In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.

[Q]: A reverse genetics system for the avian coronavirus infectious bronchitis virus (IBV) has been described in which a full-length cDNA, corresponding to the IBV (Beaudette-CK) genome, was inserted into the vaccinia virus genome following in vitro assembly of three contiguous cDNAs [Casais, R., Thiel, V., Siddell, S.G., Cavanagh, D., Britton, P., 2001. Reverse genetics system for the avian coronavirus infectious bronchitis virus. J. Virol. 75, 12359-12369]. The method has subsequently been used to generate a recombinant IBV expressing a chimaeric S gene [Casais, R., Dove, B., Cavanagh, D., Britton, P., 2003. Recombinant avian infectious bronchitis virus expressing a heterologous spike gene demonstrates that the spike protein is a determinant of cell tropism. J. Virol. 77, 9084-9089]. Use of vaccinia virus as a vector for the full-length cDNA of the IBV genome has the advantage that modifications can be made to the IBV cDNA using homologous recombination, a method frequently used to insert and delete sequences from the vaccinia virus genome. We describe the use of homologous recombination as a method for modifying the Beaudette full-length cDNA, within the vaccinia virus genome, without the requirement for in vitro assembly of the IBV cDNA. To demonstrate the feasibility of the method we exchanged the ectodomain of the Beaudette spike gene for the corresponding region from IBV M41 and generated two recombinant infectious bronchitis viruses (rIBVs) expressing the chimaeric S protein, validating the method as an alternative way for generating rIBVs.
[A]: Generation of a recombinant avian coronavirus infectious bronchitis virus using transient dominant selection

[Q]: 2 The abbreviations used are: S, spike; SARS-CoV, severe acute respiratory syndrome coronavirus; MLV, murine leukemia virus; DC-SIGN, dendritic cell-specific intercellular adhesion molecule-3-gubbing non-integrin, ACE2, argiotensin I conserting enzyme 2. FIGURE 4. Introduction of alanine residues in the S2 region modulates elastase-induced virus entry mediated by SARS-CoV S. A and B, pseudotyped virion infections were performed as described for Fig. 2. Infection was induced by treatment with elastase (A) or trypsin (B). Results are presented as relative light units (RLU). Error bars represent the S.E. of three independent experiments. C, cleavage of SARS-CoV by elastase. HEK293T cells expressing the wild type (WT) or mutant SARS-CoV spike protein were treated with 50 g/ml elastase. Cell surface proteins were biotinylated and precipitated, and cleavage products of the SARS-CoV spike protein were analyzed in Western blot with an antibody recognizing the C9 tag at the C terminus of the protein.
[A]: Elastase-mediated Activation of the Severe Acute Respiratory Syndrome Coronavirus Spike Protein at Discrete Sites within the S2 Domain * S

[Q]: A new series of 6-iodo-2-phenylquinazolin-4(3H)-one derivatives was prepared and screened for antimicrobial activity. The thioureide derivatives 4-6, the carbohydrazide derivatives 19-21 and 24 displayed excellent broad-spectrum antimicrobial activity. Some compounds showed moderate activity against Candida albicans and Pseudomonas aeruginosa. None of the tested compounds was as active as the reference standard drugs ampicillin and clotrimazole. The detailed synthesis, antimicrobial activity, and the minimum inhibitory concentrations (MIC) are reported. 2010 King Saud University. Production and hosting by Elsevier B.V. *
[A]:
Synthesis and antimicrobial activity of some new quinazolin-4(3H)-one derivatives