genetics!. key learning: genetics in animal science unit eq: why is an understanding of genetics...
TRANSCRIPT
Genetics!
Key Learning: Genetics in Animal Science
• Unit EQ: Why is an understanding of genetics important in the animal science industry?
Concept : Genetic Behavior
Lesson EQ:
How do genetics manifest?
Vocab
Crossover, Sex Linked, Sex Limited
Concept : Genetics in ANSC Industry
Lesson EQ: How can genetics affect animals and their use?
VocabACC, EPD, DTA,
MBV
Concept : HistoryLesson EQ:
How did research and knowledge of genetics evolve?
VocabPunnett Square, Dominant, Recessive, Mendel
Objectives
• Analyze Meiosis and Mitosis• Discuss Gregor Mendel and his
contributions to genetics
Essential Question
• How did research and knowledge of genetics evolve?
Back in the Day
• Gregor Mendel THE FATHER OF GENETICS
• 1822-1884• Priest • Study the inheritance traits in pea
plants • Not recognized until the 20th century
What did Mendel Study?
What did this mean?
• Selective Breeding • Crossbreeding• Heritability
– What traits get passed on?
What about today?
• Crossbreeding breeds registered• Cross bred crops
– Aprium , Pluot, Grapple• Cross Bred Animals
– Black Baldie, Labordoodle • Biotechnology
– Fish in Strawberries to prevent freezer burn
– Sub- arctic fish genes pumped into strawberries
Let’s Break it Down
• Where is the information coming from?
• Where is it stored?• What does it look like? • What information is carried?
Where is the info coming from?
• Parents
Where is it stored?
• Cells
MitosisActivity:
Please copy into your packet
Meiosis: Activity:Please
copy into your
packet
What does it look like?
• Genotype• Phenotype
What information is carried?
• Chromosomes
Why follow genetics?
• Pedigree
Activities
• Video; Intro to Genetics United Streaming
• Follow along in your packet
Vocabulary: Please Define
• Heritability• Gregor Mendel• Gene• Chromosome • Genotype• Phenotype• Pedigree• Gamete
Cross BreedingSelective BreedingMitosisMeiosis
Genetics!The Punnett Square
Objectives
• Analyze heritable traits• Calculate heritability using Punnett
Square Method
Essential Question
• What does the Punnett Square represent/ Calculate?
It started with a Pea [plant]
What is a Punnett Square?
• an n × n square used in genetics to calculate the frequencies of the different genotypes and phenotypes among the offspring of a cross
More than 1 trait
Monohybrid vs. Dihybrid
What does it mean?
• We can follow traits
How to Punnett Square [Dance]
Reading the Results
PERCENTAGES
RATIOS
1:2:1AA:Aa:aa
Let’s Practice
• Worksheet- Punnett Practice
Vocabulary
• Punnett Square• Heritability • Monohybrid• Dihybrid
What do we look for?
Genetics in Animals
Objectives
• Identify traits in animal breeding that are desirable based on breed and that are heritable
Essential Question
• Where do you find information on heritable breed traits?
General Concepts
• Certain traits are heritable • Hybrid vigor • Purebred
Dogs
• What kind of traits would you want in YOUR dog? If you had:– Children– Small apartment– Sheep herd– Loved running ?
Dogs
• Temperament can be bred for!– Especially aggression
• Watch for heritable health risks– Eye Problems
• Irish Setters and Progressive Retinal Atrophy • Collie Eye Anomaly • Cataracts • Entropion (eyelids turn in or out)
Dogs- Heritable Health Contin
• Hips and Joints– Hip dysplasia
• Malformation/degeneration of the hip joint.– Retrievers, Cocker Spaniels, Shetland Sheepdog
– Osteochondrosis Dessicans (OCD) • Bone spur or flake wears away at joint.
– Present in dogs with OCD
– Pateller Luxation• Elbow/kneecap slides out of place locking leg
– Occurs more in smaller dogs
Cats- Heritable Health • Polydactyly• Hypertrophic Cardiomyopathy
– Heart muscle thickens • Main Coon Cats
• Progressive Retinal Atrophy• Diabetes
– Burmese
• Feline Infectious Peritonitis – Some cats have a predisposition to the
development of FIA
Cattle – Dairy Cattle
• Milk production• Milk Fat Content • Efficiency
– Feed intake to Milk Output
• Calving ability
Sire Summary in Cow/Calf Op.s
Evaluation report
Birth weight Weaning weight
Yearling weight
Maternal breeding value
EPD ACC EPD ACC EPD ACC EBV ACC DTS
Bull A -1.6 0.81 -2.7 0.79 -3.2 0.72 102 0.80 13
Bull B +2.4 0.90 +39.1 0.91 +70.0 0.83 103 0.76 11
Bull C +8.3 0.97 +53.8 0.97 +80.4 0.89 93 0.66 5
Advantage for progeny weaning weightsBull B vs. Bull A + 41.8 poundsBull C vs. Bull A + 56.5 poundsBull C vs. Bull B + 14.7 pounds
ACC = accuracyDTS = number of daughters
Table 1Example of sire summary data from the 1984 Angus sire summary
University of Missouri: Extension
EPD
• EPD: Expected Progeny Difference: express the genetic transmitting ability of a sire. The EPD is reported as a plus or minus value in the unit in which the trait is measured.
• EPDs are calculated from a sire's progeny data. All bulls listed in the sire summary can be directly compared using EPD values. EPDs are an estimate of how a bull's progeny would be expected to perform compared to any other bull listed in the same summary.
ACC
• ACC: Accuracy is a measure of how much the EPD value might change as additional progeny data become available. Sires with more calves in several different herds will have higher accuracy figures
• Select bulls to use based upon their EPD values and use the accuracy figure to determine how much to use a bull.
MBV
• Maternal Breeding Value (MBV) describes how daughters of a bull are expected to produce compared to other cows in a herd. Once a bull's own daughters come into production, the MBV is calculated using the records of his own daughters in addition to those of his sire and paternal and maternal grandsires.
• Estimates of MBVs come from pedigree analysis, not sire evaluation
DTS
• Number of Daughters.
• Why would this information be needed or relevant?
Why perform strict analysis?
• Both commercial and seedstock producers should find sire summaries useful. A producer using AI can obtain semen from bulls that are superior in the traits of interest.
• Summaries also can be used to identify herds that excel in genetic merit and vice versa. A breeder who has several superior bulls listed in the report is a more reliable source of bulls than either the breeder who has no bulls listed or the breeder who has poorer than average bulls listed in the summary.
Evaluating EPD’s Exercise Worth 50 points
• Using the booklet provided at your TABLE please:– 1. Read the Packet!– 2. Formulate a Vocabulary sheet for ALL
vocab words defined (all the abbreviations) – 3. Answer the worksheet questions in
groups.– 4. Write down any questions you have. – Due Friday!
Once Finished EPD worksheet
• Summary Paper–1 paragraph double spaced
»Define the purpose of a Sire Summary. Who benefits from the sire summaries? What do sire summaries mean for producers? What information is provided on a sire summary?
Genetic Terms to know
Objectives
• Define terms normally used when explaining and discussing genetics
Essential Question
• Why is using appropriate terminology important in Veterinary Science?
Genetic Vocabulary Review
Co Dominance
• A condition in which both alleles of a gene pair in a heterozygote are fully expressed with neither one being dominant or recessive to the other
• Example: Roan coloring in cattle
Roan Coloring in Cattle
• R is Red W is white
• F1 Generation– All Roan
• F2 Generation – 25% Red– 50% Roan– 25% White– 1:2:1 Ratio
R R
W RW RW
W RW RW
R W
R RR RW
W RW WW
Sex Limited Genes
• Gene that exerts its effects primarily in one sex because of activation by androgens or estrogens
• Both sexes may have the gene• Example hen/rooster feathering
Hen/Rooster Feathering
Genotype Female Phenotype
Male Phenotype
HH Hen feathering
Hen feathering
Hh Hen feathering
Hen feathering
hh Hen feathering
Cock Feathering
Sex Determination• Mammals
– Determined at moment of fertilization– Female has regular chromosomes plus
an XX – Male has only 1 sex chromosome Y
• Birds– Females determine the sex of the
offspring Ma. X Y
X XX XY
X XX XY
Bi. Z Z
Z ZZ ZZ
W ZW ZW
Sex Influenced Genes
• Trait expressed to different extents depending on the sex of the individual.
• Normally phenotypically recognized• Examples
– Male pattern baldness in humans (comes from your mother)
– Horns in sheep– Spotting in cattle
Sex Linked Characteristics
• Genes carried on the sex chromosome • Example barred feather coloring in
chickens
Zb Zb
ZB ZB Zb ZB Zb
W Zb W Zb W
Genetics Activities
• Chromosomes and Genes – Simulation Activity
• Dihybrid Guinea Pigs• Design a Species • Hardy-Weinburg?
Genetics in Animals
• Using the terms learned today. • Find examples other than those used
in the presentation to help define 1 vocabulary word from today
• Vocab– Sex Linked - Codominance– Sex influenced - Sex limited
Gene Behavior
Objectives
• Discuss common gene behavior
Essential Question
• What types of gene behavior might appear as a phenotypic result
Linkage
• Tendency for certain traits to appear in groups in the offspring
• Genes closer together on the chromosome are more likely to stay together
Crossover
• During meiosis chromosomes line up closely
• Sometimes the genes jump and cross over forming new chromosomes with different combinations of genes
• The farther apart two genes are on a chromosome the more likely they are to make a new combination
Mutation • New trait appears that
did not exist in parents • Some are harmful some
are beneficial • Radiation will cause
genes to mutate • Example: Polled
Herefords – Cross between to horned
resulted in polled– Polled is dominant – one
parent must be polled
Mutation Activity• Research a mutation in animals. (Your
animal will be assigned) • Write a paragraph (10 sentences) summary
describing the condition, what causes the condition, and if the condition benefits or harms the animal. Include a photo. Write up + photo = NO MORE THAN 1 PAGE in length
• Provide sources in APA format have at least 2
• This will be presented, and collected for grading. COMPLETE SENTENCES please
Final Vocabulary: Use in a sentence. A good sentence means you can READ the sentence and UNDERSTAND the meaning of the word.
• Mutation• Crossover• Linkage• Sex linked• Sex influenced• Sex limited • Co-Dominance
• DTS• EPD• MBV• ACC• Hybrid Vigor• Punnett Square• Heritability • Monohybrid• Dihybrid
HeritabilityGregor MendelGeneChromosome GenotypePhenotypePedigreeGamete Cross BreedingSelective BreedingMitosisMeiosis
COPY THE FOLLOWING FROM your notes:
Should be copied on your test review
• How to complete a punnett square and give responses in ratio and percentages
• Sex Limited Genes Example (hen/Rooster feathering) Punnett Square
• Co-Dominance Example Punnett Squares (Roan Coloring)
• Sex Linked Example (Barred Feathering) Example