Tokmakov, A.A.; Teranishi, R.; Sato, K.-I. Spontaneous Overactivation of Xenopus Frog Eggs Triggers Necrotic Cell Death. International Journal of Molecular Sciences 2024, 25, 5321, doi:10.3390/ijms25105321.
Tokmakov, A.A.; Teranishi, R.; Sato, K.-I. Spontaneous Overactivation of Xenopus Frog Eggs Triggers Necrotic Cell Death. International Journal of Molecular Sciences 2024, 25, 5321, doi:10.3390/ijms25105321.
Tokmakov, A.A.; Teranishi, R.; Sato, K.-I. Spontaneous Overactivation of Xenopus Frog Eggs Triggers Necrotic Cell Death. International Journal of Molecular Sciences 2024, 25, 5321, doi:10.3390/ijms25105321.
Tokmakov, A.A.; Teranishi, R.; Sato, K.-I. Spontaneous Overactivation of Xenopus Frog Eggs Triggers Necrotic Cell Death. International Journal of Molecular Sciences 2024, 25, 5321, doi:10.3390/ijms25105321.
Abstract
Excessive activation of frog eggs, so called overactivation, can be initiated by strong oxidative stress, leading to expedited calcium-dependent non-apoptotic cell death. Overactivation also occurs spontaneously, albeit with a low frequency, in natural populations of spawned frog eggs. Currently, cytological and biochemical events of the spontaneous process are not characterized. In the present study, we demonstrate that spontaneous overactivation of Xenopus frog eggs, similarly to oxidative stress- and mechanical stress-induced overactivation, is characterized by the fast and irreversible contraction of the egg’s cortical layer, increase in the egg size, depletion of intracellular ATP, drastic increase in the intracellular ADP/ATP ratio, and degradation of M phase-specific cyclin B2. These events manifest in eggs in the absence of caspase activation within just one hour of triggering overactivation. Importantly, large amounts of ATP and ADP leak from the overactivated eggs, indicating that plasma membrane integrity is compromised in these cells. The rapture of the plasma membrane and acute depletion of intracellular ATP define explicitly necrotic cell death. Finally, we report that egg overactivation can occur in the frog’s genital tract. Our data argue that mechanical stress may be a key factor promoting egg overactivation during natural spawning in frogs.
Biology and Life Sciences, Cell and Developmental Biology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.