Egfr/Ras pathway mediates interactions between peripodial and disc proper cells in Drosophila wing discs

All imaginal discs in Drosophila are made up of a layer of columnar epithelium or the disc proper and a layer of squamous epithelium called the peripodial membrane. Although the developmental and molecular events in columnar epithelium or the disc proper are well understood, the peripodial membrane has gained attention only recently. Using the technique of lineage tracing, we show that peripodial and disc proper cells arise from a common set of precursors cells in the embryo, and that these cells diverge in the early larval stages. However, peripodial and disc proper cells maintain a spatial relationship even after the separation of their lineages. The peripodial membrane plays a significant role during the regional subdivision of the wing disc into presumptive wing, notum and hinge. The Egfr/Ras pathway mediates this function of the peripodial membrane. These results on signaling between squamous and columnar epithelia are particularly significant in the context of in vitro studies using human cell lines that suggest a role for the Egfr/Ras pathway in metastasis and tumour progression

Lamin C and chromatin organization in Drosophila

Drosophila lamin C (LamC) is a developmentally regulated component of the nuclear lamina. The lamC gene is situated in the fifth intron of the essential gene tout velu (ttv). We carried out genetic analysis of lamC during development. Phenotypic analyses of RNAi-mediated downregulation of lamC expression as well as targeted misexpression of lamin C suggest a role for lamC in cell survival. Of particular interest in the context of laminopathies is the caspase-dependent apoptosis induced by the overexpression of lamin C. Interestingly, misexpression of lamin C in the central nervous system, where it is not normally expressed, did not affect organization of the nuclear lamina. lamC mutant alleles suppressed position effect variegation normally displayed at near-centromeric and telomeric regions. Further, both downregulation and misexpression of lamin C affected the distribution of heterochromatin protein 1. Our results suggest that Drosophila lamC has a tissue-specific role during development and is required for chromatin organization

An Efficient Multi path Dynamic Routing Protocol for Computing and Constrained Mobile Ad-hoc Network Environment

Wireless mobile ad-hoc networks are classified as ad-hoc networks with logical connections. These types of networks do not have fixed topology (or physical connections) due to the mobility property of nodes, interference, propagation and loss of path. Because of all these problems the path established between sources to destination is not reliable and efficient path. Hence a dynamic source routing protocol is required for these networks to working properly. Data transfer using this protocol based on shorted path, all packets need to be transferred using same path. The researcher on MANET proposed many Routing algorithms to this task. The main idea of this paper is to study, understand, and analyze the problems with existing routing methods. In the proposed multi path dynamic routing, first identify multi paths exist between source to destination and select best shortest path and then data is segmented into packets, each packet is transferred to receiver using selected best shortest path. At receiver end received data need to be rearranged. Finally the performance proposed system is compared with existing methods and proposed method shows better performance when compared with existing methods

1-Benzhydryl-4-(4-chloro­phenyl­sulfonyl)piperazine

The title compound, C23H23ClN2O2S, was synthesized by the nucleophilic substitution of 1-benzhydrylpiperazine with 4-chloro­phenyl­sulfonyl chloride. The piperazine ring is in a chair conformation. The geometry around the S atom is that of a distorted tetra­hedron. There is a large range of bond angles around the piperazine N atoms. The dihedral angle between the least-squares plane (p1) defined by the four coplanar C atoms of the piperazine ring and the benzene ring is 81.6 (1)°. The dihedral angles between p1 and the phenyl rings are 76.2 (1) and 72.9 (2)°. The two phenyl rings make a dihedral angle of 65.9 (1)°. Intramolecular C—H⋯O hydrogen bonds are present

N-[4-Cyano-3-(trifluoro­meth­yl)phen­yl]-2-eth­oxy­benzamide

In the title compound, C17H13F3N2O2, the two aromatic rings are essentially coplanar, forming a dihedral angle of 2.78 (12)°. The non-H atoms of the eth­oxy group are coplanar with the attached ring [maximum deviation = 0.271 (3) Å]. An intra­molecular N—H⋯O hydrogen bond occurs. In the crystal structure, mol­ecules are linked by inter­molecular C—H⋯N and C—H⋯F hydrogen bonds

(Z)-3-(3,4-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile

A new dipolarophile used in the construction of bioactive heterocycles, (\it Z)-3-(3,4-dimethoxy\-phen\-yl)-2-(4-methoxy\-phen\-yl)acrylonitrile, C\sb 18H\sb 17NO\sb 3, has been synthesized by base-catalysed reaction of 3,4-dimethoxy\-benzaldehyde with (4-methoxy\-phen\-yl)acetonitrile. The olefinic bond has \it Z geometry and the mol\-ecules are linked by C—-H⋅sO and C—-H⋅sN hydrogen bonds

Signaling interactions between squamous and columnar epithelia of the Drosophila wing disc

Understanding the interactions between distinct epithelial cells would help us to understand the development of tissues. Drosophila imaginal discs, which are made up of two types of epithelial cells, provide good model systems for such studies. The disc proper or the columnar epithelial cells are apposed to a layer of squamous epithelial cells (the peripodial membrane). We have examined organization of peripodial and disc proper cells vis-à-vis their polarity since cell polarity plays an important role in the polarized transport of signaling molecules. With the help of polarity-specific cell markers, we have observed that apical surfaces of peripodial and disc proper cells face each other. This provides the cellular basis for the recently demonstrated signaling interactions between peripodial and disc proper cells during disc patterning. We also report significant similarities as well as differences between peripodial and disc proper cells in Engrailed-dependent wingdisc-patterning events, which make them an appropriate model system for studying the mechanism of diffusion of signal molecules, such as Hedgehog. Results with wild-type and two mutant forms of Hedgehog suggest that direct cell-cell contact is a requirement for the movement of wild-type Hedgehog signal and reconfirm that cholesterol-modification of Hedgehog makes it a short-range signaling molecule by restricting its movement