Question:
Topic
DNA Profiling: Paternity testing, breeding captive endangered species, crime scene investigation
Task
Do a research report on genetic engineering.
These sections will comprise the report.
Briefly introduce the particular example of genetic engineering.
Incorporate a social issue related to this example.
Histories or Background
Please describe the background and history of the creation of this particular example.
Scientists use this method
Describe the methodology used by scientists in the laboratory to create the technology.
Discussion on a pertinent social issue
Discuss a relevant social issue to genetic engineering.
Consider the opposing views and discuss more than one point of view.
Answer:
Introduction
The X chromosomes are found in human female germ cells. Human males have one X chromosome and two X chromosomes.
Female offspring are produced when fertilization is done via X-bearing sperm. Fertilization by Y-bearing sperm or X deficient sperm results into make offspring.
The ability of male gamete and the presence unique Y chromosomes within male gamete allow for paternal testing to be established (Bachtrog 2013, Battrog).
The DNA profiling or DNA fingerprinting is used to perform parental testing via the Y chromosome.
A woman can scientifically identify the father of a child by using parental testing.
A woman might also try to avoid sharing custody with her ex-husband who she knows is not the biological father of the child. This can be done using DNA profiling in parental screening.
Sometimes, an adopted child will vouch for the identity of the biological father/mother. This is when the importance of DNA profiling in paternal tests comes into play (Buckleton and al.
Background
Most violent crimes are committed by men. In most cases, the victims of sexual offences become pregnant.
The only thing that can be used to determine the true culprit is the sperm.
The Y chromosome, which is the main determinant of maleness is used to support paternal testing through DNA profiling or DNA fingerprinting (Toom 2012).
About the Y chromosome
Human Y chromosome is genetically unrelated to the X chromosome.
Later, however, it was discovered that Y chromosomes contain fewer genes than the x chromosome.
The pseudoautosomal areas (PARs), located at two extreme ends of Y-chromosome, share homology to the X-chromosome. The remaining 95% of Y-chromosome is not homologous with the latter and is called non-recombining area of Y-chromosome Y (NRY) and male specific region Y (MSY).
The MSY can be divided into heterochromatic and euchromatic regions (gene-rich)
The sex-determining region of Y (SRY) is located in the euchromatic area, which is adjacent to the PAR.
This euchromatin area, or the gene rich region on the Y chromosome, is the main target of DNA profiling for paternal testing (Jangravi et. al 2012).
The intergenic portion, which is the majority of the genome’s DNA, is composed of a mix of unique and repeated sequences. These sequences are called satellite.
These satellite are a useful tool in genetic engineering.
For paternity testing, the Variable Number Of Tandem Repeats (VNTRs) method is used.
VNTRs can be used to determine if there are any changes in the frequency of microsatellites. This provides the basic information for paternal testing (Poznik, et al.
Alec Jeffreys and his colleagues discovered the DNA fingerprinting method.
Alec Jeffreys et al. discovered DNA fingerprinting in 1985. In 1987, the first DNA fingerprinting application was made in Bristol, UK. This was to investigate a case that had a link between burglary or rape.
You can generate DNA fingerprinting using either site-specific probes or random probes simultaneously.
Jeffrey used multilocus probes that were repeated in tandem within myoglobin’s intron (Roewer 2013, Jeffrey).
Scientists Use This Method
DNA fingerprinting is the most popular method that scientists are using to test for parental rights.
The researchers employ the micro-satellites (STRs), as probes.
The gene rich region of Y-chromosome contains the DNA.
The DNA was then amplified using STRs, which are probes that are specific to either the gene rich region or the euchromatin area of the Y-chromosome.
Next, the amplified DNA undergoes restriction digestion (also known as Restriction Fragment length polymorphism or RFLP).
The DNA fragments that have been digested are then subjected to agarose electrophoresis.
This process separates the DNa based on their mass/charge.
The response of the charged electrical field makes the smallest DNA move faster.
The DNA isolated is then subject to Southern blot Hybridization.
The DNA samples are then separated from the agarose gel by using a nylon membrane. This is done under the charge electric field.
Certain chemicals are used in the running buffer to separate the double-stranded DNA from the single-stranded.
Under the UV light, the single-stranded DNA is cross-linked.
After the radio-labeled probe (microsatellite), is allowed to bind with the single stranded amplified genetic DNA, an X-ray film over the nylon gel is applied to detect radio activity.
DNA fingerprinting is the visible pattern of a radio band.
The father and the band are then compared to determine the similarity.
Recent times have seen the after product of PCR undergo restriction digestion before the digested DNA fragments are subject to sequencing.
To detect homology, the sequence pattern of the father and son is compared (Dolf 2013).
Social Issue
The parental DNA profiling can lead to many social problems.
Opposing Views
The DNA profiling used in parental testing can pose a number of risks, including financial, emotional and social.
The results can sometimes cause people to feel angry, insulted, or anxious.
The results of genetic testing can cause tension within the family, as they may reveal information that is not comfortable for other family members.
It may also open the door to genetic discrimination in insurance and employment.
The family law lawyers are of the view that although the test may provide clarity, the results can lead to emotional territory not yet known.
Parents who have adopted a child from their biological parents may be affected by the paternity test.
Legal parents who have given everything to the child’s care may be hurt by their child’s request to hunt down their biological father.
A man might be tempted to avoid financial responsibility for a child, or may feel disgusted by the fact that he isn’t the biological father of the child he nurtures (Milunsky 2012).
False positive results may also be generated by DNA profiling paternity tests.
The small tandem repeat (STR) or small nuclear polymorphisms (SNP), are unique to each individual. Therefore, random STRs may be used as a probe and could lead to false positive results (Pena 2013, Lu et. al.
Supporting Views
For women fighting for financial rights for their children and their biological fathers, DNA profiling for paternal test has proven to be very helpful.
These women are often rape victims in most caes.
The person found guilty often denies taking responsibility for his children, claiming that the girl or boy does not have his share of chromosomes.
The advent of DNA fingerprinting and DNA profiling has made it easier to identify the biological father of the children. This allows them to claim their rights as citizens.
The DNA profiling was also used to identify the convicts in rape cases (Alrc.gov.au 2017).
The process of DNA fingerprinting may be used by orphans who leave an orphanage to identify their biological father and obtain their family rights.
This theory also applies to children who are born from in-vitro fertilization or artificial reproduction (Ravelingien & Pennings 2013).
Additional supporting views are available here
The right of men to claim or test their paternity is theirs
The rights of children to know their biological parents are protected
Refer to
Y chromosome evolution. Emerging insights into the processes of Y chromosome degradation.
Nature reviews.
Taylor, D.
Interpretation of DNA evidence forforensic purposes.
CRC Press.
Bodies of science, law, and biology: Forensic DNA profiling, biological body, and biopower.
Journal of Law and Society 39(1): pp.150-166
An update on the male-specific area of the human Ychromosome.
Journal of proteome Research, 12(1), pp.6-22.
2013 and Bustamante C.D.
Sequencing Ychromosomes solves discrepancy between time and common ancestor for males and females.
DNA fingerprinting: Approaches and Applications (Vol.
Genetics and the Law.
Springer Science & Business Media.
The state of DNA fingerprinting science.
Lu, D.., Liu Q., Wu W., and Zhao H. (2012)
Mutation analysis of 24 short tandem repetitions in the Chinese Han population.
International journal of legal medicine, 126.2(2), pp. 331-335.
Ravelingien A. and Pennings G., 2013.
The right to know your parents’ genetic heritage: From open-identity genete donation to routine paternity tests.
The American Journal of Bioethics 13(5): pp. 33-41.
ALRC.
Mutation analysis of 24 short tandem repetitions in the Chinese Han population.
International journal of legal medicine, 126.2(2), pp. 331-335.