Biological parts (BioParts) are modular and standardized DNA sequences that encode biological functions and contribute to the efficient biological engineering of complex systems. Here, we characterize a short BioPart (P flp-17 , 300 bp) for bright multicopy and single-copy BAG-specific expression starting from the gastrula stage in hermaphrodite and male C. elegans . We have generated standardized P flp-17 cloning vectors for BAG-specific gfp and mScarlet expression compatible with extra-chromosomal arrays and for single-copy transgene insertion. The short P flp-17 promoter is easy to generate by gene synthesis and has been incorporated into our online transgene design tool (www.wormbuilder.org/transgenebuilder ) .