Synaptonemal Complex Components Are Required for Meiotic Checkpoint Function in Caenorhabditis elegans.
Synapsis involves the assembly of a proteinaceous structure, the synaptonemal complex (SC), between paired homologous chromosomes, and is essential for proper meiotic chromosome segregation. In Caenorhabditis elegans, the synapsis checkpoint selectively removes nuclei with unsynapsed chromosomes by inducing apoptosis. This checkpoint depends on pairing centers (PCs), cis-acting sites that promote pairing and synapsis. We have hypothesized that the stability of homolog pairing at PCs is monitored by this checkpoint. Here, we report that SC components SYP-3, HTP-3, HIM-3, and HTP-1 are required for a functional synapsis checkpoint. Mutation of these components does not abolish PC function, demonstrating they are bona fide checkpoint components. Further, we identify mutant backgrounds in which the instability of homolog pairing at PCs does not correlate with the synapsis checkpoint response. Altogether, these data suggest that, in addition to homolog pairing, SC assembly may be monitored by the synapsis checkpoint.
Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064.
Tisha
T
Bohr
Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064.
Guinevere
G
Ashley
Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064.
Evan
E
Eggleston
Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064.
Kyra
K
Firestone
Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, California 95064 nbhalla@ucsc.edu.
Needhi
N
Bhalla
D000818:Animals; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D023902:Chromosome Pairing; D008540:Meiosis; D009154:Mutation; D013573:Synaptonemal Complex / Q000235:genetics / Q000378:metabolism*
D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; C121599:HIM-3 protein, C elegans; C527587:HTP-3 protein, C elegans; C506262:Htp-1 protein, C elegans; C545959:SYP-3 protein, C elegans
checkpoint; chromosome; meiosis; synapsis; synaptonemal complex