TY - JOUR
T1 - Coincident loss of mitochondria and nuclei during lens fiber cell differentiation
AU - Bassnett, Steven
AU - Beebe, David C.
PY - 1992/6
Y1 - 1992/6
N2 - During normal differentiation, lens fiber cells lose their nuclei, mitochondria, and other membrane‐bound organelles. In the present study, a slice preparation of the embryonic chicken lens was used with laser scanning confocal microscopy to study the spatial and temporal patterns of organelle breakdown during embryonic development. At all stages examined, mitochondria in lens epithelial cells were present in perinuclear clusters. In contrast, early in development, lens fiber cells contained extremely elongated mitochondria (>100 μm) that were distributed throughout the cytoplasm and oriented along the long axis of the cells. By the 8th day of embryonic development (E8), the mitochondria in the central fiber cells began to fragment. At the same time, the nuclei in these cells became smaller and more spherical. By E10, mitochondrial staining in the central fibers became punctate. Electron microscopy of this region revealed swollen mitochondria with disrupted cristae. By E12, cells in the central region of the lens lacked mitochondria and nuclei. The loss of nuclei and mitochondria from a given cell was coincident and abrupt (2–4 hr), occurring in a previously unsuspected domain situated about 300 μm from the anterior surface of the lens. A cytoskeletal component, actin, persisted in the central cells indicating that organelle degradation represents a selective process and not simply the global degradation of supramolecular structures. Throughout embryonic development, the organelle‐free region grew at approximately the same rate as the lens and, by the time of hatching, had expanded to match the diameter of the pupil. The present results suggest that the embryonic lens will be a useful model system with which to study mechanisms of organelle degradation. © 1992 Wiley‐Liss, Inc.
AB - During normal differentiation, lens fiber cells lose their nuclei, mitochondria, and other membrane‐bound organelles. In the present study, a slice preparation of the embryonic chicken lens was used with laser scanning confocal microscopy to study the spatial and temporal patterns of organelle breakdown during embryonic development. At all stages examined, mitochondria in lens epithelial cells were present in perinuclear clusters. In contrast, early in development, lens fiber cells contained extremely elongated mitochondria (>100 μm) that were distributed throughout the cytoplasm and oriented along the long axis of the cells. By the 8th day of embryonic development (E8), the mitochondria in the central fiber cells began to fragment. At the same time, the nuclei in these cells became smaller and more spherical. By E10, mitochondrial staining in the central fibers became punctate. Electron microscopy of this region revealed swollen mitochondria with disrupted cristae. By E12, cells in the central region of the lens lacked mitochondria and nuclei. The loss of nuclei and mitochondria from a given cell was coincident and abrupt (2–4 hr), occurring in a previously unsuspected domain situated about 300 μm from the anterior surface of the lens. A cytoskeletal component, actin, persisted in the central cells indicating that organelle degradation represents a selective process and not simply the global degradation of supramolecular structures. Throughout embryonic development, the organelle‐free region grew at approximately the same rate as the lens and, by the time of hatching, had expanded to match the diameter of the pupil. The present results suggest that the embryonic lens will be a useful model system with which to study mechanisms of organelle degradation. © 1992 Wiley‐Liss, Inc.
KW - Confocal microscopy
KW - Lens
KW - Rhodamine 123
UR - http://www.scopus.com/inward/record.url?scp=0026774623&partnerID=8YFLogxK
U2 - 10.1002/aja.1001940202
DO - 10.1002/aja.1001940202
M3 - Article
C2 - 1421526
AN - SCOPUS:0026774623
SN - 1058-8388
VL - 194
SP - 85
EP - 93
JO - Developmental Dynamics
JF - Developmental Dynamics
IS - 2
ER -