The Orientation Behavior Of Mythimna Separata(Walker) And The Functional Verification Of Related Gene Cry2 And MagR

Orientation is the phenomenon that insects adjust their attitude and space position with the help of internal and external signals to get to the destination accurately.Each year,the Mythimna separata migrate to the north of China and back to the south,which have a wide range of diseases,and cause a lot of damage.However,there are only a few speculations about the wind orientation and magnetic field orientation.The previous study about the biological learning of the armyworms found that the flight was taken at night,so there was inference of the magnetic orientation.In order to define whether the armyworm use the magnetic field for orientation and the molecular mechanism of magnetic orientation,the research of the armyworm directional signal source,directional gene sequence analysis,spatiotemporal expression and functional verification are based on the directional fly,RT-PCR and RNAi.The results as follow: 1.The flight orientation rules of the indoor/field armyworm population are clarified.In order to explore the flight orientation rules of armyworm,the experiment uses a small and medium insect flight directional simulation device to compare the orienting behavior of different armyworm populations.We find that the migrants armyworm have group orientation behavior,and the directional angle is 70.3°,total directional vector length is 0.70.However,there is no obvious directional behavior in residents armyworm.The north moved armyworm populations of Jiang Yan,Jiang Su province and Luo He,He Nan province tend to northeast orientation,and the orientation angle is 60.3° and 54.8° respectively,the total directional vector length are 0.59 and 0.58 respectively,and the armyworm lose orientation ability after landing in Gong Zhuling Ji Lin province.The returned armyworm populations of Gong Zhuling Ji Lin province and Luan Xian,He Bei province tend to south orientation,and the orientation angle is 267.0° and 275° respectively,the total directional vector length are 0.73 and 0.64 respectively.The experimental results of these five points are consistent with the ideal image of the armyworm migration in the eastern half of China.The study further proves that the worm is most likely to use the geomagnetic field for orientation.2.The spatiotemporal expression pattern of the gene Cry2 and MagR is defined.The spatiotemporal expression of Cry2 and MagR gene find that the expression patterns of Cry2 and MagR gene in both male and female adult are same.Cry2 and MagR genes are common high expression in the head and thorax of the armyworm.Cry2 and MagR genes have a certain consistency in expression time.The Cry2 and MagR gene's expression of armyworm in the two parts are consistent in time and space,and 1 days of age expression quantity is low,and 1 day age expression quantity is low,and 3 days of age begin to express quantity to rise sharply,which is consistent with the behavior that the armyworm begin to migrate at 2-3 days of age.The results of spatiotemporal expression indicate that the receptor for the magnetic field may be in the thorax or head,suggesting that the Cry2 and MagR genes may be related to the orientation of the armyworm.At the same time,there may be a stick magnetic induction complex that is similar to the fruit fly which is made up with cryptochrome and magnetic receptors.3.RNA interference was used to identify the function of Cry2 and MagR genes.The RNA interference results showed that after the injection of siRNA fragments,the mucous parasite lost its directional ability,while the injection water and the NCS were still able to be directed.The results showed that Cry2 and MagR gene had a certain relationship with the orienteal function,and further experimental verification was needed.It is carried out at night and can reach the destination accurately.There must be stable directional signals that can be used,and the most stable directional signals at night are only magnetic fields.The experimental results show that the worm is orientated by using geomagnetic field.The experimental results of RNA interference preliminarily prove that the adhesive USES magnetic field orientation,but it needs further verification.