title: Chromosomal integrity of freeze-dried mouse spermatozoa after 137Cs gamma-ray irradiation.
abstract: This study demonstrated that freeze-dried mouse spermatozoa possess strong resistance to 137Cs gamma-ray irradiation at doses of up to 8 Gy. Freeze-dried mouse spermatozoa were rehydrated and injected into mouse oocytes with an intracytoplasmic sperm injection (ICSI) technique. Most oocytes can be activated after ICSI by using spermatozoa irradiated with gamma-rays before and after freeze-drying. Sperm chromosome complements were analyzed at the first cleavage metaphase. Chromosome aberrations increased in a dose-dependent manner in the spermatozoa irradiated before freeze-drying. However, no increase in oocytes with chromosome aberrations was observed when fertilized by spermatozoa that had been irradiated after freeze-drying, as compared with freeze-dried spermatozoa that had not been irradiated. These results suggest that both the chromosomal integrity of freeze-dried spermatozoa, as well as their ability to activate oocytes, were protected from gamma-ray irradiation at doses at which chromosomal damage is found to be strongly induced in spermatozoa suspended in solution.
authors.affiliation: Department of Biological Sciences, Asahikawa Medical College, 2-1-1-1 Midorigaoka-higashi, Asahikawa 078-8510, Japan. hkusa55@asahikawa-med.ac.jp
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kusakabe
authors.forename: Yujiroh
authors.initials: Y
authors.lastname: Kamiguchi
mesh_terms: D000818:Animals; D002588:Cesium Radioisotopes / Q000633:toxicity*; D043171:Chromosomal Instability; D005260:Female; D005612:Freeze Drying; D008297:Male; D051379:Mice; D013094:Spermatozoa / Q000528:radiation effects* / Q000648:ultrastructure
chemical_list: D002588:Cesium Radioisotopes