Preliminary Studies On The Morphology And Structure Of Compound Eyes And Formation Mechanisms Of The Red-eye Mutant In The Brown Planthopper,Nilaparvata LugensStal

To explore the formation mechanisms of red-eye mutation, the differences in morphology and structure of compound eyes, the content of omochromes, and gene expression profiles were analyzed by using electron microscopy, biochemical analysis and gene sequencing technology, after getting two near isogenic line strains for the red-eye mutant and the brown-eye wild-type of the brown planthopper, Nilaparvata lugens Stal.1. Morphology and structure of compound eyes in N. lugensstrainsThere was no obvious difference in morphology and ultrastructure of compound eyes in female adults between two N. lugens strains. However, the number of pigment granules in pigment cells was significantly fewer in the red-eye mutant, which more belonging to the low-density pigment granules. It suggested that the difference in eye color was related to the type and quantity of pigment granules.LOmmochrome contents in N. lugens strainsThe content of xanthommatin in the head from female and male adults of red-eye wild-type was significantly lower than those of brown-eye mutant, respectively, while pteridine content was no significant difference between two N. lugens strains. Except for the lowercontent of xanthommatin in the head of female adults fromthe red-eye mutant, xanthommatin content was significant higher than pteridine content in the head from the same sex adults of N. lugens. The contents of xanthommatin and pteridine in the head of female adults were significantly higher than those of male adults. There were significant interactions among theommochrome content, the sex and the strain of N. lugens.3.Gene expression profiling in N. lugens strainsA total of16,078gene fragments were founddifferentially expressed in twoN. lugensstrains, including some genes with relationship to the pigment synthesis and transportation, such astryptophan oxygenase, GTP cyclohydrolase, xanthine dehydrogenase, methylenetetrahydrofolate dehydrogenase and ABC transporter. Total of415genes were differentially expressedsignificantly. Compared with brown-eye wild-type, there were67gene fragments.about16%of the total, significantly up-expressed in the red-eye,while the rest significantlydown-regulated. Within the gene fragments differentially expressedsignificantly, only threefragmentsof ABC transporter (NLU005447, NLU005448and NLU008168) involving the pigment synthesis and transportation processes were found to be significantly down-expressed. The results for expression trend of genes were similar within the determination byeither sequencing orquantitative PCR.The results in this paper would contribute to screenred-eye mutant genes forthe future analysisof regional characteristics of N.lugenspopulations, to further understandthe mechanisms of the red-eye mutation in N. lugens, and to provide the basis and molecular indexes for the migrationprediction.the real-time monitoring of regional outbreaks, and themanagementof N. lugensin source areas.