Mef2 and the skeletal muscle differentiation program.

Mef2 is a conserved and significant transcription factor in the control of muscle gene expression. In cell culture Mef2 synergises with MyoD-family members in the activation of gene expression and in the conversion of fibroblasts into myoblasts. Amongst its in vivo roles, Mef2 is required for both Drosophila muscle development and mammalian muscle regeneration.

The conserved transcription factor Mef2 has multiple roles in adult Drosophila musculature formation.

Muscle is an established paradigm for analysing the cell differentiation programs that underpin the production of specialised tissues during development. These programs are controlled by key transcription factors, and a well-studied regulator of muscle gene expression is the conserved transcription factor Mef2. In vivo, Mef2 is essential for the development of the Drosophila larval musculature: Mef2-null embryos have no differentiated somatic muscle.

The transcription factor Mef2 is required for normal circadian behavior in Drosophila.

The transcription factor Mef2 has well established roles in muscle development in Drosophila and in the differentiation of many cell types in mammals, including neurons. Here, we describe a role for Mef2 in the Drosophila pacemaker neurons that regulate circadian behavioral rhythms. We found that Mef2 is normally produced in all adult clock neurons and that Mef2 overexpression in clock neurons leads to long period and complex rhythms of adult locomotor behavior.

The Him gene inhibits the development of Drosophila flight muscles during metamorphosis.

During Drosophila metamorphosis some larval tissues escape the general histolysis and are remodelled to form adult tissues. One example is the dorso-longitudinal muscles (DLMs) of the indirect flight musculature. They are formed by an intriguing process in which residual larval oblique muscles (LOMs) split and fuse with imaginal myoblasts associated with the wing disc.

mef2 activity levels differentially affect gene expression during Drosophila muscle development.

Cell differentiation is controlled by key transcription factors, and a major question is how they orchestrate cell-type-specific genetic programs. Muscle differentiation is a well studied paradigm in which the conserved Mef2 transcription factor plays a pivotal role. Recent genomic studies have identified a large number of mef2-regulated target genes with distinct temporal expression profiles during Drosophila myogenesis.

The Him gene reveals a balance of inputs controlling muscle differentiation in Drosophila.

Tissue development requires the controlled regulation of cell-differentiation programs. In muscle, the Mef2 transcription factor binds to and activates the expression of many genes and has a major positive role in the orchestration of differentiation. However, little is known about how Mef2 activity is regulated in vivo during development.

Developmental biology: micromanaging muscle growth.

Much remains to be learnt about the in vivo function of specific microRNAs. Recently, the conserved microRNA miR-1 has been found to be essential for Drosophila development. miR-1 mutants die during the rapid larval growth phase with severe muscle defects.

Muscle differentiation: how two cells become one.

A key feature of myogenesis is the fusion of myoblasts to form multinucleate myotubes. Recent work in Drosophila has uncovered a collection of genes that operate at different stages of this process. Some interactions between them have been described that begin to define links from outside the cell via the plasma membrane to the cytoskeleton.

Drosophila development: novel signal elicits visceral response.

A Drosophila screen aimed at furthering understanding of how tissues develop from the mesoderm has identified a novel signalling molecule that is proposed to signal from somatic muscle progenitors to direct the development of adjacent visceral muscle.