Analysis For The Mitochondrial Genome And Transcriptome Of Tyrophagus Putrescentiae

Objective:To identify the Tyrophagus putrescentiae based on the morphological and molecular characteristics.The mitochondrial genome and of Tyrophagus putrescentiae was sequenced,analyzed and compared with that of other Acaridida.At the same time,the transcriptome of Tyrophagus putrescentiae was sequenced,and to predict the allergen genes of Tyrophagus putrescentiae.Furthormore,to explored whether there are the allergens of Tyrophagus putrescentiae in the dust of aircondition filters.The purpose of this study was to laid a theoretical foundation for the prevention and treatment of Tyrophagus putrescentiae and the allergic diseases caused by it.Methods:The Tyrophagus putrescentiae were collected from the flour samples and then raised in large quantities.The morphology was observed under the light and electron microscopy,and the COX1 and ITS gene were amplified by PCR.The mitochondrial genome of Tyrophagus putrescentiae was acquired by high-throughput sequencing,and then analyzed the gene structure,base content,protein coding gene,codon using,ribosomal RNA gene and transfer RNA gene,and then compared with those of other Acaridida species.After a large number of feeding,the Tyrophagus putrescentiae were divided into four groups:egg,larva,nymph and adult.The transcriptome of Tyrophagus putrescentiae were sequenced by high-throughput sequencing,and annotate and analysed through NR,GO,KOG databases,to screen out differentially expressed genes and allergen genes of Tyrophagus putrescentiae at different developmental stages.Furthermore,PCR was used to amplify the expression of the allergen gene Tyr P1 and Tyr P2 in the dust of air condition filter in Anhui area.Results:?1?The body of Tyrophagus putrescentiae is oval with a smooth colorless and translucent surface,pincers and feet are brownish under the light microscope.The larva has three pairs of legs,the nymph and adult has four pairs of legs.Morphological variations of Tyrophagus putrescentiae,including its legs,setae,external genitalia and accessories,are clearly identified under scanning electron microscope.The length of the COX1 and ITS genes were 469bp and 1245bp,respectively..?2?The total length of mitochondrial genome of Tyrophagus putrescentiae is 14087bp,which is a typical closed double stranded DNA molecule.It is composed of 13 protein coding genes,19 tRNA genes and 2 rRNA genes.Compared with other Acaridida,there have a lack of tRNA^Glu,tRNA^Serer and tRNA^Phe.?3?According to the database,there are 39 613?25 272?46 292unigenes were effectively annotated acoording to NR,KOG and GO database,and 110238 CDS are predicted.Lots of differentially expressed genes are predicted at different developmental stages of Tyrophagus putrescentiae.203 allergen genes were predicted compared with those of mites such as dust mite and house dust mite,and 7 allergen genes of Tyrophagus putrescentiae.?4?A total of 144 dust samples of air condition filter the detection rate of Tyr p 1,Der f 1 and Der p 1 was 6.94%?10/144?,22.92%?33/144?and 16.67%?24/144?,respectively.Tyr p 2 is not detected from all the dust samples.There are 3 samples were detect Der f 1,Der p 1 and Tyr p 1 at the same time.The positive samples are mainly collected form Hefei and Wuhu.Conclusion:The Tyrophagus putrescentiae can be identified based on the morphological characteristics and the molecular markers of COX1 and ITS genes.Three tRNA genes were absent from the mitochondrial genome of Tyrophagus putrescentiae compared with other Acaridida mites.There are differentially expressed genes in different developmental stages of Tyrophagus putrescentiae.7 allergen genes were predicted compared with Tyrophagus putrescentiae.There is the allergens gene Tyr P 1in the dust of air condition filter inAnhui area.We should clean or replace the air condition filter regularly to reduce the breeding of mites.