Identification of a micropeptide and multiple secondary cell genes that modulate Drosophila male reproductive success

Clément Immarigeon, Yohan Frei, Sofie Y N Delbare, Dragan Gligorov, Pedro Machado Almeida, Jasmine Grey, Léa Fabbro, Emi Nagoshi, Jean-Christophe Billeter, Mariana F Wolfner, François Karch, Robert K Maeda*

*Corresponding author for this work

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Even in well-characterized genomes, many transcripts are considered noncoding RNAs (ncRNAs) simply due to the absence of large open reading frames (ORFs). However, it is now becoming clear that many small ORFs (smORFs) produce peptides with important biological functions. In the process of characterizing the ribosome-bound transcriptome of an important cell type of the seminal fluid-producing accessory gland of Drosophila melanogaster, we detected an RNA, previously thought to be noncoding, called male-specific abdominal (msa). Notably, msa is nested in the HOX gene cluster of the Bithorax complex and is known to contain a micro-RNA within one of its introns. We find that this RNA encodes a "micropeptide" (9 or 20 amino acids, MSAmiP) that is expressed exclusively in the secondary cells of the male accessory gland, where it seems to accumulate in nuclei. Importantly, loss of function of this micropeptide causes defects in sperm competition. In addition to bringing insights into the biology of a rare cell type, this work underlines the importance of small peptides, a class of molecules that is now emerging as important actors in complex biological processes.

Original languageEnglish
Article number e2001897118
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number15
Publication statusPublished - 13-Apr-2021

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