There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.
Abstract
<p class="first" id="P1">In 1936, John Joseph Bittner identified mouse mammary tumor
virus (MMTV), a milk transmitted
beta retrovirus, a form of single-stranded positive-sense RNA virus. A retrovirus
inserts a copy of its genome into the DNA of a host cell, thus altering the cell's
genome. In the current analysis, we searched for MMTV sequences within the human genome.
To compare the MMTV genome to the human genome, we used BLAT, the Blast-Like Alignment
Tool of the UCSC Genome Browser. BLAT can align a user sequence of 25 bases or more
to the genome. 60 MMTV sequences were in the human genome. Of 56 sequences from the
MMTV POL gene, 36 POL sequences were from the same part of the gene, beginning at
viral nucleotide 4800 but of different lengths. 8 viral sequences began at nucleotide
~3430 of the POL gene. Four viral sequences were from GAGdUTPase, encoded by the MMTV
PRO gene. Deoxyuridine 5′-triphosphate nucleotidohydrolase (dUTPase) is an enzyme
present in several major retroviral families. In MMTV dUTPase may be essential for
viral replication. Since BLAT identified no MMTV envelope (
<i>env)</i> sequence in the human genome, the
<i>env</i> sequences from breast tumors and normal breast tissue found in other studies
may
have come from an MMTV infection. However, no one is certain how MMTV could enter
human cells, since the cells do not have a cellular receptor for MMTV, as do mouse
cells.
</p>