Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Symmetry Breaking and Adaptation: The Genetic Code of Retroviral Env
  Proteins   Although several synonymous codons can encode the same aminoacid, this
symmetry is generally broken in natural genetic systems. In this article, we
show that the symmetry breaking can result from selective pressures due to the
violation of the synonym symmetry by mutation and recombination. We conjecture
that this enhances the probability to produce mutants that are well-adapted to
the current environment. Evidence is found in the codon frequencies of the HIV
{\it env} protein: the codons most likely to mutate and lead to new viruses
resistant to the current immunological attack, are found with a greater
frequency than their less mutable synonyms.

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The categories of this paper are: hep-th
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
24
The categories of this paper are: dg-ga
12
The categories of this paper are: nucl-th
14
The categories of this paper are: math-ph