Drosophila Spd-2 recruits PCM to the sperm centriole, but is dispensable for centriole duplication.
In C. elegans, genome-wide screens have identified just five essential centriole-duplication factors: SPD-2, ZYG-1, SAS-5, SAS-6, and SAS-4 [1-8]. These proteins are widely believed to comprise a conserved core duplication module [3, 9-14]. In worm embryos, SPD-2 is the most upstream component of this module, and it is also essential for pericentriolar material (PCM) recruitment to the centrioles [1, 4, 15, 16]. Here, we show that Drosophila Spd-2 (DSpd-2) is a component of both the centrioles and the PCM and has a role in recruiting PCM to the centrioles. DSpd-2 appears not, however, to be essential for centriole duplication in somatic cells. Moreover, PCM recruitment in DSpd-2 mutant somatic cells is only partially compromised, and mitosis appears unperturbed. In contrast, DSpd-2 is essential for proper PCM recruitment to the fertilizing sperm centriole, and hence for microtubule nucleation and pronuclear fusion. DSpd-2 therefore appears to have a particularly important role in recruiting PCM to the sperm centriole. We speculate that the SPD-2 family of proteins might only be absolutely essential for the recruitment of centriole duplication factors and PCM to the centriole(s) that enter the egg with the fertilizing sperm.
Dix
Carly I
CI
The Gurdon Institute, Tennis Court Road, Cambridge CB2 1QN, United Kingdom.
Raff
Jordan W
JW
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D002502:Centrioles / Q000378:metabolism*; D004330:Drosophila / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D005306:Fertilization / Q000502:physiology; D008297:Male; D008540:Meiosis / Q000502:physiology; D008938:Mitosis / Q000502:physiology; D013094:Spermatozoa / Q000378:metabolism* / Q000648:ultrastructure
D029742:Caenorhabditis elegans Proteins; D029721:Drosophila Proteins; C486131:SPD-2 protein, C elegans