For full credit, (a) Circle and label on the diagram and (b)Write your answers in complete sentences.
Among the several coronaviruses that are pathogenic to humans, most are associated with mild clinical symptoms, with 2 notable exceptions: severe acute respiratory syndrome (SARS) coronavirus (SARS-CoV), a novel beta coronavirus from Guangdong, China, in 2002, and resulted in> 8000 human infections and 774 deaths in 37 countries; and Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV), which was first detected in Saudi Arabia in 2012 and was responsible for 858 fatalities since September, 2012. In late December 2019, several patients with viral pneumonia were found to be epidemiologically associated with the Huanan seafood market in Wuhan, in the Hubei province of China, where a number of non-aquatic animals such as birds and rabbits were also on sale before the outbreak. A novel, human-infecting coronavirus, provisionally named 2019 novel coronavirus (2019-nCoV or COVID-19), was identified with use of next-generation sequencing. COVID-19 is affecting 176 countries as of March 20, around the world. Most of the infected patients had a high fever and some had dyspnoea, with chest radiographs revealing invasive lesions in both lungs. Phylogenetic analysis of this virus will inform our understanding of the zoonotic origin of this outbreak and take appropriate measures to control and prevent the infection (Lu et al. 2020).
Refer to the phylogenetic tree at the bottom to answer Questions 1-5.
1.)(a) Identify a monophyletic group (consisting of two or more taxa) on the tree.Name the
taxa in that group.
(b)Why is this group considered a â€œnatural groupingâ€?
2.)(a) Identify a paraphyletic group on the tree.Name the taxa in that group.
(b) Why is this group not considered a â€œnatural groupingâ€?
3.)(a) Identify a polyphyletic group on the tree.Name the taxa in that group.
(b) How is this different from a paraphyletic group?
4.)(a) What is the outgroup in this tree?
(b) Why are outgroups important (i.e. what kind of information do we get from the
5.)(a) Which of these two taxa is Human betacoronavirus (MERS-CoV) (JX869059) from Saudi Arabia more closely related to?Betacoronavirus Germany (marked in yellow) or EF065509 from Guangdong?
(b) If you were working in this lab that generated this phylogenetic tree and your next step is to develop vaccine based on strains from the animal reservoir of COVID-19 which animal would you be looking for?
Figure 1. Phylogenetic analysis of the COVID-19 virus and its closely related reference (attached below)
genomes Note: COVID-19 virus is referred to as 2019-nCoV in the figure, the interim virus name WHO announced early in the outbreak.