Question

Dr. Zoidberg investigates the genetics causes of boneitis, a (fictional) bone disease for which the symptoms become visible when individuals tum 30 years old. It is already known that the disease follows an autosomal dominant pattern, with only one locus involved. Dr. Zoidberg analyzes data from a family for which the allelic status for the gene ADHIA (encoding the ADH - Alcohol Dehydrogenase- enzyme) has already been determined via protein electrophoresis (see lecture #3). The results are shown below. Hatch patterns in the pedigree indicate individuals with dividuals are >40 years old and we assume that the disease/no-disease status is isly known for each individual. The results of the electropherogram for the ADH enzyme are shown above the pedigree for the two parents, and below the pedigree for the 8 offspring (each result vertically aligned with the corresponding individual). Figurel: Pedigree showing presence/absence of boneitis disease in eight offspring from the same two parents. Individuals with the disease are marked by a hatch pattern. Additionally, the results of an electrophoresis gel for the ADH enzyme are shown directly above (for parents) or below (for offspring) the corresponding individual. Dr. Zoidberg suspects a link between ADH and boneitis. He performs a linkage analysis using the data from Figure 1. 1.1) How many alleles of the ADHIA gene are segregating in this family? [4 pts) 1.2) List the children (numbered 1 to 8 on the Figure) who show evidence of recombination between the ADH1A and the boneitis-causing locus.

Answer 1

ans (1.1)

~ There are two alleles of ADH1A gene segregating in the family. Individuals whose electropherograms exhibit two bands are heterozygous, whereas the individuals whose electropherograms exhibit with single band are homozygous.

ans (1.2)

~ Only the 3rd child is the recombination between the ADH1A and the boneitis- causing locus.

~ As the 1st, 4th , 5th ,6th, and 7th are the children with boneitis , whereas the 2nd and 8th are the children of ADH1A gene segregating  

ans (1.3)

ans (1.5 )

(d) this analysis does not tell us anything about the molecular cause of boneitis.