A modified acetylcholine receptor delta-subunit enables a null mutant to survive beyond sexual maturation.
J Neurosci
; 28(49): 13223-31, 2008 Dec 03.
Article
em En
| MEDLINE
| ID: mdl-19052214
ABSTRACT
The contraction of skeletal muscle is dependent on synaptic transmission through acetylcholine receptors (AChRs) at the neuromuscular junction (NMJ). The lack of an AChR subunit causes a fetal akinesia in humans, leading to death in the first trimester and characteristic features of Fetal Akinesia Deformation Sequences (FADS). A corresponding null mutation of the delta-subunit in zebrafish (sofa potato; sop) leads to the death of embryos around 5 d postfertilization (dpf). In sop(-/-) mutants, we expressed modified delta-subunits, with one (delta1YFP) or two yellow fluorescent protein (delta2YFP) molecules fused at the intracellular loop, under the control of an alpha-actin promoter. AChRs containing these fusion proteins are fluorescent, assemble on the plasma membrane, make clusters under motor neuron endings, and generate synaptic current. We screened for germ-line transmission of the transgene and established a line of sop(-/-) fish stably expressing the delta2YFP. These delta2YFP/sop(-/-) embryos can mount escape behavior close to that of their wild-type siblings. Synaptic currents in these embryos had a smaller amplitude, slower rise time, and slower decay when compared with wild-type fish. Remarkably, these embryos grow to adulthood and display complex behaviors such as feeding and breeding. To the best of our knowledge, this is the first case of a mutant animal corresponding to first trimester lethality in human that has been rescued by a transgene and survived to adulthood. In the rescued fish, a foreign promoter drove the transgene expression and the NMJ had altered synaptic strength. The survival of the transgenic animal delineates requirements for gene therapies of NMJ.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peixe-Zebra
/
Receptores Colinérgicos
/
Doenças da Junção Neuromuscular
/
Longevidade
/
Mutação
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article