title: Natural Loss of eyeless/Pax6 Expression in Eyes of Bicyclus anynana Adult Butterflies Likely Leads to Exponential Decrease of Eye Fluorescence in Transgenics.
abstract: Commonly used visible markers for transgenesis use fluorescent proteins expressed at the surface of the body, such as in eyes. One commonly used marker is the 3xP3-EGFP cassette containing synthetic binding sites for the eyeless/Pax6 conserved transcription factor. This marker cassette leads to fluorescent eyes in a variety of animals tested so far. Here we show that upon reaching adulthood, transgenic Bicyclus anynana butterflies containing this marker cassette exponentially loose fluorescence in their eyes. After 12 days, transgenic individuals are no longer distinguishable from wild type individuals. The decreased eye fluorescence is likely due to significantly decreased or halted eyeless/Pax6 expression observed in wild type animals upon adult emergence. Implications from these findings include care in screening transgenic animals before these reach adulthood, or shortly thereafter, and in using adult animals of the same age for quantitative screening of likely homozygote and heterozygote individuals.
authors.affiliation: Biological Sciences, National University of Singapore, Singapore.
authors.forename: Mainak
authors.initials: M
authors.lastname: Das Gupta
authors.affiliation: Biological Sciences, Universiti Tunku Abdul Rahman, Kampar, Perak, Malaysia.
authors.forename: Sam Kok Sim
authors.initials: SK
authors.lastname: Chan
authors.affiliation: Biological Sciences, National University of Singapore, Singapore; Yale-NUS College, Singapore.
authors.forename: Antónia
authors.initials: A
authors.lastname: Monteiro
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism*; D002080:Butterflies / Q000378:metabolism*; D005123:Eye / Q000378:metabolism*; D005136:Eye Proteins / Q000378:metabolism*; D005453:Fluorescence; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism*; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D005136:Eye Proteins; D018398:Homeodomain Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins