In contrast, expression profiles in Xenopus exhibited a strict stage-dependent profile.
Although we do not fully abandon the staging systematics, we primarily build our model on the underlying data structure without immediately putting too much emphasis on strict staging labels.
Although strict staging according to the INSS criteria does not take into account bilateral tumours, such patients were included in our study if all other INSS criteria were fulfilled (Nickerson et al, 2000).
Strict INSS staging does not include stage 4s NB infants with tumoral bone marrow infiltration exceeding 10%, which has been reported as extremely rare (one patient in 80, Nickerson et al, 2000).
At the same time, there is much more variation in the competencies of individuals of the same age, and much more variation in the developmental patterns by which particular competences are achieved, than is implied by strict life stage development perspectives.
As with other antigen-specific receptor loci, recombination in the TRB locus is under strict lineage-, stage- and allele-specific regulation associated with control of RAG accessibility to RSs mediated through alterations in chromatin structure (the 'accessibility hypothesis') [ 18- 20].
Lately, a large fraction of miRNAs were found exhibiting strict developmental stage and tissue-dependent expression manner which is critical for their appropriate activities [ 15], and the clock-relevant miRNAs are the same cases.
