为了进一步探讨外源蜕皮激素（Moulting hormone ，MH）和保幼激素类似物（Juvenile hormone ana-logue ，JHA）处理家蚕的增丝机理，本试验分别于5龄24 h注射植源性MH和5龄72 h注射JHA ，采用半定量RT -PCR方法，测定了蜕皮激素受体（ecdysone receptor ，EcR）（BmEcR-B1型）基因在家蚕5龄不同发育时期在中部丝腺和后部丝腺中表达量的变化。结果表明，正常对照家蚕丝腺中，EcR基因的表达均在5龄前期表达量较低，中后期表达量较高，但丝腺不同部位，表达模式不同。5龄24 h用M H处理后，无论是中部丝腺还是后部丝腺，EcR基因的表达活性与对照组相比，总体上均是先上调后下降；而5龄72 h用J H A处理， EcR基因的表达一直到对照熟蚕前均低于对照区；但两种处理区在对照区熟蚕之后仍有不同程度的表达。说明外源激素可通过影响MH受体基因的表达，从而影响了MH信号转导，进一步影响丝蛋白的合成。%In order to further discuss the increasing silk production mechanism by MH and JHA treatment ,MH and JHA were injected with Bombyx mori ,respectively in the 24h and 72h of the 5th instar in this experiment , RT -PCR technology was used to detect the change of the ecdysone receptor (EcR)(BmEcR-B1)gene expression quantity in the central and posterior silk gland of Bombyx mori at different periods of 5th instar .The results showed in the normal controls ,the expression of ECR gene was lower in the prior period than that in the middle and later periods ,but the expression existed difference in different part of the silk gland with a distinctive expres-sion pattern .After treated with MH in 24h of the 5th instar ,the expression of EcR gene at both the middle and posterior of the silk gland presented the trend of first rising and then falling compared with the control group ;af-ter treated with JHA in 72h of the 5th instar ,EcR gene expression was lower than that in the control area until matured ;different degrees of expressions were observed in two processing areas of the control until matured . These results illustrate that exogenous hormones can affect the MH signal transduction by affecting the expres-sion of MH receptor gene ,and further influence fibroin synthesis .
展开▼
