Melatonin increases the number of atretic
follicles in mice (35).
Ciliated pithelium can be observed in the spawning ducts with postvitellogenic, and degenerating oocytes (overmaturated and atretic
oocytes) The area occupied by the gonad is usually smaller compared with the early spawned stage.
05) increases in the mean number of atretic
follicles on days 7, 14 and 28 in both treatment groups in comparison with the controls.
Few ovaries containing vitellogenic oocytes (excluding the samples with atretic
oocytes) were observed in January, February, and November.
These consequences include 1) considerable follicular shrinkage (Witthames and Greer-Walker, 1987), 2) likely loss of atretic
follicles and POFs (Klibansky and Juanes, 2007), and 3) incompatibility with histological methods (Hunter and Macewicz, 2003).
The highest fractions of atretic
vitellogenic oocytes occurred in females with oocytes in early stages of vitellogenesis.
This hypothesis was supported when we found both oil droplet oocytes and atretic
advanced-stage oocytes in the spent ovaries of nine specimens collected in 1993 (Fig.
On the other hand, late atretic
pre-ovulatory follicles separate from the epithelium and concentrate medially in the lamellae--a pattern that has also been observed in other fish species such as striped mullet (Mugil cephalus) (McDonough et al.
However, because 1) all postspawning females had POFs present and 2) there were no females that had atretic
yolked oocytes without POFs, it is unlikely that mature females were misclassified as immature in this study.
Granulomatous inflammation and fibrosis occurred in association with dead worms and, occasionally, atretic
ovaries were found in all age classes, and resting females were found in every age class except age 0 (Fig.
New POFs are easily identifiable, but those that have degenerated are difficult to distinguish from atretic
Ovulation is infrequent and follicular development abnormal, often resulting in a higher percentage of atretic
, or degenerating follicles.
follicles count for the higher-dose rats was significantly increased (P<0.
Furthermore, the number of corpus lutea and atretic
follicles were significantly higher in groups B and C (p<0.