Mining of expressed sequence tags

overlapping.Multiplesequencealignmentwasperformedandconsensussequences

along with a quality value for each base were computed. Human brain tissue-based

ESTs from 15 ABC transporter genes were subjected to cluster analysis. Distance

matrix for all ABC transporters ESTs from human brain was computed GeneBee

server and converted into graphical representation using Microsoft Excel 2007.

Database Similarity Searches

The consensus sequences of putative genes obtained from clustering were identified

using freely available tools like BLASTN and BLASTX. For sequence analysis,

all 15 ESTs of ABC transporter genes were aligned to the genome sequence of the

human using specialized program like GeneBee server to assist genome mapping

and gene discovery.

Phylogenetic tree construction

15 ABC transporters ESTs identified from human brain tissue were aligned and

subjected to phylogenetic tree construction in PHYLIP format. Complete EST

sequences were used for both cluster and topological algorithms with bootstrap

values. Phylogenetic tree was represented in slanted form for better homology and

evolutionary analysis.

Results and Discussion

Screening and identification of ESTs

All 48 members from 7 families of ABC transporter genes, 15 ESTs from human

brain were identified from dbEST on NCBI.

Sequence similarity in ESTs of ABC transporters in human brain

The database similarity search by querying 15 ESTs on GeneBee against human

genome revealed that all the ABC transporter contigs were showing high degree

of sequence homology. Refined alignment with power value of 54.46 was found to

be highly significant and showed 8.1% of sequence homology.

ESTs cluster generation

From several successful and widely accessed EST databases, the UniGene database

was selected as it uses mRNA and other coding sequence data of GenBank as

reference sequence for cluster generation.After search for humanABC transporter

genes in dbEST, the EST sequences of human brain were selected due to their

association and greater functionality in the onset and progression of human brain

tumors such as gliomas. Distance matrix was calculated from the generated cluster

database and converted into graphical representation showing high degree of

Int. J. Bioinformatics and Biological Sci.: v.2 n.1&2, p. 7-12. March & June 2014

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