Chapter 3 Answers to Select Review Questions

3.  What are the two primary disadvantages of using human E cells for therapeutic applications?

There are ethical concerns related to the use of human embryonic stem cells in basic research and diagnosing or treating disease.  There are also issues related to the immune system compatibility of ES cells and their progeny transplanted allogeneically (transplantation from one human to another, genetically non-identical human).  Immunorejection is a real concern for allogeneic transplants of any sort, and is of particular concern in cell transplantation, given its widespread applications. 

6.  How do epiblast stem cells differ from embryonic stem cells?

EpiSCs are derived from E5.5 to E6.5 post-implantation mouse embryos and thus are strikingly different than their ES counterparts.  For example, LIF and BMP do not allow for their derivation, but, in a manner similar to that for human ES cells, both the activin/nodal and FGF signaling pathways are critical in this respect.  In addition, genome-wide profiling has revealed that EpiSCs are transcriptionally different than ES cells and resemble the genomic profile of epiblasts.

9.  What properties of rhesus monkeys make them a challenge to study with respect to embryological research?


Release of a single oocyte during ovulation
Relatively long gestation period of 5 months
Sexual maturity age of 4-5 years

15.  Why is the mouse P19 embryonal carcinoma line so popular with developmental biologists?

P19 cells have the inherent capacity to differentiate into lineages representing the three primary germ layers.  In addition, the P19 line is the most widely studied EC line with respect to the characterization of cardiogenesis, skeletal muscle differentiation and neurogenesis pathways.  Exposure of P19 cells to dimethyl sulfoxide (DMSO) induces the development of cardiac and skeletal muscle while exposure of the cells to retinoic acid induces neuronal and glial cell formation.

17.  What are the basic properties of fetal stem cells?

Fetal stem cells exhibit “stemness”, express specific markers and have an ability to self-renew.  In most cases, however, fetal stem cells have a considerably restricted ability to differentiate into various cells types, i.e. they are multipotent, in contrast to pluripotent embryonic stem cells.