Question

Consider seven recessive genes, a, e, d, j, l, y and r. The seven loci are closely linked in the centromeric region of an autosome but their order is unknown. Six deletions are examined in an individual that is heterozygous for all seven genes. All six deletions resulted in pseudodominance of at least two genes, and two deletions spanned the region of the centromere. Deletion Centromere included in deletion Genes exhibiting pseudodominance del 1 No e and j del 2 Yes a, l and r del 3 No a and d del 4 Yes e, l and r del 5 No d and y del 6 No e and l Determine the gene order and the location of the centromere.

Answer 1

Answer:

Gene order: y,d,a,(r,l),e,j

Centromere: between l and r

Explanation:

If you see your data you can conclude that:

- deletions that include the centromere include r and l genes.

- At one side of the centromere is gene a and at the other side is gene e

- when you see mutation 3, the gene that is away from the centromere is d, then in mutation 5 the gene that is further is y

- On the other side, the mutation 6 tell us that e gene is by l gene side

- In mutation one you see that the gene further the centromere by that side is j