Xenin: the oldest after insulin?

Xenin is a regulatory peptide first isolated from the human gastric mucosa. Using an open-access protein database MEDLINE (33 million molecules; 11 billion amino acid residues) and our original computer program, we conducted a search for the xenin motifs in the primary structure of proteins across almost the entire taxonomic range of evolution. Motifs with 40% homology to human xenin are already present in prokaryotes.

Biogenic Amines in Insect Antennae.

Insect antenna is a multisensory organ, each modality of which can be modulated by biogenic amines. Octopamine (OA) and its metabolic precursor tyramine (TA) affect activity of antennal olfactory receptor neurons. There is some evidence that dopamine (DA) modulates gustatory neurons.

Drosophila Hook-Related Protein (Girdin) Is Essential for Sensory Dendrite Formation.

The dendrite of the sensory neuron is surrounded by support cells and is composed of two specialized compartments: the inner segment and the sensory cilium. How the sensory dendrite is formed and maintained is not well understood. Hook-related proteins (HkRP) like Girdin, DAPLE, and Gipie are actin-binding proteins, implicated in actin organization and in cell motility.

A migrating ciliary gate compartmentalizes the site of axoneme assembly in Drosophila spermatids.

Background: In most cells, the cilium is formed within a compartment separated from the cytoplasm. Entry into the ciliary compartment is regulated by a specialized gate located at the base of the cilium in a region known as the transition zone. The transition zone is closely associated with multiple structures of the ciliary base, including the centriole, axoneme, and ciliary membrane.

A proximal centriole-like structure is present in Drosophila spermatids and can serve as a model to study centriole duplication.

Most animals have two centrioles in spermatids (the distal and proximal centrioles), but insect spermatids seem to contain only one centriole (Fuller 1993), which functionally resembles the distal centriole. Using fluorescent centriolar markers, we identified a structure near the fly distal centriole that is reminiscent of a proximal centriole (i.e.