The Study Of The Transtriptional Level Of Synthetase Of Pyridoxal-5'-phosphate And The Transcriptomics Analysis In The Silkworm,Bombyx Mori

Vitamin B6(VB6)is an essential nutrient for sustaining the normal metabolic activity,and its major coenzyme form is PLP(Pyridoxal-5'-phosphate)which is the essential to metabolic transitions of amino acids and participates in biosynthesis of some substance.The dynamic balance and synthesis of PLP is the core of VB6 nutrition problems,associated with kinds of human neurological diseases.PLK(Pyridoxal kinase)and PNPO(Pyridoxine-5'-phosphate oxidase)are critical enzymes in the synthesis of PLP,and regulate the dynamic equilibrium of cells and tissues in the mammals.The regulation of enzyme generally from two aspects: structure and synthetic level.Structure level has studied thoroughly,synthetic level such as transcription and translation aspects still need further research,synthetic regulation has many ways,the level of hormone is the main,but theregulation of hormone to PLP and VB6 has not been reported.Due to a large number of silkprotein synthesis in the short time,amino acid metabolism become vigorous and PLP requirements increase in 5th instar larvae,so its synthetase may be regulated by hormone.The growth and development of silkworm are to be regulated mainly by means of the Juvenile hormone(JH)and the 20-hydroxyecdysone(20-E).In this study,fifth instar larvae were treated with juvenile hormone analogue(JHA)and 20-E,we observed the effect of their growth and development,then analyzed the transcription levels of PLK and PNPO of the silkworm by RT-qPCR.Transcriptomics were applied to sequence the fat body of late stage larvae post 20-E treatment.The main results are as follows:1.The early stage of the 5th larvae delayed the growth and development when they were treated with low dose of 20-E,however grow abnormal until to death with high dose of 20-E.The middle and late stage larvae shorten their growth when were post 20-E.JHA can prolong the growth and development of the early and middle stage larvae while had no significant effect on the late stage larvae.2.20-E promoted significantly the transcriptional levels of PLK and PNPO of silk gland in the early stage of the 5th instar larvae while had no influence on the late stage larve.JHA significantly repressed the transcriptional levels of PLK and PNPO of silk gland in late stages larvae had no effect on the early stage larvae.20-E improved the transcription level of PNPO of the fat body in the early stage larve,but reduced it in the late age.The early and middle stage instar larvae decreased the transcriptional levels of PLK at 48 h after post JHA.To the late stage larve,JHA decreased the transcriptional level of PLK in fat body while improved the PNPO.3.Transcriptomics were applied to sequence the fat body of day-5 5th instar larvae of silkworm post 20-E treatment,untreated larvae were used as the control,we obtained 606 differentially expressed genes.GO term analysis found that these genes were significantly focus on biological processes,especially the various metabolic processes.Pathway analysis showed that the enriched metabolic pathways mainly related to metabolism and immune system.This study identified the effect of 20-E and JHA on the regulation of PLK and PNPO in silkworm,lay a foundation for further analysis on the dynamic balance of PLP and VB6 metabolic work,provide reference for human VB6 nutritional problems.