Association of mammalian SMC1 and SMC3 proteins with meiotic chromosomes and synaptonemal complexes.
In somatic cells, the heterodimeric Structural Maintenance of Chromosomes (SMC) proteins are involved in chromosome condensation and gene dosage compensation (SMC2 and 4), and sister chromatid cohesion and DNA recombination (SMC1 and 3). We report here evidence for an involvement of mammalian SMC1 and SMC3 proteins in meiosis. Immunofluorescence analysis of testis sections showed intense chromatin association in meiotic prophase cells, weaker staining in round spermatids and absence of the SMC proteins in elongated spermatids. In spermatocyte nuclei spreads, the SMC1 and SMC3 proteins localize in a beaded structure along the axial elements of synaptonemal complexes of pachytene and diplotene chromosomes. Both SMC proteins are present in rat spermatocytes and enriched in preparations of synaptonemal complexes. Several independent experimental approaches revealed interactions of the SMC proteins with synaptonemal complex-specific proteins SCP2 and SCP3. These results suggest a model for the arrangement of SMC proteins in mammalian meiotic chromatin.
Eijpe
M
M
Department of Biomolecular Sciences, Laboratory of Genetics, Wageningen University, NL-6703 HA, Wageningen, The Netherlands.
Heyting
C
C
Gross
B
B
Jessberger
R
R
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D018797:Cell Cycle Proteins / Q000032:analysis / Q000378:metabolism*; D011508:Chondroitin Sulfate Proteoglycans; D002846:Chromatography, Affinity; D002868:Chromosomal Proteins, Non-Histone / Q000032:analysis / Q000378:metabolism*; D002875:Chromosomes / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000032:analysis; D005455:Fluorescent Antibody Technique; D008297:Male; D008322:Mammals; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000032:analysis; D011485:Protein Binding / Q000502:physiology; D051381:Rats; D013090:Spermatocytes / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism*; D013573:Synaptonemal Complex / Q000502:physiology*
D018797:Cell Cycle Proteins; D011508:Chondroitin Sulfate Proteoglycans; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C492316:SMC3 protein, rat; C113093:Sycp2 protein, rat; C085453:Sycp3 protein, rat