Regional diversity - Ecologists have often partitioned the overall species diversity of a region into different components.

TLS Online TPP Program

#Id: 3854

#Unit 5. Developmental Biology

RegA is activated by phosphorylation of an aspartate in its response regulator domain.

TLS Online TPP Program

#Id: 3855

#Unit 5. Developmental Biology

Dictyostelia (social amoebas)

solitary haploid amoebae live on decaying logs, eating bacteria and reproducing by binary fission.

TLS Online TPP Program

#Id: 3856

#Unit 5. Developmental Biology

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

(1) Microcyst formation, favoured in dark & wet conditions, or ammonia levels are high.
(2) Zygote formation, favoured in dark & wet conditions, & triggered by ethylene produced by the cells.
(3) Cell aggregation & differentiation

TLS Online TPP Program

#Id: 3857

#Unit 5. Developmental Biology

Phosphorylation of RegA is mediated by sensor histidine kinases/phosphatases which either phosphorylate or dephosphorylate themselves on a histidine residue when a signal molecule binds to their sensor domain.

TLS Online TPP Program

#Id: 3858

#Unit 5. Developmental Biology

Cell Aggregation & Differentiation is common to all Dictyostelids.
It consists of an interconnected programme of cell movement and cell differentiation.

TLS Online TPP Program

#Id: 3859

#Unit 5. Developmental Biology

The binding of ammonia to the sensor domain of DhkC leads to the activation of its histidine kinase activity and to the autophosphorylation of a DhkC histidine residue.