Premium
Fluorescent in situ hybridization of the telomere repeat sequence in hamster sperm nuclear structures
Author(s) -
de Lara Jocelyn,
Wydner Karen L.,
Hyland Katherine M.,
Ward W. Steven
Publication year - 1993
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240530306
Subject(s) - telomere , in situ hybridization , in situ , biology , sperm , hamster , sequence (biology) , fluorescence in situ hybridization , genetics , microbiology and biotechnology , dna , chemistry , gene , gene expression , organic chemistry , chromosome
The flat, hooked‐shaped architecture of the hamster sperm nucleus makes this an excellent model for in situ hybridization studies of the three dimensional structure of the genome. We have examined the structure of the telomere repeat sequence (TTAGGG) n with respect to the various nuclear structures present in hamster spermatozoa, using fluorescent in situ hybridization. In fully condensed, mature sperm nuclei, the telomere sequences appeared as discrete spots of various sizes interspersed throughout the volume of the nuclei. While the pattern of these signals was non‐random, it varied significantly in different nuclei. These discrete telomere foci were seen to gradually lengthen into linear, beaded signals as sperm nuclei were decondensed, in vitro, and were not associated with the nuclear annulus. We also examined the relationship of telomeres to the sperm nuclear matrix, a residual nuclear structure that retains the original size and shape of the nucleus. In these structures the DNA extends beyond the perimeter of the nucleus to form a halo around it, representing the arrangement of the chromosomal DNA into loop domains attached at their bases to the nuclear matrix. Telomere signals in these structures were also linear and equal in length to those of the decondensed nuclei, and each signal represented part of a single DNA loop domain. The telomeres were attached at one end to the nuclear matrix and extended into the halo. Sperm nuclear matrices treated with Eco RI retained the telomere signals. These data support sperm DNA packaging models in which DNA is coiled into discrete foci, rather than spread out linearly along the length of the sperm nucleus.