Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
Gen Comp Endocrinol. 2019 Aug 1;279:114-119. doi: 10.1016/j.ygcen.2019.02.012. Epub 2019 Feb 11.
Authors have recently reported a gradual increase in neuropeptide Y expression in the ovarian follicles of Clarias batrachus with the progression of oogenesis, coinciding with increasing photoperiod and temperature. This indicates the involvement of photoperiod and temperature in controlling NPY expression. Therefore, a study was designed to investigate the role of photoperiod and temperature in regulation of NPY expression in ovarian follicles. The catfish were exposed to different photo-thermal regimes during the late-quiescence and late-recrudescence phases for one month, and the expression of NPY was analyzed along with other ovarian activities. Though the exposure of catfish to long photoperiod induced a marginal increase (1.5 fold) in NPY expression in follicular cells, the high temperature stimulated its expression more effectively (6-10 fold), irrespective of photoperiodic exposures. Exposure to long photoperiod and high temperature together induced NPY expression maximally in granulosa and thecal cells of fully grown oocytes, but exposure to low temperature decreased its expression significantly. The oogenic and steroidogenic activities were also promoted simultaneously after the exposure to high temperature and long photoperiod alone or in combination. However, the low temperature exposure suppressed the ovarian activities leading to atresia of advanced follicles. Thus it is suggested that photoperiod and temperature both affect NPY expression and ovarian recrudescence in fish but the influences of temperature seem to be more prominent.
作者最近报道，随着卵母细胞发生的进行，爪蟾卵巢滤泡中的神经肽 Y 表达逐渐增加，这与光照时间和温度的增加相一致。这表明光照时间和温度参与了对 NPY 表达的控制。因此，设计了一项研究来调查光照时间和温度在调节卵巢滤泡中 NPY 表达中的作用。在晚期静止期和晚期复苏期，将鲶鱼暴露于不同的光热条件下一个月，并分析 NPY 表达以及其他卵巢活动。尽管鲶鱼暴露于长光照时间仅引起滤泡细胞中 NPY 表达的轻微增加（1.5 倍），但高温更有效地刺激其表达（6-10 倍），而与光照时间无关。长时间光照和高温共同诱导完全生长卵母细胞的颗粒细胞和膜细胞中 NPY 表达最大化，但低温显著降低其表达。在单独或组合暴露于高温和长光照时间后，卵发生和类固醇生成活性也同时得到促进。然而，低温暴露抑制了卵巢活动，导致晚期滤泡的闭锁。因此，建议光照时间和温度都会影响鱼类的 NPY 表达和卵巢复苏，但温度的影响似乎更为突出。
