ANS/PLSS 433: Production-linked Genes, Reproductive-related Technologies and Miscellaneous Animal Biotechnologies

I. Reproductive-related Technologies

	1. Artificial Insemination
		A. Commonly used in livestock
			a. 90-95% of Dairy Cattle
			b. 99% of Turkeys
	2. In vitro fertilization
		A. Must induce sperm capacitation
			a. Oviductal fluid in media
		B. Technique well worked out
	3. Superovulation & Ovulation induction
		A. Hormonal Treatments
			a. PMSG+hCG--most common
			b. Sex Steroids
			c. GnRH--ovulation only
	4. Estrus Synchronization
		A. Management tool
			a. Breed at same time
			b. Parturition around same time
		B. Hormonal treatment
			a. Prostaglandin
			b. Sex steroids
			c. Combinations
	5. Embryo Transfer
		A. Very successful in cattle
	6. Embryo Splitting
		A. 	Blastomeres must be totipotent
			--8-16 cell stage
		B.	Cell Mass cut with glass knife 
			dividing groups of blastomeres
		C.	One set of cells put into denuded zona pellucida
		D.	Identical twins result
	7. Reproductive Immunization
		A.	Anti-hormones
			a. GnRH--Stop Reproduction
			b. Prostaglandin--Stop Reproduction
			c. Sex Steroids--Increase Ovulation
				  --Decrease Embryonic Mortality	
			d. Inhibin--Increase Ovulation
		B.	Anti-zona pellucida
			a.	Covering of Ovum
			b.	Sperm can't attach
			c.	Birth Control
				--Already being used with Wild horses 
					and donkeys

	8. Transgenic Animals
	9. Sperm and Embryo Sexing
		A. Production Applications
			a. Dairy and Egg production require more females
			b. Meat production prefer males
		B. Most successful methods for sperm sexing in animals
			a. Albumin separation
				--75-80% Y sperm purification
			b. Sephadex filtration
				--70-75% X sperm purification
			c. MABs have promising future applications
				--affinity chromatography
		C. PCR amplification of sex-specific genes now possible for sexing embryos
			a. H-Y antigen
			b. Testis determining factor
	10. Nuclear Fusion
		A. Fusion of same sex gametes (Pronuclei)
			a. Male/Male--androgenomes
			b. Female/Female--gynegenomes
		B. Only develop through blastocyst to gastrula stages
			a. Female genome needed for conceptus development
			b. Male genome needed for placental development
		C. Oocytes can be induced to undergo parthenogenesis
			a. Electrical shock
			b. Cold shock
			c. Hyaluronidase treatment
			d. Gynegenomes

	11.	Nuclear Transfer--"Cloning"

		A.	Cell nucleus from another donor put 
			into enucleated recipient
			a.	Resulting offspring is a clone of the donor
			b.	Until "Dolly" all donors were embryonic 
				in origin
		B.	Frogs done in early 70s
		C.	Mammals
			a.	Mice (Early 80s)
			b.	Cattle (Mid 80s)
			c.	Sheep (Late 80s)
		D.	"Dolly" the sheep was the first "clone" from an adult.
			a.	Mammary cells from a 6 year old ewe.
			b.	Cells were arrested in G0 of cell cycle 
				(quiescent stage)
				--Serum Starve
			c.	Recipient cells were enucleated oocytes
				--Oocytes have been found to be better 
					recipients than Zygotes
			d.	Donor nuclei transferred to oocytes 
				and activated by an electrical pulse
			e.	In vitro maturation to morula/blastocyst
			f.	Embryo transfer into recipient
			g.	Dolly born in 1996
				--DNA fingerprint matched Ewe donor
		E.	Applications
			a.	Propagation of genetically superior lines
			b.	New way to make transgenics
				--Transfect as in ES cells
			c.	Studies of imprinting and aging
		F.	Ethical Considerations????
			--Are humans next?

II. Identification of Production-linked Genes 

	1. Uses Restriction Site Mapping and RFLP
	2. Used in Breeding or as a Diagnostic
	3. Examples:
		A. Milk Production gene in Dairy Cattle--PRL (Prolactin)
		B. Stress gene in pigs (PSS)--RYR1 (Ryanodine Receptor)
		C. Fertility gene in pigs--ER (Estrogen Receptor)
		D. Muscling gene in Meat Animals--c-SKI (Proto-oncogene)
	4. Hot area in animal breeding and genetics


III. Using Biotechnology to Handle Animal Wastes

	1. Major Environmental Concerns
	2. Goal:  Bioconversion (Bioremediation/Biomass) of manure into 
			a more manageable waste or useful byproduct.
	3. Methods?:
		A. Microorganisms
		B. Higher Animals
			a. Fish
			b. Zebra Mussels
				i.  Biological Filter
					--1 liter/day/mussel
				ii. Pseudofeces
					--More easily handled
					--Possible livestock feed
		C. Plants
			a.  Duckweed
		D. Combinations of organisms???

IV. Genetic Engineering of Animal Feedstuffs

	1. Plant Molecular Biotechnology
		a. Transgenics
		b. RFLP & RAPD
	2. Example: Phytoestrogens
		a. Found in Legumes (Forages & Soybeans)
		b. Effect Reproduction
			--Negative (Cervix)
			--Positive (Increase Ovulation?)
		d. Other positive effects (humans)
			--Anti-cancer
			--Lower cholesterol
			--Menopause