Changes in germ cell population in young and adult female mice from two inbred strains: CBA/Kw and KE.
Female mice from two inbred strains CBA/Kw and KE differ markedly in fertility. The gametes of females from KE strain are of poorer quality than those of CBA/Kw. We analyzed the number of oocytes per ovary in KE and CBA/Kw mice aged 5, 25, 90, 180 and 360 days. The ovaries were dissected and processed according to the routine histological methods. In case of five-day-old females we used a modified distributed point counting method while in order to examine the gonads of older females, the nucleoli counting method was applied. In general, we observed gradual decrease in germ cell number throughout the whole life of females from both strains. The noticeable wave of oocyte loss occurs between 5th and 25th days of life. The mice from KE inbred strain on day 25th (1650 +/- 322 vs. 1140 +/- 210) and 90(th) (1040 +/- 211 vs. 692 +/- 89) days have significantly (p<0.005) more germ cells than the females from CBA/Kw strain. In older females the differences were not statistically significant. Interestingly, CBA/Kw females were found to have more rapid loss of primordial follicles throughout their lives. This can explain their shortened reproductive lifespan which was observed earlier.
Szot
Maria
M
Department of Genetics and Evolution, Institute of Zoology, Jagiellonian University, Ingardena 6, 30-060 Kraków, Poland. szot@zuk.iz.uj.edu.pl
Baran
Katarzyna
K
Czech
Urszula
U
Styrna
Józefa
J
D000818:Animals; D001835:Body Weight; D002452:Cell Count; D005260:Female; D005298:Fertility / Q000502:physiology*; D007247:Infertility, Female / Q000473:pathology* / Q000503:physiopathology*; D051379:Mice; D008808:Mice, Inbred CBA; D009865:Oocytes / Q000166:cytology* / Q000502:physiology*; D009929:Organ Size; D006080:Ovarian Follicle / Q000473:pathology / Q000503:physiopathology; D013045:Species Specificity