PIGEONETICS LAB PART 1 Name: Period: Date: This activity will challenge you to use what you ve learned about Mendelian Traits, Punnett Squares, and Sex-Linkage, as well as some new types of complex inheritance, to solve genetics puzzles and become a virtual pigeon breeder! 1. Please go to: http://learn.genetics.utah.edu/content/pigeons/ or search for University of Utah Pigeon Breeding and click on Pigeonetics. (Be sure the volume on your computer is not muted.) 2. As you work through the puzzles, answer the questions about the genetics of each trait and make any additional notes that you think will be helpful in solving the puzzles! 3. The game automatically saves the puzzles that you have completed. Click the pause symbol in the lower right corner to see a list of the puzzles you have completed and to jump ahead to the puzzles you have remaining. Trait Draw/Describe: Questions/Notes: Sex (Puzzle 1) Male or Female Male Sex Chromosomes = Female Sex Chromosomes = Crest (Puzzle 3) Is the allele for having a crest dominant or recessive? How do you know? (Hint: Look closely at the example pigeons.) Slipper (Puzzle 6) Look closely at the birds in your population. How many different Phenotypes (appearances) are there for slipper feet? Sketch an example of what EACH phenotype looks like: Underneath each sketch, please write the genotype (alleles) needed to produce that phenotype. Grouse (Puzzle 8) Is the allele for grouse dominant or recessive? How do you know? Birds who have both the grouse and slipper trait are called.
Wing Pattern (Puzzle 9) List the 4 different possible wing patterns for pigeons: 1. 2. 3. 4. If a pigeon has one allele for the bar pattern and another for check, what phenotype will it have? (Hint: Look carefully at the pigeons in your population.) If a pigeon has one allele for the barless pattern and another for t-check, what phenotype will it have? Rank the four alleles for wing pattern in order from most dominant (#1) to least dominant (#4). (Hint: You may wish to click on the explain button for more information.) Feather Color (Puzzle 13) List the possible colors for pigeons. 1. 2. 3. Rank the three alleles for color in order from most dominant (#1) to least dominant (#3). Notice that the inheritance of feather color was different in male and female birds. Please propose an explanation for why this might be. Puzzles 17-26 are required for the Honors Extension. They are optional for others. Spread Is the allele for spread dominant or recessive? (Puzzle 17) How might the alleles for spread interact with the alleles for wing pattern?
Recessive Red How is recessive red different than the feather color trait we ve already seen? (Puzzle 19) How many alleles are possible for this gene? How many recessive red alleles are necessary to produce a recessive red phenotype? Is recessive red sex-linked? How can you tell? Dilute How many different possible alleles are there for this trait? (Puzzle 23) Is dilute dominant or recessive? What chromosome is the dilute gene carried on? Is dilute a Mendelian trait? Why or why not? How do the dilute and recessive red alleles interact? (Hint: Look carefully at your offspring pigeon.)
ANALYSIS: Review Mendelian Traits: Recall that a Mendelian trait is controlled by exactly 1 gene with 2 possible alleles, one of which is dominant and the other is recessive. Because of this, Mendelian traits follow the most simple pattern of inheritance. 1. Which pigeon trait(s) are Mendelian traits? 2. For each of the non-mendelian traits, please explain why it is not Mendelian. Review Sex Linkage: Any trait, regardless of whether or not it is Mendelian, can also be sex-linked if it is carried on one of the sex chromosomes. 3. How does this affect the inheritance (possible breeding outcomes) of this trait? 4. Which pigeon trait(s) are sex-linked? How do you know? 5. How do pigeon sex-chromosomes differ from human sex-chromosomes? 6. If a male pigeon has one allele for blue color, is it possible that he will be red? If a female pigeon has one allele for blue color, is it possible that she will be red? Please explain.
Incomplete Dominance: There are other, more complex, patterns of inheritance as well. For example, in incomplete dominance, each allele contributes to the phenotype. As a result, there are 3 possible phenotypes, instead of only the 2 (a dominant and a recessive) that we see in a Mendelian trait. 7. Which pigeon trait showed incomplete dominance? 8. Please draw the three phenotypes for this trait & describe the genotype necessary for each of them. Multiple Alleles: Inheritance also becomes more complex when there are multiple (more than 2) possible alleles for a gene. 9. Which pigeon traits had multiple alleles? 10. How is the phenotype of a trait with multiple alleles different from a Mendelian trait? 11. What is the difference between multiple alleles and multiple genes? Epistasis (Honors Extension): We would say that gene for spread is epistatic over the gene for wing pattern. 12. In your own words, please describe what you think epistasic means. 13. Identify two other examples of epistasis in pigeon genetics.
Polygenic Traits (Honors Extension): A trait that is impacted by more than one gene is known as a polygenic trait. 14. Describe one pigeon trait that is polygenic. 15. What is the difference between a polygenic trait and a trait with multiple alleles? 16. Identify one human trait that is likely to be polygenic. How do you know? SUMMARY: 1. Describe the phenotype of a pigeon with the following genotype: Has two Z chromosomes Has one allele for crest and one allele for no crest Has one allele for slipper another for no slipper Has two alleles for no grouse Has one allele for bar and another allele for check Has one allele for brown and other allele for blue 2. Honors Extension: How would the pigeon described above be different with the addition two recessive red alleles?
Check for Understanding: 1. Which of the following traits are Mendelian? (Select all that apply.) a. Slipper b. Crest c. Grouse d. Wing Pattern e. Feather Color 2. Flower color is incompletely dominant in Japanese Four-o-clock flowers. When a purebred red flower is bred with a purebred white flower, what phenotype(s) would you expect in the offspring? In what fractions/percentages? The trait of feather color is best described as a. sex linked b. multiple alleles 3. Is blue feather color dominant or recessive? Explain why that is a difficult question to answer. 4. One of the traits we breed pigeons for is called grouse or feathers on the legs. Based on this pigeon, is the grouse allele dominant or recessive? 5. Epistasis is a relationship between genes in which the expression of one gene hides (or masks) another. Which two genes have an epistatic relationship in pigeons? - Spread is epistatic over wing pattern - Recessive red is epistatic over color, pattern & spread - Dilute is epistatic over all alleles that control color and pattern (including recessive red) A male pigeon with breeds with a female pigeon with. The offspring are. Based on this cross, and you notes from pigeon breeding, you can conclude that The gene for feather color is carried on which chromosome? Carried on the Z chromosome Describe the pigeon that would be produced from the following genotype: What genotype (alleles) would be necessary to create a pigeon with: