Overview of egg stem cells
Abstract
Currently, the ability of a woman to produce eggs is limited by the age of the woman and the quality of the eggs that the older women produce. The research that was done about stem egg cells can address the issues of age and quality of eggs. Egg stem cells are eggs that are able to differentiate, or develop to other types of cells of the human being. There are possibilities that the new discoveries of egg stem cells is that they could be used and developed into new eggs. Even if this is not a possibility they could still be used to rejuvenate the eggs that women already have
Overview
Research has shown that women have egg stem cells in their ovaries and carry these cells to their adulthood. This discovery brings the possibility of extending the age at which a woman can have children. Research is being undertaken to have this discovery yield some fruitful discoveries regarding women. (Daley 2010).
Methodologies to egg stem cells research
There are emerging egg stem cells in the research that is being carried out in this field of egg stem cells.
Mice cell approach
One of the approaches is that of using mice cells. This has produced live and normal mice. This approach has been used, for a while as scientists have been able to coax stem cells to be able to create different types of cells in the human body. One issue that has been experienced is that of generation of mature human cells in the whole process. This has been elusive in the process. Japan scientists have reported that they have been able to use mouse embryonic cells and mouse cells that have been reprogrammed. This is so that they behave as though they were stem cells. These have been in order to produce mouse egg precursor cells. They then combined the precursor cells with that of mouse fetal cells and implanted them in the ovaries of a mouse. The ovary helped the eggs to develop into oocytes which were then transplanted to in vitro process so that an embryo could be created(Hayashi & Saitou 2013).
Adult mammal approach
Another approach was that of using adult mammals to make new eggs. This approach was undertaken in an experiment that tried to prove that women of the age of reproduction are able to create new eggs. The researchers made use of the knowledge of the mice to find out new knowledge regarding new cells from those that still subdivide(Tachibana et al. 2009).
Comparison of the approaches
The first approach seems to have a long way to go because of the fact that there is still a lot of research to be undertaken. This is because of the need to be able to use mature human cells in the research. The second research is viable because of the fact that stem cells can be used to regenerate new human cells. The disadvantage of the first approach of using egg stem cells of adult mice is that it is still hard to get viable results from mature adults. There is still a lot of research that needs to be undertaken in the process(Oatley & Hunt 2012).
In the use of in vitro process, there are ethical issues that need to be undertaken and solved before the method can be considered to be successful.
Issues that still need to be address
There still issues that need to be solved in the whole process. One of the issues that still need to be solved is that of the fact that egg stem cells that were found in the ovaries of women were not found to be useful and functional and would help in any way.
Nanopore sequencing
Abstract
The nanopore technology gives a spaced which is highly confined and enables the analysis of a nucleic acid at high throughput using one of the approaches. There are various approaches which have been developed in the entire process and give a way in which different comparison can be undertaken. This paper will focus on the approaches that have been used in research of nanopore sequencing.
Overview
This is a method that was developed to determine the order in which nucleotides occur in DNA strands. The theory that was used in this development is that when a nanopore is immersed in conducting fluid and voltage is applied across the fluid, there is an observation of electric current that is seen in the fluid. The size of the current that is used in the process is sensitive to the shape and the size of the nanopore that is used(Rhee & Burns 2007).
Methodologies use for nanopore sequencing research
Fluorescence
There are many methods that are used in the development of this technology. One of the approaches is fluorescence approach. This is an approach where there is the conversion of each base into characteristic representation of many nucleotides. These nucleotides bind together so that they form fluorescent probe dsDNA. The identification of the bases is undertaken using two color schemes which have been proposed(Rhee & Burns 2006).
One advantage of this approach is that there is a clear readout of the sequencing process. This makes it use camera instead of using noisy outputs. One disadvantage of this approach is that there is a need to convert each sample preparation to expanded codes of binary(Branton et al. 2008).
Electron tunneling
This is another approach to nanopore sequencing. This is an improved process where electron tunneling is measured through bases as ssDNA moves through nanopore. The procedure is undertaken by creating a collection of pores which are then chemical vapor deposition are used to develop nanotubes that will develop across the array(Derrington & Butler 2010).
Comparison of the approach
The advantage of this method is that it is possible to control the sense of the bases. Unlike the fluorescence technology, the method can be used to control the translocation process of the bases and the speed of translocation.
Issues that still need to be addressed
The issues that still need to be resolved include refining the method so that it will be able to detect single bases. In the early methods where paper was used, a nucleotide had to be, sequentially, repeated about 100 times in order to realize measurable characteristic changes(Rhee & Burns 2007).
References
Branton, D., Deamer, D. & Marziali, A., 2008. The potential and challenges of nanopore sequencing. Nature .
Daley, G., 2010. Stem cells: roadmap to the clinic. The Journal of clinical investigation.
Derrington, I. & Butler, T., 2010. Nanopore DNA sequencing with MspA. Proceedings of the .
Hayashi, K. & Saitou, M., 2013. Generation of eggs from mouse embryonic stem cells and induced pluripotent stem cells. Nature protocols.
Oatley, J. & Hunt, P., 2012. Of mice and (wo) men: purified oogonial stem cells from mouse and human ovaries. Biology of reproduction.
Rhee, M. & Burns, M., 2007. Nanopore sequencing technology: nanopore preparations. TRENDS in Biotechnology.
Rhee, M. & Burns, M., 2006. Nanopore sequencing technology: research trends and applications. Trends in biotechnology.
Tachibana, M., Sparman, M. & Sritanaudomchai, H., 2009. Mitochondrial gene replacement in primate offspring and embryonic stem cells. Nature.
