Construction Of EST Library, And Functional Notation And Database Management System Of Part Of ESTs Of Maize

With the CLONTEECH vector pDNR-LIB, an EST library of the drought-tolerant maize (Zea mays L.) YQ7-96 was made from the mixed tissues containing leaves, stems and floral buds at the stage( i.e. up to 12 leaves) of differentiation of the sex organs under normal cultivation without stresses and in the presence of co-stress of water deprivation for 24h?48h and 72h. This library consisted of over 2.0×105 EST clones ,which was over 4 times more than about 5×104genes predicated in the maize genome. The fragments of insertion cDNAs of 843 clones selected at random ranged from 0.25 to 2kb, in which 37.5% cDNA fragments were in 0.25-0.5kb,54.9% in 0.5-1.0kb and 7.7% in 1.5-2.0kb. 96 of the clones were sequenced both from 5' and 3' end of the cDNAs, Sequencing showed that 3' ends of 96 cDNAs all had poly(A) tails. In addition, 2976 of the clones were sequenced from 5' end of the cDNAs. The total 3027 cDNA were sequenced . But there were 2098 valid ESTs, which met the following criterions : non rRNA genes and chondriogenes , <5% N and >50bp in length. After assembling, 1861 Unigenes were presented which consisted of 168 contigs and 1693 singlets. According to BLASTn analysis in the GeneBank, 130 (6.98%)of 1861 Unigenes belonged to novel gene sequences. The 21 ESTs could been localized on different chromosomes of maize. Based upon a BLASTx analysis, 1007 (48.00 %) of 2098 ESTs had functional or product information .The above results suggested that our ESTs would be complementary to maize ESTs database deposited in the public databases.Using the Visual Basic for Applications (VBA) language in Microsoft Excel 2003,we established a management system of macroprocessor-Management System of Sequences and Notation Database of Expressed Genes (MSSNDBEG),which could massively and automatically extract and process key items of data from the results of a large number of EST sequence and functional notation texts.The MSSNDBEG has the following functions exporting texts with different forms or patterns, extracting information items from the database once more and establishing the massive link between the original ESTs' sequences and their corresponding notation results, etc. The MSSNDBEG is suitable not only for data management of EST notation and but also for data management of other DNA sequence notation. The advantage of this system is that it can be recognized by the database management of the MicroGridTAS Microarrayer (BioRobotics Ltd,UK) ,therefore, extremely reduce work load when largely uploading the data information of sample spots into the microarrayer in future.