Hello. I am trying to create a GeneRegionTrack for Gviz, using the mm10 genome. I can't seem to display the gene symbol rather than the Ensembl transcript ID in the gene track. I've tried changing the transcription annotation to gene and symbol but neither work. Please see below:

library(Gviz)
library(GenomicRanges)
library(Mus.musculus)

chr <- 'chr11'
gen <- 'mm10'

txdb <- TxDb.Mmusculus.UCSC.mm10.knownGene

grtrack <- GeneRegionTrack(txdb, genome = gen,
                           chromosome = chr, name = "UCSC known genes",
                           transcriptAnnotation='symbol')
plotTracks(grtrack, chromosome=11,from=102885336, to=102899200)

This is the output

If I change symbol to gene:

grtrack <- GeneRegionTrack(txdb, genome = gen,
                           chromosome = chr, name = "UCSC known genes",
                           transcriptAnnotation='gene')
plotTracks(grtrack, chromosome=11,from=102885336, to=102899200)

This is the new output

I want the transcript IDs to be replaced with the gene symbol. A side note that this works fine with the human genome, but not the mouse. I'm not sure why.