Conference Paper
Heart development and regeneration in Astyanax mexicanus
Stockdale, W.T., Tang, J.L.Y., Hu, Z., Potts, H.G., Lemieux, M.E., Yamamoto, Y. and Mommersteeg, M.T.M.
Record Number:
4276
Year:
2019
Journal:
AIM 2019
Pages:
26
Abstract:
Astyanax mexicanus has been a valuable research model for different research fields for
decades, however, its heart has largely been ignored. We have identified differences in heart
size, morphology, cell populations (melanocytes and adipocytes) and beating frequency between
the Astyanax mexicanus surface fish and different populations of cave-dwelling fish. These
differences already occur very early in development, but become increasingly apparent over life.
The ventricle of the Pachón heart is not only smaller than the surface fish ventricle, it is also
spongier and much less triangular in shape. The same holds true for the other cavefish
populations examined. As these differences already occur very early during heart development,
before external factors start to play a role, this suggests that the differences in morphology are
genetically regulated. Moreover, the F1 hybrid generation displays heart morphology intermediate
of the 2 parental populations, further indicating that the genetic determinants are quantitatively
inherited. Pyramidal hearts have been found to correlate with active lifestyles in fish, while
rounder hearts are found in fish that are relatively inactive. Therefore, the larger and more
triangular heart in surface fish compared to Pachón suggests adaptation to a more active life in
the rivers compared to the caves. The adaptation to a relatively inactive cave life and resulting
changes in metabolism might also underlie the the fact that adult surface fish can regenerate their
heart after injury, while Pachón cannot and form a permanent fibrotic scar, similar to the human
heart. Quantitative Trait Locus (QTL) analysis as well as RNAseq analysis comparing surface
fish and Pachón hearts after injury point to differences in metabolism as well as immune response
and scarring as the main causes underlying the difference in regeneration. We are now looking
in more detail into how these differences in scarring, immune response and metabolism influence
heart regeneration versus scarring.
Times Cited:
1
Conference Name:
Astyanax Interrnational Meeting
Relevent Species: