Analyses For Development Phenotypes And Transcriptomes Of Small Brown Planthopper Under The Near-zero Magnetic Field

Insects,as being the largest animal group on the earth,are interacting with their surrounding environment for adaptive selection of their fitness,which is precisely the main study topics of Insect Ecology.The magnetic fields,as being an easily neglected but ubiquitous abiotic factor,not only offer orientation information for some living organisms(i.e.,geomagnetic field,GMF),but also can exert specific magnetic bio-effects on organisms(i.e.,triggered by changes in field intensity).Thus,related studies on magnetic fields has attracted more and more attention.Given that the NZMF can be used for the simulation of GMF decay and the magnetic environment in space,to study bio-effects of the NZMF on organisms is crucial for revealing magnetoreception of organisms and the potential relationships between the magnetic fields and biological evolution.With small brown planthopper,Laodelphax striatellus,as the model insect,and changes in magnetic field intensity(NZMF vs.GMF)as the environmental factor,we aimed to explore magnetic responses of growth and development,reference gene stability and the transcriptomes to changes in magnetic field intensity.The main results of this study are as follows:1.Effects of NZMF on growth and development of L.striatellusIn order to explore the adaptative strategy of L.striatellus to near-zero magnetic field(vs.GMF),biological effects on growth and development were studied.Compared with the GMF,the results showed that NZMF had no significant effects on hatching period,but it significantly extended the total nymphal duration of L.striatellus.NZMF also significantly decreased body weight of the newly emerged adults.In addition,NZMF significantly shortened the longevity of adult females but significantly extended that of adult males.2.The stability evaluation on reference genes in L.Striatellus under NZMFTo screen available reference genes used in the following qRT-PCR experiments and to ensure analyses for magnetic responses of L.Striatellus transcriptomes to the NZMF(vs.GMF),we evaluated stability of selected reference genes in one-day-old adult females and males under the NZMF vs.GMF.The results showed that EF-la and RPL9 expressed stabable in one-day-old female adults,and a2-tubulin and RPL9 expressed stabable in one-day-old male adults under the NZMF vs.GMF.3.Analyses for transcriptomic responses of L.Striatellus to NZMFWith L.Striatellus as the model insect,we use transcriptome sequencing to examine the magnetic response of newly emerged female adult L.Striatellus to NZMF(vs.GMF).The results showed that a total of 498 DEGs(246 down-regulated genes and 252 up-regulated genes)were found in L.Striatellus under the NZMF vs.GMF(i.e.,OBF/BF).We chose 12 DEGs,and have verified the reliability of DEGs in transcriptome by qRT-PCR.The Gene Ontology(GO)analyses revealed that items of male mating behavior,endoplasmic reticulum,lipid particle,etc.are enriched in OBF/BF.In addition,the pathway analyses revealed that items of Axon guidance,AMPK signaling pathway,Focal adhesion,Fatty acid metabolism,Regulation of actin cytoskeleton,etc.are enriched in OBF/BF.Our study indicates that changes in magnetic field intensity might affect the nervous system,energy metabolism,intercellular communication and cellular structure.For the first time,we have explored response mechanisms of a migratory insect to changes in magnetic field intensity.Moreover,this work will offer a powerful basis for further verifying gene functions related to magnetoreception in organisms.