The term modifications in genetics refers to both naturally occurring and engineered changes in DNA.

Incidental, or natural, mutations occur following errors during replication and repair, either spontaneously or due to environmental stressors. Intentional modifications are done in a laboratory for various purposes, developing hardier seeds and plants, and increasingly to treat human disease. The use of gene editing technology remains controversial.

Genetic modifications (incidental and intentional)

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Modifications are changes in an individual's DNA due to incidental mutation or intentional genetic modification using various biotechnologies. Although confusion exists between the terms "modification" and "mutation" as they are often used interchangeably, modification differentiates itself from mutation because it acts as an umbrella term, encompassing both definitions of mutation and genetic engineering. Although heritability plays a large role in an individual's expression, like in cases of epigenetic modifications, not all instances of modification are heritable. No matter the origins of such genetic variation, it impacts the creation and interaction of proteins, changing cell function, phenotype, and organism function.

Types of modification

Genetic modifications can occur naturally, through aforementioned mutations in an organism's genome, or through biotechnological methods of selecting a gene of interest to manipulate in order to make something new or improve upon what already exists. Although cellular processes are highly efficient, they are not perfect, causing disparities between organisms of the same species. The timing and duration of exposure to such elements is a critical factor, as it can significantly impact the phenotypic response of an organism, generally increasing severity with time.

Methods:

There are several methods, or forms, of mutation that exist including spontaneous mutation, errors during replication and repair, as well as mutation due to environmental effects. These origins of mutations can cause many different types of mutations which influence gene expression on both large and small scales. This type of modification can involve insertions or deletions of DNA bases into the existing genetic code. In biotechnological methodology, a series of four steps are used in order to create a genetically modified organism (GMO).

  1. Identify
  2. Researchers identify a trait of interest usually based on a desire to solve a problem. Since 2012, scientists have worked to develop this technology, which has the opportunity to both cure genetic diseases and genetically modify traits to be most desirable, purposefully altering DNA with a high degree of precision.

Examples

Mutation (incidental)

The dandelion: Most dandelions have long stems, but an increase in potential threats in their environment have caused average dandelion stem length to decrease within certain species, allowing them to better avoid said threats. This adaptation was possible due to a mutation occurring in a shorter-stemmed individual being selected by environmental pressures. Because the shorter-stemmed dandelions had higher fitness than long-stemmed dandelions and were able to survive more often, the genetic frequency of the population was altered, genetically modified through the original occurrence of a mutation. However, when a person has this disease due to inheriting two mutated copies of the HBB gene due to a base pair point mutation, their red blood cells are shaped differently.

Genetic engineering (intentional)

Alzheimer's disease: In a synthetic example in a laboratory, scientists isolated the amyloid precursor protein (APP) gene, known for using Alzheimer's in humans, and transmitted it into the nerve cells of worms. Through the following steps, scientists are able to genetically engineer a medical product that millions of people rely on worldwide: The scientific community recommends continued evaluation of risks and benefits of utilizing genetically modified organisms in everyday life. Genetic modifications are studied by researchers under controlled conditions after they are inserted into an organism, allowing for improved scientific understanding of the effects of certain gene modifications and certain organism responses.

Humans

In April 2015, gene editing technology was used on human embryos and debate about the ethics of such actions persisted since. Nonetheless, scientists and policymakers are in agreement that public deliberations should decide the legality of germ line genome editing. Modifying a person's non-heritable DNA with the goal of improving one's medical condition is generally accepted and has a plethora of ethical protocols monitoring such procedures. Regulations have been implemented for approval of genetically modified foods to reduce some uncertainty that remains in this field. The reasons in favor of development of genetically modified foods include to meet the demands of the exponentially growing human population, to substitute for the decrease in farmable land, and to address the decrease in genetic diversity which limits possible improvement of species. The biotechnology of genetic engineering provides the opportunity to achieve global food security by addressing these problems and positively impacting the food production economy.