Romanov Assignment Part B
Part II: Hemophilia
1. Using your knowledge from Module 4, on what chromosome is the gene that causes hemophilia? The gene that causes Hemophilia is on the X chromosome.
2. Describe the mutation that apparently caused hemophilia in Alix, (and probably all of the European families that had hemophilia). Hemophilia disease is caused by a mutation of the gene coding for the F8 gene or the F9 gene. The mutation that caused hemophilia in Alix was a substitution in the splice acceptor site of exon four in the F9 gene. This mutation was a nitrogenous base substitution that resulted in an amino acid sequence change.
3. Using your knowledge from Module 7, describe how the mutation you described in #2 could result in a faulty gene product. The mutation could result in a faulty gene product due to how it caused a change in the amino acid sequence. Missense mutations cause a different amino acid to be placed in the polypeptide chain. The amino acid sequence change was the result of a mutation of the F9 gene hindering one’s blood clotting properly. For Hemophilia B, the mutation created one less clotting factor needed to prevent our blood from bleeding profusely.
4. Again, using your knowledge from Module 4, give the genotype for a carrier of hemophilia. The genotype for a carrier of hemophilia would be XHXh (h= Recessive Hemophilia Gene).
Part III: Molecular Analysis of People in a Mass Grave
5. Mitochondrial DNA testing was also done on both Nicholas II and Alix. Why was information from Alix’s, but not Nicholas,’ mitochondrial DNA used to identify three females as belonging to Alix? The information from Alix’s mitochondrial DNA, and not Nicholas,’ was used to identify the three females as her daughters because a child’s mitochondrial DNA can only be passed down from their mother. The three daughters’ mitochondrial DNA matched Alix’s.
6. HRH Prince Philip, the Duke of Edinburgh, provided mitochondrial DNA used to identify Alix and her three daughters.
- Why was his mitochondrial DNA used? HRH Prince Philip’s mitochondrial DNA was used to identify Alix and her three daughters because Alix was his great-aunt from his mother’s side. Since mitochondrial DNA can only be passed down from a mother to her child, Prince Philip’s mother was Alix’s niece who was the daughter of one of Alix’s sisters, which makes Prince Philip’s grandmother Alix’s sister. Alix and Prince Philip’s grandmother shared the same mitochondrial DNA from their mother, which would then be passed down to their children and then their children’s children. Prince Philip’s mitochondrial DNA proved that there was a maternal relationship between Alix and her three daughters because his mitochondrial DNA had remnants of Alix’s mother’s mitochondrial DNA, which was also in Alix’s mitochondrial DNA.
- Who was the HRH Prince Philip, the Duke of Edinburgh in today’s world? Do you ever hear of his grandchildren (in magazines while you are waiting to check out of a store)? In today’s world, Prince Philip, the Duke of Edinburgh, was married to Queen Elizabeth II of the United Kingdom. I do hear about his grandchildren. Prince William and Harry are known figures around the world; however, I do not keep up with the royal family as often as others might.
7. Who was missing from the mass grave? Alexei and one of his sisters, either Anastasia or Maria, were missing from the mass grave.
8. The Duke of Fife and Princess Xenia provided mitochondrial DNA used to identify Nicholas. One of these is a female and another is a male. Does that matter? What general statement can you make about their genetic relationship to Nicholas. No, it does not matter that the Duke of Fife and Princess Xenia’s mitochondrial DNA were used to identify Nicholas because they all shared the same remnants of mitochondrial DNA from Louise of Hesse-Cassel who was Nicholas’s grandmother. The Duke of Fife and Princess Xenia were maternal relatives of Tsar Nicholas indicating that their mother’s side of the family was related to one another, allowing the passage of the same mitochondrial DNA. The Duke of Fife’s great-great-grandmother was Nicholas’s mother’s sister. Princess Xenia’s great-grandmother was Nicholas’ sister.
9. What was discovered in the mitochondrial DNA of Nicholas that was not identified in either the Duke of Fife or Princess Xenia? A single point of heteroplasmy at the position 16169 C/T was discovered in the mitochondrial DNA of Nicholas and not his maternal relatives. The Duke of Fife and Princess Xenia both had fixed positions in 16169 T.
10. What is the term given to the existence of two (or more) genetically different mitochondria in the cell? The term given to the existence of two or more genetically different mitochondria in the cell is heteroplasmy.