hand, the stability of HY5, a transcription factor required by light to promote photomorphogenesis, is enhanced in the light and in situations with compromised GA biosynthesis. And, on the other hand, the promotion of growth during etiolation is exerted by the PIF family of transcription factors, whose abundance is enhanced by the absence of light, and whose activity is regulated by functional interaction with gibberellin signaling. In this addendum we propose that the control of the activity of light-dependent transcription factors by gibberellins is a common theme in other developmental processes, such as shade avoidance and photoperiodic regulation of cell expansion.
gibberellins; photomorphogenesis; shade avoidance; cell expansion
Plant growth and development are tightly regulated by both plant growth substances and environmental factors such as temperature. Taking into account the above, it was reasonable to point out that indole-3-acetic acid (IAA), the most abundant type of auxin in plants, could be involved in temperature- dependent growth of plant cells. We have recently shown that growth of maize coleoptile segments in the presence of auxin (IAA) and fusicoccin (FC) shows the maximum value in the range 30–35°C and 35–40°C, respectively. Furthermore, simultaneous measurements of growth and external medium pH indicated that FC at stressful temperatures was not only much more active in the stimulation of growth, but was also more effective in acidifying the external medium than IAA. The aim of this addendum is to determine interrelations between the action of IAA and FC (applied together with IAA) on growth and medium pH of maize coleoptile segments incubated at high temperature (40°C), which was optimal for FC but not for IAA.
auxin; fusicoccin; coleoptile segments; elongation growth; medium pH
Brain derived neurotrophic factor (BDNF) is crucial for the formation of appropriate synaptic connections during development and for learning and memory in adults. Secretion of this neurotrophin is under activity-dependent control. Understanding which patterns of physiological activity regulate BDNF secretion is therefore an important step in the comprehension of its role. We have recently shown that back propagation of action potentials (bAPs) is the principal triggering mechanism of dendritic BDNF secretion occurring during ongoing neuronal activity in neuronal cultures. In the present addendum we discuss possible implications of bAPs-induced BDNF secretion on the construction and reorganization of neuronal networks.
BDNF; peptide secretion; back propagating action potentials; synaptic plasticity; neuromodulation; acetylcholine
Using a live-cell imaging approach to study individual micro-tubules, we have compared microtubule behavior between net-like and aligned cortical arrays. In contrast to previous studies, a steep angled collision between the growing end of a microtubule and a preexisting microtubule was found to favor crossover. Frequencies of microtubule crossovers, bundling and catastrophes are similar regardless of whether the cell exhibited a net-like or aligned microtubule array. In the predominantly aligned array of petiole cells, severing occurs at the sites of microtubule crossovers and serves to remove unaligned microtubules and to increase microtubule density. Severing was observed to be rare in net-like arrays. Microtubule severing is carried out by the katanin enzyme. In this addendum, we present new insights into the possible mechanism of crossing over and preliminary data looking at organization of the array in a katanin mutant.
cortical array; collision; catastrophe; severing; katanin; petiole; pavement; cotyledons; YFP
Recent large scale phosphoproteomics studies have helped identify many phosphorylation sites of both membrane and soluble proteins. In most cases the relevance of specific sites has yet to be established whereas in a small number of cases their potency in modulating protein activity is evident. With the increasing amount of data it is becoming clear that phosphosites are often conserved within protein families, pointing to generic regulatory mechanisms. In addition, such mechanisms may be conserved across species. In this addendum evidence is presented for these phenomena occurring in rice and Arabidopsis.
Arabidopsis; kinase; phosphoproteomics; rice
It is well known for a long time, that nitric oxide (NO) functions in variable physiological and developmental processes in plants, however the source of this signaling molecule in the diverse plant responses is very obscure.1 Although existance of nitric oxide sythase (NOS) in plants is still questionable, LNMMA (NG-monomethyl-L-arginine)-sensitive NO generation was observed in different plant species.2,3 In addition, nitrate reductase (NR) is confirmed to have a major role as source of NO.4,5 This multifaced molecule acts also in auxin-induced lateral root (LR) formation, since exogenous auxin enhanced NO levels in regions of Arabidopsis LR initiatives. Our results pointed out the involvement of nitrate reductase enzyme in auxin-induced NO formation. In this addendum, we speculate on auxin-induced NO production in lateral root primordial formation.
atnoa1; indole-3-butyric acid; nia1; nia2 double mutant; nitric oxide