Be described mathematically using trigonometric ratios. It is to be noted that the universal constants p and e have a role in calculating the trigonometric ratios and FD, and have been identified in analysis of the T-cell repertoire [10], which would imply that the TCR locus may be arranged in conformity with these constants, and demonstrate self-similarity as well as periodic characteristics. An inspection of the known sequence of the TCR loci with attention to V and J gene segment size and spacing supports this notion. In this theoretical paper, an examination of the TCR a and b loci, in light of e and p is presented in support of the hypothesis that TCR locus organization may influence T-cell repertoire.rsif.royalsocietypublishing.org J. R. Soc. Interface 13:2. Material and methods2.1. Human T-cell receptor lociData on the T-cell receptor a/d (TRA) and b (TRB) loci were obtained from the NCBI, using the public database (http://www.ncbi.nlm. nih.gov/nuccore/114841177?report=graph; http://www.ncbi.nlm. nih.gov/nuccore/99345462?report=graph) (SCIO-469 site get (��)-BGB-3111 electronic supplementary material, tables S1 and S2). The graphic format, with locus identification was used. Data collected included the position of the initial (start; first nucleotide of exon 1 for V gene segments) and final (stop: last nucleotide of exon 2 for V gene segments) nucleotides of all the TCR gene segments, beginning from the centromeric (50 end) of the locus and going to the telomeric (30 end). Segment length was taken from the NCBI database, and the intergenic spacing between consecutive segments was calculated by taking the difference between the numeric value of the initial nucleotide (or base pair) position (xf ) of a gene segment and the initial nucleotide position (xi) of the following segment (electronic supplementary material, tables S1 and S2). In the ensuing calculations, numeric data were either considered without any modification or transformed to natural logarithms to eliminate the effect of relative magnitude between the variables being examined, and also to allow comparisons across different scales, e.g. segment size in hundreds or tens of nucleotides versus intergenic spacing in the thousands or hundreds of nucleotides, respectively. MICROSOFT EXCEL (v. 14.2.5) was used to perform various calculations presented in this paper.2.2. Gene segment distribution on the T-cell receptor locusAn examination of the TCR gene segments on the TRA and TRB loci reveals that the V segments are longer in length and spread farther apart than the J segments which are shorter and clustered together more closely (http://imgt.org/IMGTrepertoire/index. php?section=LocusGenes repertoire=locus species=humangroup=TRB; http://imgt.org/IMGTrepertoire/index.php?section=LocusGenes repertoire=locus species=human group=TRA). This suggests that the sets of V and J gene segments in both the TRA and TRB loci are self-similar in their geometry, that is, they have the same distribution albeit at different scales of magnitude. To investigate the possible fractal nature of the TCR locus, as the basis for a deterministic TCR gene rearrangement paradigm, individual V and J gene segments and the adjacent intergenic segment together were considered line segments. Gene segments were chosen as scaling factor, because of their relatively uniform length (in base pairs), and because the gene segments are the coding regions brought together in TCR gene rearrangement. In other words, if the TCR loci are represented.Be described mathematically using trigonometric ratios. It is to be noted that the universal constants p and e have a role in calculating the trigonometric ratios and FD, and have been identified in analysis of the T-cell repertoire [10], which would imply that the TCR locus may be arranged in conformity with these constants, and demonstrate self-similarity as well as periodic characteristics. An inspection of the known sequence of the TCR loci with attention to V and J gene segment size and spacing supports this notion. In this theoretical paper, an examination of the TCR a and b loci, in light of e and p is presented in support of the hypothesis that TCR locus organization may influence T-cell repertoire.rsif.royalsocietypublishing.org J. R. Soc. Interface 13:2. Material and methods2.1. Human T-cell receptor lociData on the T-cell receptor a/d (TRA) and b (TRB) loci were obtained from the NCBI, using the public database (http://www.ncbi.nlm. nih.gov/nuccore/114841177?report=graph; http://www.ncbi.nlm. nih.gov/nuccore/99345462?report=graph) (electronic supplementary material, tables S1 and S2). The graphic format, with locus identification was used. Data collected included the position of the initial (start; first nucleotide of exon 1 for V gene segments) and final (stop: last nucleotide of exon 2 for V gene segments) nucleotides of all the TCR gene segments, beginning from the centromeric (50 end) of the locus and going to the telomeric (30 end). Segment length was taken from the NCBI database, and the intergenic spacing between consecutive segments was calculated by taking the difference between the numeric value of the initial nucleotide (or base pair) position (xf ) of a gene segment and the initial nucleotide position (xi) of the following segment (electronic supplementary material, tables S1 and S2). In the ensuing calculations, numeric data were either considered without any modification or transformed to natural logarithms to eliminate the effect of relative magnitude between the variables being examined, and also to allow comparisons across different scales, e.g. segment size in hundreds or tens of nucleotides versus intergenic spacing in the thousands or hundreds of nucleotides, respectively. MICROSOFT EXCEL (v. 14.2.5) was used to perform various calculations presented in this paper.2.2. Gene segment distribution on the T-cell receptor locusAn examination of the TCR gene segments on the TRA and TRB loci reveals that the V segments are longer in length and spread farther apart than the J segments which are shorter and clustered together more closely (http://imgt.org/IMGTrepertoire/index. php?section=LocusGenes repertoire=locus species=humangroup=TRB; http://imgt.org/IMGTrepertoire/index.php?section=LocusGenes repertoire=locus species=human group=TRA). This suggests that the sets of V and J gene segments in both the TRA and TRB loci are self-similar in their geometry, that is, they have the same distribution albeit at different scales of magnitude. To investigate the possible fractal nature of the TCR locus, as the basis for a deterministic TCR gene rearrangement paradigm, individual V and J gene segments and the adjacent intergenic segment together were considered line segments. Gene segments were chosen as scaling factor, because of their relatively uniform length (in base pairs), and because the gene segments are the coding regions brought together in TCR gene rearrangement. In other words, if the TCR loci are represented.