Esterase as a Marker to Study the Genetic Fidelity of Micropropagated Banana

Isozymic profiles of different micropropagated banana (Musa spp.) cultivars (Giant Governor, Dwarf Cavendish, Robusta, Champa, Kachakel and Chatim) of West Bengal, India were assessed at different subcultural passages. Variation with respect to the banding pattern was noticed only in esterase but not in peroxidase and acid phosphatase. Of the six cultivars, four showed variation both at isozymic and yield level. Two cultivars (Kachakel and Chatim) maintained their esterase profile and genetic stability even after twenty subcultural passages. This revised version was published online in July 2006 with corrections to the Cover Date.     

Kinesin-2 transports Orco into the olfactory cilium of Drosophila melanogaster at specific developmental stages

The cilium, the sensing centre for the cell, displays an extensive repertoire of receptors for various cell signalling processes. The dynamic nature of ciliary signalling indicates that the ciliary entry of receptors and associated proteins must be regulated and conditional. To understand this process, we studied the ciliary localisation of the odour-receptor coreceptor (Orco), a seven-pass transmembrane protein essential for insect olfaction. Little is known about when and how Orco gets into the cilia. Here, using Drosophila melanogaster, we show that the bulk of Orco selectively enters the cilia on adult olfactory sensory neurons in two discrete, one-hour intervals after eclosion. A conditional loss of heterotrimeric kinesin-2 during this period reduces the electrophysiological response to odours and affects olfactory behaviour. We further show that Orco binds to the C-terminal tail fragments of the heterotrimeric kinesin-2 motor, which is required to transfer Orco from the ciliary base to the outer segment and maintain within an approximately four-micron stretch at the distal portion of the ciliary outer-segment. The Orco transport was not affected by the loss of critical intraflagellar transport components, IFT172/Oseg2 and IFT88/NompB, respectively, during the adult stage. These results highlight a novel developmental regulation of seven-pass transmembrane receptor transport into the cilia and indicate that ciliary signalling is both developmentally and temporally regulated.

Jana, Dutta, Jain et al., show that the odour-receptor coreceptor only enters the cilia expressed on olfactory sensory neurons at specified developmental stages requiring heterotrimeric kinesin-2. The motor binds to the coreceptor and plays a crucial role in localising them to a compact, environment-exposed domain at the ciliary outer-segment.     

Bacteria classification using Cyranose 320 electronic nose

Background  

An electronic nose (e-nose), the Cyrano Sciences' Cyranose 320, comprising an array of thirty-two polymer carbon black composite sensors has been used to identify six species of bacteria responsible for eye infections when present at a range of concentrations in saline solutions. Readings were taken from the headspace of the samples by manually introducing the portable e-nose system into a sterile glass containing a fixed volume of bacteria in suspension. Gathered data were a very complex mixture of different chemical compounds.     

Direct shoot organogenesis and plant regeneration in safflower

Summary  Adventitious shoot buds were induced directly on the adaxial surface of the cotyledons of eight safflower cultivars after 14 d of culture initiation on Murashige and Skoog's (MS) medium supplemented with various levels of 6-benzylaminopurine (BA). Maximum shoot organogenesis of 54.4% with 10.2 shoots per responding cotyledon was obtained with 8.87 μM BA in the cv. S-144. Regenerated shoots were classified into three groups on the basis of their morphological features and were found to be correlated with the levels of BA. The highest number of normal shoots was obtained from 2.2 μM BA treatment. The regenerated shoots of group I (normal shoots) were rooted on half-strength MS medium supplemented with 5.3 μM α-naphthaleneacetic acid, 3% sucrose and 0.8% bacto-agar. Rooted plantlets were successfully transferred to soil and appeared morphologically normal. Histological studies revealed that shoot buds originated adventitiously from subepidermal cells.     

Promoter hypermethylation of p16INK4A, p14ARF, CyclinD2 and Slit2 in serum and tumor DNA from breast cancer patients

Epigenetic mechanisms such as DNA methylation play important role in cancer. Epigenetic alterations involved in the onset and progression of breast cancer may serve as biomarkers for early detection and prediction of disease prognosis. Furthermore, using body fluids such as serum offers a non-invasive method to procure multiple samples for biomarker analyses. The aim of this study is to determine the correlation between methylation status of multiple cancer genes, p16(INK4A), p14(ARF), Cyclin D2 and Slit2 in invasive ductal carcinoma of the breast and paired serum DNA and clinicopathological parameters. Of the 36 breast cancer patients investigated, 31 (86%) tumors and 30 (83%) paired sera showed methylation of at least one of these 4 genes. Methylation frequencies varied from 27% for CyclinD2, 44% for p16(INK4A), 47% for p14(ARF) to 58% for Slit2. There was concordance between DNA methylation in tumor and paired serum DNA of each gene. This study underscores the potential utility of DNA methylation based screening of serum as a surrogate marker for tumor DNA methylation status of these genes in breast cancer. Further, expression profile of p16(INK4A) could be linked to epigenetic events, thus suggesting this pathway as a potential target for therapeutic strategies based on reversal of epigenetic silencing.     

Sterols and fatty acids from three species of mangrove

The hydrolysis of steryl esters on thin-layer chromatographic plates by porcine pancreatic lipase is described. The sterols and fatty acids produced were separated on the same plate, recovered, and analysed by gas-liquid chromatography for their compositions. Synthetic cholesteryl esters containing various saturated and unsaturated fatty acids and synthetic steryl oleates with various sterols were lipolysed along with steryl esters of Acanthus ilicifolius, Bruguiera gymnorhiza and Rhizophora mucronata mangrove leaves. The major sterol was sitosterol which was accompanied by cholesterol, campesterol, stigmasterol and 28-isofucosterol. In addition, stigmast-7-en-3β-ol was present in R. mucronata leaves. The component fatty acids found in all three species were 16:0, 18:0, 18:1, 18:2 and 18:3. The relative proportions of the sterols and fatty acids were significantly different from the chemotaxonomic standpoint. The results obtained by carrying out plate lipolysis for 45 min at 40° compared well with those produced by conventional chemical hydrolysis.