Nurturing Life Sciences
#Id: 3701
In any particular cell, most genes are expressed at a low level
Only a small number of genes, whose products are specialized for the cell type, are highly expressed.
mRNAs expressed at low levels overlap extensively when different cell types are compared.
The abundantly expressed mRNAs are usually specific for the cell type.
#Id: 2365
#Unit 5. Developmental Biology
Sigma neoblasts are highly proliferative and are the only stem cells directly responsive to injury.
#Id: 2366
Sigma neoblasts generate a huge variety of cell types, as well as the progenitor population for zeta neoblasts.
#Id: 2367
Zeta neoblasts give rise to epidermal cell fates through a prog-1-positive postmitotic precursor state.
#Id: 2368
Loss of the zeta population
Epidermal cell types do not fully regenerate in the absence of zeta neoblasts, the remaining neoblasts (likely sigma) and their derived cell types are unaffected.
#Id: 2369
In regenerating planaria, Wnt/β-catenin functions to establish anterior-posterior polarity.
#Id: 2370
In planaria, Wnts functioning through β-catenin promotes tail development while repressing head regeneration
