Genetic Technology Unit

Embryonic Stem Cells

-An undifferentiated cell, taken from the inner cell mass of a blastocyst, a stage of embryonic development -Pluripotent: has the potential to give rise to cell or tissue types of the three main layers that all human parts and organelles develop from: the ectoderm, mesoderm, and endoderm -Used to build our body in the developmental stage

Gene therapy vs enhancement implications

-Germline gene therapy could be targeted to egg and sperm cells (germ cells), however, which would allow the inserted gene to be passed to future generations, thus enhancing the gene's expression -While it could spare future generations in a family from having a particular genetic disorder, it might affect the development of a fetus in unexpected ways or have long-term side effects that are not yet known. -Because people who would be affected by germline gene therapy are not yet born, they can't choose whether to have the treatment.

cancer stem cells

-Slow dividing, tumor-forming cells in a cancer that can give rise to all the cell types in a particular form of cancer. -Have the properties of normal stem cells: self-renewal and ability to differentiate into multiple cell types. -control tumor development: Involved in the growth and proliferation of tumor mass, metastatic dissemination: spread to other organs, drug resistance and cancer recurrence.

somatic cell nuclear transfer

-Technique for cloning -Removing the nucleus of an unfertilized egg cell, and replacing it with the material from the nucleus of a "somatic cell" (a skin, heart, or nerve cell, for example), stimulating this cell to begin dividing.

Physical state of active genome

-The genome is relaxed, and loosely wrapped around the histones, making the coding genes easily accessible -few methyl molecules are attached, while many acetyl tags are. -Because the gene is accessible, transcription can occur, and creating many mRNA transcripts

stem cell

-Unspecialized -Ability to self-renew: can divide for long periods of time while remaining undifferentiated -Have potency: give rise to different differentiated cell types -give rise to all of the differentiated tissues and organs in our body & help to heal and maintain our bodies

Whole Genome Evaluation (implications)

-Whole genome sequencing is the list of the billions of base pairs of the DNA that make up your genetic code -You can learn about a recommended nutrition and diet, your ancestry, disease risk, and discover improper sequences in the genome

Physical state of inactive genome

-chromatin is tightly wrapped around the histones, making the gene unreadable -few acetyl molecules are attached, while many methyl molecules are. -Because the gene is not accessible, transcription can't occur, so there are few mRNA transcripts

CNVs

-copy number variants -When the number of copies of a particular genetic sequence is different between individuals. -some are linked with disease, like diabetes, while others have no effect.

Cell Replacement Therapy utilizing iPS

-iPS cells can be generated from the actual patient, meaning they are genetically identical to the individual patient. -This way, we can generate embryonic-like cells that can differentiate into new cells, forming new organs and tissues that won't be rejected by the patient's immune system after transplantation.

SNPs

-single nucleotide polymorphisms -variations in the DNA sequence that occur when a single nucleotide in the genome is altered -account for the genetic differences between you and everyone else on the planet -most lead to no observable differences

4 environmental factors that influence the epigenome

1. Diet 2. differences in physical activity 3. exposure to toxins 4. stress

2 Functions of regulatory proteins

1. Switch specific genes on or off; They attach to and control a specific sequence of DNA on one or more genes. 2. Recruit enzymes that add and remove epigenetic tags to DNA, the histones, or both. These tags give the cell a way to "remember" long-term what its genes should be doing.

Regulatory Gene

A gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes.

Explain how a high-nurturing mother rat shapes her pup's epigenome, and what that pup's response to stress will be.

A high-nurturing mother rat shapes her pup's epigenome by activating the pup's GR gene, causing her pup to have a lower heart rate and an easier time relaxing after stress.

DNA chips

A microarray of DNA oligonucleotides fixed with high precision to a glass slide (spotting). The specific binding properties of bases then serve to detect complementary patterns in the test sample -Gene expression profiling -genotyping -DNA sequencing

activator

A protein that binds to DNA and stimulates transcription of a specific gene. -increases the affinity that RNA polymerase has for the promoter.

Repressor

A protein that binds to an operator and physically blocks RNA polymerase from binding to a promoter site. -suppresses the transcription of a gene -Activated by tryptophan

microRNA

A small, noncoding RNA molecule, typically about 21 bases long, that binds to mRNA to inhibit its translation. -Post-transcriptional regulation of gene expression

GWAS

A type of study that evaluates the entire genome of multiple people to test whether certain genetic variants correlate to particular traits. -See if any unique set of SNPs might be associated with a particular Common Disease

In rats, does licking by the mother activate, or deactivate her pup's GR gene?

Activate; this activation will most likely be consistent throughout the rest of its life.

induced pluripotent stem cells (iPS)

Any cell, even a highly differentiated cell in the adult body, that has been genetically reprogrammed to mimic the pluripotent behavior of embryonic stem cells -core of regenerative medicine: to repair damaged tissues with the stem cells of their own body without any worry of the body's immune system rejecting the cell line.

Bio-artificial Organs

Bioengineered organs or tissues that are implanted into a person intended to replace the functions of a natural organ (such as an artificial heart).

Gene Expression and Regulation

By controlling which genes are active, a cell can take on special characteristics. All cells have the same DNA, however regulatory mechanisms result in selective gene expression.

True or False. Cell signals play a role in shaping gene expression only during development.

False; After birth and as life continues, a wider variety of environmental factors play a role in shaping the epigenome, for example social interactions, physical activity, and diet. They can all generate signals that travel from cell to cell throughout the body.

Heterochromatin

Highly condensed chromatin that is transcriptionally inactive.

Often, the physical characteristics of genetically identical twins become increasingly different as they age, even at the molecular level. Why?

Identical twins result when a single embryo splits in two, each with the same genome and epigenome. -Because twins share the same environment, their epigenomes are very similar at birth and through the early years of life -as the twins age their environments begin to differ. -Thus, their genomes remain the same but signals from the environment act on the twins epigenomes to activate and silence different genes.

Genetic Transformation Lab

Inserting a recombinant plasmid with the genes of interest into a bacterial cell, giving the bacteria new genes that allows it to produce proteins that glow under UV light (GFP gene), and the ability to resist antibiotic amphicillin (beta-lactamase gene)

Relate humans to rats

Like rats, humans are largely affected by the way they were nurtured. Their epigenomes develop differences that affect their response to stress later in life, depending on whether they received high or low nurturing. If positive relationships are developed with a child's high-nurturing parents, the child is likely to develop into a person that copes with stress better than others. In addition, when there are positive social implications, the child will be friendlier and have an easier time developing relationships with others.

Gene expression

Process in which the specific information from a gene is used in the production of proteins. It determines what a cell can do.

What molecule is primarily responsible for carrying cell signals to DNA?

Proteins; Once a signal reaches a cell, proteins carry information inside, passing information to one another in a series until the information is ultimately passed to a gene regulatory protein that attaches to a specific sequence of letters on the DNA.

Operator

Region of DNA that controls RNA polymerase's access to a set of genes for transcription or not

Asymmetric replication

Stem cell property: - 2 cells from mitotic division not identical - one is a daughter cell that is differentiated, and the other is identical to the original stem cell. -The differentiated daughter cell can go on to become more specialized, while the new stem cell replaces the stem cell that divided initially.

Epigenome

The DNA wrapped around the histone covered in chemical tags -made up of chemical compounds and proteins that can attach to DNA and direct such actions as turning genes on or off, controlling the production of proteins in particular cells.

Therapeutic cloning

The cloning of human cells by nuclear transplantation for therapeutic purposes, such as the generation of embryonic stem cells to treat disease. -The generated embryonic stem cells will have a genetic match to the nucleus donor.

Explain how cortisol and the GR protein work together in the brain to relax a rat pup. You may draw a diagram.

The cortisol binds to GR proteins and when enough cortisol's are binded to GR proteins the brain sends out a message to stop the production of cortisol and stop the fight or flight stress.

euchromatin

The less condensed form of eukaryotic chromatin that is available for transcription.

Somatic stem cells VS embryonic stem cells

Under natural conditions, adult stem cells can give rise to just a few cell types,

Reproductive cloning

Using a somatic cell from a multicellular organism to make one or more genetically identical individuals. -Implementing the newly formed egg cell with the somatic cell nucleus into a surrogate mother and brought to full term in order to create a cloned individual (dolly the sheep)

Are epigenetic tags passed to daughter cells?

Yes; As cells grow and divide, cellular machinery copies epigenetic tags along with the DNA. This is important during embryonic development, as past experiences inform future choices, which allows the epigenome to remember their past experiences long after signals fade away.

Can the diets of parents affect their offspring's epigenome?

Yes; When pregnant the mother should eat a methyl enriched diet to provide enough methyl for her offspring. On the other hand, the amount of food the father eats can affect if his offspring will have diabetes or have a long or short life span. The less food he eats the longer his offsprings life should be.

methylation

a biochemical process that influences behavior by suppressing gene activity and expression -addition of a methyl group -causes inactive heterochromatin that is transcriptionally silent

transcription factors

a collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription -Bind to a section of the promoter, usually the TATA box -They have a binding domain (contains the affinity for a specific DNA sequence) and an activation domain (binds to other regulatory proteins to enhance transcription)

CRISPR/Cas9

a unique technology, derived from the immune system of simple prokaryotes, that enables geneticists and medical researchers to edit parts of the genome by removing, adding or altering sections of the DNA sequence. -allows highly specific and low cost gene editing -CRISPR stores the genetic information and requires a protein to make the edits Cas9: a type of enzyme that can cut any DNA sequence at a precise location, by changing the guide RNA to match the target.

differentiated cells

cells that have different functions - become specialized into tissues, organ and organ systems.

chimeric embryos

embryos made from tissues of more than one genetic source -surrogate hosts, like pigs, can use a hybrid zygote from a human and pig in order to develop an embryo and grow the organs that can later be transplanted into humans.

Imprinted gene

genes expressed in a parent-specific manner, because they contain the tags of the mom or dad's chromosomes after fertilization.

Histones

protein molecules around which DNA is tightly coiled in chromatin

Promoter

region of DNA that indicates to an enzyme (RNA polymerase) where to bind to make RNA through the process of transcription

Adult (somatic) stem cells

stem cells that are found in adults that are multipotent: differentiate and form a limited number of cells -play an important role in growth, maintenance, and repair. Replenishing tissues that need to be replaced

acetylation

the addition of acetyl group to DNA and histones causes nucleosomes to loosen and spread apart -allows for the structure to be easily accessed by transcriptional machinery for the expression of genes

How does the food we eat affect gene expression?

the amount of food containing methyl-making supplements and change the gene expression to have more or less methyl depending on the food you eat

Operon

the promoter, the operator, and a group of genes operating together

epigenetics

the study of environmental influences on gene expression that occur without a DNA change

Gene therapy

the transplantation of normal genes into cells in place of missing or defective ones in order to correct genetic disorders.

multifactorial traits

traits that result from the interaction of one or more environmental factors and two or more genes

Positive gene regulation

when a regulatory protein interacts directly with the genome to switch transcription on