RuBisCO is the carbon fixation bottleneck, the slowest, least efficient enzyme on Earth. Increasing farm output fold for the same inputs is a carefully forbidden triviality. It is a monetary sop thrown to his good buddies. In it grewacres of rice in desert!
Genes, through the proteins they encode, determine how efficiently we process foods, how effectively we detoxify poisons, and how vigorously we respond to infections. In the past 20 years, amazing new techniques have allowed scientists to learn a great deal about how genes work and how they are linked to disease.
This rapid pace of discovery of genetic factors, responsible for certain diseases, has allowed scientists to genetically test asymptomatic individuals and predict their risk of certain diseases.
In this paper, I am going to discuss the following areas pertaining to the topic of genetic testing: The definition and purpose of genetic testing Distinguishing major testing techniques with particular interest in the DNA chip Ethical considerations regarding genetic testing, explaining views on both sides Public policy pertaining to genetic testing and the use of the DNA chip and My personal opinion regarding the use of the DNA chip.
Definition of Genetic Testing Genetic testing is the analysis of human DNA, RNA, chromosomes, proteins, and certain metabolites in order to detect heritable disease-related genotypes, mutations, phenotypes, or karyotypes for clinical purposes 6.
There are several genetic tests currently in use which are used to look for a possible predisposition to certain diseases, as well as to confirm a suspected mutation in an individual or family. These tests vary from newborn screening, with the detection of abnormal or missing gene products to carrier testing, which allows couples to learn if they carry a recessive allele for an inherited disease and thus risk passing that allele onto their children.
They can also be used as a predictive gene test, which helps to identify people who are at risk of getting a disease before any symptoms appear The information from genetic tests can help provide people and families with answers to their questions: Genetic tests also provide scientists with information regarding disease pathogenesis.
For instance, by studying the genetic makeup of individuals with breast cancer, scientists can find out what particular mutation in the DNA, or in several genes, is causing the cancer and use that to screen high-risk individuals.
Researchers are also taking advantage of genetic tests to find gene mutations that make bacteria or viruses resistant to drugs. Screening Techniques The immediate challenge in genetic testing is being able to design an effective mutation analysis method that offers a rapid, accurate, cost-effective, and user-friendly test for scanning several susceptibility genes at once.
According to the article in Nature Biotechnology, by Charis Eng and Jan Viig, genetic testing techniques are grouped into two main categories: Screening methods involve probing specific genes for previously identified mutations.
For example, in breast cancer, mutations can be found anywhere within the large BRCA1 and BRCA2 genes, two of the many genes that have been implicated in breast cancer 1. Development of a separate DNA probe for each mutation has proven to be too expensive and time consuming to make screening methods feasible.
Scanning methods involve testing the gene or genes having no assumptions about any previous mutations 3. A major limitation in this method is that only the coding regions, splice sites and promoter regions are scanned 3. This excludes mutations within the regulatory regions other than the promoters, introns, as well as other genes whose protein products could potentially interact with the disease-causing gene.
Some of the scanning methods include: One of the major obstacles in developing successful screening techniques involves the size and complexity of disease related genes. DNA Chip Initially developed to enhance genomic sequencing projects, especially the Human Genome Project, DNA chips are finding applications throughout the field of molecular biology 2.
Gene scanning techniques that are based on oligonucleotide arrays called DNA chips, provide a rapid method to analyze thousands of genes simultaneously.
DNA chips are thus potentially very powerful tools for gaining insight into the complexities of gene expression, detecting genetic variations, making new gene discoveries, fingerprinting and developing new diagnostic tools 7. The production of DNA chips have evolved along two major pathways: In either case, the problem lies with how to attach the nucleic acids or cDNA to the chip.
Chips using nucleic acids are produced using photolithography. Photolithography, according to the Science article by Stephen Fodor, consists of the modification of synthetic linkers, containing photochemically removable protecting groups, attached to a glass substrate, usually a silicon-derivative glass chip.
Light is directed at the photolithographic "mask" at specific areas of the chip in order to facilitate the removal of the photoactive groups, yielding 5 hydroxy groups. These modified groups are now capable of binding other nucleotides, generating a highly specific probe, which contains the sequence of a known disease causing genetic mutation.
The other method, described in the DNA Chips and Microassays website, uses purified single-stranded cDNA from an individual with a known genetic disease, requiring the use of touch or fine micropipetting, to spot the cDNA onto the surface of the chip.
The cDNA immobilizes on the chip through covalent bonds, due to the positively charged surface, produced by amino silane or polylysine 2. For both types of chips, a potential DNA target sequence, from an asymptomatic individual, is fluorescently tagged and allowed to interact with the probes.
Hybridization will occur at complementary sequences between the two samples resulting in a fluorescent image, which is then scanned by a laser beam and analyzed by a computer.
This approach, requiring only minute consumption of chemical reagents and minute preparations of biological samples, can scan more thanprobes placed on a single chip measuring 1.Whole genome sequencing (also known as WGS, full genome sequencing, complete genome sequencing, or entire genome sequencing) is ostensibly the process of determining the complete DNA sequence of an organism's genome at a single time.
This entails sequencing all of an organism's chromosomal DNA as well as DNA contained in the mitochondria and, for plants, in the chloroplast. Genetic engineering is the direct manipulation of an organism's genome using certain biotechnology techniques that have only existed since the s.
Human directed genetic manipulation was occurring much earlier, beginning with the domestication of plants and animals through artificial selection. Genetic engineering is the science of altering living things by changing the information encoded in their deoxyribonucleic acid or "DNA".
Genetic information is stored in DNA using four different chemicals called adenine, cytosine, guanine and thymine. (Ralwel/Dreamstime) Conservatives and progressives both have reasons for opposing it.
T he genetic engineering of human beings has been a dream and a nightmare since scientists first speculated. Genetic engineering, also called genetic modification or genetic manipulation, is the direct manipulation of an organism's genes using biotechnology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms.
- Cracking Your Genetic Code: A Review of Genetic Testing In Gattaca, the plot focuses on the ethics, the risks, and the emotional impact of genetic testing in the nearby future.
The film was released in the 90s; yet in the present, the film does not give the impression of science fiction.