The mir-7 and bag of marbles genes regulate Hedgehogpathway sig naling in blood cell progen itors in Drosophilalarval lymph glands

Hedgehog (Hh) pathway signaling is crucial for the maintenance of blood cell progenitors in thelymph gland hematopoietic organ present in Drosophila third instar larvae. Previous studies fromour lab have likewise shown the importance of the mir-7 and bag of marbles (bam) genes in main-taining the progenitor state. Thus, we sought to investigate a possible interaction between the Hhpathway and mir-7/bam in the prohemocyte population within this hematopoietic tissue. Gain offunction mir-7 was able to rescue a blood cell progenitor depletion phenotype caused by Patched(Ptc) inhibition of Hh pathway signaling in these cells. Similarly, expression of a dominant/negativeversion of Ptc was able to rescue the severe reduction of prohemocytes due to bam loss of func-tion. Furthermore, we demonstrated that Suppressor of fused [Su(fu)], another known inhibitor ofHh signaling, likely serves as a translational repression target of the mir-7 miRNA. Our results sug-gest the mir-7/bam combination regulates the Hh signaling network through repression of Su(fu)to maintain hemocyte progenitors in the larval lymph gland.