135 research outputs found
Gene action in short-duration pigeonpeas
F1-F2 hybrids from a half diallel set of crosses involving 7 early Cajanus cajan lines were studied for yield and a number of yield-related traits. Parental performance was a good predictor of breeding value for most traits in the F1, but in the F2 a significant positive association between GCA effects and the parental performance was seen only for number of days to flowering. GCA variance predominated for all traits in the F1 and F2. The results suggested exploitation of the additive genetic variation in breeding for improvement of the cro
Ketamine-Induced Apoptosis in Normal Human Urothelial Cells
Recreational abuse of ketamine has been associated with the emergence of a new bladder pain syndrome, ketamine‐induced cystitis, characterised by chronic inflammation and urothelial ulceration. This study investigated the direct effects of ketamine on normal human urothelium maintained in organ culture or as finite cell lines in vitro.
Exposure of urothelium to ketamine resulted in apoptosis, with cytochrome c release from mitochondria and significant subsequent caspase 9 and 3/7 activation. The anaesthetic mode‐of‐action for ketamine is mediated primarily through N‐methyl Daspartate receptor (NMDAR) antagonism; however, NHU cells were unresponsive to NMDAR agonists or antagonists and no expression of NMDAR transcript was detected. Exposure to non‐cytotoxic concentrations of ketamine (≤1 mM) induced rapid release of ATP, which activated purinergic P2Y receptors and stimulated the inositol trisphosphate receptor to provoke transient release of calcium from the endoplasmic reticulum into the cytosol. Ketamine concentrations >1 mM were cytotoxic and provoked a largeramplitude increase in cytosolic [Ca2+] that was unresolved. The sustained elevation in cytosolic [Ca2+] was associated with pathological mitochondrial oxygen consumption and ATP deficiency.
Damage to the urinary barrier initiates bladder pain and in ketamine‐induced cystitis, loss of urothelium from large areas of the bladder wall is a reported feature. This study offers first evidence for a mechanism of direct toxicity of ketamine to urothelial cells by activating the intrinsic apoptotic pathway
Regionalização para o cultivo do feijão no Rio Grande do Sul com base na interação genótipo x ambiente¹.
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A Differential Role for Macropinocytosis in Mediating Entry of the Two Forms of Vaccinia Virus into Dendritic Cells
Vaccinia virus (VACV) is being developed as a recombinant viral vaccine vector for several key pathogens. Dendritic cells (DCs) are specialised antigen presenting cells that are crucial for the initiation of primary immune responses; however, the mechanisms of uptake of VACV by these cells are unclear. Therefore we examined the binding and entry of both the intracellular mature virus (MV) and extracellular enveloped virus (EV) forms of VACV into vesicular compartments of monocyte-derived DCs. Using a panel of inhibitors, flow cytometry and confocal microscopy we have shown that neither MV nor EV binds to the highly expressed C-type lectin receptors on DCs that are responsible for capturing many other viruses. We also found that both forms of VACV enter DCs via a clathrin-, caveolin-, flotillin- and dynamin-independent pathway that is dependent on actin, intracellular calcium and host-cell cholesterol. Both MV and EV entry were inhibited by the macropinocytosis inhibitors rottlerin and dimethyl amiloride and depended on phosphotidylinositol-3-kinase (PI(3)K), and both colocalised with dextran but not transferrin. VACV was not delivered to the classical endolysosomal pathway, failing to colocalise with EEA1 or Lamp2. Finally, expression of early viral genes was not affected by bafilomycin A, indicating that the virus does not depend on low pH to deliver cores to the cytoplasm. From these collective results we conclude that VACV enters DCs via macropinocytosis. However, MV was consistently less sensitive to inhibition and is likely to utilise at least one other entry pathway. Definition and future manipulation of these pathways may assist in enhancing the activity of recombinant vaccinia vectors through effects on antigen presentation
Chemical–Genetic Profiling of Imidazo[1,2-a]pyridines and -Pyrimidines Reveals Target Pathways Conserved between Yeast and Human Cells
Small molecules have been shown to be potent and selective probes to understand cell physiology. Here, we show that imidazo[1,2-a]pyridines and imidazo[1,2-a]pyrimidines compose a class of compounds that target essential, conserved cellular processes. Using validated chemogenomic assays in Saccharomyces cerevisiae, we discovered that two closely related compounds, an imidazo[1,2-a]pyridine and -pyrimidine that differ by a single atom, have distinctly different mechanisms of action in vivo. 2-phenyl-3-nitroso-imidazo[1,2-a]pyridine was toxic to yeast strains with defects in electron transport and mitochondrial functions and caused mitochondrial fragmentation, suggesting that compound 13 acts by disrupting mitochondria. By contrast, 2-phenyl-3-nitroso-imidazo[1,2-a]pyrimidine acted as a DNA poison, causing damage to the nuclear DNA and inducing mutagenesis. We compared compound 15 to known chemotherapeutics and found resistance required intact DNA repair pathways. Thus, subtle changes in the structure of imidazo-pyridines and -pyrimidines dramatically alter both the intracellular targeting of these compounds and their effects in vivo. Of particular interest, these different modes of action were evident in experiments on human cells, suggesting that chemical–genetic profiles obtained in yeast are recapitulated in cultured cells, indicating that our observations in yeast can: (1) be leveraged to determine mechanism of action in mammalian cells and (2) suggest novel structure–activity relationships
Male-sterility systems in pigeonpea and their role in enhancing yield
Male-sterility has been successfully used for enhancing yield in a number of cereal and vegetable crops. In food legumes, this technology could never be used either due to non-availability of natural out-crossing system, or an efficient male-sterility system or both. Pigeonpea [Cajanus cajan (L.) Millsp.] is a partially cross-pollinated food legume and recent success in breeding a stable male-sterility system has allowed breeders to exploit hybrid vigour for increasing yields. The cytoplasmic-nuclear male-sterility (CMS)-based hybrids have recorded 28.4% yield superiority over local checks in farmers' fields. This paper besides summarizing the reports of all the genetic and CMS systems, also discusses the prospects of utilizing these male-sterility systems in commercial hybrid breeding programmes
Development and Commercialization of CMS Pigeonpea Hybrids
The role of heterosis in enhancing productivity in food crops is well known.
Legume breeders have not been able, however, to take advantage of this genetic
phenomenon for a long time, due to biological restrictions, such as the requirement
of high seeding rate and the inability to produce large quantities of F1
hybrid seed. Recently, in pigeonpea (Cajanus cajan (L.) Millsp.), a breakthrough
has been realized with the development and marketing of the world’s first legume
hybrid, ICPH 2671. The key for this achievement was breeding and using a
stable cytoplasmic nuclear male sterility (CMS) system obtained from the cross
between C. cajanifolius, a wild relative of pigeonpea, and the cultivated type.
The inherent partial natural out‐crossing of pigeonpea was knitted with this CMS
system to facilitate economically‐viable large‐scale hybrid seed production.
These developments provided opportunities to overcome the historic stagnant
low yield (0.6–0.8 t ha–1) through heterosis breeding. Among hundreds of
hybrid combinations tested, a cross between ICPA 2043 and ICPL 87119 (=ICPR
2671), designated as ICPH 2671, was the most promising, with >40% yield
superiority (reaching yields above 3 t ha–1) over the prevalent cultivar ‘Maruti’,
in multi‐location, multi‐year, on‐station trials, as well as on‐farm evaluations.
The outstanding performance of ICPH 2671 led to its release in 2010 as the
first medium duration commercial pigeonpea hybrid in India. Subsequently,
two additional pigeonpea hybrids, ICPH 3762 and ICPH 2740 were also released
for commercial cultivation in India in 2014 and 2015, respectively. According
to recent estimates, in 2015 the CMS‐based pigeonpea hybrids were grown over
150,000 hectares in central and southern India. In this review, we summarize
the research efforts that led to the milestone of developing the first commercial
hybrid in food legumes
The Mouse Cytomegalovirus Gene m42 Targets Surface Expression of the Protein Tyrosine Phosphatase CD45 in Infected Macrophages
The receptor-like protein tyrosine phosphatase CD45 is expressed on the surface of cells of hematopoietic origin and has a pivotal role for the function of these cells in the immune response. Here we report that following infection of macrophages with mouse cytomegalovirus (MCMV) the cell surface expression of CD45 is drastically diminished. Screening of a set of MCMV deletion mutants allowed us to identify the viral gene m42 of being responsible for CD45 down-modulation. Moreover, expression of m42 independent of viral infection upon retroviral transduction of the RAW264.7 macrophage cell line led to comparable regulation of CD45 expression. In immunocompetent mice infected with an m42 deletion mutant lower viral titers were observed in all tissues examined when compared to wildtype MCMV, indicating an important role of m42 for viral replication in vivo. The m42 gene product was identified as an 18 kDa protein expressed with early kinetics and is predicted to be a tailanchored membrane protein. Tracking of surface-resident CD45 molecules revealed that m42 induces internalization and degradation of CD45. The observation that the amounts of the E3 ubiquitin ligases Itch and Nedd4 were diminished in cells expressing m42 and that disruption of a PY motif in the N-terminal part of m42 resulted in loss of function, suggest that m42 acts as an activator or adaptor for these Nedd4-like ubiquitin ligases, which mark CD45 for lysosomal degradation. In conclusion, the down-modulation of CD45 expression in MCMV-infected myeloid cells represents a novel pathway of virus-host interaction
The ARID1B spectrum in 143 patients: from nonsyndromic intellectual disability to Coffin–Siris syndrome
Purpose: Pathogenic variants in ARID1B are one of the most frequent causes of intellectual disability (ID) as determined by large-scale exome sequencing studies. Most studies published thus far describe clinically diagnosed Coffin–Siris patients (ARID1B-CSS) and it is unclear whether these data are representative for patients identified through sequencing of unbiased ID cohorts (ARID1B-ID). We therefore sought to determine genotypic and phenotypic differences between ARID1B-ID and ARID1B-CSS. In parallel, we investigated the effect of different methods of phenotype reporting. Methods: Clinicians entered clinical data in an extensive web-based survey. Results: 79 ARID1B-CSS and 64 ARID1B-ID patients were included. CSS-associated dysmorphic features, such as thick eyebrows, long eyelashes, thick alae nasi, long and/or broad philtrum, small nails and small or absent fifth distal phalanx and hypertrichosis, were observed significantly more often (p < 0.001) in ARID1B-CSS patients. No other significant differences were identified. Conclusion: There are only minor differences between ARID1B-ID and ARID1B-CSS patients. ARID1B-related disorders seem to consist of a spectrum, and patients should be managed similarly. We demonstrated that data collection methods without an explicit option to report the absence of a feature (such as most Human Phenotype Ontology-based methods) tended to underestimate gene-related features
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