单色绿光对鸡胚褪黑激素合成的影响

摘要

本研究旨在探讨单色绿光对鸡胚松果体发育以及褪黑激素合成的影响,为研究单色绿光影响鸡胚发育提供依据,选用120枚质量为(65±3)g的受精鸡胚,随机分为两组,分别在绿光(波长560 nm,光强15 lx)和黑暗条件下孵化,每组设4个重复,每个重复5枚鸡胚,分别在E(胚龄)15、E18和E21取材,探索鸡胚孵化过程中单色绿光对松果体的发育以及褪黑激素合成的影响.结果表明:①孵化期间给予绿光照射,鸡胚质量增加11.19％～21.41％ (P＜0.05);②单色绿光促进松果体小叶发育;③褪黑激素合成关键酶——乙酰基转移酶(AANAT)转录水平的表达随着胚龄的增加而升高,其中黑暗组E21时AANAT mRNA表达较E15和E18时显著高29.84％～47.06％(P＜0.05),但是E15与E18间差异不显著(P＞0.05);而绿光组中,E18 mRNA水平较E15 AANATmRNA的表达显著高17.76％ (P＜0.05),E21时较E15和E18时松果体中AANAT mRNA表达水平显著高26.37％～48.81％ (P＜0.05);并且单色绿光组高于黑暗组12.85％～15.95％ (E18～E21,P＜0.05);④血浆褪黑激素含量随着胚龄的增加而升高,黑暗组E21褪黑激素含量为E15和E18的2.6和1.9倍,绿光组中E21为E15和E18的2.8和1.8倍;在E21和E18,绿光组鸡胚外周血褪黑激素水平高于黑暗组的13.13％和18.20％ (P＜0.05),并且与外周血中生长激素水平极显著正相关(P＜0.001).由此可知,在鸡胚孵化期间给予单色绿光刺激可促进松果体发育以及褪黑激素的合成与释放,进而促进生长激素水平,最终促进鸡胚发育.%To explore the effects of monochromatic green light on chick pineal body development and melatonin secretion,120 chick embryos at weight of 65±3 g were selected and divided them into two groups randomly with one group hatched in monochromatic green light and the other in darkness.Both research groups conducted four repeat,each including five chick embryos,and relative tissue extracted from embryos at the embryonic age (E) of 15th,18th and 21st day,for observation,to fulfill the objective,so as to explore the effects of monochromatic green light.The result exhibits:①Chick embryos with monochromatic green light during incubation period had an increase in birth weight of 11.19％-21.41％ (P＜0.05);(②)Monochromatic green light promoted the development of pineal parenchymal lobules;③Expression of AANAT mRNA,key of melatonin synthesis increased as the embryos developed.Compared with E15 group and E18group form the darkness group,melatonin secretion of E21 group increased obviously by 29.84％-47.06％ (P＜0.05),however,no significant difference between E15 and E18;In green light group,the AANAT mRNA expression of E18 group was significant higher by 17.76％ than that of E15 (P＜0.05),E21 was significant higher by 26.37％-48.81％ than E15 and E18 (P＜0.05);Significant differences were found between green light group and the darkness group,green light group higher by 12.85％-15.95％ than the darkness group (E18-E21,P＜0.05);④Plasma melatonin increased as the embryo developed,in the darkness group,E21 was 2.6 times of E15 and 1.9 times of E18;In green light group,E21 equaled to 2.8 times of E15 and 1.8 times of E18;and for E18 and E21,plasma melatonin of green light group was higher than that of darkness group by 13.13％ and 18.20％ (P＜0.05);Plasma melatonin was associated with plasma growth hormone notably (P＜0.001).Providing monochromatic green light during incubation attributed to chick embryo's growth by promoting the synthesis and secretion of melatonin,and then promoted growth hormone,finally promoted chick embryo's development.