Bio
Packages
The featureTree package is used to represent the features of a GFF file as a tree, using the Parent attribute of the file to create parent/child relationships. To ensure that the parsed tree is meaningful, the package imposes limitations on the structure of the resulting tree, which is modelled after the standard structure used by genome databases, such as maizeGDB. The resulting tree must adhere to the parent/child relationships in this diagram: 
Note that the package generally avoids acronyms: 5' UTRs are referred to as leaders, 3' as terminators, and CDS as coding sequences. The tree structure allows for intuitive parsing up and down the tree. To avoid subtle errors, navigating to a different location in the tree generally requires "knowing where you are," that is, to find the Gene parent of a transcript, you must know that it is a transcript.