TmCalculator - Extending Nucleic Acid Melting Temperature Analysis from
Sequence-Level Computation to Genome-Wide Thermodynamic
Profiling
Accurate calculation of nucleic acid melting temperature
(Tm) is fundamental to many molecular biology applications, and
this software scales Tm analysis from individual sequences to
genome‑wide thermodynamic profiling. This package extends Tm
analysis from simple sequence level computation to
comprehensive genome-wide thermodynamic profiling. It takes
multiple input formats including sequence strings, FASTA files,
genomic coordinates. The implementation provides three Tm
calculation methods: the Wallace rule (Thein & Wallace, 1986),
empirical GC‑content formulas (Marmur, 1962; Schildkraut, 2010;
Wetmur, 1991; Untergasser, 2012; von Ahsen, 2001), and
nearest‑neighbor thermodynamics (Breslauer, 1986; Sugimoto,
1996; Allawi, 1998; SantaLucia, 2004; Freier, 1986; Xia, 1998;
Chen, 2012; Bommarito, 2000; Turner, 2010; Sugimoto, 1995;
Allawi, 1997; SantaLucia, 2005). Corrections are supported for
salt ions (SantaLucia, 1996, 1998; Owczarzy, 2004, 2008) and
for chemical conditions such as dimethyl sulfoxide and
formamide. This package returns result as a GRanges object for
interoperability with Bioconductor workflows and downstream
multi-omics analyses (e.g., ATAC‑seq, ChIP‑seq, RNA‑seq,
QTL/GWAS). Data-level integration reconciles Tm windows with
external multi-omics GRanges objects through overlap,
nearest-feature, windowed-count, and binned-average strategies,
returning a single unified GRanges object ready for downstream
analysis. Visualization-level integration renders multiple
feature layers as independent concentric tracks on a shared
genomic axis, each retaining its native coordinate resolution.
Group comparison supports Wilcoxon rank-sum and Student's
t-tests with multiple available correction methods for
contrasting Tm and other features across region classes.