The fine structure of bivalents from golden hamster and house cricket spermatocytes has been studied with a whole mount surface-spreading method combined with negative staining. The elements of the synaptonemal complex show detail of structure which is absent in other preparative procedures. The transverse filaments found in the central region of the synaptonemal complex from both species are s...

Synapsis and chiasma formation have been analyzed at the ultrastructural level in trihaploid wheat with and without chromosome 5B by spreading of microsporocytes. The euhaploids were obtained by anther culture of euhexaploid or monosomic 5B Chinese Spring wheat or from the hexaploid Chinese winter wheat variety Kedong. All three types of euhaploid wheat were virtually achiasmatic. Analysis of 3...

Meiosis is distinguished from mitosis by the way double-strand breaks are made and by the synapsis and segregation of homologous chromosomes. Recent studies with the yeast Saccharomyces cerevisiae have identified some of the key players that link homologous recombination to synaptonemal complex formation.

The relationship between synaptonemal complex formation (synapsis) and double-strand break formation (recombination initiation) differs between organisms. Although double-strand break creation is required for normal synapsis in Saccharomyces cerevisiae and the mouse, it is not necessary for synapsis in Drosophila and Caenorhabditis elegans. To investigate the timing of and requirements for doub...

We have used polyclonal antibodies against fusion proteins produced from cDNA fragments of a meiotic chromosome core protein, Cor1, and a protein present only in the synapsed portions of the cores, Syn1, to detect the occurrence and the locations of these proteins in rodent meiotic prophase chromosomes. The 234 amino acid Cor1 protein is present in early unpaired cores, in the lateral domains o...

Synaptonemal complexes (SCs) are meiosis-specific multiprotein complexes that are essential for synapsis, recombination, and segregation of homologous chromosomes, but the molecular organization of SCs remains unclear. We used immunofluorescence labeling in combination with super-resolution imaging and average position determination to investigate the molecular architecture of SCs. Combination ...

The synaptonemal complex (SC) is involved in the pairing of chromosomes during meiosis. We found that antibodies raised against a protein component (P1) of the mouse synaptonemal complex, mouse SCP1, also identified the SC in human primary spermatocytes. Biopsies from 18 men presented with infertility were evaluated by light-field microscopy and grouped into five categories: normal spermatogene...

In budding yeast, absence of the meiosis-specific Zip3 protein (also known as Cst9) causes synaptonemal complex formation to be delayed and incomplete. The Zip3 protein colocalizes with Zip2 at discrete foci on meiotic chromosomes, corresponding to the sites where synapsis initiates. Observations suggest that Zip3 promotes synapsis by recruiting the Zip2 protein to chromosomes and/or stabilizin...

Although in Saccharomyces cerevisiae the initiation of meiotic recombination, as indicated by double-strand break formation, appears to be functionally linked to the initiation of synapsis, meiotic chromosome synapsis in Drosophila females occurs in the absence of meiotic exchange. Electron microscopy of oocytes from females homozygous for either of two meiotic mutants (mei-W68 and mei-P22), wh...