Asterless is a centriolar protein required for centrosome function and embryo development in Drosophila

Area of Science:

• Cell Biology
• Molecular Biology
• Developmental Biology

Background:

• Centrosomes organize the microtubule network and are composed of centrioles and pericentriolar material (PCM).
• PCM stabilization at the centrosome is centriole-dependent, but centriolar proteins remain poorly characterized.
• Few centriolar proteins identified in Drosophila are linked to centriole duplication.

Purpose of the Study:

• To identify and characterize novel proteins involved in Drosophila centriole composition and function.
• To investigate the role of the asterless (asl) gene in centrosome biology and embryonic development.

Main Methods:

• Cloning of the asterless (asl) gene.
• Analysis of Asl protein localization and function.
• Phenotypic analysis of asl-deficient Drosophila embryos.

Main Results:

• The asterless (asl) gene encodes a 120 kD coiled-coil protein, a constitutive component of centrioles and basal bodies.
• Loss of asl function impairs pericentriolar material stabilization at the centrosome.
• Embryos lacking Asl function exhibit developmental arrest immediately after fertilization.
• Asl shows homology to human CEP152, a centrosome component with unknown function.

Conclusions:

• The cloning of asterless provides new insights into the molecular makeup of Drosophila centrioles and suggests a model for its human homolog's function.
• The phenotype of asl-deficient flies underscores the critical requirement of a functional centrosome for Drosophila embryonic development.