Estudo de genes expressos em frutos de camu-camu: seqüenciamento de ests.

Abstract

The camu-camu (Myrciaria dubia (H.B.K.) McVaugh) is a native sort of the Amazonian region, whose fruit presents elevated content of ascorbic acid (vitamin C). The study of the functional genome in camu-camu fruits has like base the expressed sequence tags sequencing - ESTs. Faced with the displayed the present thesis is going to analyze and identify express genes in camu-camu fruits by means of ESTs sequencing. The total RNA was extracted from the shell-pulp. The extremity 5’sequencing' of cDNA insert was carried out so much in the Technology of the DNA Laboratory (UFAM) and in the Sequencing Platform (EMBRAPA/CENARGEN). The ESTs sequences obtained were submitted to the System Genome, program of genomic annotation that integrates analysis management programs and viewing of nucleotides sequences. It developed an efficient procedure for total RNA extraction of camu-camu fruits that enabled the obtaining of mRNAs of quality, utilized in the making of cDNAs of sizes varied (500pb to 4Kb). From the sequencing were obtained 3196 ESTs valid, being formed 1546 singletons and 358 contigs, resulting of 2586 ESTs sequences in total with similarity the sequences found in the gene bank. The analysis library clusterization revealed an index of 81% novelty and 32,54% redundancy. Around 90% of the contigs presented decrease redundancy (2-4 reads by contigs). The facts of the categorization of the proteins identified detached the posttranslational modification, protein turnover, chaperones (13,2%) category. From the hoist of the species with bigger number of ESTs with similarity the camu-camu sequences detached itself Arabidopsis thaliana with 49%. Around 10 uniques presented very high similarity (and-value 0.0) to known genes. The ESTs more abundantly express in camu-camu fruits encode to gluthatione s-transferase. They were observed around 3% sequences (97 ESTs) with decrease similarity (e-value > e-10) and 15% did not they present similarity with no contained sequence in the gene bank. They were identified 138 ESTs sequences (4,3%) that they encode molecular chaperones with prevalence of the sHSP family that represents 33% of express chaperones. ESTs related to the ascorbic acid metabolism also were identified, being nine related the synthesis and six come back for ascorbic acid conversion and recycling. ESTs related to the ripening and mechanisms of defense of the fruit also were noticeable.