Patterning of angiogenesis in the zebrafish embryo

Development ◽  
2002 ◽  
Vol 129 (4) ◽  
pp. 973-982 ◽  
Author(s):  
Sarah Childs ◽  
Jau-Nian Chen ◽  
Deborah M. Garrity ◽  
Mark C. Fishman
Keyword(s):  
Zebrafish Embryo ◽  
Regular Pattern ◽  
Wild Type ◽  
Cell Fates ◽  
Mutagenesis Screen ◽  
The Third ◽  
Shaped Cell ◽  
Vessel Growth ◽  
Lateral Posterior ◽  
Lineage Analysis

Little is known about how vascular patterns are generated in the embryo. The vasculature of the zebrafish trunk has an extremely regular pattern. One intersegmental vessel (ISV) sprouts from the aorta, runs between each pair of somites, and connects to the dorsal longitudinal anastomotic vessel (DLAV). We now define the cellular origins, migratory paths and cell fates that generate these metameric vessels of the trunk. Additionally, by a genetic screen we define one gene, out of bounds (obd), that constrains this angiogenic growth to a specific path. We have performed lineage analysis, using laser activation of a caged dye and mosaic construction to determine the origin of cells that constitute the ISV. Individual angioblasts destined for the ISVs arise from the lateral posterior mesoderm (LPM), and migrate to the dorsal aorta, from where they migrate between somites to their final position in the ISVs and dorsal longitudinal anastomotic vessel (DLAV). Cells of each ISV leave the aorta only between the ventral regions of two adjacent somites, and migrate dorsally to assume one of three ISV cell fates. Most dorsal is a T-shaped cell, based in the DLAV and branching ventrally; the second constitutes a connecting cell; and the third an inverted T-shaped cell, based in the aorta and branching dorsally. The ISV remains between somites during its ventral course, but changes to run mid-somite dorsally. This suggests that the pattern of ISV growth ventrally and dorsally is guided by different cues. We have also performed an ENU mutagenesis screen of 750 mutagenized genomes and identified one mutation, obd that disrupts this pattern. In obd mutant embryos, ISVs sprout precociously at abnormal sites and migrate anomalously in the vicinity of ventral somite. The dorsal extent of the ISV is less perturbed. Precocious sprouting can be inhibited in a VEGF morphant, but the anomalous site of origin of obd ISVs remains. In mosaic embryos, obd somite causes adjacent wild-type endothelial cells to assume the anomalous ISV pattern of obd embryos. Thus, the launching position of the new sprout and its initial trajectory are directed by inhibitory signals from ventral somites. Zebrafish ISVs are a tractable system for defining the origins and fates of vessels, and for dissecting elements that govern patterns of vessel growth.

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.

scholarly journals THE EFFECTS OF HETEROZYGOSITY CHANGES ON VIABILITY IN DROSOPHILA MELANOGASTER

Genetics ◽  
1972 ◽  
Vol 70 (4) ◽  
pp. 595-610
Author(s):  
Ray Moree
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Background ◽  
Laboratory Strain ◽  
Theoretical Expectation ◽  
Wild Type ◽  
Small Deviations ◽  
The Third ◽  
The Difference

ABSTRACT The viability effects of chromosomes from an old and from a new laboratory strain of D. melanogaster were studied in eight factorial combinations and at two heterozygosity levels. The combinations were so constructed that heterozygosity level could be varied in the third chromosomes of the carriers of a homozygous lethal marker, in the third chromosomes of their wild-type segregants, and in the genetic backgrounds of both. Excluding the effect of the marker and the exceptional outcomes of two of the combinations, and taking into account both large and small deviations from theoretical expectation, the following summary is given as the simplest consistent explanation of the results: 1) If total heterozygosities of two segregant types tend toward equality their viabilities tend toward equality also, whether background heterozygosity is high or low; if background heterozygosities is higher the tendency toward equality is slightly greater. 2) If total heterozygosity of two segregant types are unequal the less heterozygous type has the lower viability; the difference is more pronounced when background heterozygosity is low, less when it is high. 3) Differences between segregant viabilities are correlated with differences between the total heterozygosities of the two segregants; genetic background is effective to the extent, and only to the extent, that it contributes to the magnitude of this difference. This in turn appears to underlie, at least partly, the expression of a pronounced interchromosomal epistasis. Thus in this study viability is seen to depend upon both the quantity and distribution of heterozygosity, not only among the chromosomes of an individual but among the individuals of a given combination as well.

Specification of anterior-posterior differences within the AB lineage in the C. elegans embryo: a polarising induction

Development ◽  
1995 ◽  
Vol 121 (5) ◽  
pp. 1559-1568 ◽  
Author(s):  
H. Hutter ◽  
R. Schnabel
Keyword(s):  
Cell Fate ◽  
Tissue Type ◽  
Cell Stage ◽  
Anterior Portion ◽  
Developmental Potential ◽  
C Elegans ◽  
The Third ◽  
Inductive Signal ◽  
Anterior Posterior ◽  
Lineage Analysis

In a C. elegans embryo the third cleavages of descendants of the anterior blastomere AB of the 2-cell stage create pairs of blastomeres that develop differently. By laser ablation experiments we show that the fates of all the posterior daughters of this division depend on an induction occurring three cleavages before these blastomeres are born. The time of induction precludes a direct effect on cell fate. Alternatively, we suggest that the induction creates a heritable cell polarity which is propagated through several divisions. We suggest a model to demonstrate how a signal could be propagated through several rounds of cell division. An important implication of our observations is that this early induction acts to specify blastomere identity, not tissue type. A detailed lineage analysis revealed that altering the inductive signal alters complex lineage patterns as a whole. The induction described here, together with two inductions described previously can be used to illustrate how the anterior portion of the C. elegans embryo can be successively subdivided into blastomeres with unique developmental potential.

Administration of the Third Dose of Oral Poliomyelitis Vaccine at 6 to 18 Months of Age

PEDIATRICS ◽  
1994 ◽  
Vol 94 (5) ◽  
pp. 774-775 ◽  
Author(s):  
Keyword(s):  
United States ◽  
Health Care Providers ◽  
The United States ◽  
Preschool Age ◽  
Healthy Children ◽  
Care Providers ◽  
Wild Type ◽  
The Third ◽  
Primary Series ◽  
Poliomyelitis Vaccine

This statement describes a modification of the recommended routine schedule for administering trivalent oral poliomyelitis vaccine (OPV). The American Academy of Pediatrics previously has recommended that healthy children receive a three-dose primary series of OPV at 2, 4, and 15 to 18 months of age and a fourth dose at the time of school entry (4 to 6 years of age).1 Available data indicate that the response rates to the third dose of OPV administered at 6 months of age are as good as the rates following administration of this dose at 15 to 18 months of age. Completion of the three-dose primary series at an earlier age will help health care providers induce immunity against poliomyelitis at an early age. Although wild type poliomyelitis has not caused disease in the United States for many years, the virus remains prevalent in many countries. Continued introduction of the virus into the United States by travelers could result in transmission and disease if high levels of immunity are not maintained in preschool age children. For example, wild type poliovirus type 3 was recently introduced into Canada by a religious sect that did not believe in immunization.2 The virus was probably imported from the Netherlands, where a small epidemic of poliomyelitis occurred in members of the same sect in 1992 and 1993.3 SERUM ANTIBODY RESPONSE FOLLOWING OPV ADMINISTRATION After two doses of OPV are administered at 2 and 4 months of age, 89 to 100% of children vaccinated in the United States have evidence of humoral immunity to poliomyelitis types 1 and 3, and 99 to 100% have immunity to type 2 (Table).

Wingless signaling generates pattern through two distinct mechanisms

Development ◽  
1997 ◽  
Vol 124 (19) ◽  
pp. 3727-3736 ◽  
Author(s):  
R. Hays ◽  
G.B. Gibori ◽  
A. Bejsovec
Keyword(s):  
Cell Fate ◽  
Cellular Response ◽  
Biological Activities ◽  
Essential Feature ◽  
Structural Features ◽  
Protein Distribution ◽  
Wild Type ◽  
Cell Fates ◽  
Amino Acid Region ◽  
Acid Region

wingless (wg) and its vertebrate homologues, the Wnt genes, play critical roles in the generation of embryonic pattern. In the developing Drosophila epidermis, wg is expressed in a single row of cells in each segment, but it influences cell identities in all rows of epidermal cells in the 10- to 12-cell-wide segment. Wg signaling promotes specification of two distinct aspects of the wild-type intrasegmental pattern: the diversity of denticle types present in the anterior denticle belt and the smooth or naked cuticle constituting the posterior surface of the segment. We have manipulated the expression of wild-type and mutant wg transgenes to explore the mechanism by which a single secreted signaling molecule can promote these distinctly different cell fates. We present evidence consistent with the idea that naked cuticle cell fate is specified by a cellular pathway distinct from the denticle diversity-generating pathway. Since these pathways are differentially activated by mutant Wg ligands, we propose that at least two discrete classes of receptor for Wg may exist, each transducing a different cellular response. We also find that broad Wg protein distribution across many cell diameters is required for the generation of denticle diversity, suggesting that intercellular transport of the Wg protein is an essential feature of pattern formation within the epidermal epithelium. Finally, we demonstrate that an 85 amino acid region not conserved in vertebrate Wnts is dispensable for Wg function and we discuss structural features of the Wingless protein required for its distinct biological activities.

scholarly journals Determination of the Factor V Leiden Single-Nucleotide Polymorphism in a Commercial Clinical Laboratory by Use of NanoChip Microelectronic Array Technology

2002 ◽  
Vol 48 (9) ◽  
pp. 1406-1411 ◽  
Author(s):  
Jess G Evans ◽  
Cindy Lee-Tataseo
Keyword(s):  
Clinical Laboratory ◽  
Factor V Leiden ◽  
Factor V ◽  
Third Wave ◽  
Wild Type ◽  
Wave Analysis ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
The Third ◽  
Array Technology

Abstract Background: Methods for analysis of the single-nucleotide polymorphism (SNP) known as factor V Leiden (FVL) are described. The technique provides rapid, highly accurate detection of the point mutation that encodes for replacement of arginine-506 with glutamine. After formal assay qualification, 758 clinical samples that had previously been analyzed by the InvaderTM Monoplex Assay were tested as research samples in a commercial clinical laboratory. Methods: Primers specific for factor V (FV) were prepared, and PCR was performed. Samples were analyzed using the NanoChip® Molecular Biology Workstation with fluorescently labeled reporters for wild-type and SNP sequences. Results: Of the 635 samples classified by the Third WaveTM assay as FV wild type, 10 were identified as heterozygous FVL by the NanoChip technique. Similarly, of the 114 putative heterozygous samples, 4 were wild type, and of the 9 reported homozygous samples, 6 were homozygous, 2 were heterozygous, and 1 was FV wild type by the NanoChip assay. All 17 results that were discordant with the Third Wave analysis were confirmed by DNA sequencing to be correctly classified by the NanoChip technology. The Nanochip system was 100% accurate in characterizing wild-type, heterozygous, and homozygous samples compared with accuracies of 99.2%, 90.2%, and 100% for the comparable Third Wave analysis. Conclusions: The NanoChip microelectronic chip array technology is an accurate and convenient method for FVL screening of research samples in a clinical laboratory environment.

Sporulation mutants in Cochliobolus carbonum

1973 ◽  
Vol 51 (1) ◽  
pp. 207-209 ◽  
Author(s):  
K. J. Leonard
Keyword(s):  
Ultraviolet Irradiation ◽  
Segregation Ratio ◽  
Wild Type ◽  
Cochliobolus Carbonum ◽  
The Third ◽  
Germ Tubes

Three types of mutants were induced in cultures of Cochliobolus carbonum by ultraviolet irradiation. The mutant C1 abc formed abnormally shaped conidia which proliferated in chains rather than being arranged in a spiral on the conidiophore as in wild-type isolates; a second mutant, C2 pcg, produced conidia which germinated precociously while still attached to the conidiophore and which formed secondary conidia at the ends of short germ tubes; and the third, C1 nc1, formed no conidia. A fourth mutant, C1 nc2, which also failed to form conidia was isolated from a culture grown on a medium containing acriflavin. A 1: 1 segregation ratio was obtained in crosses of C1 abc × wild type, but in crossesC2 pcg × wild type and C1 nc1 × wild type nearly all of the progeny were wild type. The mutants C2 pcg and C1 nc1 failed to form perithecia but could serve as male parents; C1 nc2 was completely infertile. Preliminary attempts to determine whether the pcg and nc mutants were controlled cytoplasmically were inconclusive.

scholarly journals Cell lineage analysis of kynurenine producing organs inDrosophila melanogaster

1975 ◽  
Vol 26 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Moti Nissani
Keyword(s):  
Drosophila Melanogaster ◽  
Fat Body ◽  
Cell Lineage ◽  
Chromosome Loss ◽  
Wild Type ◽  
Fate Map ◽  
Lineage Analysis

SUMMARYSix hundred and ten gynandromorphs were produced in which anXchromosome loss uncovered the vermilion mutation. The mosaic patterns observed indicate that wild type ocelli are incapable of kynurenine production and that, in addition to the eyes, postembryonic kynurenine producing cells originate from two separate regions of the blastoderm. The positions of these regions on the genetic fate map ofDrosophila melanogastercorrespond to the embryonic precursors which give rise to the kynurenine producing cells of the larval fat body and Malpighian tubes.

scholarly journals Interaction of PomB with the Third Transmembrane Segment of PomA in the Na+-Driven Polar Flagellum of Vibrio alginolyticus

2004 ◽  
Vol 186 (16) ◽  
pp. 5281-5291 ◽  
Author(s):  
Toshiharu Yakushi ◽  
Shingo Maki ◽  
Michio Homma
Keyword(s):  
Marine Bacterium ◽  
Vibrio Alginolyticus ◽  
Wild Type ◽  
Transmembrane Segment ◽  
Mutant Proteins ◽  
Transmembrane Segments ◽  
The Third ◽  
Close Proximity ◽  
Flagellar Rotation ◽  
Lines Of Evidence

ABSTRACT The marine bacterium Vibrio alginolyticus has four motor components, PomA, PomB, MotX, and MotY, responsible for its Na+-driven flagellar rotation. PomA and PomB are integral inner membrane proteins having four and one transmembrane segments (TMs), respectively, which are thought to form an ion channel complex. First, site-directed Cys mutagenesis was systematically performed from Asp-24 to Glu-41 of PomB, and the resulting mutant proteins were examined for susceptibility to a sulfhydryl reagent. Secondly, the Cys substitutions at the periplasmic boundaries of the PomB TM (Ser-38) and PomA TMs (Gly-23, Ser-34, Asp-170, and Ala-178) were combined. Cross-linked products were detected for the combination of PomB-S38C and PomA-D170C mutant proteins. The Cys substitutions in the periplasmic boundaries of PomA TM3 (from Met-169 to Asp-171) and the PomB TM (from Leu-37 to Ser-40) were combined to construct a series of double mutants. Most double mutations reduced the motility, whereas each single Cys substitution slightly affected it. Although the motility of the strain carrying PomA-D170C and PomB-S38C was significantly inhibited, it was recovered by reducing reagent. The strain with this combination showed a lower affinity for Na+ than the wild-type combination. PomA-D148C and PomB-P16C, which are located at the cytoplasmic boundaries of PomA TM3 and the PomB TM, also formed the cross-linked product. From these lines of evidence, we infer that TM3 of PomA and the TM of PomB are in close proximity over their entire length and that cooperation between these two TMs is required for coupling of Na+ conduction to flagellar rotation.

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