By counting the number of sites to which ORC binds, we can estimate that there are about 400 origins of replication in the yeast genome.

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#Unit 5. Developmental Biology

An anterior-to-posterior gradient of Erk signaling functions as a positive inducer of head specification

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#Unit 5. Developmental Biology

 Wnt signaling achieves its repression of head regeneration by inhibiting Erk

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#Unit 5. Developmental Biology

Regulation of the balance between Wnt and Notum signals underlie not only head-tail specification but also regulation of organ size.

 

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#Unit 5. Developmental Biology

Two distinct populations of neoblasts exist:

1. Sigma neoblast population 

2. Zeta neoblast population 

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#Unit 5. Developmental Biology

Dictyostelia (social amoebas)

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#Unit 5. Developmental Biology

Dictyostelium can utilize one of three survival strategies when food starvation-

Microcyst formation, favoured in dark & wet conditions, or ammonia levels are high.

Zygote formation, favoured in dark & wet conditions, & is triggered by ethylene produced by the cells. 

Cell aggregation & differentiation