AZ1.0

Background
The Azadirachta indica (neem) tree is a source of a wide number of natural products, including the potent
biopesticide azadirachtin. In spite of its widespread applications in agriculture
and medicine, the molecular aspects of the biosynthesis of neem terpenoids remain
largely unexplored. The current report describes the draft genome and four transcriptomes
of A. indica and attempts to contextualise the sequence information in terms of its molecular
phylogeny, transcript expression and terpenoid biosynthesis pathways. A. indica is the first member of the family Meliaceae to be sequenced using next generation sequencing approach.

Results
The genome and transcriptomes of A. indica were sequenced using multiple sequencing platforms and libraries. The A. indica genome is AT-rich, bears few repetitive DNA elements and comprises about 20,000 genes.
The molecular phylogenetic analyses grouped A. indica together with Citrus sinensis from the Rutaceae family validating its conventional taxonomic classification. Comparative transcript
expression analysis showed either exclusive or enhanced expression of known genes
involved in neem terpenoid biosynthesis pathways compared to other sequenced angiosperms.
Genome and transcriptome analyses in A. indica led to the identification of repeat elements, nucleotide composition and expression
profiles of genes in various organs.

Conclusions
This study on A. indica genome and transcriptomes will provide a model for characterization of metabolic
pathways involved in synthesis of bioactive compounds, comparative evolutionary studies
among various Meliaceae family members and help annotate their genomes. A better understanding of molecular
pathways involved in the azadirachtin synthesis in A. indica will pave ways for bulk production of environment friendly biopesticides.