title: Genetic and molecular characterization of the caenorhabditis elegans gene, mel-26, a postmeiotic negative regulator of mei-1, a meiotic-specific spindle component.
abstract: We have previously described the gene mei-1, which encodes an essential component of the Caenorhabditis elegans meiotic spindle. When ectopically expressed after the completion of meiosis, mei-1 protein disrupts the function of the mitotic cleavage spindles. In this article, we describe the cloning and the further genetic characterization of mel-26, a postmeiotic negative regulator of mei-1. mel-26 was originally identified by a gain-of-function mutation. We have reverted this mutation to a loss-of-function allele, which has recessive phenotypes identical to the dominant defects of its gain-of-function parent. Both the dominant and recessive mutations of mel-26 result in mei-1 protein ectopically localized in mitotic spindles and centrosomes, leading to small and misoriented cleavage spindles. The loss-of-function mutation was used to clone mel-26 by transformation rescue. As suggested by genetic results indicating that mel-26 is required only maternally, mel-26 mRNA was expressed predominantly in the female germline. The gene encodes a protein that includes the BTB motif, which is thought to play a role in protein-protein interactions.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
authors.forename: M R
authors.initials: MR
authors.lastname: Dow
authors.forename: P E
authors.initials: PE
authors.lastname: Mains
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000251:Adenosine Triphosphatases / Q000235:genetics*; D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000235:genetics*; D005799:Genes, Dominant; D017238:Genes, Helminth; D005808:Genes, Recessive; D015801:Helminth Proteins / Q000235:genetics*; D008540:Meiosis / Q000235:genetics*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D017386:Sequence Homology, Amino Acid
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D015801:Helminth Proteins; C114960:Mel-26 protein, C elegans; D012333:RNA, Messenger; D000251:Adenosine Triphosphatases; C086678:MEI-1 protein, C elegans