A member of the developmental gene family assigning regional identities along the body axis. Temporal and spatial expression order can be related, but need not follow one universal rule in all animals.
A context-dependent tendency for posterior Hox functions to dominate more anterior Hox functions where their domains overlap. It is not a universal rule for all tissues.
A grouping of related Hox genes corresponding to an ancestral member retained in duplicated clusters. Sequence relationships, synteny and gene history jointly support the assignment.
A genomic grouping of related Hox genes whose organization can support shared and sequential developmental regulation. Clustering is widespread but is not a universal requirement for positional Hox expression.
The cis-regulatory domains flanking the mouse HoxD cluster. Developmental changes in enhancer contacts support distinct proximal and distal limb expression programmes.
An association between genomic position and expression level or prevalence in a developmental domain. It is a separate property from spatial and temporal order.
Sequential onset of Hox expression following genomic order in relevant developmental contexts. Rearrangements can alter onset timing without equivalently changing every later spatial boundary.
Correspondence between gene order and the anterior boundaries of Hox expression domains along a body axis. It must be distinguished from temporal collinearity.
