The efficiency of amplification declines with an increase in the length of the target sequence.

TLS Online TPP Program

#Id: 7017

#Unit 5. Developmental Biology

Chemical regulation of stem cells takes the form of secreted proteins from surrounding cells that influence stem cell states and progenitor differentiation through endocrine, paracrine, or juxtacrine mechanisms.

TLS Online TPP Program

#Id: 7018

#Unit 5. Developmental Biology

In many cases, signaling factors maintain the stem cell in an uncommitted state.

TLS Online TPP Program

#Id: 7019

#Unit 5. Developmental Biology

Once stem cells become positioned farther from the niche, signaling factors cannot reach them, and differentiation commences.

TLS Online TPP Program

#Id: 7020

#Unit 5. Developmental Biology

Intracellular regulatory mechanisms include:

Regulation by cytoplasmic determinants

Transcriptional regulation 

Epigenetic regulation

TLS Online TPP Program

#Id: 7021

#Unit 5. Developmental Biology

The adult stem cell is housed in and controlled by its own adult stem cell niche, which regulates stem cell self-renewal, survival, and differentiation of those progeny that leave the niche.

TLS Online TPP Program

#Id: 7022

#Unit 5. Developmental Biology

Stem cell niches in the testes of male Drosophila illustrate the importance of local signals, cell-to-cell adhesion, and asymmetric cell division.