Comparative genomic mapping of the HCR genes in human and T. nigroviridis All genes are represented by an arrow that indicates the orientation of transcription. A) Clusters of HCR in the human genome. Orientation of transcription is relative to the centromere indicated on the left of the figure. MT stands for the human homolog of the S cerevisiae YDR140w gene. All genes are around 30 kb long. The MT gene is approximately 4 Mb centromeric to the IFNAR2 gene. B) The unique T. nigroviridis HCR cluster. TnC21orf4 is for the T. nigroviridis homolog of the human C21orf4 gene. TnMT is for the T. nigroviridis homolog of the S cerevisiae YDR140w gene. All genes are around 3 kb long.