The small GTPase Rho is a molecular switch that is best known for its role in regulating the actomyosin cytoskeleton. We have investigated its role in the developing Drosophila embryonic epidermis during the process of dorsal closure. By expressing the dominant negative DRhoA(N19) construct in stripes of epidermal cells, we confirm that Rho function is required for dorsal closure and demonstrat...

Development doesn’t always follow the plan. Ducuing et al. identify a control loop that enables Drosophila embryos to cope with environmental or genetic challenges and close a gap in their backs (1). Environmental changes or inappropriate gene expression can upset the intricate cellular choreography of development. Organisms have mechanisms to buffer these disturbances and ensure that cells end...

Dorsal closure is a paradigm epithelial fusion episode that occurs late in Drosophila embryogenesis and leads to sealing of a midline hole by bonding of two opposing epithelial sheets. The leading edge epithelial cells express filopodia and fusion is dependent on interdigitation of these filopodia to prime formation of adhesions. Since the opposing epithelia are molecularly patterned there must...

Cell shape changes within epithelia require the regulation of adhesive molecules that maintain tissue integrity. How remodelling of cell contacts is achieved while tissue integrity is maintained remains a fundamental question in morphogenesis. Dorsal Closure is a good system to study the dynamics of DE-Cadherin during morphogenesis. It relies on concerted cell shape changes of two epithelial sh...

The Drosophila myoblast city (mbc) locus was previously identified on the basis of a defect in myoblast fusion (Rushton et al., 1995. Development [Camb.]. 121:1979-1988). We describe herein the isolation and characterization of the mbc gene. The mbc transcript and its encoded protein are expressed in a broad range of tissues, including somatic myoblasts, cardial cells, and visceral mesoderm. It...

avulsion injury of the flexor digitorum profundus (fdp) with concomitant fracture of the distal phalanx dorsal base is uncommon. simultaneous avulsion fractures of the insertion of this tendon associated with rupture of the tendon from the bony fragment and combination with dorsal base fracture is very rare and also complicated. a 36- year- old man fell and injured his right little finger. fdp ...

introduction: although hippocampus is the most famous brain area involved in temporal lobe epilepsy, hippocampal kindling (hk) develops very slowly. hence, rapid kindling is usually preferred to the traditional kindling and it is widely used. in this article we aimed at finding the optimal stimulus pattern, which yields the fastest hk rate. methods: stimulus patterns with different duration (2,...

The processes thought to function in Xenopus gastrulation include bottle cell formation, migration of cells on the roof of the blastocoel, and autonomous convergent extension of the circumblastoporal region. A review of recent and classical results shows that only the last accounts for the bulk of the tissue displacement of gastrulation, including spreading of the marginal zone toward the blast...

Cadherins aggregate and stabilize cell-cell junctions through interactions with adjacent cells. In addition, N-cadherin and E-cadherin concentrate at free edges or at the lamellipodia of migrating cells and are found within large vesicles called macropinosomes, which develop from membrane ruffles. The binding properties of cadherins have not previously been associated with the localization of c...

Differentiation of distinct cell types at specific locations within a developing organism depends largely on the ability of cells to communicate. A major class of signalling proteins implicated in cell to cell communication is represented by members of the TGF beta superfamily. A corresponding class of transmembrane serine/threonine kinases has recently been discovered that act as cell surface ...