SYP-3 restricts synaptonemal complex assembly to bridge paired chromosome axes during meiosis in Caenorhabditis elegans.
Synaptonemal complex (SC) formation must be regulated to occur only between aligned pairs of homologous chromosomes, ultimately ensuring proper chromosome segregation in meiosis. Here we identify SYP-3, a coiled-coil protein that is required for assembly of the central region of the SC and for restricting its loading to occur only in an appropriate context, forming structures that bridge the axes of paired meiotic chromosomes in Caenorhabditis elegans. We find that inappropriate loading of central region proteins interferes with homolog pairing, likely by triggering a premature change in chromosome configuration during early prophase that terminates the search for homologs. As a result, syp-3 mutants lack chiasmata and exhibit increased chromosome mis-segregation. Altogether, our studies lead us to propose that SYP-3 regulates synapsis along chromosomes, contributing to meiotic progression in early prophase.
Smolikov
Sarit
S
Department of Genetics, Harvard Medical School, Boston, MA 02115, USA.
Eizinger
Andreas
A
Schild-Prufert
Kristina
K
Hurlburt
Allison
A
McDonald
Kent
K
Engebrecht
JoAnne
J
Villeneuve
Anne M
AM
Colaiácovo
Mónica P
MP
D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000502:physiology* / Q000648:ultrastructure; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000502:physiology*; D023902:Chromosome Pairing / Q000235:genetics / Q000502:physiology; D020090:Chromosome Segregation / Q000235:genetics / Q000502:physiology; D017931:DNA Primers / Q000235:genetics; D018509:DNA, Helminth / Q000235:genetics; D017238:Genes, Helminth; D008540:Meiosis / Q000235:genetics / Q000502:physiology; D008957:Models, Genetic; D009154:Mutation; D013573:Synaptonemal Complex / Q000235:genetics* / Q000502:physiology* / Q000648:ultrastructure
D029742:Caenorhabditis elegans Proteins; D017931:DNA Primers; D018509:DNA, Helminth