01-human perspective on genetics

8/3/2019 01-Human Perspective on Genetics

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Ahumanperspec-veongene-cs

Objectives: explain How genetics developed as a discipline What genes are, the basic way they work, and how

they are transmitted from parents to offspring

Methods employed to study genes The many ways in which the eugenics movement has

had an impact on society The impact on our lives ofbiotechnology and the

Human Genome Project


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Genes and genetics

What is genetics? The study of heredity. Of how traits are passed from

generation to generation

Importance: Genes control what cells and organisms are and look like;

how an organism develops and reproduces

Understanding genes is key to understand life Genetic-based technology (biotechnology) is ahead of public

policy and laws and constantly ignites debates

Knowing about genetics is important to make informeddecisions about personal and public life


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Genes and genetics

What are genes? How do they work? The structural and functional unit of genetics

A string of chemical units (nucleotides) in a DNAmolecule

The sequence of nucleotides stores information in theform of a genetic code

The genetic code holds the key to build chemical unitsthat make up gene products, mainly proteins

The action of proteins produces characteristics we canstudy (the phenotype)


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Genes and genetics

What are genes? How do they work? Properties of a gene

Genes can change (mutate) Genes can be expressed (turned on) or not (turned off) Genes can move from one chromosome to another

(recombine)


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Genes and genetics

How are genes transmitted? What we know about how genes are passed from one generation

to another is thanks to Gregor Mendel, a Czech/Austrian monk

from the 19th century

Mendel used plants with define discrete traits and did multiplecrossings keeping detailed records of the traits of eachgeneration

Mendel determined traits are inherited due to factors (latercalled genes), passed from parents to offspring

He observed each parent has two genes per trait, but onlypass one to their offspring

Mendels work went unnoticed until the early 20th centurywhen it was rediscovered, and acknowledged as having

seminal importance


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Genes and genetics

How are genes studied? Approaches

Transmission (a.k.a. Mendelian) genetics: The most basic approach; it studies how observable traits are

passed from generation to generation. Studied by directobservation (like Mendel did) or by pedigree analyses

Cytogenetics: Study of chromosome number and structure, and their link to

abnormalities. Main tool: Karyotypes

Molecular genetics: It uses recombinant DNA technology to identify, analyze, and

manipulate genes (and proteins)

Population genetics: It studies distributions and frequencies of genes and gene

variants (alleles) in populations and their relation to evolution


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Genes and genetics

How are genes studied? Genetics in basic and applied research

Genetics has the same dualities of any science Basic research: to understand a process or a

phenomenon; how things work Knowledge generates more questions and more research

Appliedresearch: Solving practical problems usingknowledge from basic research

In applied research controversies exist Impact of genetically modified organisms in nature and human health Manipulation of hormones to increase the production of milk or meat Privacy of genetic information obtained from individuals

Understanding concepts in genetics is important to know howto use biotechnology in our lives Good youre taking this class


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Genetics and society

Impact on social policy Afterthe origin of species was published Darwins cousin, Francis Galton, proposed the use ofnatural

selection to improve the human species

He started the field ofeugenics Claim: The social, intellectual, and economic level of humans

can be improved by selective breeding (!!!), to save resources

and lessen human suffering

discouragingundesirables to procreate Do only genes matter? Hereditarianism Who decides what an undesirable trait is? Eugenics influenced public policy in the 20th century


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Eugenics and immigration law Eugenics impacted immigration law, because it associated social

problems, like crime and poverty, with genetics

Immigration from Asia and southern and eastern Europe wasdiscouraged

Immigration from Northern and Western Europe wasencouraged

because of the inhabitants genetic superiority Is there such thing?


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Eugenics and reproductive rights Eugenics also impacted reproductive rights because claims were

believed by some legislators

Acts were passed requiring sterilization of those who weregenetically, morally, or intellectually inferior

criminals, mentally disabled (imbeciles), prostitutes,promiscuous people (who some times were actually

rape victims)

Between 1927 and 1979 over 60 000 people weresterilized in the U.S.

Mainly in CA, VA, NC, MI, GA Some have recently apologized


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Eugenics and the Nazi movement Sterilization was initially prohibited in Germany

until eugenicists allied with the Nazis who encouraged the use of eugenics to preserve the

Aryan race

Hitler passed laws to sterilize the undesirable Eventually to execute them

Jews, gypsies, alcoholics, communists andgovernment detractors were eventually covered by

this definition. Gas chambers were designed to make the executions

more efficient

Popularity of Eugenics among Nazis made it increasinglyunpopular in the U.S.


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Impact of genetics today Since the discovery and isolation of restriction enzymes in the

1970s

recombinant DNA technology has become the foundationof many applications

Gene therapy, genetic testing, CSI, biotechnologyindustry, among many more

One of the most important projects based on the use ofrecombinant DNA technology

is the Human Genome Project (HGP) The final version of the human genome sequence was

published in 2003

We now know the human genome has around 3 billionnucleotides and somewhere between 20K and 25K

genes


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Impact of genetics today Information from the HGP is

being used in a large variety of

new projects

many of which involve researchfor curing or preventing diseases The study of the human genome

and other complete genomes

gave rise to the field ofgenomics

An entire genome can bescreened using microarrays,

a.k.a. DNA chips


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Impact of genetics today Biotechnology is another way in which genetics impacts

everydays life

Products and services based on recombinant DNAtechnology are wide spread in todays world

Products are found in Drugstores Grocery stores Hospitals Places related to the chemical industry

Services are provided/used by Hospitals and pharmaceutical industry The justice system Farmers NGOs Private citizens


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A human perspective on genetics

Objectives revisited: explain How genetics developed as a discipline

What genes are, the basic way they work, and howthey are transmitted from parents to offspring

Methods employed to study genes The many ways in which the eugenics movement has

had an impact on society

The impact on our lives ofbiotechnology and theHuman Genome Project


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Homework for Lab 01

01-human perspective on genetics

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