Ariadne-1: a vital Drosophila gene is required in development and defines a new conserved family of ring-finger proteins.

We report the identification and functional characterization of ariadne-1 (ari-1), a novel and vital Drosophila gene required for the correct differentiation of most cell types in the adult organism. Also, we identify a sequence-related gene, ari-2, and the corresponding mouse and human homologues of both genes. All these sequences define a new protein family by the Acid-rich, RING finger, B-box, RING finger, coiled-coil (ARBRCC) motif string.

Presynaptic calcium-channel currents in normal and csp mutant Drosophila peptidergic terminals.

The study of regulated vesicle exocytosis, which underlies neurotransmitter and neuropeptide release, has benefited from a convergence of several independent approaches. These include the use of genetically tractable organisms and model preparations that allow a direct characterization of presynaptic ionic currents. Aiming for a comprehensive analysis of release, we had already developed a Drosophila preparation in which electrophysiological recordings from peptidergic terminals are feasible.

Presynaptic recordings from Drosophila: correlation of macroscopic and single-channel K+ currents.

We have performed direct electrophysiological recordings from Drosophila peptidergic synaptic boutons in situ, taking advantage of a mutation, ecdysone, which causes an increase in size of these terminals. Using patch-clamp techniques, we have analyzed voltage-dependent potassium currents at the macroscopic and single-channel level. The synaptic membrane contained at least two distinct voltage-activated potassium currents with different kinetics and voltage sensitivity: an IA-like current with fast activation and inactivation kinetics and voltage-dependent steady-state inactivation; a complex delayed current that includes a slowly inactivating component, resembling the IK described in other preparations; and a noninactivating component.

Angiotensinogen-like epitopes are present in the CNS of Aplysia california and co-localize with urotensin I- and urotensin II-like immunoreactivities in the cerebral ganglia.

Immunohistochemistry was used to demonstrate urotensin I (UI), urotensin II (UII), and angiotensinogen (Ao)-like immunoreactivities (ir) in the CNS of Aplysia californica. The fish UI is a 41 amino acid peptide that has 50% identity with mammalian corticotropin-releasing factor (CRF). Identity also exists between UI and angiotensinogen in a tetrapeptide at the N-terminus.