pqIs3 [alp-1::GFP]. Maintain by picking GFP+. GFP is inserted in-frame in exon 18: all four ALP-1 isoforms will be expressed but only ALP-1b, ALP-1c, and ALP-1d will be tagged with GFP. Isoforms ALP-1b, ALP-1c, and ALP-1d are collectively known as the Enigma isoforms or ALP-1bcd/Enigma::GFPs. References: McKeown et al. Dev Dyn. 2006 Feb;235(2):530-8 & Han & Beckerle Cell 2009 May; 20(9):2361-70.