PURPOSE. To collect an entire set of full-length cDNA clones derived from human retina-derived cell lines and to identify full-length transcripts for retinal preferentially expressed genes. METHODS.
View Article and Find Full Text PDFFull-length complementary DNAs (cDNAs) are an essential resource for functional genomics. Recently, we have developed a simple and efficient method for preparing a full-length cDNA library from a small amount of total RNA, named the "vector-capping" method. The biggest advantage of this method is that the intactness of the cDNA can be assured by the presence of dG at the 5' end of the full-length cDNA.
View Article and Find Full Text PDFRecently, we have developed a vector-capping method for constructing a full-length cDNA library. In the present study, we performed in-depth analysis of the vector-capped cDNA library prepared from a single type of cell. As a result of single-pass sequencing analysis of 24,000 clones randomly isolated from the unamplified library, we identified 19,951 full-length cDNA clones whose intactness was confirmed by the presence of an additional G at their 5' end.
View Article and Find Full Text PDFPurpose: To identify nucleotide sequence variations in the rhodopsin (RHO) gene of Japanese patients with retinitis pigmentosa (RP) in order to search for mutations or haplotypes responsible for RP.
Methods: The entire region of RHO locus including a promoter region and introns was sequenced using blood-derived genomic DNA samples donated by 68 patients with RP and 68 control subjects.
Results: We found 39 single nucleotide substitutions including 17 rare substitutions of less than 1% in frequency, one insertion/deletion polymorphism, and one CA-repeat polymorphism in a 7.
Full-length cDNAs play an essential role in identifying genes and determining their promoter regions. Here we describe a simple method for constructing a full-length cDNA library, which has the following advantages: (i) it consists of only three steps including direct ligation between a vector and a cDNA strand using T4 RNA ligase, (ii) it contains neither a PCR process generating mutations nor restriction enzyme treatment causing truncation of cDNA, (iii) the intactness of cDNA is assured due to the presence of an additional dGMP at its 5' end, (iv) approximately 95% of cDNA clones are full-length when cultured cells or fresh tissues are used, (v) several micrograms of total RNA without mRNA purification is sufficient for preparation of a library containing >10(5) independent clones, and (vi) a long-sized full-length cDNA up to 9.5 kbp can be cloned.
View Article and Find Full Text PDFSmall subunit rRNA gene sequences were identified without cultivation from parabasalid symbionts of termites belonging to the hypermastigid orders Trichonymphida (the genera Hoplonympha, Staurojoenina, Teranympha, and Eucomonympha) and Spirotrichonymphida (Spirotrichonymphella), and from four yet-unidentified parabasalid symbionts of the termite Incisitermes minor. All these new sequences were analyzed by Bayesian, likelihood, and parsimony methods in a broad phylogeny including all identified parabasalid sequences available in databases and some as yet unidentified sequences probably derived from hypermastigids. A salient point of our study focused on hypermastigids was the polyphyly of this class.
View Article and Find Full Text PDFThe sequence analysis of the 5' ends of cDNAs prepared using the anchor ligation method has revealed that most of the full-length cDNAs have an additional dGMP at their 5' end that is absent in the corresponding genome sequence. Using model RNA transcripts with cap analogues possessing 7-methylguanosine and adenosine, the base of the added nucleotide has been shown to be complementary to the base of the cap analogue, suggesting that the cDNAs possessing an additional dGMP are derived from intact mRNAs with the cap structure. On the other hand, cap-free RNA did not produce cDNA with an extra dGMP.
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