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Cloning Cattle

Cloning Cattle. A. (Sandy) E. McClintock. Embryo Multiplication and Transfer “Cloning”. Until recently - embryo cloning only Many labs are involved worldwide Institute for Reproduction and Development -IRD Now - Adult cloning too…. The Scottish System ProBio ABS. IRD / Genetics

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Cloning Cattle

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  1. CloningCattle A. (Sandy) E. McClintock

  2. Embryo Multiplication and Transfer“Cloning” • Until recently - embryo cloning only • Many labs are involved worldwide • Institute for Reproduction and Development -IRD • Now - Adult cloning too…. • The Scottish System • ProBio • ABS

  3. IRD / Genetics Australia System Potentially a Cheap and efficient process Embryo Multiplication & Transfer (EMT) -No selection. 1. Semen from an elite bull 3. Remove the fertilised egg from the cow 4. Check that the embryo is male. 2. Fertilises the egg in an elite donor cow 5. Use the genes from this elite embryo to reprogram eggs salvaged from an abattoir from “any old cow” … but not necessarily highly valuable Cheap Identical bulls 6. Transfer copied embryos to recipient cows

  4. Cloning with Testing and Selection

  5. 0% Reliability of a Bull’s Test 100% Reliability The more recorded progeny, the more reliable the bull’s assessment. (Progeny Testing) 50% Number of progeny Records 0 100 200 300

  6. 20% 10% 0% Reliability 25% Heritability 100% Clones 90% 80% Bulls progeny test 70% 60% 50% 40% 30% Records 0 50 100 150 200 250 300 350

  7. Reliability Low (5%) Heritability 100% Clones 90% Bulls progeny test 80% 70% 60% 50% 40% 30% 20% Records 10% 0% 0 200 400 600 800 1000 1200 1400 1600

  8. Cloning • Roughly four to five times fewer clone records to obtain the same level of Reliability as a Progeny Test • Initially farmers may want to sacrifice selection pressure so as to gain accuracy • For traits with a heritability of 5% to 25%, we can expect little change in the within herd variation. • Clones will not be “like peas in a pod”

  9. IRD / Genetics Australia System 4b. Freeze some embryos for later use Possible Selection Scheme - Terminal Beef Sires EMT with Family Testing and Selection 1. Make perhaps 200 embryos using a variety of breeds and crosses 4a. Test fertility traits of the entire calves. Also test the carcass traits of the steers 3. Make a limited number (?50) bull calves from these 2. Select the male embryos 5. Discard 95% of the frozen embryos on the basis of fertility, growth & carcase Super Quality Identical bulls 6. Make thousands of bulls from the top few lines

  10. IRD / Genetics Australia System 4b. Freeze some embryos for later use Possible Selection Scheme - Straightbred Beef Sires EMT with Family Testing and Selection 1. Make perhaps 200 embryos using a variety of breeds and crosses 3. Make a limited number (?50) bull calves from these 4a. Test fertility and growth potential of these bulls (and steers) 2. Select the male embryos 5. Discard 50-80% of the frozen embryos on the basis of fertility, growth & carcase 6. Run Progeny Test. Discard those with poorer daughter fertility and steer progeny performance Super Quality Identical Bulls 7. Make thousands of bulls from the top lines

  11. Scottish System Expensive & Inefficient Process Adult Cloning 1. Collect a cell from the donor bull 2. Use the ‘Adult’ genes to reprogram an embryo from “any old cow” 3. Transfer reprogrammed embryo to a recipient cow Expensive but High Quality Identical bull

  12. Scottish System plus Monash System Potential system to copy top beef bulls 1. Collect a cell from a mature top bull Adult Cloning followed by EMT 4. Transfer copies of the reprogrammed embryo to recipient cows 2. Use the ‘Adult’ genes to reprogram an embryo from “any old cow” 3. Make thousands of copies of this embryo using EMT Cheap Identical copies of a High Quality beef bull

  13. Three Scenarios • Scenario One –Adult clones Too good to be true • Scenario Two —One generation Cloned Embryo Testing Terminal sires mainly • Scenario Three —Two generation Cloned Embryo Testing Straightbred sires and terminal sires

  14. Salvage eggs from abattoir cows Get embryo from elite parents Grow embryo in the lab Remove genes Break embryo into 20-30 identical cell. - + Transfer to recipients when enough have been made. Some can be frozen for later use. Electric pulse merges the two parts 5 to 10 times more embryos each 4 days. Some embryos start to develop Monash IRD / Genetics Australia EMT System

  15. Salvage eggs from abattoir cows Get tissue sample from an elite animal. Eg skin Grow cells in the lab Tissue culture Remove genes Take a cell from a culture with a million identical cells. Transfer to recipients Direct Injection merges the two parts Some embryos ready for freezing Some embryos start to develop Alternative Monash / Genetics Australia EMT System

  16. Cloning Targets • Price per embryo - $30? • Transfers done by trained AI technicians • Eggs consumed per embryo sold - Low! • Calving rate - 50% (two embryos at a time?) • Calf health - Good! • Chance of becoming a commercial success in the next 5 years - 10%

  17. Impact of Cloning • Impact on genetic improvement programs. • Demise of PT systems? • MOET Nucleus Breeding Programs? • Sale of Natural Service super bulls? • Impact on production systems • Beef from Dairy herds • Terminal breed Males and F1 females • Twins?

  18. Costs and benefits • Benefit:Cost too small at present due to:- • Conception rates are far too low. • Family sizes are too small. • Cloned embryos are too expensive. • $30 Cloned F1 embryos sold. (Mainly females - Dairy) • $300 Cloned embryos sold as Elite Breeding stock (Males & Females) • $3000 Cloned embryos sold as Elite Breeding stock (Males mainly)

  19. Conclusion • Calves born per $ spent is critical! • Unless cloned embryos cost little more than $30 the benefits will be too low except for cloned beef bulls.

  20. Overuse of Cattle Clones? • Dangers of ‘Monoculture’ • Potato famine • Several lines per herd recommended • Some farmers will reject cloning • Emergence of specialist genotypes for Niche Markets • Optimisation rather than maximisation • Initial rapid gain then lowered B:C ratios

  21. Politics • Impact Of Public Perception • Transgenic pigs • BST (Growth hormone) • Soy meal for cows • Gene Banks • Which countries have a gamete museum? • The cost of long term storage is minimal • Now is the time to act

  22. Monash University Genetics Australia Alan Trounson Kym Boekel Kim Giliam Tiki Gougoulidis Mark Lane Ian Lewis Teija Peura David Pushett Steven Wild Collaborating scientist Orly Lacham-Kaplan Bernie Harford Peter Coleman Chris Closter Andrew Harford Ian Lewis Glenn Lyons Sandy McClintock John Owens Michael Ryan Visiting Scientist Gabor Vajta -Embryo Technology Center, Foulum, Denmark

  23. Summary • Higher Accuracy with clones • Mainly cloned BULLS for beef industry • How to make clones • How to test clones • 90% certain - not possible in next 5 years • Need to retain genetic diversity

  24. Other Aspects • Impact on genetic improvement programs • Dramatic if cloned embryos are cheap • Cloning from Adult, rather than Foetal cells • Nice, but not essential for genetic improvement • Reproduction without the need for males • Could we ‘cross’ 2 female clone lines to create new genetic variation?

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