Cellular contacts required for neural induction in Xenopus embryos: evidence for two signals

Development ◽  
1989 ◽  
Vol 106 (4) ◽  
pp. 749-757 ◽  
Author(s):  
J.E. Dixon ◽  
C.R. Kintner
Keyword(s):  
Cell Layer ◽  
Rnase Protection Assay ◽  
Neural Induction ◽  
Neural Tissue ◽  
The Other ◽  
Protection Assay ◽  
Rnase Protection ◽  
Rna Transcripts ◽  
Anterior Dorsal ◽  
Dorsal Mesoderm

Neurogenesis begins in amphibian embryos around the time of gastrulation when a portion of the ectoderm receives an inducing signal from dorsal mesoderm. Two different proposals have been made for how ectoderm must come into contact with dorsal mesoderm in order for the inducing signal to pass between the two tissues. Induction in one proposal would require normal gastrulation movements to bring dorsal mesoderm underneath, and into apposition with, the overlying ectoderm. The inducing signal in this case would pass between dorsal mesoderm and ectoderm as apposed tissue layers. The other proposal is that induction requires only a small contact between ectoderm and dorsal mesoderm at the boundary they share before gastrulation. The inducing signal by this proposal would pass laterally across this small area of contact between mesoderm and ectoderm, perhaps before gastrulation, and spread within the ectodermal cell layer. Since it is not known to what extent neurogenesis depends on each of these proposed contacts between ectoderm and dorsal mesoderm, we have generated explants of embryonic tissue in which one or the other type of contact between mesoderm and ectoderm is favored. The amount of neural tissue formed under these various conditions was then assessed using a quantitative RNase protection assay to measure the levels of two neural-specific RNA transcripts. The results show that neural tissue forms efficiently when ectoderm and dorsal mesoderm only interact laterally within a plane of tissue. In contrast, neural tissue forms extremely poorly when ectoderm is placed experimentally in apposition with involuting, anterior-dorsal mesoderm.(ABSTRACT TRUNCATED AT 250 WORDS)

A new quantitative solution hybridisation-RNase protection assay for APP and APLP2 mRNA

1996 ◽  
Vol 43 (1-2) ◽  
pp. 77-84 ◽  
Author(s):  
Janet A Johnston ◽  
Svante Norgren ◽  
Göran Annerén ◽  
Richard F Cowburn ◽  
Lars Lannfelt
Keyword(s):  
Rnase Protection Assay ◽  
Protection Assay ◽  
Rnase Protection

Abnormal myocyte Ca2+homeostasis in rabbits with pacing-induced heart failure

1998 ◽  
Vol 275 (4) ◽  
pp. H1441-H1448 ◽  
Author(s):  
Atsushi Yao ◽  
Zhi Su ◽  
Akihiko Nonaka ◽  
Iram Zubair ◽  
Kenneth W. Spitzer ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ventricular Myocytes ◽  
Rnase Protection Assay ◽  
Protection Assay ◽  
Rnase Protection ◽  
Contraction Coupling ◽  
Intracellular Ca ◽  
Rapid Pacing ◽  
Sodium Binding ◽  
The Times

To determine whether there are abnormalities in myocyte excitation-contraction coupling and intracellular Ca2+concentration ([Ca2+]i) homeostasis in pacing-induced heart failure (PF), we measured L-type Ca2+ current ( I Ca,L) and Na+/Ca2+exchanger current ( I Na/Ca) with voltage clamp and measured intracellular Na+ concentration ([Na+]i) and [Ca2+]iwith the use of sodium-binding benzofuran isophthalate (SBFI) and fluo 3 in ventricular myocytes isolated from control and paced rabbits. The peak systolic and diastolic levels and the amplitude of electrically stimulated [Ca2+]itransients (0.25 Hz, extracellular Ca2+ concentration = 1.08 mM) were significantly less in PF myocytes. Also, there was prolongation of the times to peak and decline of [Ca2+]itransients. I Ca,Ldensity was markedly decreased in PF myocytes. I Na/Ca at −40 mV elicited by rapid exposure to 0 Na+ solution with a rapid solution switcher was significantly reduced in PF myocytes, suggesting that the function of the Na+/Ca2+exchanger is impaired in these myocytes. In PF myocytes the decline of the [Ca2+]itransient when the Na+/Ca2+exchanger was abruptly disabled was markedly prolonged compared with the decline in control myocytes, consistent with depressed sarcoplasmic reticulum (SR) Ca2+-ATPase function. RNase protection assay showed decreased levels of Na+/Ca2+exchanger and SR Ca2+-ATPase mRNA in PF hearts, consistent with the function studies. We conclude that the functions of L-type Ca2+channels, Na+/Ca2+exchanger, and SR Ca2+-ATPase are impaired in myocytes from rabbit hearts with failure induced by rapid pacing. These abnormalities result in reduced [Ca2+]itransients and systolic and diastolic dysfunction and appear to account for the abnormal ventricular function observed.

RNase Protection Assay

2019 ◽  
pp. 109-116
Author(s):  
Jianzhu Zhao ◽  
Jun Tang ◽  
Justin Elfman ◽  
Hui Li
Keyword(s):  
Rnase Protection Assay ◽  
Protection Assay ◽  
Rnase Protection

Gestational changes in fetal renal and hepatic angiotensinogen mRNA and protein

1998 ◽  
Vol 10 (5) ◽  
pp. 399 ◽  
Author(s):  
David Y. Zhang ◽  
Eugenie R. Lumbers ◽  
June J. Wu
Keyword(s):  
Fetal Liver ◽  
Rnase Protection Assay ◽  
Protein Product ◽  
Late Gestation ◽  
Protection Assay ◽  
Rnase Protection ◽  
Fetal Sheep ◽  
Protein Levels ◽  
Adult Kidney ◽  
Liver And Kidney

The aim of the study was to determine the amount of angiotensinogen expression and its protein product in fetal sheep liver and kidney in the last third of gestation. Angiotensinogen mRNA was measured by RNase protection assay and its protein levels were measured by radioimmunoassay. Levels were measured at 80, 95, 111, 125 and 139 days. Angiotensinogen mRNA was present in all fetal liver and kidney samples tested. The ratio of hepatic angiotensinogen mRNA/18 S rRNA increased by 100% (P<0.001) and angiotensinogen levels increased by 33% (P<0.001) in fetal sheep from 80 to 139 d. Over the same period the ratio of renal angiotensinogen mRNA/18 S rRNA increased by 170% (P<0.001) and renal angiotensinogen protein increased by 41% (P<0.001). The levels of angiotensinogen mRNA and its protein in the adult kidney were less than in kidneys of 139 d old fetuses (P<0.01). There was a direct relationship between levels of angiotensinogen mRNA and its protein in the liver (r = 0.53, P<0.01, n = 25) and in the kidney (r = 0.75, P<0.0001, n = 24). These findings demonstrate that there is a significant increase in both hepatic and renal angiotensinogen gene expression in the last third of gestation in the fetal sheep and that this increase is associated with an increase of angiotensinogen levels in both tissues. This increase in angiotensinogen in late gestation could influence the activity of both the intrarenal and circulating renin angiotensin systems.

Melatonin receptor mRNA localization and rhythmicity in the retina of the domestic chick, Gallus domesticus

2002 ◽  
Vol 19 (3) ◽  
pp. 265-274 ◽  
Author(s):  
ARJUN K. NATESAN ◽  
VINCENT M. CASSONE
Keyword(s):  
Ganglion Cell ◽  
Ganglion Cell Layer ◽  
Cell Layer ◽  
Rnase Protection Assay ◽  
Inner Nuclear Layer ◽  
Constant Darkness ◽  
Melatonin Receptor ◽  
Rnase Protection ◽  
Receptor Mrna ◽  
Lower Amplitude

The indoleamine hormone melatonin is synthesized and released by photoreceptors during the night within the chick retina, and confers timing information to modulate retinal physiology. Three subtypes of melatonin receptor with nearly identical pharmacological profiles have been described in chickens and are present in the retina. In this study, the spatial localization and temporal pattern of the mRNA for each of these receptors within the retina are described. The localization and rhythmicity of receptor mRNA were analyzed using in situ hybridization and RNase protection assay, respectively, with probes against specific nucleotide sequences encoding these receptors. Mel1A and Mel1C receptor mRNA have similar patterns of expression, primarily in the inner segments of photoreceptors, vitread portion of the inner nuclear layer, and in the retinal ganglion cell layer. Mel1B receptor mRNA is expressed at higher levels in the retina, with expression in photoreceptors, throughout the inner nuclear layer, and in the ganglion cell layer. Mel1A receptor mRNA is rhythmic in both light:dark (LD) cycles and in constant darkness (DD); Mel1A peaks during midday and mid-subjective day, respectively. Mel1C receptor mRNA is also rhythmically expressed in LD, but with a lower amplitude, such that transcript is high during the day and low during the night. In DD, Mel1C rhythms become 180 deg out of phase with a slight increase at night. Mel1B mRNA expression was highly variable and arrhythmic.

The mCK-5 Multiprobe RNase Protection Assay Kit Can Yield Erroneous Results for the Murine Chemokines IP-10 and MCP-1

2000 ◽  
Vol 286 (2) ◽  
pp. 193-197 ◽  
Author(s):  
Bruno Luckow ◽  
Holger Maier ◽  
Silvia Chilla ◽  
Guillermo Pérez de Lema
Keyword(s):  
Rnase Protection Assay ◽  
Protection Assay ◽  
Rnase Protection

Differential expression of the epidermal K1 and K10 keratin genes during mouse embryo development

1990 ◽  
Vol 68 (2) ◽  
pp. 448-453 ◽  
Author(s):  
Thérèse Ouellet ◽  
Marc Lussier ◽  
Feridoun Babaï ◽  
Line Lapointe ◽  
André Royal
Keyword(s):  
Histological Examination ◽  
Intermediate Filaments ◽  
Mouse Embryo ◽  
Rnase Protection Assay ◽  
Epidermal Differentiation ◽  
Protection Assay ◽  
Mouse Development ◽  
Rnase Protection ◽  
Stage Of Development ◽  
Mouse Embryo Development

Induction of genes coding for the K1 and K10 keratins during mouse development was studied by measuring the accumulation of their respective mRNAs in day 10 to 17 embryos using an RNase protection assay. Although these two keratins are coexpressed in the suprabasal layers of the epidermis, it was found that while K1 mRNA was detectable as soon as day 10, K10 mRNA was not detectable before day 12. The expression of these genes at this stage of development was not expected since they are specifically associated with keratinization, a process that does not begin before day 17 of gestation. Histological examination of the epidermis of day 10 to 17 embryos suggests that both genes are induced in cells committed to epidermal differentiation, after stratification has started but before the onset of keratinization. It was also found that the two mRNAs increased in abundance steadily and significantly until day 16 and that, in spite of the expectation that filaments should contain equivalent amounts of each subunit, K1 mRNA remained more abundant than K10 mRNA at all times including in adult epidermis. These observations indicate that the two genes are regulated independently during development.Key words: intermediate filaments, keratinization, differentiation, RNase protection, histology.

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