A genome-wide analysis reveals that the Drosophila transcription factor Lola promotes axon growth in part by suppressing expression of the actin nucleation factor Spire.

Background: The phylogenetically conserved transcription factor Lola is essential for many aspects of axon growth and guidance, synapse formation and neural circuit development in Drosophila. To date it has been difficult, however, to obtain an overall view of Lola functions and mechanisms.

Results: We use expression microarrays to identify the lola-dependent transcriptome in the Drosophila embryo.

Alternative splicing of lola generates 19 transcription factors controlling axon guidance in Drosophila.

The Drosophila melanogaster transcription factor Lola (longitudinals lacking) is a pivotal regulator of neural wiring that sets the precise expression levels of proteins that execute specific axon guidance decisions. Lola has a zinc finger DNA binding domain and a BTB (for Broad-complex, Tramtrack and Bric a brac) dimerization motif. We now show that alternative splicing of the lola gene creates a family of 19 transcription factors.

Notch steers Drosophila ISNb motor axons by regulating the Abl signaling pathway.

The central problem in axon guidance is to understand how guidance signals interact to determine where an axon will grow. Here we investigate a specific axon guidance decision in Drosophila embryos, the sharp inward turn taken by the ISNb motor nerve to approach its muscle targets. We find that this turn requires Notch and its ligand Delta.

Dry to wet weight biomass conversion constant for Tetrahymena elliotti (Ciliophora, Protozoa).

The wet and dry weights of both axenic and monoxenic cultures of the ciliate Tetrahymena were determined directly. These estimates are dependent upon the method of volume determination. Assuming a prolate spheroidal shape for the ciliate, we calculate a mean wet weight of 0.