Stage-specific damage to synaptonemal complexes and metaphase chromosomes induced by X rays in male mouse germ cells

Technical Report · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5733284

Backer, L C; Sontag, M R; Allen, J W

Synaptonemal complexes (SCs) reveal mutagen-induced effects in germ cell meiotic chromosomes. The study was aimed at characterizing relationships between SC and metaphase I chromosome damage following radiation exposure at various stages of spermatogenesis. Male mice were irradiated with doses of 0, 2, or 4 Gy, and spermatocytes were harvested at times consistent with earlier exposures as spermatogonial stem cells, preleptotene cells (premeiotic DNA synthesis), or meiotic prophase cells. After stem-cell exposure, twice as many rearrangements were observed in SCs as in metaphase I chromosomes. Irradiation during premeiotic DNA synthesis resulted in dose-related increases in SC breakage and rearrangements (including novel forms) and in metaphase chromosomal aberrations. Following prophase exposure, various types and levels of SC and metaphase damage were observed. Irradiation of zygotene cells led to high frequencies of chromosome multivalents in metaphase I without a correspondingly high level of damage in preceding prophase SCs. Thus, irradiation of premeiotic and meiotic cells results in variable relationships between SC and metaphase chromosome damage.

• Research Organization: Environmental Health Research and Testing, Inc., Research Triangle Park, NC (USA)
• OSTI ID: 5733284
• Report Number(s): PB-91-182238/XAB; CNN: EPA-68-01-4456
• Country of Publication: United States
• Language: English

Related Subjects

560120* -- Radiation Effects on Biochemicals
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CELL CYCLE
CHROMOSOMAL ABERRATIONS
DNA REPLICATION
DOSES
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
GERM CELLS
IONIZING RADIATIONS
MAMMALS
MICE
MICROSCOPY
MUTAGENESIS
MUTATIONS
NUCLEIC ACID REPLICATION
RADIATION DOSES
RADIATION EFFECTS
RADIATIONS
RADIOINDUCTION
RODENTS
SPERMATOCYTES
VERTEBRATES
X RADIATION