Tissue-specific mitotic inhibition in the kidneys of embryonic grafts and partially nephrectomized host Xenopus laevis

Development ◽  
1971 ◽  
Vol 25 (3) ◽  
pp. 321-329
Author(s):  
D. P. Chopra ◽  
J. D. Simnett
Keyword(s):  
Cell Division ◽  
Xenopus Laevis ◽  
Partial Nephrectomy ◽  
Liver Extract ◽  
Rat Kidney ◽  
Control Level ◽  
Metaphase Arrest ◽  
Tissue Specific ◽  
Mitotic Inhibition ◽  
Embryonic Grafts

Immature Xenopus laevis were unilaterally nephrectomized and implanted subcutaneously with stage 38 (prefeeding) larvae. Rat kidney extract was injected 8 and 16 days after the operation and the mitotic incidence (MI) in the host and implant tissues was measured by the colcemid metaphase arrest technique. The MI in the kidney of nephrectomized hosts was higher than normal at 8 days but had returned to the control level at 16 days. Injection of kidney extract inhibited mitosis in the host kidney both at 8 and 16 days after partial nephrectomy. The MI of implant pronephros was higher in nephrectomized than in control hosts both at 8 and 16 days. Injection of kidney extract into nephrectomized hosts inhibited mitosis in the implant pronephros both at 8 and 16 days. Neither host nephrectomy nor injection of kidney extract had any effect on the MI in the epidermis of the implants. Unoperated immature Xenopus were injected with rat kidney or liver extracts. Kidney extract inhibited mitosis in the kidney but not in the liver, while liver extract inhibited mitosis in the liver but not in the kidney. The rate of mitosis in the kidney and liver of normal animals may be controlled by tissuespecific inhibitors of cell division.

Stimulation of cell division in pronephros of embryonic grafts following partial nephrectomy in the host (Xenopus laevis)

Development ◽  
1970 ◽  
Vol 24 (3) ◽  
pp. 525-533
Author(s):  
D. P. Chopra ◽  
J. D. Simnett
Keyword(s):  
Cell Division ◽  
Xenopus Laevis ◽  
Mitotic Activity ◽  
Partial Nephrectomy ◽  
Vascular Supply ◽  
Significant Difference ◽  
And Control ◽  
Mitotic Inhibitor ◽  
Embryonic Grafts ◽  
Stimulation Of

Following partial nephrectomy in juvenile metamorphosed Xenopus laevis the mitotic activity in the regenerating kidney reached its maximum on the 6th day and returned to its normal level by the 16th day. The mitotic activity was measured in the pronephros and epidermis of prefeeding Xenopus larvae (stage 38) at different intervals after their implantation into the lymph sacs of partially nephrectomized and control metamorphosed hosts. Ten days after partial nephrectomy, during the period of increased mitotic activity in the regenerating kidney of the host, the mitotic activity in the implant pronephros was twice as high as that in the implant pronephros of the control hosts. Eighteen days after partial nephrectomy when the mitotic activity in the regenerating host kidney had returned to normal, there was no difference between the mitotic activity of pronephros of implants in nephrectomized and control hosts. There was no significant difference between the mitotic activity of epidermis of the implants in nephrectomized and control hosts, nor was there any difference between the epidermal mitotic activity in implants examined 10 and 18 days after host nephrectomy. It was concluded that a circulating factor (or factors) responsible for the control of mitotic activity in the regenerating host kidney enters the implant through its vascular supply and influences the mitotic activity in the homologous embryonic tissue. It is possible that this factor is a tissue-specific mitotic inhibitor synthesized by the host kidney.

scholarly journals Tissue-specific expression of the Ets gene Xsap-1 during Xenopus laevis development

2001 ◽  
Vol 109 (2) ◽  
pp. 433-436 ◽  
Author(s):  
Oliver Nentwich ◽  
Frank E. Münchberg ◽  
Götz Frommer ◽  
Alfred Nordheim
Keyword(s):  
Xenopus Laevis ◽  
Specific Expression ◽  
Tissue Specific ◽  
Tissue Specific Expression

trans activation of rat phosphoenolpyruvate carboxykinase (GTP) gene expression by micro-coinjection of rat liver mRNA in Xenopus laevis oocytes

1989 ◽  
Vol 9 (11) ◽  
pp. 5244-5247
Author(s):  
N Benvenisty ◽  
T Shoshani ◽  
Y Farkash ◽  
H Soreq ◽  
L Reshef
Keyword(s):  
Gene Expression ◽  
Xenopus Laevis ◽  
Reporter Gene ◽  
Rat Liver ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Xenopus Laevis Oocytes ◽  
Activation Process ◽  
Tissue Specific ◽  
Chimeric Construct

To study the liver-specific trans activation of the rat phosphoenolpyruvate carboxykinase (PEPCK) gene, the PEPCK promoter was linked to a reporter gene and was microinjected into Xenopus laevis oocytes alone or in conjunction with rat liver poly(A)+ RNA. The rat liver mRNA markedly enhanced the expression of the PEPCK-chimeric construct. This effect appeared to be sequence specific, as it was dependent on the presence of the intact promoter. Moreover, the RNA effect was limited to mRNA preparations from PEPCK-expressing tissues only. Finally, microinjection of size-fractionated liver mRNA revealed that the trans-acting factor(s) is encoded by RNA of 1,600 to 2,000 nucleotides, providing a direct bioassay for the gene(s) involved in this tissue-specific trans-activation process.

Identification of non-tissue-specific helix-loop-helix genes in Xenopus laevis

Gene ◽  
1995 ◽  
Vol 165 (2) ◽  
pp. 319-320 ◽  
Author(s):  
Daniel H. Shain ◽  
Mauricio X. Zuber
Keyword(s):  
Xenopus Laevis ◽  
Tissue Specific ◽  
Helix Loop Helix

scholarly journals Elements and factors involved in tissue-specific and embryonic expression of the liver transcription factor LFB1 in Xenopus laevis.

1993 ◽  
Vol 13 (10) ◽  
pp. 6416-6426 ◽  
Author(s):  
D Zapp ◽  
S Bartkowski ◽  
B Holewa ◽  
C Zoidl ◽  
L Klein-Hitpass ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Xenopus Laevis ◽  
Tissue Distribution ◽  
Consensus Sequence ◽  
Deletion Analysis ◽  
Maternal Factor ◽  
Tissue Specific ◽  
Specific Transcription Factor ◽  
The Core ◽  
Promoter Deletion Analysis

LFB1 (HNF1) is a tissue-specific transcription factor found in the livers, stomachs, intestines, and kidneys of vertebrates. By analyzing the promoter of the Xenopus LFB1 gene, we identified potential autoregulation by LFB1 and regulation by HNF4, a transcription factor with a tissue distribution similar to that of LFB1. Injection of LFB1 promoter-chloramphenicol acetyltransferase constructs into Xenopus eggs revealed embryonic activation that is restricted to the region of the developing larvae expressing endogeneous LFB1. Proper embryonic activation was also observed with a rat LFB1 promoter. Deletion analysis of the Xenopus and rat promoters revealed that in both promoters embryonic activation is absolutely dependnet on the presence of an element that contains CCNCTCTC as the core consensus sequence. Since this element is recognized by the maternal factor OZ-1 previously described by N. Ovsenek, A. M. Zorn, and P. A. Krieg (Development 115:649-655, 1992), we might have identified the main constituents of a hierarchy that leads via LFB1 to the activation of tissue-specific genes during embryogenesis.

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