Table 2. Functional categorization of putative transcriptional units affected by piggyBac insertion shows significant enrichment for genes involved in nucleic acid metabolism/nucleic acid binding/transcription in the severely attenuated mutants (P<0.05).

Functional Category	Number of genes affected in each category
	Severely attenuated	Moderately attenuated	Non-attenuated
Biochemical pathways/protein metabolism/protein modification	4	12	11
Conserved proteins with unknown function	6	13	21
Exported proteins	2	3	3
Membrane/structural proteins/trafficking/signal transduction	1	2	6
Nucleic acid metabolism/nucleic acid binding/transcription	8	2	7
Total	21	32	48