Essential role of Bmp7 (snailhouse) and its prodomain in dorsoventral patterning of the zebrafish embryo

Development ◽  
2000 ◽  
Vol 127 (2) ◽  
pp. 343-354 ◽  
Author(s):  
A. Dick ◽  
M. Hild ◽  
H. Bauer ◽  
Y. Imai ◽  
H. Maifeld ◽  
...  
Keyword(s):  
Bone Morphogenetic Proteins ◽  
Double Mutant ◽  
Essential Role ◽  
Zebrafish Embryo ◽  
Temperature Sensitive ◽  
Dorsoventral Patterning ◽  
Cell Fates ◽  
Higher Temperature ◽  
Reduced Activity

Bone morphogenetic proteins (Bmps) are signaling molecules that have been implicated in a variety of inductive processes. We report here that zebrafish Bmp7 is disrupted in snailhouse (snh) mutants. The allele snh(st1) is a translocation deleting the bmp7 gene, while snh(ty68) displays a Val->Gly exhange in a conserved motif of the Bmp7 prodomain. The snh(ty68) mutation is temperature-sensitive, leading to severalfold reduced activity of mutant Bmp7 at 28 degrees C and non-detectable activity at 33 degrees C. This prodomain lesion affects secretion and/or stability of secreted mature Bmp7 after processing has occurred. Both snh(st1) and snh(ty68) mutant zebrafish embryos are strongly dorsalized, indicating that bmp7 is required for the specification of ventral cell fates during early dorsoventral patterning. At higher temperature, the phenotype of snh(ty68) mutant embryos is identical to that caused by the amorphic bmp2b mutation swirl swr(ta72) and similar to that caused by the smad5 mutation somitabun sbn(dtc24). mRNA injection studies and double mutant analyses indicate that Bmp2b and Bmp7 closely cooperate and that Bmp2b/Bmp7 signaling is transduced by Smad5 and antagonized by Chordino.

scholarly journals RNA11 protein is associated with the yeast spliceosome and is localized in the periphery of the cell nucleus.

1988 ◽  
Vol 8 (6) ◽  
pp. 2379-2393 ◽  
Author(s):  
T H Chang ◽  
M W Clark ◽  
A J Lustig ◽  
M E Cusick ◽  
J Abelson
Keyword(s):  
Cell Nucleus ◽  
Specific Antibody ◽  
Essential Role ◽  
Mrna Splicing ◽  
Temperature Sensitive ◽  
Gene Products ◽  
Nonpermissive Temperature ◽  
Exogenous Rna

The yeast rna mutations (rna2 through rna10/11) are a set of temperature-sensitive mutations that result in the accumulation of pre-mRNAs at the nonpermissive temperature. Most of the yeast RNA gene products are involved in and essential for mRNA splicing in vitro, suggesting that they code for components of the splicing machinery. We tested this proposal by using an in vitro-synthesized RNA11 protein to complement the temperature-sensitive defect of the rna11 extract. During the in vitro complementation, the input RNA11 protein was associated with the 40S spliceosome and a 30S complex, suggesting that the RNA11 protein is indeed a component of the spliceosome. The formation of the RNA11-associated 30S complex did not require any exogenous RNA substrate, suggesting that this 30S particle is likely to be a preassembled complex involved in splicing. The RNA11-specific antibody inhibited the mRNA splicing in vitro, confirming the essential role of the RNA11 protein in mRNA splicing. Finally, using the anti-RNA11 antibody, we localized the RNA11 protein to the periphery of the yeast nucleus.

scholarly journals Interactions between fused, a segment-polarity gene in Drosophila, and other segmentation genes

Development ◽  
1991 ◽  
Vol 112 (2) ◽  
pp. 417-429 ◽  
Author(s):  
B. Limbourg-Bouchon ◽  
D. Busson ◽  
C. Lamour-Isnard
Keyword(s):  
Double Mutant ◽  
Posterior Part ◽  
Germ Band ◽  
Cell Fates ◽  
Segmentation Genes ◽  
Segment Polarity ◽  
Mutant Phenotypes ◽  
Segment Polarity Gene ◽  
Polarity Gene

Fused (fu) is a segment polarity gene whose product is maternally required in the posterior part of each segment. To define further the role of fused and determine how it interacts with other segmentation genes, we examined the phenotypes obtained by combining fused with mutations of pair rule, homeotic and other segment polarity loci. When it was possible, we also looked at the distribution of corresponding proteins in fused mutant embryos. We observed that fused-naked (fu;nkd) double mutant embryos display a phenotypic suppression of simple mutant phenotypes: both naked cuticle and denticle belts, which would normally have been deleted by one of the two mutants alone, were restored. In fused mutant embryos, engrailed (en) and wingless (wg) expression was normal until germ band extension, but partially and completely disappeared respectively during germ band retraction. In the fu;nkd double mutant embryo, en was expressed as in nkd mutant at germ band extension, but later this expression was restricted and became normal at germ band retraction. On the contrary, wg expression disappeared as in fu simple mutant embryos. We conclude that the requirements for fused, naked and wingless activities for normal segmental patterning are not absolute, and propose mechanisms by which these genes interact to specify anterior and posterior cell fates.

scholarly journals Germ plasm anchors at tight junctions in the early zebrafish embryo

2021 ◽  
Author(s):  
Nadia Rostam ◽  
Alexander Goloborodko ◽  
Stephan Riemer ◽  
Andres Hertel ◽  
Sabine Klein ◽  
...  
Keyword(s):  
Zebrafish Embryo ◽  
Germ Plasm ◽  
Early Cleavage ◽  
Cell Fates ◽  
Cell Specification ◽  
Germ Cell Specification ◽  
Muscle Myosin ◽  
First Time ◽  
Bucky Ball

AbstractThe zebrafish germline is specified during early embryogenesis by inherited maternal RNAs and proteins collectively called germ plasm. Only the cells containing germ plasm will become part of the germline, whereas other cells will commit to somatic cell fates. Therefore, proper localization of germ plasm is key for germ cell specification and its removal is critical for the development of soma. The molecular mechanism underlying this process in vertebrates is largely unknown. Here we show that germ plasm localization in zebrafish is similar toXenopusand amniotes but distinct fromDrosophila. We identified non muscle myosin II (NMII) and tight junction (TJ) components as interaction candidates of Bucky ball (Buc), which is the germ plasm organizer in zebrafish. Remarkably, we also found that TJ protein ZO1 colocalizes with germ plasm and electron microscopy (EM) of zebrafish embryos uncovered TJ like structures at early cleavage furrows. In addition, injection of the TJ-receptor Claudin-d (Cldn-d) produced extra germ plasm aggregates. Our findings discover for the first time a role of TJs in germ plasm localization.

RNA11 protein is associated with the yeast spliceosome and is localized in the periphery of the cell nucleus

1988 ◽  
Vol 8 (6) ◽  
pp. 2379-2393 ◽  
Author(s):  
T H Chang ◽  
M W Clark ◽  
A J Lustig ◽  
M E Cusick ◽  
J Abelson
Keyword(s):  
Cell Nucleus ◽  
Specific Antibody ◽  
Essential Role ◽  
Mrna Splicing ◽  
Temperature Sensitive ◽  
Gene Products ◽  
Nonpermissive Temperature ◽  
Exogenous Rna

The yeast rna mutations (rna2 through rna10/11) are a set of temperature-sensitive mutations that result in the accumulation of pre-mRNAs at the nonpermissive temperature. Most of the yeast RNA gene products are involved in and essential for mRNA splicing in vitro, suggesting that they code for components of the splicing machinery. We tested this proposal by using an in vitro-synthesized RNA11 protein to complement the temperature-sensitive defect of the rna11 extract. During the in vitro complementation, the input RNA11 protein was associated with the 40S spliceosome and a 30S complex, suggesting that the RNA11 protein is indeed a component of the spliceosome. The formation of the RNA11-associated 30S complex did not require any exogenous RNA substrate, suggesting that this 30S particle is likely to be a preassembled complex involved in splicing. The RNA11-specific antibody inhibited the mRNA splicing in vitro, confirming the essential role of the RNA11 protein in mRNA splicing. Finally, using the anti-RNA11 antibody, we localized the RNA11 protein to the periphery of the yeast nucleus.

The smad5 mutation somitabun blocks Bmp2b signaling during early dorsoventral patterning of the zebrafish embryo

Development ◽  
1999 ◽  
Vol 126 (10) ◽  
pp. 2149-2159 ◽  
Author(s):  
M. Hild ◽  
A. Dick ◽  
G.J. Rauch ◽  
A. Meier ◽  
T. Bouwmeester ◽  
...  
Keyword(s):  
Zebrafish Embryo ◽  
Expression Patterns ◽  
Marker Gene ◽  
Single Amino Acid ◽  
Dorsoventral Patterning ◽  
Wild Type ◽  
Cell Fates ◽  
Marker Gene Expression ◽  
Smad Proteins ◽  
Set Up

Signaling by members of the TGFbeta superfamily is thought to be transduced by Smad proteins. Here, we describe a zebrafish mutant in smad5, designated somitabun (sbn). The dominant maternal and zygotic effect of the sbntc24 mutation is caused by a change in a single amino acid in the L3 loop of Smad5 protein which transforms Smad5 into an antimorphic version, inhibiting wild-type Smad5 and related Smad proteins. sbn mutant embryos are strongly dorsalized, similarly to mutants in Bmp2b, its putative upstream signal. Double mutant analyses and RNA injection experiments show that sbn and bmp2b interact and that sbn acts downstream of Bmp2b signaling to mediate Bmp2b autoregulation during early dorsoventral (D-V) pattern formation. Comparison of early marker gene expression patterns, chimera analyses and rescue experiments involving temporally controlled misexpression of bmp or smad in mutant embryos reveal three phases of D-V patterning: an early sbn- and bmp2b-independent phase when a coarse initial D-V pattern is set up, an intermediate sbn- and bmp2b-dependent phase during which the putative morphogenetic Bmp2/4 gradient is established, and a later sbn-independent phase during gastrulation when the Bmp2/4 gradient is interpreted and cell fates are specified.

The molecular nature of zebrafish swirl: BMP2 function is essential during early dorsoventral patterning

Development ◽  
1997 ◽  
Vol 124 (22) ◽  
pp. 4457-4466 ◽  
Author(s):  
Y. Kishimoto ◽  
K.H. Lee ◽  
L. Zon ◽  
M. Hammerschmidt ◽  
S. Schulte-Merker
Keyword(s):  
Pattern Formation ◽  
Bone Morphogenetic Proteins ◽  
Zebrafish Embryo ◽  
Mutant Phenotype ◽  
Mesoderm Induction ◽  
Dorsoventral Patterning ◽  
Wild Type ◽  
Maternal Role ◽  
Vertebrate Embryos ◽  
Molecular Nature

Early dorsoventral pattern formation in vertebrate embryos is regulated by opposing activities of ventralizing bone morphogenetic proteins (BMPs) and dorsal-specific BMP antagonists such as Chordin, Noggin and Follistatin. Specific defects in early dorsoventral patterning have been recently found in a number of zebrafish mutants, which exhibit either a ventralized or dorsalized phenotype. One of these, the ventralized mutant chordino (originally called dino) is caused by a mutation in the zebrafish chordin homologue and interacts genetically with the dorsalized mutant swirl. In swirl mutant embryos, dorsal structures such as notochord and somites are expanded while ventral structures such as blood and nephros are missing. Here we demonstrate that the swirl phenotype is caused by mutations in the zebrafish bmp2 gene (zbmp2). While injection of mRNAs encoded by the mutant alleles has no ventralizing effect, injection of wild-type zbmp2 mRNA leads to a complete rescue of the swirl mutant phenotype. Fertile adult mutant fish were obtained, showing that development after gastrulation is not dependent on zbmp2 function. In addition zBMP2 has no maternal role in mesoderm induction. Our analysis shows that swirl/BMP2, unlike mouse BMP2 but like mouse BMP4, is required for early dorsoventral patterning of the zebrafish embryo.

Essential role of Sharpin in TNFα dependent NFκB activation in primary hepatocytes

2012 ◽  
Vol 50 (01) ◽  
Author(s):  
N Lange ◽  
S Sieber ◽  
A Erhardt ◽  
G Sass ◽  
HJ Kreienkamp ◽  
...  
Keyword(s):  
Essential Role ◽  
Primary Hepatocytes

Different Abilities of Thrombin Receptor Activating Peptide and Thrombin to Induce Platelet Calcium Rise and Full Release Reaction

1995 ◽  
Vol 74 (05) ◽  
pp. 1323-1328 ◽  
Author(s):  
Dominique Lasne ◽  
José Donato ◽  
Hervé Falet ◽  
Francine Rendu
Keyword(s):  
Essential Role ◽  
Calcium Influx ◽  
Dense Granule ◽  
Receptor Interaction ◽  
Thrombin Receptor ◽  
Release Reaction ◽  
External Calcium ◽  
Maximum Rise ◽  
Granule Release

SummarySynthetic peptides (TRAP or Thrombin Receptor Activating Peptide) corresponding to at least the first five aminoacids of the new N-terminal tail generated after thrombin proteolysis of its receptor are effective to mimic thrombin. We have studied two different TRAPs (SFLLR, and SFLLRN) in their effectiveness to induce the different platelet responses in comparison with thrombin. Using Indo-1/AM- labelled platelets, the maximum rise in cytoplasmic ionized calcium was lower with TRAPs than with thrombin. At threshold concentrations allowing maximal aggregation (50 μM SFLLR, 5 μM SFLLRN and 1 nM thrombin) the TRAPs-induced release reaction was about the same level as with thrombin, except when external calcium was removed by addition of 1 mM EDTA. In these conditions, the dense granule release induced by TRAPs was reduced by over 60%, that of lysosome release by 75%, compared to only 15% of reduction in the presence of thrombin. Thus calcium influx was more important for TRAPs-induced release than for thrombin-induced release. At strong concentrations giving maximal aggregation and release in the absence of secondary mediators (by pretreatment with ADP scavengers plus aspirin), SFLLRN mobilized less calcium, with a fast return towards the basal level and induced smaller lysosome release than did thrombin. The results further demonstrate the essential role of external calcium in triggering sustained and full platelet responses, and emphasize the major difference between TRAP and thrombin in mobilizing [Ca2+]j. Thus, apart from the proteolysis of the seven transmembrane receptor, another thrombin binding site or thrombin receptor interaction is required to obtain full and complete responses.

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