The Tsf1m10 deletion was made by GenetiVision. They sent me the following information about the guide RNAs and deleted region: "Our search on CG6168 and its neighboring sequences let us find two gRNA targets sequences, aaccggttgagtcaccacggtgg and gagtggtgtgaaaagccaattgg, respectively, which would allow us to delete the entire gene of Tsf1 ( X:18 ,387,084..18,390,344 +)." GenetiVision verified that a GFP cassette was inserted at the expected location in the mutant line. (I simply verified that the mutant line does not have any detectable Tsf1 mRNA or protein.)