Inositol deficiency increases the susceptibility to neural tube defects of genetically predisposed (curly tail) mouse embryos in vitro

Teratology ◽  
1992 ◽  
Vol 45 (2) ◽  
pp. 223-232 ◽  
Author(s):  
D. L. Cockroft ◽  
F. A. Brook ◽  
A. J. Copp
Development ◽  
1982 ◽  
Vol 69 (1) ◽  
pp. 151-167
Author(s):  
A. J. Copp ◽  
M. J. Seller ◽  
P. E. Polani

A dye-injection technique has been used to determine the developmental stage at which posterior neuropore (PNP) closure occurs in normal and mutant curly tail mouse embryos. In vivo, the majority of non-mutant embryos undergo PNP closure between 30 and 34 somites whereas approximately 50% of all mutant embryos show delayed closure, and around 20% maintain an open PNP even at advanced stages of development. A similar result has been found for embryos developing in vitro from the headfold stage. Later in development, 50–60% of mutant embryos in vivo develop tail flexion defects, and 15–20% lumbosacral myeloschisis. This supports the view that delayed PNP closure is the main developmental lesion leading to the appearance of caudal neural tube defects in curly tail mice. The neural tube is closed in the region of tail flexion defects, but it is locally overexpanded and abnormal in position. The significance of these observations is discussed in relation to possible mechanisms of development of lumbosacral and caudal neural tube defects. This paper constitutes the first demonstration of the development of a genetically induced malformation in vitro.


2002 ◽  
Vol 16 (6) ◽  
pp. 619-621 ◽  
Author(s):  
Melanie C. Fisher ◽  
Steven H. Zeisel ◽  
Mei-Heng Mar ◽  
Thomas W. Sadler

Development ◽  
1985 ◽  
Vol 88 (1) ◽  
pp. 39-54
Author(s):  
Andrew J. Copp

The relationship between timing of closure of the posterior neuropore (PNP) and development of spinal neural tube defects (NTD) has been studied in individual mutant curly tail mouse embryos maintained in culture. Moderate delay in PNP closure results in development of tail flexion defects whereas extreme delay of PNP closure is associated with development of open NTD. Experimental enlargement of the PNP at the stage of 25 to 29 somites leads to delayed PNP closure and development of tail flexion defects in 36 % and 38 % respectively of non-mutant A/Strong embryos. In curly tail embryos, the effect of experimental enlargement of the PNP summates with the genetic predisposition to produce an increased incidence of spinal NTD among which open defects are proportionately more common. These results indicate that a causal relationship exists between delay in PNP closure and development of spinal NTD in mouse embryos. The method described for distinguishing between prospective normal and abnormal curly tail embryos at a stage prior to the appearance of malformations provides an opportunity to study the morphogenetic processes that precede the development of genetically determined spinal NTD.


Development ◽  
1988 ◽  
Vol 104 (2) ◽  
pp. 297-303 ◽  
Author(s):  
A.J. Copp ◽  
J.A. Crolla ◽  
F.A. Brook

Homozygous mutant curly tail mouse embryos developing spinal neural tube defects (NTD) exhibit a cell-type-specific abnormality of cell proliferation that affects the gut endoderm and notochord but not the neuroepithelium. We suggested that spinal NTD in these embryos may result from the imbalance of cell proliferation rates between affected and unaffected cell types. In order to test this hypothesis, curly tail embryos were subjected to influences that retard growth in vivo and in vitro. The expectation was that growth of unaffected rapidly growing cell types would be reduced to a greater extent than affected slowly growing cell types, thus counteracting the genetically determined imbalance of cell proliferation rates and leading to normalization of spinal neurulation. Food deprivation of pregnant females for 48 h prior to the stage of posterior neuropore closure reduced the overall incidence of spinal NTD and almost completely prevented open spina bifida, the most severe form of spinal NTD in curly tail mice. Analysis of embryos earlier in gestation showed that growth retardation acts by reducing the incidence of delayed neuropore closure. Culture of embryos at 40.5 degrees C for 15–23 h from day 10 of gestation, like food deprivation in vivo, also produced growth retardation and led to normalization of posterior neuropore closure. Labelling of embryos in vitro with [3H]thymidine for 1 h at the end of the culture period showed that the labelling index is reduced to a greater extent in the neuroepithelium than in other cell types in growth-retarded embryos compared with controls cultured at 38 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)


Placenta ◽  
2017 ◽  
Vol 51 ◽  
pp. 118-119
Author(s):  
N. Santander ◽  
C. Lizama ◽  
A. Quiroz ◽  
A. Rigotti ◽  
D. Busso

Development ◽  
1995 ◽  
Vol 121 (3) ◽  
pp. 681-691
Author(s):  
W.H. Chen ◽  
G.M. Morriss-Kay ◽  
A.J. Copp

A role for all-trans-retinoic acid in spinal neurulation is suggested by: (1) the reciprocal domains of expression of the retinoic acid receptors RAR-beta and RAR-gamma in the region of the closed neural tube and open posterior neuropore, respectively, and (2) the preventive effect of maternally administered retinoic acid (5 mg/kg) on spinal neural tube defects in curly tail (ct/ct) mice. Using in situ hybridisation and computerised image analysis we show here that in ct/ct embryos, RAR-beta transcripts are deficient in the hindgut endoderm, a tissue whose proliferation rate is abnormal in the ct mutant, and RAR-gamma transcripts are deficient in the tail bud and posterior neuropore region. The degree of deficiency of RAR-gamma transcripts is correlated with the severity of delay of posterior neuropore closure. As early as 2 hours following RA treatment at 10 days 8 hours post coitum, i.e. well before any morphogenetic effects are detectable, RAR-beta expression is specifically upregulated in the hindgut endoderm, and the abnormal expression pattern of RAR-gamma is also altered. These results suggest that the spinal neural tube defects which characterise the curly tail phenotype may be due to interaction between the ct gene product and one or more aspects of the retinoic acid signalling pathway.


1998 ◽  
Vol 128 (10) ◽  
pp. 1819-1828 ◽  
Author(s):  
Marian C. E. Peeters ◽  
Jan L.M.C. Geelen ◽  
Johan W. M. Hekking ◽  
Niels Chavannes ◽  
Joep P. M. Geraedts ◽  
...  

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