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

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

Cloning with Testing and Selection

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

25% Heritability 30% 40% 50% 60% 70% 80% 90% 100% Clones Bulls progeny test Reliability Records

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Clones Bulls progeny test Reliability Records Low (5%) Heritability

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”

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

2. Select the male embryos Possible Selection Scheme - Straightbred Beef Sires EMT with Family Testing and Selection IRD / Genetics Australia System 4a. Test fertility and growth potential of these bulls (and steers) 1. Make perhaps 200 embryos using a variety of breeds and crosses 7. Make thousand s of bulls from the top lines Super Quality Identical Bulls 3. Make a limited number (?50) bull calves from these 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 4b. Freeze some embryos for later use

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

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

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

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

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

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%

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?

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) Costs and benefits

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.

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

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

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

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

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?