Adults Lack Stem Cells for Making New Eggs

Picture Source:

http://images.tutorvista.com/content/reproduction-in-animals/human-ovum-structure.jpeg

Article Link:

http://www.biologynews.net/archives/2013/04/29/adults_lack_stem_cells_for_making_new_eggs.html

Human and mouse ovaries both contain a big supply of germ cells before birth. Some of these will develop into eggs that will be released from follicles during ovulation. It has long been believed that there is a fixed supply of follicles after birth, leading to menopause when they run out. Researchers within the last decade have questioned this finding. Claims have now been made that the follicle pool is constantly resupplied. The scientists used a tracking technique to follow individual cells within a living animal over time. Their findings showed that follicles are very stable and stem cell activity cannot be detected. One stem cell division every two weeks was detected in the mice, but that was not a significant level. According to Spradling, the scientist researching this topic, "the same safety and reliability concerns would apply as to any laboratory-generates cell type that lacks a normal counterpart in the body."

I always thought that women were born with as many eggs as they would have for the rest of their life. From these findings, it is shown that this is mostly true, although new eggs are slowly being remanufacture in the body. Similar to any other mammalian females, humans have the ability to release one egg each month, which will never be gained back in the count.

NOS Themes:

• Science is based on evidence- the findings in the mice helped the researchers develop a conclusion about the topic
• Importance of repeatability- It is important to repeat this experiment to make sure that the findings would be consistent
• Role of chance- It is possible that one mouse may differ from another in the timing that this egg production takes place