Transcriptome profiling of Drosophila adults from multiple generations including flies with genetically-ablated insulin-producing cells as founders.

Transgenerational epigenetic inheritance is a subject of immense current interest. In a newly developed Drosophila model in the laboratory, genetic ablation of insulin-producing cells (IPCs) was found to affect whole -body triglyceride levels not only in the ablated flies but also in their male-line derived, non-ablated future generations. To further characterize this genetic-factor-induced transgenerational inheritance model, we have now performed whole body microarray gene expression profiling of adult males and females with genetically ablated IPCs, and of three consecutive, paternally derived non-ablated generations of adult males and females originating from ablated males. Interestingly, like altered levels of triglycerides, transcriptomic alterations are found not only in the ablated flies but also in their male-line-derived, non-ablated future generations. Test and control line Drosophila cultures were grown at 250C in parallel, with whole body RNA isolated from adults used in gene expression profiling of at least three biological replicates. Adult males and females of the genotype rpr/cyo; dilp3/ser in w1118 background served as F0 test, and that isolated from w1118 background strain as F0 control. F0 test males were mated to F0 control females to generate test line F1 males and females, with the genotypes rpr/+; ser/+, rpr/+; dilp3/+, cyo/+; ser/+, and cyo/+; dilp3/+. All these genotypes were expression profiled. On the other hand, F0 control males mated to F0 control females produced F1 individuals, which were not profiled but used in crosses as described below. F1 test males of the genotype rpr/+; ser/+ were mated to control line F1 females to generate F2 individuals, of which only balancer-free flies were used further. Similarly, F1 control males and females were mated to generate F2 controls. Next, balancer-free F2 test males were crossed to F2 control females to generate F3 individuals. Similarly, mating between F2 control males and females yielded F3 controls.