Chapter 20 Biotechnology and Animal Breeding

Transcription

1 Source: NILGS (Japan) I. Reproductive Technologies II. Molecular Technologies

2 Learning Objective: To learn about recent biotechnologies that are currently available and are likely to affect animal breeding. Transfer of a donor cell to an enucleated oocyte (Nuclear Transfer)

3 I. Reproductive Technologies Artificial Insemination Embryo Transfer Sex Control Breeding for GCC Cloning Same-Sex Mating Conservation Genetics

4 I. Reproductive Technologies Artificial Insemination A process whereby semen is collected and then used in fresh or frozen form to impregnate females. AI has contributed to tremendous genetic progress in livestock. Round Oak Rag Apple Elevation

5 I. Reproductive Technologies Embryo Transfer - A process in which embryos from elite donor females are collected and transferred in fresh or frozen form to recipient females. Satur Veterinary Clinic

6 I. Reproductive Technologies Sex Control An attempt to manipulate or control the determination of gender of an embryo.

7 Breeding for heat resistance in the wake of GCC

8 Breeding for heat resistance in the wake of GCC

9 Breeding for slick and light-colored hair coats in the wake of GCC

10 The best SNP is at on chr5. A quick web search tells me different mutations in the PMEL gene are responsible for white/dilution in Charolais, Highland and Galloway cattle, and dilution phenotypes in dogs and horses. PMEL is 4.5Mbp from our top SNP so very like the gene... Matthew Littlejohn (Livestock Improvement Corporation, Cnr Ruakura and Morrinsville Roads, Newstead, Hamilton 3240, New Zealand)

11 I got results back from our PMEL sequencing project yesterday and now have an answer on what makes Tuli white. These animals carry the 3bp deletion variant also shared by Galloway and Highland cattle. This is interesting given the reputed heritage of Tuli, though I suppose the mutation could still go back to a common ancestor and have been independently maintained in the European and African taurine lineages. Matthew Littlejohn (Livestock Improvement Corporation, Cnr Ruakura and Morrinsville Roads, Newstead, Hamilton 3240, New Zealand)

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13 I. Reproductive Technologies Cloning A method used for producing genetically identical individuals. Cloned pigs (UK) Cloned rabbits (China) Cloned Mule (US)

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16 I. Reproductive Technologies Same-Sex Mating A system for mating individuals of the same sex. Involves a process known as nuclear fusion whereby gametes from the same sex of parent (or selfing) are fused by artificial fertilization. For example, in mammals, two genetically elite sires (race horses) could have their sperm nuclei fused, resulting in a 2:1 of male to female offspring. Two elite dams would produce only female offspring. Seattle Slew and Affirmed

17 I. Reproductive Technologies Conservation Genetics The branch of genetics dedicated to preservation of germplasm. The National Center for Genetic Resources Preservation Rare Breeds: White Park cattle and Ossabaw hogs

18 II. Molecular Technologies DNA Fingerprinting Animal Identification Other Applications Marker Assisted Selection (MAS) Simply-Inherited Traits Polygenic Traits Gene Transfer

19 II. Molecular Technologies DNA Fingerprinting Animal Identification A laboratory method for graphically character-izing an individual s DNA, creating a unique genetic fingerprint (e.g., paternal test). The DNA microsatellite banding pattern to be identical with that of the individual in the third lane from the left.

20 II. Molecular Technologies DNA Fingerprinting 1) To determine breed composition of crossbred animals (e.g., 2/3-2BRC or 4/7-3BRC) for the purpose of qualifying for registration (3/4 or 7/8), thereby reducing the number of backcross generations required. 2) To predict hybrid vigor between distantly-related breeds or lines, or even in individual planned matings.

21 II. Molecular Technologies Marker Assisted Selection Simply-Inherited Traits Detection of specific alleles using genetic markers - a detectable gene or DNA fragment used to identify alleles of primary interest at a linked locus (e.g., horns, red color, HYPP, curly calf syndrome, and PSS) for the sake of culling and decreasing gene frequencies.

22 II. Molecular Technologies Marker Assisted Selection Polygenic Traits Quantitative Trait Locus (QTL) A locus that affects a quantitative trait with a major affect ( Stars ).

23 II. Molecular Technologies Gene Transfer Transplantation of specific genes from one individual to another using laboratory techniques. Transfer of genes for valuable proteins into bacteria Transgenic animals producing human proteins and even life-saving compounds in their blood or milk Used to delete or repair faulty genes