Do spermatogonial stem cells have a circadian rhythm?
| Autor: | C. C. Cummings, C. Huckins, E. F. Oakberg, D. G. Gosslee |
|---|---|
| Rok vydání: | 1986 |
| Předmět: |
Male
medicine.medical_specialty Mitotic index Ratón Mitosis Biology Mice Internal medicine medicine Mitotic Index Spermatogonial stem cells Animals Circadian rhythm Cell Differentiation Cell Biology General Medicine Spermatozoa Epithelium Spermatogonia Circadian Rhythm medicine.anatomical_structure Endocrinology Seminiferous Epithelium Stem cell Spermatogenesis |
| Zdroj: | Cell and tissue kinetics. 19(4) |
| ISSN: | 0008-8730 |
| Popis: | Mitotic index was determined in whole mounts of segments of seminiferous tubules of (101 × C3Hf)F1 male mice at 3 hr intervals from 18.00 to 06.00 hours, and at hourly intervals from 08.00 to 16.00 hours. the highest frequency of metaphase-anaphase figures occurred at 10.00 and 11.00 hours, but was not significantly higher than for other times. Injection of 25 μCi 3H-TdR per mouse, followed 24 hr later by exposure to 300 rad X-rays and killing 207 hr after labelling was used to test for circadian rhythm in DNA synthetic activity of the long-cycling A, spermatogonia. No significant effect of time of day was observed. Likewise, the number of undifferentiated spermatogonia scored 183 hr after 300 rad showed no effect of time of day. the testis therefore appears to have no circadian rhythm in mitotic activity. Stage of the cycle of the seminiferous epithelium, however, showed a significant effect on mitotic index of As spermatogonia and on DNA synthetic activity of undifferentiated spermatogonia. These data are compared with those for other organisms and tissues in respect to which properties of stem cells are general for all organisms and tissues and which are specific for spermatogonia. |
| Databáze: | OpenAIRE |
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