Chinmo is the larval member of the molecular trinity that directs Drosophila metamorphosis

The molecular control of insect metamorphosis from larva to pupa to adult has long been a mystery. The Broad and E93 transcription factors, which can modify chromatin domains, are known to direct the production of the pupa and the adult, respectively. We now show that chinmo, a gene related to broad is essential for the repression of these metamorphic genes. Chinmo is strongly expressed during the formation and growth of the larva and its removal results in the precocious expression of broad and E93 in the first stage larva, causing a shift from larval to premetamorphic functions. This trinity of Chinmo, Broad, and E93 regulatory factors is mutually inhibitory. The interaction of this network with regulatory hormones likely ensures the orderly progression through insect metamorphosis.

Automated summary

This study reveals that the gene chinmo, related to Broad, plays a crucial role in repressing metamorphic genes during larval development. Removal of Chinmo results in premature expression of Broad and E93 in early larvae, causing a shift from larval to premetamorphic functions. The mutual inhibitory regulation between Chinmo, Broad, and E93, along with the interaction with regulatory hormones, likely ensures the orderly progression through insect metamorphosis.