About This Simulation
The Animal Genetics Lab guides the student in learning about Mendelian inheritance and how a mutation in the DNA can give rise to an altered phenotype. Students use PCR and gel electrophoresis to perform genotyping in order to discover the gene causing double muscling in cattle.
Filling in the pedigree: Students arrive on a farm where they observe normal and double muscular cattle. Students fill in a pedigree that identifies double muscled cattle provided by the farm. By studying the pedigree, students learn about hereditary traits and whether double muscling is autosomal or sex-linked and whether it is dominant or recessive. The student then draws a blood sample from which they extract DNA and perform further experiments in the laboratory.
Identifying the candidate gene: Students perform genome scanning where they search the entire genome and identify the candidate gene. They use STR (Short Tandem Repeat) as markers; polymorphic sequences found evenly spaced in mammalian genomes that vary in different individuals. Recognizing STR patterns and similar gene sequence in double muscled cattle DNA, the student narrows down the genomic location of the candidate gene. They do so by amplifying the STR using PCR (Polymerase Chain Reaction) and analyzing the PCR product size using gel electrophoresis. This step reduces the number of genes that they need to investigate further.
Developing a DNA test: After identifying the responsible gene for double muscling, the student then develops a DNA test. This test will be used to identify meat that is sold with an organic label, because it is prohibited to sell organic meat coming from double muscled cattle. Students will use their newly developed DNA test on 3 meat packages from an organic farm.
Going through the Animal Genetics lab, students learn about Mendelian inheritance, genetic disease as well as molecular biology techniques in veterinary science. 3D animation and quiz questions provide thorough content in PCR and gel electrophoresis techniques to ensure student understanding.