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