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In-Depth Information
the link between childhood obesity and early puberty, it has become increas-
ingly important to better understand the ways nutrition affects timing of
maturation. Together with the influence of gut microbes on metabolism
and obesity in humans, the link between the gut microbiota, dietary amino
acids, and timing in
Drosophila
opens avenues for future research. Genetic
studies on model organisms like
Drosophila
may provide valuable insight into
how pathological conditions, such as obesity and diabetes, may affect onset
of puberty.
Although systemic insulin signaling affects the steroidogenic activity of
the PG, it might not be the primary means by which the timing of ecdysone
pulses is determined. Both systemic insulin and DILP8 may act via PTTH to
regulate ecdysone synthesis and future studies may shed light on how these
signals converge on the PTTH-ecdysone axis. Another important question
is how the developmental timing program decodes inputs from different
nutrients, like sugar and protein, that both affect systemic insulin signaling.
Perhaps DILP1-7 have different roles, which may be related to the type of
diet. Interestingly,
upd2
is regulated in response to fat and sugar, but not pro-
tein which is the primary nutritional cue that promotes growth and matu-
ration via systemic insulin signaling. This implies the existence of other
amino acid-dependent secreted factors from the fat body. Further investiga-
tions of the “secretome” therefore undoubtedly will reveal diffusible mol-
ecules that are important for timing of maturation in environments with
fluctuating nutrient availability.
ACKNOWLEDGMENTS
This work was supported by the Danish Council for Independent Research, Natural Sciences
grant 11-105446 to K.F.R.
REFERENCES
