Identification And Determine Initial Function Of New Micrornain Maize Seeds

MicroRNA(miRNA) are a class of endogenous regulatory monconding RNAs , ranging in size from 21 to 25 nucleotides. miRNA always has one or more target RNAs and it can adjust the level of gene expression by slicing or translational inhibition.miRNA regulate many important life processes, such as cell growth, development, gene transcription, translation. It is necessary to identify novel ncRNAs in different organisms and probe the roles which they may play in development.In this study, i found an improved method for total RNA Extraction from the maize seeds. we use illumine technology to find the new miRNAs in the different stage of maize seeds. I select 23 miRNAs whose expression were Significant differential at different stages; analysis the structural characteristics by Bioinformatic methods; predicted target genes of the 23 miRNAs; detect the expression of 23 miRNA after pollination 4days, 5days, 6days, 7days, 9days, 10days, 12days, 14days, 18days, 20days, 22days; modifiy the total RNA of extraction method. Results are as follows1. I compare the 23 miRNAs with the existing miRNA database, found that 19 miRNAs were attributed to 6 miRNA family;2. Their precursor are ranging from 100nt to 260nt, the average length is 149nt, of which 70% of them between 100~140nt, the longest reach 260nt;3. All of them have the secongdary structure and their abundance rang from 24689.6 to 308788.1;4. The expression of miRNA1, miRNA2, miRNA3, miRNA4, miRNA5, miRNA10, miRNA12, miRNA13, miRNA15 and miRNA16 rising during maturity, miRNA6, miRNA7, miRNA8 and miRNA21 reach the highest level at the first 7 days , miRNA9, miRNA14 at the first 12 days, miRNA11, miRNA17, miRNA18, miRNA19, miRNA20, miRNA22 and miRNA23 decreasing;5. Identified miRNA9, miRNA10, miRNA12, miRNA21, miRNA22 and miRNA23 and their expression by Northern Blot, the results were similar with the sequencing. 6. The target gene prediction showed that 15 putative target genes as these miRNAs are predicted and some of them play a significant role in maize seeds development.