Differential distribution and association of repeat DNA sequences in the lateral element of the synaptonemal complex in rat spermatocytes.
The synaptonemal complex (SC) is an evolutionarily conserved structure that mediates synapsis of homologous chromosomes during meiotic prophase I. Previous studies have established that the chromatin of homologous chromosomes is organized in loops that are attached to the lateral elements (LEs) of the SC. The characterization of the genomic sequences associated with LEs of the SC represents an important step toward understanding meiotic chromosome organization and function. To isolate these genomic sequences, we performed chromatin immunoprecipitation assays in rat spermatocytes using an antibody against SYCP3, a major structural component of the LEs of the SC. Our results demonstrated the reproducible and exclusive isolation of repeat deoxyribonucleic acid (DNA) sequences, in particular long interspersed elements, short interspersed elements, long terminal direct repeats, satellite, and simple repeats. The association of these repeat sequences to the LEs of the SC was confirmed by in situ hybridization of meiotic nuclei shown by both light and electron microscopy. Signals were also detected over the chromatin surrounding SCs and in small loops protruding from the lateral elements into the SC central region. We propose that genomic repeat DNA sequences play a key role in anchoring the chromosome to the protein scaffold of the SC.
Hernández-Hernández
Abrahan
A
Laboratorio de Microscopia Electrónica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, México, DF, CP 04510, México.
Rincón-Arano
Héctor
H
Recillas-Targa
Félix
F
Ortiz
Rosario
R
Valdes-Quezada
Christian
C
Echeverría
Olga M
OM
Benavente
Ricardo
R
Vázquez-Nin
Gerardo H
GH
D000818:Animals; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers; D004268:DNA-Binding Proteins; D016678:Genome; D017403:In Situ Hybridization; D017404:In Situ Hybridization, Fluorescence; D020084:Long Interspersed Nucleotide Elements / Q000502:physiology*; D008297:Male; D049469:Meiotic Prophase I / Q000235:genetics; D009687:Nuclear Proteins / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012091:Repetitive Sequences, Nucleic Acid / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020086:Short Interspersed Nucleotide Elements / Q000502:physiology*; D013090:Spermatocytes / Q000502:physiology*; D013573:Synaptonemal Complex / Q000235:genetics* / Q000648:ultrastructure; D020079:Terminal Repeat Sequences / Q000502:physiology*
D002843:Chromatin; D017931:DNA Primers; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; C085453:Sycp3 protein, rat