Human Intervention Human Intervention in evolutionin evolution

Chapter 16Chapter 16

Selective breedingSelective breeding

Artificial selection used Artificial selection used to improve herd quality.to improve herd quality.

Select best male to mate Select best male to mate with breeding females.with breeding females.

The deliberate selection The deliberate selection by a breeder of specific by a breeder of specific animals to provide the animals to provide the genetic material for the genetic material for the next generations-next generations-Selective breeding.Selective breeding.

Contrast of random Contrast of random matingmating

Artificial Artificial SelectionSelection

Occurs when breeders favour Occurs when breeders favour particular inherited features in particular inherited features in their livestock because of their their livestock because of their economic value or aesthetic economic value or aesthetic value & use selective breeding value & use selective breeding to enhance those features & to enhance those features & inc. their frequency.inc. their frequency.

Contrast to Natural Selection as Contrast to Natural Selection as favours aesthetic/economic favours aesthetic/economic features, not those for features, not those for survival/reproduction.survival/reproduction.

Not necessarily features that Not necessarily features that good for survival/reproductiongood for survival/reproduction

Negative feature stays in gene Negative feature stays in gene pool only by humans pool only by humans intervening. intervening.

Reproductive technologies-Reproductive technologies-Human interventionHuman intervention

Artificial inseminationArtificial insemination Involves collecting semen from Involves collecting semen from

a stud animal and place it into a stud animal and place it into reproductive tract of female-reproductive tract of female-same speciessame species

Inc. no of offspring stud animal Inc. no of offspring stud animal can make. Split sperm into 10-can make. Split sperm into 10-put into 10 diff. females.put into 10 diff. females.

Freezing involved.Freezing involved.– Fertilise more femalesFertilise more females– Fertilise females that are distantFertilise females that are distant– Fertilise females after deadFertilise females after dead– Specific allele will become more Specific allele will become more

prominent & alternatives goneprominent & alternatives gone– Potential to lose valuable allelesPotential to lose valuable alleles

Oestrus synchronisationOestrus synchronisation When is possible to When is possible to

predict oestrus cycle of predict oestrus cycle of females in a narrow females in a narrow time frame.time frame.

Advantages:Advantages:– Less time needed to test Less time needed to test

animals to see if fertileanimals to see if fertile– Higher fertilisation rates Higher fertilisation rates

& birth rates& birth rates– More manageable and More manageable and

uniform crops of animalsuniform crops of animals– Lower mortality rates of Lower mortality rates of

newbornsnewborns

Reproductive technologies-Reproductive technologies-Human InterventionHuman Intervention

Sex selectionSex selection Chromosome dyed & can see Chromosome dyed & can see

sex chromosome now. X sex chromosome now. X larger than Y chromosome, larger than Y chromosome, more DNA so brighter.more DNA so brighter.

Can separate sperm now so Can separate sperm now so sex selected-males.sex selected-males.Manipulate breeding cycleManipulate breeding cycle

Done through Oestrus Done through Oestrus synchronisation-become synchronisation-become fertile in specific period.fertile in specific period.– High fertilisation rateHigh fertilisation rate– Lower mortalityLower mortality– Managing young easier-same Managing young easier-same

timetime– Less tests neededLess tests needed

Reproductive technologies-Reproductive technologies-Human interventionHuman intervention

Artificial pollinationArtificial pollination Involves:Involves:

– Removal of unripe stamensRemoval of unripe stamens– Protect stigma of selected Protect stigma of selected

female from stray pollenfemale from stray pollen– Collection of desired pollenCollection of desired pollen– Transfer of pollen to stigmaTransfer of pollen to stigma– Make new species by mixing Make new species by mixing

pollen & stigma of closely pollen & stigma of closely related species. Chemical related species. Chemical treatment needed. treatment needed.

Reproductive technologies-Reproductive technologies-Human interventionHuman intervention

Cloning-No sex Cloning-No sex Asexual reproduction-DNA from 1 Asexual reproduction-DNA from 1

parent only.parent only. Embryo SplittingEmbryo Splitting: cells of early : cells of early

embryo are seperated. Each ind. embryo are seperated. Each ind. cell put into uterus of surrogatecell put into uterus of surrogate

Identical ind. FormIdentical ind. Form Nuclear transferNuclear transfer: remove nucleus : remove nucleus

from cell (enucleated).from cell (enucleated). Transfer nucleus from 1 cell into Transfer nucleus from 1 cell into

another cell.another cell. Fuse somatic cell with enucleated Fuse somatic cell with enucleated

cellcell Downside, low success rate, Downside, low success rate,

constant implanations e.g. 1 in 87 constant implanations e.g. 1 in 87 eggs fertilised for CC, cloned cat, eggs fertilised for CC, cloned cat, premature aging because telomere premature aging because telomere shortens.shortens.

Cloning in plants: through cuttings, Cloning in plants: through cuttings, runners. Cut section or parent runners. Cut section or parent plant.plant.

Reproductive technologies-Reproductive technologies-Human interventionHuman intervention

Gene Transfer between speciesGene Transfer between species Complete set of genes & non-Complete set of genes & non-

coding DNA called genome. coding DNA called genome. Normal transfer of genes-parent Normal transfer of genes-parent

to offspring. If unable to because to offspring. If unable to because of species ‘species barrier’. of species ‘species barrier’.

Genetic engineering stops Genetic engineering stops species barrier-manipulates DNA species barrier-manipulates DNA & allows it to be transferred.& allows it to be transferred.

Org. with foreign DNA or Org. with foreign DNA or segment termed transgenic segment termed transgenic organism. Results in permanent organism. Results in permanent change.change.– If cell used are prokaryote If cell used are prokaryote

(bacteria) they’re transformed.(bacteria) they’re transformed.– If cell used are eukaryotic, they’re If cell used are eukaryotic, they’re

transferred.transferred.

GMOGMO Genetically modified Genetically modified

organism (GMO) refers to organism (GMO) refers to org. whose genetic org. whose genetic makeup has been makeup has been artificially changed.artificially changed.– Genotype has been Genotype has been

modified but doesn’t modified but doesn’t involve insertion of genes involve insertion of genes from diff. species. E.g. from diff. species. E.g. silencing (switching off) a silencing (switching off) a genegene

Transferring genes done Transferring genes done byby– Micro-injection of DNA, Micro-injection of DNA,

transfer using virus, electric transfer using virus, electric pulse (electroporation)pulse (electroporation)

Gene TherapyGene Therapy Where a faulty allele in Where a faulty allele in

an org. is replaced by an org. is replaced by the normally functioning the normally functioning allele.allele.– Aim to treat inherited Aim to treat inherited

disordersdisorders Wants to add copies of Wants to add copies of

the normal allele of a the normal allele of a gene into the cells of a gene into the cells of a target tissue, turning target tissue, turning them on to make the them on to make the protein missing in the protein missing in the individual.individual.

Stem CellsStem Cells Are undifferentiated that Are undifferentiated that

have the ability to have the ability to differentiate into many diff. differentiate into many diff. and specialised cell types:and specialised cell types:– Nerve, blood, bone, heartNerve, blood, bone, heart– Replace faulty/dead cellsReplace faulty/dead cells

3 types of stem cells: 3 types of stem cells: Totipotent, pluripotent, Totipotent, pluripotent, multipotent (Booklet)multipotent (Booklet)

Embryonic stem cells: Embryonic stem cells: obtained from inner cell obtained from inner cell mass of an embryo mass of an embryo (Blastocyst). Single cell (Blastocyst). Single cell isolated from inner mass, isolated from inner mass, grown, divide by mitosis & grown, divide by mitosis & produce stem cells produce stem cells (pluripotent)(pluripotent)

Adult Stem cells (somatic): Adult Stem cells (somatic): from bone marrow, skin, from bone marrow, skin, umbilical cord. Multipotent: umbilical cord. Multipotent: can give rise to blood cells.can give rise to blood cells.

CloningCloning Reproductive cloning- Reproductive cloning-

produce a new organism.produce a new organism. Therapeutic cloning- Therapeutic cloning-

produce stem cells for produce stem cells for use in treatment. Done use in treatment. Done through nuclear transfer through nuclear transfer technique. Treat patient technique. Treat patient with spine injury etc… & with spine injury etc… & embryo created is embryo created is genetic match.genetic match.

Legislation in Australia Legislation in Australia has strict controls on has strict controls on embryo use in labs.embryo use in labs.

Can you imagine a world Can you imagine a world with…with…

4 DAVID’S…. F*%K!!!3 Chong Phat’s

2 Ha’s, Meagan’s & Duyen’s !

4DEMI’S!!!

Genetic screeningGenetic screening Where DNA sample is Where DNA sample is

analysed to detect the analysed to detect the presence of 1 or more alleles presence of 1 or more alleles associated with an inherited associated with an inherited disorder.disorder.

Breast cancer geneBreast cancer gene– Adult screening (test if they Adult screening (test if they

transmit disease)transmit disease)– Embryo biopsy: single cell Embryo biopsy: single cell

removed to see if fetus is removed to see if fetus is affectedaffected

– Pre-natal screening: see genetic Pre-natal screening: see genetic status of fetus to see inherited status of fetus to see inherited disorder presentdisorder present

– Predicitve screening: ID a perfon Predicitve screening: ID a perfon at risk of developing a late onset at risk of developing a late onset disease.disease.

Stopping ConceptionStopping Conception Production of a zygote & its Production of a zygote & its

implementation into the implementation into the uterus walls called uterus walls called conception-any technique conception-any technique which prevents this called which prevents this called contraception.contraception.

Overcoming InfertilityOvercoming Infertility InfertilityInfertility is the inability to is the inability to

conceive or carry a conceive or carry a pregnancy to a live birth. pregnancy to a live birth.

Pelvic inflammatory disease Pelvic inflammatory disease (PID) leads to fallopian tube (PID) leads to fallopian tube problems (bacteria)problems (bacteria)

Several ways to overcome itSeveral ways to overcome it

Overcoming InfertilityOvercoming InfertilityDonor InseminationDonor Insemination

Fertilise a women with donor Fertilise a women with donor sperm (80%).sperm (80%).

In-vitro fertilisation (IVF)In-vitro fertilisation (IVF) Egg is fertilised externally Egg is fertilised externally

with sperm (can be frozen with sperm (can be frozen using cryoprotectant).using cryoprotectant).

Female given artificial Female given artificial hormones to stimulate hormones to stimulate ovaries. Eggs removed by ovaries. Eggs removed by laparoscope. Sperm added laparoscope. Sperm added (protein coat removed)= (protein coat removed)= fertilisation. Transferred to fertilisation. Transferred to mothers uterus at 2-4 cell mothers uterus at 2-4 cell stage. (20%)stage. (20%)

Pg 648Pg 648

Overcoming infertilityOvercoming infertilityDonation of eggsDonation of eggs

Egg donated voluntarily by Egg donated voluntarily by another woman in IVF another woman in IVF program. Fertilised with program. Fertilised with sperm of recipient husband.sperm of recipient husband.

SurrogacySurrogacy Surrogate mother is a Surrogate mother is a

woman who agrees to have woman who agrees to have a baby for another woman. a baby for another woman. Altruistic-no money Altruistic-no money involved.involved.

Egg is fertilised using Egg is fertilised using sperm of husband of sperm of husband of mother who is unable to mother who is unable to have the child.have the child.