DSCI 422 Test 1

• A Pregnancy
• A live calf
• A heifer calf
• (want pregnancy rather than genetics)

measures genes by looking at the individual chromosomes

• Organisms Vary
• Variation may or may not be inherited
• Struggle for survived in nature
• The best adapted to survival leave the most descendants

• Select most desirable animals
• Produce superior genotypes

• Single Nucleotide polymorphisms
• Rung of ladder on DNA sequence

• 60 chromosomes
• 30 pairs

• Phenotype= what the animal looks like
• -Genotype+Environmental
• Genetoype= DNA build up

• Heritability-the likelihood of a trait to be passed on
• Selection differential-superiority of parents over the mean of the population
• Generation interval-the time between generations

• No genetic material
• Cell Function

• Genetic Material
• Paired chromosomes

• Body Cells, 2n (cows 60)
• Cytoplasm varies with function

• Reproduction cells 1n (cows 30)
• Male/Female sex cells
• -Spermatogonia
• -Oogonia

the genetic code

• Homozygous: identical genes at a locus
• Heterozygous: not identical, different genes at a locus

• Dominant: genes with observable effects in only one member of a chromosomes pair
• Recessive: no effect unless present in both members of a chromo, pair
• Additive: a gene has a given + or - effect

Refers to the study of cell (cyto) genetics

• Basis of genetics
• Within the nucleus of all cells
• Made up of DNA

• Centromere: attaches to spindle fibers during division
• Chromatids: arms made up of genetic material (chromatin)

• Matacentric:in center
• Submatacentric: not in middle
• Acrocentric: close to the end
• Telocentric: at the end or top

A molecule that carries genetic material

• Mammals 
• -X and Y
• -XX =female XY=male
• Freemartins
• -XX/XY chimeric
• Birds
• -Z and W
• -ZZ=male ZW=female

• Change in a functional genetic unit
• Could be a single nucleotide
• Biochemical polymorphism
• A genetically determined variant of proteins

• A unit of inheritance, which does not subdivide
• A unit of function or expression, a cistron (biochemical term)
• The smallest unit that can undergo change, may be one nucleotide

• A chromosome becomes broken
• Becomes attached to another chromosome
• May be carried through meiosis

• around 1.6 billion 
• 2^30

• Each chromosome duplicates itself
• Somatic cell (body cells) division
• Daughter cells have the same number of chromosomes
• (radiation can cause exact replication to sometimes cause genetic abnormalities

• Interphase: Rest phase
• chromatids duplicate near end
• few to 100 hours
• Prophase: chromatids shorten and thicken
• Early-centriol divides and migrates
• Late-Spindle fibers, 30 mins
• (1 pair of tele centric, 1 pair of metracentric)

• Metaphase: chromosomes align along equatorial plane
• 5 mins
• Anaphase: chromosome divides at centromere
• two arms back to one arm, 5 mins
• Telophase: chromosomes cluster around centriol
• Cell divides, ten minutes

• Interphase: chromatids duplicate
• Prophase: Shorten and thicken
• Metaphase: Chromosomes align
• Anaphase: Centromere divides
• Telophase: Cell divides

• Cell division in which chromosome number is reduced
• Daughter cells receive one member of the chromosome pair
• Gametes (egg and sperm) are produced
• Have Meiosis I and II

• Interphase: rest phase, chromatids duplicate near end
• Prophase: chromatids shorten and thicken. Paired chromosomes attach to each other (synapsis)
• Metaphase: Paired chromosomes align along equatorial plane
• Anaphase: Homologus pairs separate (2n to 1n), still have two armed cromatids
• Telophase: chromosomes cluster around centriol, two new haploid daughter cells

• Prophase: shorten and thicken, with 1n
• Metaphase: align along equatorial plane
• Anaphase: centromere divides, 1n remains
• Telophase: chromosomes cluster around centriol, Two new daughter cells

• Diploid-2n cells, somatic cells (body cells)
• Haploid-1n cells, gametes (sex cells)

• with a single SNP
• Dominant, recessive, etc
• will continue to occur

• Born with the defect (may or may not be genetic)
• EED: some are repro problems, some are genetic

• Artificial Insemination
• Line breeding (inbreeding)
• If breed numbers are small

• BD: Bulldog
• BL:Bovine leukocyte adhesion deficiency (BLAD)
• TL: Tested free of BLAD
• MF: Mule-Foot
• PO: Observed Polled
• PC: Tested Heterozygous Polled
• PP: Tested Homozygous Polled
• RC: Red Hair Color
• B/R: Black/Red
• TR: Tested free of Red hair color

• 1.Progeny Testing (mate a suspect animal)
• 2.Biotechnology (with DNA probes look at strand of DNA that carries)
• 3. Blood Testing

• 1. Cull sires that have produced genetic defect offspring
• 2. Evaluate pedigrees of future sires
• 3. Remove females that produce genetic defect offspring
• 4. Progeny test prospective herd sires
• 5. Cull other close relatives
• 6. _______

• An animal bred to an affected animal-50% chance of identifying
• An animal bred to a known carrier - 25% chance of identifying
• An animal bred to its own offspring - 12.5% chance of identifying

• AA, Aa, aa
• 1. AA x AA
• 2. AA x as 
• 3. aa x aa
• 4. AA x Aa
• 5. Aa x aa
• 6. Aa x Aa

• Three gene effects at the same allele
• Black dominant over Black/red and over red
• Black/red dominant over red
• 3 alleles= B b b^B
• b^B=black/red dom. over red
• ^bb=red 

• red x white = roan
• roan x roan = 1/4 red, 1/4 white, 1/2 roan
• F1 mating red bull to white cow (or vise-versa) will produce all roan calves

F2 mating roan to roan 1/4 red, 1/4 white, 1/2 white

• A = 6,000 lbs. milk
• a = 4,000 lbs. milk
• B = 5,000 lbs. milk
• b = 3,000 lbs. milk
• C = 2,000 lbs. milk
• c = 1,000 lbs. milk

• milk
• fat 
• protein
• type
• weight gain
• milking speed
• longevity
• mastitis
• overall health
• many others

when two or more phenotypes exist in the same population of a species

biotechnology of DNA sequencing of sets of genes of the complete genomes of selected organisms

the number and visual of the chromosomes in the cell nuclei of an organism or species.

a compound consisting of a nucleotide linked to a phosphate group. Nucleotides form the basic structural unit of nucleic acids such as DNA.

• Gene: the functional and physical unit of heredity passed from parent to offspring.
• Genome: The DNA comprising the complete genetic complement of an organism
• Genomics: 1986 - a new scientific discipline of mapping, sequencing, and analyzing genomes

G C A T

Qualitative Trait Loci: process enzyme taken to cut a piece of DNA to search for a certain gene

• Genomic predictions significantly better than parent average for all 26 traits tested
• Gains in reliablity equivalent on average to 15 daughters with records
• -analysis used 3,576 historical bulls
• -Current data includes 5,285 proven bulls
• Larger populations require more SNPs

Improve accuracy

• something that causes embryonic death
• 23.4% presence in haplotype of Jersey breed
• Holstein presence is 4.5%, 4.6%, and 4.7%
• Stretch of chromosome or DNA that is transmitted as a unit from one generation to the next

• these haplotypes are never observed in a homozygous state in any live animals
• Decreased conception rate was observed when a carrier sire was mated to a daughter of a carrier maternal grandsire

certain haplotypes never appear in a homozygous condition

• due to modern genomic technology, undesirable genetic conditions are no longer considered rare
• We expect to find them in some of our best genetic families
• We should use the haplotype information to improve our breeds without causing undue economic hardship to the breeders of these animals