Biology Reference
In-Depth Information
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family microRNAs, catalyzing stage transitions through the body, or
quiescence by shutting down the heterochronic and molting timers. Some
of the same components that regulate developmental timing and metabolism
during maturation are co-opted to regulate life span in response to signals
from the reproductive system. Steroid receptor DAF-12 acts at the conver-
gence of these pathways conveying environmental information into these
circuits. The studies in the worm point to many new directions to be
explored in the future. How are environmental cues integrated to produce
hormonal signals? What is the molecular architecture of feedback loops
governing commitments to reproductive development and how are they
integrated into developmental timing? What is the relationship between
the molt cycle and the heterochronic timer? How do these circuits regulate
the life span? The foremost question is to what extent are these physiologic
functions conserved? Answers to these questions in the future are certain to
help us understand the fundamental mechanisms underlying specification of
life stages, longevity, and the nature of biological time.
ACKNOWLEDGMENTS
The author would like to thank members of the Antebi lab for reading the manuscript, and
Dr. Birgit Gerisch for help with the figures. The author apologizes to those colleagues whom
he could not cite due to length restrictions.
REFERENCES
