First published online August 13, 2003
Journal of Cell Science 116, e1803 (2003)
Copyright © 2003 The Company of Biologists Limited
Nuclear transplantation - faulty architecture
Cloning of animals by nuclear transplantation has demonstrated that a
somatic cell nucleus can be reprogrammed when placed in oocyte cytoplasm. The
clones rarely survive, however, which suggests that the reprogramming is
usually not complete. Speculating that architectural remodelling of
transplanted nuclei might be an important aspect of this, Philippe Collas and
co-workers have examined the structural changes that occur following nuclear
transplantation (see p.
3713). They observe that transplanted mouse embryos misexpress A-type
lamin intermediate filaments - DNA-binding components of the nuclear lamina
that are normally present only in differentiated cells - as well as the
nuclear matrix protein NuMA. The authors also find that, in common with normal
embryos, the transplanted embryos retain maternal AKAP95, a scaffold protein
thought to bridge chromatin and the nuclear envelope; however, AKAP95 and DNA
in the transplanted nuclei are more resistant to in situ extraction, which
indicates that they have higher levels of silent DNA. Collas and co-workers
suggest that such inappropriate lamin and/or AKAP95 architecture could have a
significant effect on chromatin modification or transcription and prevent the
complete reprogramming necessary for an embryo to develop correctly.
Related articles in JCS:
- Architectural defects in pronuclei of mouse nuclear transplant embryos
- Pedro N. Moreira, James M. Robl, and Philippe Collas
JCS 2003 116: 3713-3720.
[Abstract]
[Full Text]
