不同饲育方式对家蚕产卵量及卵黄蛋白相关基因表达的影响

Effects of Different Feeding Modes on Egg Production and Expression of Yolk Protein Related Genes in Bombyx mori

为探究人工饲料与桑叶不同搭配饲育方式对家蚕产卵情况及卵黄蛋白相关基因表达的影响,本研究采用全龄桑叶育(Mul1-5)、1~2龄人工饲料育+3~5龄桑叶育(Art1-2)、1~3龄人工饲料育+4~5龄桑叶育(Art1-3)、1~4龄人工饲料育+5龄桑叶育(Art1-4)4种饲育方式饲养菁松×皓月,调查不同饲育方式下的造卵量、产卵量、百粒卵重及卵黄蛋白基因Vg、30Kc19、ESP、VgR的表达情况。结果表明,Mul1-5的24 h产卵量、造卵量及百粒卵重均最高,造卵数量和百粒卵重都随人工饲料饲喂龄期延长呈现下降趋势;Mul1-5和Art1-2的造卵量显著高于Art1-3和Art1-4,Mul1-5的百粒卵重显著高于其他3个组合。利用荧光定量PCR方法测定了4种饲育方式下卵黄蛋白相关基因的表达情况,结果显示,Vg从5龄第7天开始到整个蛹期结束持续表达,整体表现为Art1-3的表达量最高,Art1-2的次之,Art1-4的最低;30Kc19在5龄第7天及上蔟第1天表达量较高,并分别以Art1-2和Art1-3方式下最高,蛹期基本不表达;ESP和VgR在整个蛹期都有表达,但以第5~8天的表达量较高,且第5~7天以Art1-4的最高,第8天以Art1-3的最高。综合来看,人工饲料育替代桑叶育的龄期越长,家蚕产卵数量和百粒卵重下降越明显,卵黄蛋白相关基因的表达受影响越大,这可能与人工饲料的配方、家蚕对人工饲料的吸收利用程度及人工饲料育后家蚕的体质有关,具体影响机制还需进一步研究。

In order to explore the effects of different feeding modes with artificial diet and mulberry leav-es on egg production and expression of yolk protein related genes of silkworm(Bombyx mori),Jingsong×Haoyue was raised by four feeding modes including reared with mulberry leaves for all instars(Mul1-5),reared with artificial diet for the 1st and 2nd instars and mulberry leaves for the 3th to 5th instars(Art1-2),reared with artificial diet for the 1st to 3th instars and mulberry leaves for the 4th and 5th instars(Art1-3),reared with artificial diet for the 1st to 4th instars and mulberry leaves for the 5th instar(Art1-4).The total egg amount,egg laying amount,100-egg weight and the expression of Vg,30Kc19,ESP and VgR genes under dif-ferent feeding modes were investigated.The results showed that Mul1-5 had the highest egg laying amount in 24 hours,total egg amount and 100-egg weight,and the total egg amount and 100-egg weight showed down-ward trends with the extension of feeding time with artificial diet.The total egg amount of Mul1-5 and Art1-2 was significantly higher than that of Art1-3 and Art1-4,and the 100-egg weight of Mul1-5 was significantly higher than that of the other three combinations.The expression of yolk protein related genes under the four feeding modes was measured by fluorescence quantitative PCR method.The results showed that Vg continuous-ly expressed from the 7th day of the 5th instar to the whole pupal stage,generally showing the highest expres-sion in Art1-3,the second in Art1-2,and the lowest in Art1-4.The expression of 30Kc19 was higher on the 7th day of the 5th instar and the 1st day of wandering stage,and was the highest in Art1-2 and Art1-3,respec-tively;but it almost did not express at the whole pupal stage.ESP and VgR expressed at the whole pupal stage,especially from the 5th to 8th day;their expression level was the highest in Art1-4 from the 5th to 7th day and in Art1-3 on the 8th day.In conclusion,the longer instar that the artificial diet replaced mulberry leaves,the more obviously the egg laying amount and 100-egg weight decreased,and also the influence to the expression of yolk protein related genes.These results might be caused by the formula of artificial diet,absorp-tion and utilization of silkworm to artificial diet and silkworm constitution after fed with artificial diet,but the mechanisms need further research.