Grid of all species-tissue combinations colored by what type of data is now available for each combination (observed, imputed, or both). Observed combinations were observed in at least one individual and have no imputed data available. Combinations with both observed and imputed data available (Observed + Imputed) were both observed in at least one individual and had predictions generated for it in cross-validation. Imputed combinations represent all combinations without observed data and were included in the final imputed data compendium only. Species are sorted top-to-bottom by the number of available tissues. Tissues are sorted left-to-right by the number of available species. Species and tissues available in the same number of tissues or species, respectively, listed in alphabetical order. Number of individual samples in each species and tissue type (listed in same order as figure) available in Additional file 1. Subset of species and tissues outlined in the dotted red line highlighted for use in b .
