cloning, stem cells and genome editing Flashcards
are identical twins clones
yes
what is cloning
Creating a genetically identical copy
dolly the sheep
- Not the first clone, but the first to becloned from an adult cell, rather than an embryo
- Somatic cell nuclear transfer (SCNT)
- 1996: Roslin Institute, University of Edinburgh
- Ian Wilmut
benefits to cloning
- Human genes inserted into sheep/cattle that
then cloned produce therapeutic agents in milk - Research where genetic background important
- Producing multiple copies of prized stock
disadvantage to cloning
extremely inefficient
concerns with premature aging
Doesn’t resolve lack of genetic diversity
Concerns around premature aging with cloning, why
Shortened telomeres in some clones
how can we use cloning to save endangered species
- Nuclear material from species to be cloned
- Donor egg from related species
why would cloning be used to save endangered species
- Too few reproductively capable animals left
- Can’t, or won’t, mate
3 general classes of stem cells
- Embryonic Stem Cells
- Adult Stem Cells
- Induced Pluripotent Stem Cells
embryonic stem cells
- From the inner cell mass of the blastocyst
- Inner cell mass gives rise to the embryo
- Cells are pluripotent
adult stem cells
- Mesenchymal Stem Cells
- Majority of tissues
- Tissue maintenance & repair
- Restricted differentiation potential
- multipotent
are adult stem cells multipotent or pluripotent
multipotent
are embryonic stem cells multipotent or pluripotent
pluripotent
induced pluripotent stem cells
- Generated from differentiated cells
- Skin fibroblasts: adult, juvenile
- ‘Reprogrammed’
- Pluripotent state
- Very similar to ESCs, but without the need to harvest embryos
how are induced pluripotent stem cells different to embryonic stem cells
Very similar to ESCs, but without the need to harvest embryos
Both ESCs & iPSCs are
pluripotent
ESCs require ____ which makes them problematic to use in endangered species
embryos
IPSCs don’t require embryos, only
a skin punch biopsy
using reprogramming to produce an embryo uses a similar protocol to that used to produce ____
iPSCs
Using Reprogramming to Produce an Embryo results in an
in vitro-derived blastocyst
key point of woolly mammoth revival
“The goal is not to make perfect copies of extinct woolly mammoths, but to focus on the mammoth adaptations needed for Asian elephants to live in the cold climate of the tundra” ie the DNA is not complete
steps of woolly mammoth revival
- Sequence the extinct genome
- Copy/paste DNA from the mammoth into living elephant cell cultures (fibroblasts)
- Reprogramme fibroblasts into iPSCs
immediate benefits of wooly mammoth revival
- Differentiate iPSCs into specific tissue types
- Study the effects of mammoth genes on the traits of these cells
- Mammoth Hb can release O2 at low temps
- Research into embryology, reproductive biology
- Development of technologies & resources in embryology, assisted reproduction
- Gene technology for disease resistance
thoroughbred gene (crispr-ing race horses)
- Recent analysis of DNA from Thoroughbred race
horses - Identified the specific allele of the Myostatin gene
responsible for their speed & precocity - Myostatin inhibits muscle cell growth
- Single nucleotide polymorphism (SNP, C(ytosine) instead of T(hymine)
- influences speed
- C/C: best suited to fast, short-distance sprints
(1-1.6 km) - C/T: best in middle-distance races (1.4-2.4 km)
- T/T: have greater stamina so best suited to long-distance races (>2 kms)
