In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[EX Q]: Context: Pandemic strains of HIV-1 (group M) encode a total of nine structural (gag, pol, env), regulatory (rev, tat) and accessory (vif, vpr, vpu, nef) genes. However, some subtype A and C viruses exhibit an unusual gene arrangement in which the first exon of rev (rev1) and the vpu gene are placed in the same open reading frame. Although this rev1-vpu gene fusion is present in a considerable fraction of HIV-1 strains, its functional significance is unknown.', 'Examining infectious molecular clones (IMCs) of HIV-1 that encode the rev1-vpu polymorphism, we show that a fusion protein is expressed in infected cells. Due to the splicing pattern of viral mRNA, however, these same IMCs also express a regular Vpu protein, which is produced at much higher levels. To investigate the function of the fusion gene, we characterized isogenic IMC pairs differing only in their ability to express a Rev1-Vpu protein. Analysis in transfected HEK293T and infected CD4+ T cells showed that all of these viruses were equally active in known Vpu functions, such as down-modulation of CD4 or counteraction of tetherin. Furthermore, the polymorphism did not affect Vpu-mediated inhibition of NF-кB activation or Rev-dependent nuclear export of incompletely spliced viral mRNAs. There was also no evidence for enhanced replication of Rev1-Vpu expressing viruses in primary PBMCs or ex vivo infected human lymphoid tissues. Finally, the frequency of HIV-1 quasispecies members that encoded a rev1-vpu fusion gene did not change in HIV-1 infected individuals over time.\Question: Does a Naturally Occurring rev1-vpu Fusion Gene Confer a Fitness Advantage to HIV-1?
[EX A]: Expression of a rev1-vpu fusion gene does not affect regular Rev and Vpu functions or alter HIV-1 replication in primary target cells. Since there is no evidence for increased replication fitness of rev1-vpu encoding viruses, this polymorphism likely emerged in the context of other mutations within and/or outside the rev1-vpu intergenic region, and may have a neutral phenotype.

[EX Q]: Context: Primary pneumonic plague is a rare but often fatal form of Yersinia pestis infection that results from direct inhalation of bacteria and is potentially transmissible from person to person. We describe a case of primary pneumonic plague in a wildlife biologist who was found deceased in his residence 1 week after conducting a necropsy on a mountain lion.', "To determine cause of death, a postmortem examination was conducted, and friends and colleagues were interviewed. Physical evidence was reviewed, including specimens from the mountain lion and the biologist's medical chart, camera, and computer. Human and animal tissues were submitted for testing. Persons in close contact (within 2 meters) to the biologist after he had developed symptoms were identified and offered chemoprophylaxis.", 'The biologist conducted the necropsy in his garage without the use of personal protective equipment. Three days later, he developed fever and hemoptysis and died approximately 6 days after exposure. Gross examination showed consolidation and hemorrhagic fluid in the lungs; no buboes were noted. Plague was diagnosed presumptively by polymerase chain reaction and confirmed by culture. Tissues from the mountain lion tested positive for Y. pestis, and isolates from the biologist and mountain lion were indistinguishable by pulsed-field gel electrophoresis. Among 49 contacts who received chemoprophylaxis, none developed symptoms consistent with plague.\Question: Do primary pneumonic plague contracted from a mountain lion carcass?
[EX A]: The biologist likely acquired pneumonic plague through inhalation of aerosols generated during postmortem examination of an infected mountain lion. Enhanced awareness of zoonotic diseases and appropriate use of personal protective equipment are needed for biologists and others who handle wildlife.

[EX Q]: Context: Recently described slow-cooling cryopreservation protocols involving elevated sucrose concentration have improved survival frequencies of human oocytes, potentially overcoming a major hurdle that has limited the adoption of oocyte storage. Because implantation rates of embryos from frozen oocytes remain generally low, it is still debated whether, irrespective of survival rates, this form of cryopreservation leads inevitably to the disruption or complete loss of the metaphase II (MII) spindle.', 'Human oocytes with an extruded polar body I (PBI) were cryopreserved using a slow-cooling method including 1.5 mol/l propane-1,2-diol (PrOH) and alternative sucrose concentrations (either 0.1 or 0.3 mol/l) in the freezing solution. Fresh control and frozen-thawed survived oocytes were analysed by confocal microscopy to evaluate MII spindle and chromosome organizations.', 'Of the 104 oocytes included in the unfrozen group, 76 (73.1%) displayed normal bipolar spindles with equatorially aligned chromosomes. Spindle and chromatin organizations were significantly affected (50.8%) after cryopreservation involving lower sucrose concentration (61 oocytes), whereas these parameters were unchanged (69.7%) using the 0.3 mol/l sucrose protocol (152 oocytes).\Question: Does sucrose concentration influence the rate of human oocytes with normal spindle and chromosome configurations after slow-cooling cryopreservation?
[EX A]:
Partial disruption of the MII spindle and associated chromosomes accompanies inadequate cryopreservation during slow cooling. However, protocols adopting higher sucrose concentration in the freezing solution promote the retention of an intact chromosome segregation apparatus comparable in incidence to freshly collected oocytes.