Vol. 2, Issue 4, Part A (2015)

Author(s): Bernardo Pérez-Zamorano, Verónica Valverde-Garduno

Abstract: Some biological processess require a rapid increase in the production of specific proteins. A temporal or permanent increase in the number of copies of the relevant gene contributes to achive high levels of protein product in short periods of time. Polyploid cells may arise as a result of injury, stress, devolpmental and environmental signals. In insects, the innate immune response is a demanding process that requires the rapid synthesis of antimicrobial effectors. Here we investigated the potential involvement of DNA synthesis in Aedes aegypti response to immune challenge. An efficient way to selectively analyze genomic regions undergoing active nucleotide incorporation, is to label DNA in vivo while it is being synthetized. First, a reliable, practical technique to achieve in vivo BrdU-labelling of culicid DNA was developed. This BrdU feeding method allows in vivo incorporation that was detected by Southern blot and immunofluorescence. Both detection techniques confirmed BrdU incorporation into DNA from specific mosquito tissue. Labelling tools described in this work provide an integrative approach for the in vivo study of DNA replication and repair related phenomena in the culicid. Here we show that Aedes aegypti adult female fat body cells undergo de novo DNA synthesis upon injury and that immune challenge triggers DNA synthesis and subsequent formation of a pattern consistent with multiple nuclei in these cells. This multinuclear pattern suggest fat body cells may undergo endomitosis.

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