Q19 - Genotyping T-DNA Insertion Lines by PCR Band Pattern

As part of the functional analysis of the april gene found in a diploid plant, a mutant strain was discovered in which a DNA fragment (T-DNA) of 3 kb or more was inserted into one april gene. Since this strain is considered heterozygous for the april gene, seeds were obtained by self-pollination. Figure 1 shows the gene map of the april gene and the T-DNA insertion site, with primer 1 and primer 2 flanking the insertion site (250 bp on either side) and primer 3 sitting within the T-DNA reading outward. Genomic DNA was extracted from three different plants (A, B, C), and PCR was performed using the designed primers. Figure 2 shows the agarose gel electrophoresis results for primer 1+2 and primer 1+3 combinations.

Figure 1.

Using the information and data, determine which of the statements are true or which are false.

Question reproduced from IBO 2020, Theoretical Exam 2, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)