6.3.1-2 - AI and Genetic Change Flashcards
Marker assisted breeding
DNA markers assist in selective breeding, as they are used to check for specific traits in offspring at young ages, before the trait is expressed.
This is by determining the entire genetic makeup of the model organism through DNA sequencing. Therefore, this altered DNA sequence can be identified, and used to identify detect the trait in any stage of the crossing process.
This is useful in integrating desired traits (such as recombinantly edited) into varieties preferred by farmers. DNA isolated from the young plant and is analysed for the DNA marker (gene sequenced from the model plant). This reduces time incorporating traits, increasing efficiency and helps maintain biodiversity by integrating desired traits not through cloning but through hybridisation.
CRISPR
A gene editing tool, allowing gene editing to occur faster and more efficiently than before to speed up research into diseases such as cancer and mental illness.
Two components: Cas9 protein that can cut DNA, guide RNA that recognises the sequence that is to be editied.
DNA sequencing is a preliminary step - guide RNA based off of this to identify the harmful sequence.
The CRISPR/Cas9 sequence is introduced to target cells - locate target letter sequence and makes cuts. Scientists can modify, delete, insert new sequences.
Future: used to develop critical advances in patient care, or cure inherited disease
Comparison of genetic technologies and reproductive technologies
Definition:
* G: Manipulates/alters the DNA
* R: aides organisms in reproduction, genetic or artificial transfer of gametes
* E: GMOs, gene cloning, CRISPR, gene therapy.
* P: Remove faulty DNA from an individual (ultimately a species), increase population numbers, introduce new traits, improve traits.
Examples:
* G: GMOs, Gene therapy, CRISPR, gene cloning
* R: IVF, whole organism cloning, artificial pollination, artificial insemination.
* P: To promote sexual reproduction in a population, increase population number, increase genetic diversity, pass on favourable traits, increase allele frequency of a specific trait.
Artificial insemination
Collecting male gametes and artifiically inserting them into one or several female.
Outcomes:
1. Certain animals with specific traits reproduce with the aim of porducing offspring with both parent’s traits: high milk production, meat quality.
2. No need for maintenance of a breeding bull for a herd (reducing cost)
3. Prevents spread of certain disease and sterility due to gentical diseases.
4. It increases the rate of conception
5. Better record keeping of family pedigree
6. Old, heavy, injured sires can be used.
Advantages:
1. Can aquire specific traits
2. Higher profits - no transport of animals but sperm + less maintenance for males + less strain on environment (more resources per animal)
3. Conception rate is higher - helping endangered species and efficiently growing the herd.
4. Gene flow – increase genetic variation of the species.
Disadvantages:
1. Decreased genetic diversity
2. Susceptible to extinction due to reduced gene pool and allele frequency.
3. Inbreeding - accumulation of mutations
4. Ethically could be stated as unnatural.
Artificial Pollination
Controlled pollination - instead of natural animal/environmental pollinators. The stamen of the flower is removed or pollen is removed and dusted.
Advantages
* Wild bees are becoming nearly extinct worldwide (completely extinct in China) due to overuse of pesticides and destruction of their natural habitats. Artificial pollination is an important tool for agriculture.
* Apple and pear are hand pollinated - pots of pollen and paintbrushes to pollinate each flower individually.
* Monoculture: not enough food or shelter for wildlife. Therefore, decrease of natural pollinators and biodiversity. Artificial pollination helps alleviate this shortage. E.g. almond orchards have a short flower time so bees cannot survive naturally (no other plants to feed on).
Disadvantages:
* Takes a lot of time to apply
* May not be cost effective
* Often reduces the size of fruit.
Selective breeding
AKA artificial selection, ensures that desirable traits reproduce and are maintained for future generations.
Agriculture: crops like wheat and corn are selectively bred for higher yields, resistance to pests, better nutritional content
Advantages:
* Increased productivity
* Allows for better adaptation to environmental conditions
Disadvantages:
* Inbreeding - accumulation of mutations
* Reduces genetic diversity
* Desired traits can have negative health implications (pugs)
IVF
In Vitro Fertilisation: An assisted reproductive technology that helps individuals or couples conceive when natural reproduction is not possible or has low success rates
Steps:
1. Ovarian stimulation: hormonal medications are given to stimulate the ovaries to produce multiple eggs.
2. Egg retrieval: minor surgical procedure extract mature eggs from ovaries.
3. Sperm collection and fertilisation: sperm is collected and either mixed with the eggs in a petri dish or injected directly into an egg
4. Embryo culture: monitored for growth and development
5. Embryo transfer: one or more healthy embryos are transferred into the uterus for implantation.
6. Pregnancy test: blood test performed about two weeks later to determine if the implantation was successful.
Advantages:
* Helps overcome fertility challenges
* Increases the chances of pregnancy when other methods fail.
* Genetic screening to prevent hereditary diseases.
Disadvantages
* Physically and emotionally demanding
* Expensive, not always covered by insurance.
* Ethical concerns around unused embryos.
* Implications to the rise of “designer babies”
