College of Marine Sciences, Ningbo University, Ningbo, China.
Key Laboratory of Applied Marine Biotechnology, Ningbo University, Ministry of Education, Ningbo, China.
J Fish Biol. 2023 Jul;103(1):59-72. doi: 10.1111/jfb.15413. Epub 2023 May 8.
Photoperiod has a great influence on the growth and ovarian development and maturation of fishes. To analyse the effects of photoperiod on growth and ovarian development of an important marine economic fish, silver pomfret Pampus argenteus, short photoperiod group (L:D = 8:16), control group (L:D = 12:12) and long photoperiod group (L:D = 18:6) were set up for 60 days. The growth performance, ovarian development, changes in hormones and key enzyme activities in the hypothalamic-pituitary-gonadal (HPG) axis and expressions of key regulatory genes in the HPG axis were studied under different photoperiod conditions. The results showed that the final weight gain, body weight index, specific growth rate for weight, specific growth rate for length and average daily growth were the highest in the long photoperiod group, and the feed conversion rate was the lowest. Under long photoperiod condition, gonado-somatic index and hepato-somatic index were higher, ovarian maturity was better and expressions of HPG axis-related regulatory genes foxl2a, foxl2b, cyp19a1a, cyp19a1b, kiss, gpr54-2, gnrh2, fsh and lh were higher. When compared with the other two groups, in the long photoperiod group, the change trend of estradiol (E2) was consistent with those of luteinizing hormone, melatonin (MT) and kisspeptin, and the levels were higher on the 20th and 50th days. These results indicate that prolongation of the photoperiod can improve the growth performance of P. argenteus and promote ovary development and maturation. The authors speculate that photoperiod may regulate the ovarian activity of P. argenteus through MT and kisspeptin/gpr54 signalling pathways. The results show that photoperiod can regulate the ovarian development of P. argenteus, which would help in breaking the seasonal restrictions of animals and regulating an animal's reproductive cycle.
光周期对鱼类的生长和卵巢发育与成熟有很大影响。为分析光周期对银鲳卵巢发育与成熟的影响，设置了短光照组（L:D=8:16）、对照组（L:D=12:12）和长光照组（L:D=18:6），进行 60 天实验。研究了不同光周期条件下银鲳生长性能、卵巢发育、激素变化及下丘脑-垂体-性腺（HPG）轴关键酶活性，以及 HPG 轴关键调控基因的表达。结果表明，长光照组的末重增重率、体重指数、增重特定生长率、全长特定生长率和平均日增重最高，饲料转化率最低。长光照组的性腺指数和肝体指数较高，卵巢成熟度较好，HPG 轴相关调控基因 foxl2a、foxl2b、cyp19a1a、cyp19a1b、kiss、gpr54-2、gnrh2、fsh 和 lh 的表达量较高。与其他两组相比，长光照组雌二醇（E2）的变化趋势与促黄体生成素、褪黑素（MT）和 kisspeptin 一致，第 20 天和第 50 天的水平较高。这些结果表明，延长光周期可以提高银鲳的生长性能，促进卵巢发育和成熟。作者推测，光周期可能通过 MT 和 kisspeptin/gpr54 信号通路调节银鲳的卵巢活动。研究结果表明，光周期可以调节银鲳的卵巢发育，有助于打破动物季节性限制，调节动物的生殖周期。
