In order to predict the color of offspring between two parents a Punnett Square is used. Results of the chart allow breeders to determine possible allelic combinations as well as the percentages that will be available in a litter. Dominant forms of the allele are depicted by the use of capital letters within the chart, while lower-case letters depict recessive alleles.
USING A PUNNETT SQUARE
Steps to properly set up a Punnett Square 1. Determine the genotype. This can the the most difficult step. Determining which allele is being expressed is simple, it is the color that you see. Deciding what allele is not being expressed is difficult. If you have bred the rabbit before you can make assumptions based on its offspring or if you know the parents of the rabbit you can make an educated guess. Sometimes it is beneficial to do two Punnett Squares to see what the possibilities are if you are not certain of the unexpressed allele. 2. Assign proper capitalization to the alleles. Dominant alleles recieve upper-case letters while recessive alleles recieve lower-case letters. 3. Write the sire’s alleles along the side of the chart. 4. Write the dam’s alleles along the top of the chart. 5. Start with the sire’s alleles, in the boxes directly below write the same letter representing the allele. 6. For the dam write the corresponding allele in the boxes going across. 7. Assess the results.
EXAMPLES