Tissue inhibitors of metalloproteinases (TIMPs) modulate extracellular matrix remodeling during embryonic develop- ment and disease. TIMP-3 expression was examined during Xenopus laevis embryogenesis: TIMP-3 transcrip...Tissue inhibitors of metalloproteinases (TIMPs) modulate extracellular matrix remodeling during embryonic develop- ment and disease. TIMP-3 expression was examined during Xenopus laevis embryogenesis: TIMP-3 transcripts detected in the maternal pool of RNA increased at the mid-blastula transition, decreased dramatically during gastrulation and increased again during neurulation and axis elongation. Interestingly, the decrease during gastrulation was not seen in LiCl treated (dorsalized) embryos. Whole mount in situ hybridization of TIMP-3 using DIG-labeled RNA probes demonstrated that the transcripts were present in all dorsal tissues during embryogenesis, but were prominent only in head structures starting at stage 35. Overexpression of TIMP-3 through transgenesis and RNA injections led to devel- opmental abnormalities and death. Both overexpression strategies resulted in post-gastrulation perturbation including those to neural and head structures, as well as truncated axes. However, RNA injections resulted in more severe early defects such as failure of neural tube closure, and transgenesis caused truncated axes and head abnormalities. No transgenic embryo expressing TIMP-3 survived past stage 40.展开更多
Objectives To study the expression patterns of two Eph family molecules, the receptor EphA5, and the ligand ephrin-A5, during spinal cord development. Methods The receptor expression was analyzed using beta-galactosid...Objectives To study the expression patterns of two Eph family molecules, the receptor EphA5, and the ligand ephrin-A5, during spinal cord development. Methods The receptor expression was analyzed using beta-galactosidase knockin mice, and affinity ligand probe binding. The ligand expression was assessed using two different affinity probes, and knockout mouse tissues as controls. Results EphA5 was expressed in the ventral spinal cord, while ephrin-A5 was located in the dorsolateral regions of the spinal cord throughout development. Conclusions These results show that EphA5 and ephrin-A5 are expressed over broad developmental stages and may play important roles in establishing the dorsoventral organization of the spinal cord.展开更多
文摘Tissue inhibitors of metalloproteinases (TIMPs) modulate extracellular matrix remodeling during embryonic develop- ment and disease. TIMP-3 expression was examined during Xenopus laevis embryogenesis: TIMP-3 transcripts detected in the maternal pool of RNA increased at the mid-blastula transition, decreased dramatically during gastrulation and increased again during neurulation and axis elongation. Interestingly, the decrease during gastrulation was not seen in LiCl treated (dorsalized) embryos. Whole mount in situ hybridization of TIMP-3 using DIG-labeled RNA probes demonstrated that the transcripts were present in all dorsal tissues during embryogenesis, but were prominent only in head structures starting at stage 35. Overexpression of TIMP-3 through transgenesis and RNA injections led to devel- opmental abnormalities and death. Both overexpression strategies resulted in post-gastrulation perturbation including those to neural and head structures, as well as truncated axes. However, RNA injections resulted in more severe early defects such as failure of neural tube closure, and transgenesis caused truncated axes and head abnormalities. No transgenic embryo expressing TIMP-3 survived past stage 40.
基金This work was supported in part by grants from New Jersey Commission on Spinal Cord Research and the National Science Foundation （No. 0548561,USA）.
文摘Objectives To study the expression patterns of two Eph family molecules, the receptor EphA5, and the ligand ephrin-A5, during spinal cord development. Methods The receptor expression was analyzed using beta-galactosidase knockin mice, and affinity ligand probe binding. The ligand expression was assessed using two different affinity probes, and knockout mouse tissues as controls. Results EphA5 was expressed in the ventral spinal cord, while ephrin-A5 was located in the dorsolateral regions of the spinal cord throughout development. Conclusions These results show that EphA5 and ephrin-A5 are expressed over broad developmental stages and may play important roles in establishing the dorsoventral organization of the spinal cord.
