A Sri Lankan child with 49,XXXXY syndrome

Pentasomy 49,XXXXY is a rare sex chromosome disorder usually presenting with ambigous genitalia, facial dysmorphism, mental retardation and a combination of cardiac, skeletal and other malformations. The incidence of the condition is estimated to be 1 in 85,000 male births. Previously, this condition was identified as a Klinefelter variant. The condition is suspected in a patient, by a combination of characteristic clinical findings, and the diagnosis is confirmed by chromosome culture and karyotyping. In the case we report here, the main presentation of ambiguous genitalia led to a suspicion of a sex chromosome aneuploidy which was subsequently confirmed by chromosomal analysis.     

Potential hypotensive agents: synthesis and hypotensive activity of oxime ethers derived from 1-naphthoxepines and related compounds

The synthesis and pharmacological evaluation of substituted oximino-ethers 1 and 2 of naphth[1,2-b]- and naphth[2,1-b]-oxepin-5-ones (4 and 8) were carried out. The hypotensive activity of oximino-ethers 1 and 2 was evaluated on anaesthetized cats. The results indicated that 1c caused a fall of 80 mm/Hg for >100' at a dose of 5mg/kg iv in anaesthetized cats.     

Haplotype inference in crossbred populations without pedigree information

Background

Current methods for haplotype inference without pedigree information assume random mating populations. In animal and plant breeding, however, mating is often not random. A particular form of nonrandom mating occurs when parental individuals of opposite sex originate from distinct populations. In animal breeding this is called crossbreeding and hybridization in plant breeding. In these situations, association between marker and putative gene alleles might differ between the founding populations and origin of alleles should be accounted for in studies which estimate breeding values with marker data. The sequence of alleles from one parent constitutes one haplotype of an individual. Haplotypes thus reveal allele origin in data of crossbred individuals.

Results

We introduce a new method for haplotype inference without pedigree that allows nonrandom mating and that can use genotype data of the parental populations and of a crossbred population. The aim of the method is to estimate line origin of alleles. The method has a Bayesian set up with a Dirichlet Process as prior for the haplotypes in the two parental populations. The basic idea is that only a subset of the complete set of possible haplotypes is present in the population.

Conclusion

Line origin of approximately 95% of the alleles at heterozygous sites was assessed correctly in both simulated and real data. Comparing accuracy of haplotype frequencies inferred with the new algorithm to the accuracy of haplotype frequencies inferred with PHASE, an existing algorithm for haplotype inference, showed that the DP algorithm outperformed PHASE in situations of crossbreeding and that PHASE performed better in situations of random mating.     

Predation drives recurrent convergence of an interspecies mutualism

Mutualisms are important ecological interactions that underpin much of the world's biodiversity. Predation risk has been shown to regulate mutualism dynamics in species‐specific case studies; however, we lack studies which investigate whether predation can also explain broader patterns of mutualism evolution. We report that fish‐anemone mutualisms have evolved on at least 55 occasions across 16 fish families over the past 60 million years and that adult body size is associated with the ontogenetic stage of anemone mutualisms: larger‐bodied species partner with anemones as juveniles, while smaller‐bodied species partner with anemones throughout their lives. Field and laboratory studies show that predators target smaller prey, that smaller fishes associate more with anemones, and that these relationships confer protection to small fishes. Our results indicate that predation is likely driving the recurrent convergent evolution of fish‐anemone mutualisms and suggest that similar ecological processes may have selected convergence in interspecies interactions in other animal clades.     

Nitric oxide induces apoptosis in cutaneous T cell lymphoma (HuT-78) by downregulating constitutive NF-κB

Constitutive active NF-κB have been shown to protect cutaneous T cell lymphoma (CTCL) cells from apoptosis. In the present study, we have studied the cytotoxic potential of nitric oxide generating compound, sodium nitroprusside (SNP) on CTCL cell line, HuT-78. Treatment of cells with SNP resulted in decrease in mitochondrial membrane potential, cytochrome c release, activation of caspase-3 and poly (ADP ribose) polymerase cleavage. SNP treatment inhibited activation of NF-κB in a concentration dependent manner. SNP increased the expression of IκBα without affecting the phosphorylation of IκBα. Downregulation of NF-κB by SNP decreased p65 nuclear translocation as evident by confocal fluorescence microscopy. Further it was found that SNP treatment caused downregulation of Bcl-2 family member (Bcl-xl) in HuT-78 cells. Thus, we have provided evidence that SNP induces apoptosis in CTCL cell line, HuT-78 by downregulating constitutive NF-κB and thereby Bcl-xl expression.     

Novel Neuroprotective Function of Apical-Basal Polarity Gene Crumbs in Amyloid Beta 42 (Aβ42) Mediated Neurodegeneration

Alzheimer''s disease (AD, OMIM: 104300), a progressive neurodegenerative disorder with no cure to date, is caused by the generation of amyloid-beta-42 (Aβ42) aggregates that trigger neuronal cell death by unknown mechanism(s). We have developed a transgenic Drosophila eye model where misexpression of human Aβ42 results in AD-like neuropathology in the neural retina. We have identified an apical-basal polarity gene crumbs (crb) as a genetic modifier of Aβ42-mediated-neuropathology. Misexpression of Aβ42 caused upregulation of Crb expression, whereas downregulation of Crb either by RNAi or null allele approach rescued the Aβ42-mediated-neurodegeneration. Co-expression of full length Crb with Aβ42 increased severity of Aβ42-mediated-neurodegeneration, due to three fold induction of cell death in comparison to the wild type. Higher Crb levels affect axonal targeting from the retina to the brain. The structure function analysis identified intracellular domain of Crb to be required for Aβ42-mediated-neurodegeneration. We demonstrate a novel neuroprotective role of Crb in Aβ42-mediated-neurodegeneration.     

Alzheimer's associated variant ubiquitin causes inhibition of the 26S proteasome and chaperone expression

Intracellular protein inclusions in Alzheimer's disease and progressive supranuclear palsy contain UBB+1, a variant ubiquitin. UBB+1 is able block the 26S proteasome in cell lines. Proteasome inhibition by drug action has previously been shown to induce a heat-shock response and render protection against stress. We investigated UBB+1 by developing a stable, conditional expression model in SH-SY5Y human neuroblastoma cells. Induction of UBB+1 expression caused proteasome inhibition as was confirmed by reduced ability to process misfolded canavanyl proteins, accumulation of GFPu, a proteasome substrate, and reduced cleavage of a fluorogenic substrate. We show that expression of UBB+1 induces expression of heat-shock proteins. This priming of the chaperone system in these cells promotes a subsequent resistance to tert-butyl hydroperoxide-mediated oxidative stress. We conclude that although UBB+1-expressing cells have a compromised ubiquitin-proteasome system, they are protected against oxidative stress conditions.     

Targeting of the GRIP domain to the trans-Golgi network is conserved from protists to animals

The GRIP domain, found in a family of coiled-coil peripheral membrane Golgi proteins, is a specific targeting sequence for the trans-Golgi network of animal cells. In this study we show that a coiled-coil protein with a GRIP domain occurs in the primitive eukaryote, Trypanosoma brucei, and that reporter proteins containing this domain can be used as a marker for the poorly characterized trans Golgi/trans-Golgi network of trypanosomatid parasites. The T. brucei GRIP domain, when fused to the carboxyl terminus of the green fluorescent protein (GFP-TbGRIP), was efficiently localized to the Golgi apparatus of transfected COS cells. Overexpression of GFP-TbGRIP in COS cells displaced the endogenous GRIP protein, GCC1p, from the Golgi apparatus indicating that the trypanosomatid and mammalian GRIP sequences interact with similar membrane determinants. GFP fusion proteins containing either the T. brucei GRIP domain or the human p230 GRIP (p230GRIP) domain were also expressed in the trypanosomatid parasite, Leishmania mexicana, and localized by fluorescence and immuno-electron microscopy to the trans face of the single Golgi apparatus and a short tubule that extended from the Golgi apparatus. Binding of GFP-p230GRIP to Golgi membranes in L. mexicana was abrogated by mutation of a critical tyrosine residue in the p230 GRIP domain. The levels of GFP-GRIP fusion proteins were dramatically reduced in stationary-phase L. mexicana promastigotes, suggesting that specific Golgi trafficking steps may be down-regulated as the promastigotes cease dividing. This study provides a protein marker for the trans-Golgi network of trypanosomatid parasites and suggests that the GRIP domain binds to a membrane component that has been highly conserved in eukaryotic evolution.     

Fish community reassembly after a coral mass mortality: higher trophic groups are subject to increased rates of extinction

Since Gleason and Clements, our understanding of community dynamics has been influenced by theories emphasising either dispersal or niche assembly as central to community structuring. Determining the relative importance of these processes in structuring real‐world communities remains a challenge. We tracked reef fish community reassembly after a catastrophic coral mortality in a relatively unfished archipelago. We revisited the stochastic model underlying MacArthur and Wilson's Island Biogeography Theory, with a simple extension to account for trophic identity. Colonisation and extinction rates calculated from decadal presence‐absence data based on (1) species neutrality, (2) trophic identity and (3) site‐specificity were used to model post‐disturbance reassembly, and compared with empirical observations. Results indicate that species neutrality holds within trophic guilds, and trophic identity significantly increases overall model performance. Strikingly, extinction rates increased clearly with trophic position, indicating that fish communities may be inherently susceptible to trophic downgrading even without targeted fishing of top predators.     

Improvement of N-glycan site occupancy of therapeutic glycoproteins produced in Pichia pastoris

Yeast is capable of performing posttranslational modifications, such as N- or O-glycosylation. It has been demonstrated that N-glycans play critical biological roles in therapeutic glycoproteins by modulating pharmacokinetics and pharmacodynamics. However, N-glycan sites on recombinant glycoproteins produced in yeast can be underglycosylated, and hence, not completely occupied. Genomic homology analysis indicates that the Pichia pastoris oligosaccharyltransferase (OST) complex consists of multiple subunits, including OST1, OST2, OST3, OST4, OST5, OST6, STT3, SWP1, and WBP1. Monoclonal antibodies produced in P. pastoris show that N-glycan site occupancy ranges from 75–85 % and is affected mainly by the OST function, and in part, by process conditions. In this study, we demonstrate that N-glycan site occupancy of antibodies can be improved to greater than 99 %, comparable to that of antibodies produced in mammalian cells (CHO), by overexpressing Leishmania major STT3D (LmSTT3D) under the control of an inducible alcohol oxidase 1 (AOX1) promoter. N-glycan site occupancy of non-antibody glycoproteins such as recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) was also significantly improved, suggesting that LmSTT3D has broad substrate specificity. These results suggest that the glycosylation status of recombinant proteins can be improved by heterologous STT3 expression, which will allow for the customization of therapeutic protein profiles.