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.

[EX Q]: Background: The HIV-1 RNA genome has a biased nucleotide composition with a surplus of As. Several hypotheses have been put forward to explain this striking phenomenon, but the A-count of the HIV-1 genome has thus far not been systematically manipulated. The reason for this reservation is the likelihood that known and unknown sequence motifs will be affected by such a massive mutational approach, thus resulting in replication-impaired virus mutants. We present the first attempt to increase and decrease the A-count in a relatively small polymerase (pol) gene segment of HIV-1 RNA. To minimize the mutational impact, a new mutational approach was developed that is inspired by natural sequence variation as present in HIV-1 isolates. This phylogeny-instructed mutagenesis allowed us to create replication-competent HIV-1 mutants with a significantly increased or decreased local A-count. The local A-count of the wild-type (wt) virus (40.2%) was further increased to 46.9% or reduced to 31.7 and 26.3%. These HIV-1 variants replicate efficiently in vitro, despite the fact that the pol changes cause a quite profound move in HIV-SIV sequence space. Extrapolating these results to the complete 9 kb RNA genome, we may cautiously suggest that the A-rich signature does not have to be maintained. This survey also provided clues that silent codon changes, in particular from G-to-A, determine the subtype-specific sequence signatures.
[EX A]: HIV-1 tolerates changes in A-count in a small segment of the pol gene

[EX Q]: Charley, B., McCullough, K. and Martinod, S., 1988. Antiviral and antigenic properties of recombinant porcine interferon gamma. Vet. Immunol. Immunopathol., Recombinant porcine interferon gamma (rPoIFN7) induced a dose-dependent inhibition of the cytopathic effect produced by vesicular stomatitis virus (VSV) challenge of both homologous and heterologous (bovine) cell lines. In addition, an antiviral effect of rPoIFN7 was demonstrable against the coronavirus transmissible gastroenteritis virus (TGEV) infection of porcine epithelial cells and of pulmonary macrophages. A rabbit anti-PoIFN7 antiserum was prepared and shown to specifically neutralize the antiviral effects of natural and recombinant porcine IFN7 preparations. This antiserum could also neutralize recombinant bovine IFN7 but not recombinant human IFNT. These results suggest antigenic homology of porcine and bovine IFN~ but antigenic differences between these molecules and human IFNT.
[EX A]: Antiviral and Antigenic Properties of Recombinant Porcine Interferon Gamma

[EX Q]: classified as a member of the genus coronavirus in the family coronaviridae. The enveloped virus has a positive-sense, single-stranded RNA genome of approximately 28 kilo-bases, which has a 5 cap structure and 3 polyadenylation tract. The complete genome sequence of infectious bronchitis virus (IBV), Beijing isolate, was determined by cloning sequencing and primer walking. The whole genome is 27733 nucleotides in length, has ten open reading frames: 5 -orf1a-orf1ab-s-3a-3b-e-m-6a-6b-n-3 . Alignments of the genome sequence of IBV Beijing isolate with those of two AIBV strains and one SARS coronavirus were performed respectively. The genome sequence of IBV Beijing isolate compared with that of the IBV strain LX4 (uncompleted, 19440 bp in size) was 91.2% similarity. However, the full-length genome sequence of IBV Beijing isolate was 85.2% identity to that of IBV Strain Beaudette, and was only 50.8% homology to that of SARS coronavirus. The results showed that the genome of IBV has remarkable variation. And IBV Beijing isolate is not closely related to SARS coronavirus. Phylogenetic analyses based on the whole genome sequence, S protein, M protein and N protein, also showed that AIBV Beijing isolate is lone virus in group and is distant from SARS coronavirus. In conclusion, this study will contribute to the studies of diagnosis and diseases control on IBV in China. Keywords: avian infectious bronchitis virus (AIBV), severe acute respiratory syndrome coronavirus (SARS-CoV), primer walking, sequence analysis.
[EX A]:
Genome sequencing and characterization analysis of a Beijing isolate of chicken coronavirus infectious bronchitis virus