In addition, Li et al. proposed that a 5-bp deletion in exon 3 of the B. rapa GL1 gene is the basis of a hairless phenotype that arose from a normally hairy double haploid brown-seeded line. Hence, the extremely dense trichome coverage of B. villosa could be due to a combination of relatively higher transcription of GL2, hydrophobic amino acids and evolutionary changes in GL1, as well as the replacement of serine in all BvTRY sequences, and potentially a different function for TRY-1, CPC-1, and ETC3-3. Moreover, the glabrous leaves of the C genome relative B. oleracea could result from two non-synonymous substitutions, five continuous amino acid replacements, one nonsense mutation leading to a shortened GL1 amino acid sequence, and a missing aa stretch in the bHLH DNA binding region of BoEGL31 and BoEGL3-2. Our study adds additional sequence variation data to a previous report detailing two 1 bp deletions and 1 bp insertion in exon 3 of the B. oleracea GL1 sequence. Changes in protein function with individual amino acid modifications are also seen in other species and genes. Yeam et al. showed that a G/R polymorphism at aa 107 of the Capsicum eukaryotic translation initiation factor 4E protein is sufficient for the acquisition of resistance against several Capsicum and tobacco etch potyvirus strains by expressing the amino acid substituted gene in potato. Likely, the genetic variation we have uncovered is the ����tip of the iceberg���� in terms of variation that affects the function of Brassica trichome genes, since the trichome pathway in the simpler A. thaliana genome is already considered to be an integrated hierarchy of regulation by complex cell cycle status, transcriptional control and cytoskeletal function. This is confirmed by the ever increasing number of trichome genes being discovered in A. thaliana mutant Bay 11-7085 populations and by the on-going discovery of cis-regulatory sequences that provide greater diversification in gene function, eg. for GL1 and MYB23. The constant improvement in genomic-scale sequencing technology, SNP analysis, and computation can now be applied to characterize large within-accession and within-species variance in trichome gene patterning in the TGR5 Brassicaceae and identify statistically robust associations hitherto undetectable.