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| Titel: |
Cytological studies of the pineal in relation to the annual cycles in the testis and climatological variables of free-living roseringed parakeets (Psittacula krameri) |
| Auteur: |
Maitra, Saumen Kumar Dey, Mamata |
| Verschenen in: |
Biological rhythm research |
| Paginering: | Jaargang 24 (1993) nr. 1 pagina's 43-55 |
| Jaar: |
1993-02 |
| Inhoud: |
Cytological studies of the pineal and the testes in free-living roseringed parakeets (Psittacula krameri) show that the activities of both organs undergo definite annual changes. The features of hyperactivity of pinealocytes were noted during the months of April through September, after which a gradual loss of the signs of cellular activity occurred till March, when the pineal appeared to be highly regressed, followed by an abrupt change in the opposite direction in April to repeat the cycle. On the other hand, studies of the testes indicated that the species attains maximum testicular maturation during March, after which sudden regression occurs and the testes remain in the quiescent state till September when recovery of spermatogenesis takes place and steady growth and development towards the annual peak follow. A significant negative correlation was found between the seasonal values for nuclear diameter of the pinealocytes and each of the studied parameters of testes. Among the considered climatological variables, the duration of light or photoperiod length appeared to be positively correlated with the karyometric values of pinealocytes during each annual cycle. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 2 van 9 gevonden artikelen
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