Publisher's version (útgefin grein).Mechanisms underlying fat accumulation for long-distance migration are not fully understood. This
is especially relevant in the context of global change, as many migrants are dealing with changes in
natural habitats and associated food sources and energy stores. The continental Black-tailed godwit
Limosa limosa limosa is a long-distance migratory bird that has undergone a considerable dietary shift
over the past few decades. Historically, godwits fed on an animal-based diet, but currently, during the
non-breeding period godwits feed almost exclusively on rice seeds. The latter diet may allow building
up of their fuel stores for migration by signifcantly increasing de novo lipogenesis (DNL) activity. Here,
we performed an experiment to investigate lipid fux and the abundance of key enzymes involved in
DNL in godwits, during fasting and refueling periods at the staging site, while feeding on rice seeds or
fy larvae. Despite no signifcant diferences found in enzymatic abundance (FASN, ME1, ACC and LPL)
in stored fat, experimental godwits feeding on rice seeds presented high rates of DNL when compared
to fy-larvae fed birds (~35 times more) and fasted godwits (no DNL activity). The increase of fractional
DNL in godwits feeding on a carbohydrate-rich diet can potentially be enhanced by the fasting period
that stimulates lipogenesis. Although requiring further testing, these recent fndings provide new
insights into the mechanisms of avian fat accumulation during a fasting and refueling cycle and
associated responses to habitat and dietary changes in a migratory species.Te authors acknowledge fnancial support from Fundação para a Ciencia e Tecnologia (FCT) in the form of
fellowships to PMA (SFRH/BD/69238/2010), IV (SFRH/BPD/90032/2012) and JAA (SFRH/BPD/91527/2012)
and research Project CGL2017-89009-P. NMR data were collected at the UC-NMR facility that is supported
by FEDER and FCT (RECI/QEQ-QFI/0168/2012, CENTRO-07-CT62-FEDER-002012) and Rede Nacional
de Ressonancia Magnética Nuclear (RNRMN). Tis study benefted from funding by the strategic program of
MARE, fnanced by FCT (UID/MAR/04292/2019), and by FTC/MCTES to CESAM, (UID/AMB/50017 – POCI01-0145-FEDER-007638), through national funds.Peer Reviewe