Preimplantation Diagnosis: A new opportunity for ET. Dr. Hanna Grothmann Head of Masterrind IVP and Molecular Biology laboratories

Transcription

1 Preimplantation Diagnosis: A new opportunity for ET Dr. Hanna Grothmann Head of Masterrind IVP and Molecular Biology laboratories

2 Animal Husbandry Animal husbandry = Determination of a breeding goal Selection of individuals that come closest to the required goal

3 Conventional Breeding Programs Selection of a bull dam AI ET 50% chance of a bull calf Nearly 100% of a bull calf Upbringing and testing Breeding value at the age of 5,5 years

4 Conventional Breeding Programs Annual breeding progress = Intensity of Selection x Accuracy of selection x Variance within the selection group Generation intervall Limiting factor

5 Conventional Breeding Programs Situation in Germany until 2012: Use of very young heifers (= decrese of generation intervall = increase of breeding progress) in breeding programs! at the same time the accuracy of selection is decresed Only ¼ th of the animals that were bred with high effort actually met the expectations as potential sire dams.

6 Embryo Production +15 points Genomic BV PI? Genomic BV -15 points Full sibs

7 Preimplantation Genetic Diagnosis Pre-implantation genetic diagnosis (PGD or PIGD) is the genetic profiling of embryos prior to implantation( ), and sometimes even of oocytes prior to fertilization. is considered in a similar fashion to prenatal diagnosis. When used to screen for a specific genetic disease, its main advantage is that it avoids selective pregnancy termination as the method makes it highly likely that the baby will be free of the disease under consideration. is an adjunct to assisted reproductive technology, and requires in vitro (IVF) to obtain oocytes or embryos. ( )

8 Breeding Value Determination Phenotypes Genotypes Statistic Model 65% Estimation of Breeding values without phenotypical information Conventional breeding value (Pedigree index):! ½ BW Sire+ ½ BW dam Direct genomic BW by SNP analysis grzg = genomically supported BW! Combination of PI and genomically supported BW (with young sires the a BW that relies more strongly on grandfather s PI is employed)

9 SNP- Analyses SNP Single Nucteotide Polymorphism(s) Variation in a base pair of a complementary DNAstrand Specific phenotypes are associated with certain SNPs If enough data are available it is possible to determine a breeding value on a genetic basis Only DNA is needed (usually full blood or ear cartilage) the Illumina Chip analyses SNPs Costs lay at around 50 per sample In Germany the calculation of the breeding value is performed by a complex model at the VIT

10 Reliability of Genomic Breeding Values Reliabilities vary from over 70% to below 50%: Increased for higher heritable traits such as milk yield and fat content than for traits with low heriditability as daughter fertility Combination of genetic breeding value and PI increases safety in young animals only about 1-5% Zws_Bes_deu.pdf

11 How does the Embryonic Breeding Value Determination work? RZG 165

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13 Cell and DNA Processing DNA Extraction DNA Amplification BW Calculation <a href=' by Freepik</a> SNP Analyses

14 Breeding Programs using Genomic Selection Annual breeding progress = Genomic analysis Intensity of Selection x Accuracy of selection x Variance within the selection group Generation intervall More offspring of the best female and male individuals Offspring from young animals

15 Development of Total Breeding Values International comparision of breeding values in 2000 International comparision of breeding values in 2015 Milk yield Exterior SCN Economic life Fertility Calving other Milk yield Exterior SCN Economic life Fertility Calving other Breeding values have been defined by economic demands at all times Output increasing traits (i.e. milk yield) + cost decreasing traits (health, calving traits, longevity) Output -Data have been documented better than health traits! breeding progress higher in this section In Germany since 2008 productivity traits 45%, direct health traits 40%, 15% exterior Abb: Dr. Dierck Segelcke, ViT

16 Perspectives for the Development of Breeding Values in Germany Implementation of new breeding values GEN O describes economic value of an animal with regards to useful life, somatic cell number, milk yield, calving traits, daughter fertility (MASTERRIND) Klauen plus, Mastitis plus, Kalbung plus, sytematic recording of diseases, hoof health, calving data, birth weight of live and still born calves, Klauenschnittdaten, Geburtsverläufe, Body weight at AI, heifer classifications. (RinderAllianz und Rinderzucht Berlin Brandenburg)

17 Preimplantation Genetic Diagnosis - Legal situation in Germany EMBRYONENSCHUTZGESETZ Sex determination illegal Preimplantation genetic diagnosis possible under severe requirements Interdiction to artificially modify human germ cells Cloning illegal Chimera-/Hybridgeneration illegal! ONLY FOR ART IN HUMAN MEDICINE

18 Preimplantation genetic diagnosis - Legal situation in Italy 2004 Italian Law 40 was passed max number of embryos produced per donor restricted to 3; all viable embryos had to be transferred Banned use of PGD Restricted access to ART only for those patients with a diagnosis of infertility 2005 referendum failed Regional Administrative Court of Latinum declares ban of PGD unconstitutional. Nevertheless, all embryos still had to be transferred 2009 Italian Constitutional Court declared that the rule that only three embryos could be created and all must be transferred unconstitutional! PGD was instantly used! ONLY FOR ART IN HUMAN MEDICINE

19 Legal Basis for Preimplantation Diagnosis in Veterinary Medicine IETS Manual International Embryo Technology Society Practical and ethical considerations for embryo transfer in the 21st century Scientific foundations for the epidemiological safety of embryo transfer Potential for disease control or transmission by transfer of embryos produced in vitro General sanitary procedures and welfare considerations associated with in vivo production of embryos General sanitary procedures associated with in vitro production of embryos Recommendations for the sanitary handling of in vivo-derived embryos Use of antimicrobial substances in embryo production General hygiene and quality control practices in an embryo-production laboratory Certification and identification of embryos Health care and well being of animal clones Safety of food derived from animal clones

20 Legal Basis for Preimplantation Diagnosis in Veterinary Medicine Direttiva 89/556/CEE: condizioni di polizia sanitaria per gli scambi all'interno dell'ue e le importazioni da paesi terzi di embrioni di animali domestici della specie bovina

21 Acknowledgements Dr. Björn Petersen, FLI, Mariensee Dr. Knut Roschlau, Masterrind GmbH, Verden Prof. Dr. Christine Wrenzycki, JLU, Gießen Dr. Dierck Segelcke, VIT, Verden

22 Vielen Dank für Ihre Aufmerksamkeit

23 New Breeding Technologies New breeding techniques (NBTs) are new methods of genetic engineering that give scientists the ability to more precisely genetically modify crops and animals. 1. Site-Directed Nucleases (SDN) (dazu gehören u.a. Zinc Finger Nuclease-1/2/3, TALENs, Meganucleases und CRISPR Systeme) 2. Oligonucleotide Directed Mutagenesis (ODM) 3. Cisgenesis 4. RNA-dependent DNA methylation (RdDM) 5. Grafting (non-gm scion on GM rootstock) ZINK-Finger Nukleasen Meganukleasen 6. Reverse breeding TALENs 7. Agro-infiltration (Agro-infiltration sensu stricto, Agro-inoculation) CRISPR/Cas

24 New Breeding Technologies

25 Potential practical applications Animal Wellfare Polled animals Economic applications in animal production Knock-out of MSTN! increased muscular gain f2 o t Resilience/resistance against diseases en m g d Swine with increased resilience/resitence African Juagainst a i r Cu Swine Fever by introduction of a sequence of the RELA gene as found in african warthog PRRS immune pigs by CD 163 knockout mittels CRISPR/Cas Increased resilience against Mycobacterium bovis 8