Ectoderm nuclei from sea urchin embryos contain a Spec-DNA binding protein similar to the vertebrate transcription factor USF

Development ◽  
1990 ◽  
Vol 110 (1) ◽  
pp. 259-272 ◽  
Author(s):  
C.R. Tomlinson ◽  
M.T. Kozlowski ◽  
W.H. Klein
Keyword(s):  
Transcription Factor ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Dna Interaction ◽  
Initiation Site ◽  
Upstream Stimulatory Factor ◽  
Transcriptional Initiation ◽  
Lytechinus Pictus ◽  
Conserved Sequence ◽  
A Cell

The Spec gene family of Stronglyocentrotus purpuratus is expressed exclusively in aboral ectoderm cells during embryogenesis. To investigate the regulation of Spec gene activity, the region around the Spec1 transcriptional initiation site was analyzed for sites of protein-DNA interaction. One high-affinity site bound a factor termed SpF1 within the Spec1 5′ untranslated leader region at position +39 to +60. The core sequence recognized by SpF1, CACGTG, is the same as that of the upstream stimulatory factor (USF), a widely occurring vertebrate transcription factor containing a myc-HLH motif. A comparison of USF- and SpF1-binding activities suggested that SpF1 was a sea urchin version of USF. SpF1 activity was detectable only in ectoderm cells of the embryo, implying that it has a role as a cell type-specific transcription factor. SpF1-binding sites were also found upstream of the Spec2a and Spec2c genes in the same conserved sequence block as Spec1. Extracts from Lytechinus pictus embryos showed an SpF1-like activity, suggesting that SpF1 is conserved in sea urchins. Surprisingly, changes in the Spec1, Spec2a, or Spec2c genes that removed or modified the SpF1-binding site had no effect on expression when reporter gene fusions containing these mutations were injected into sea urchin eggs and analyzed for expression during embryogenesis. We propose that, while SpF1 may not be essential for expression of the exogenously introduced reporter genes, it may be required for proper regulation of the endogenous Spec genes.

scholarly journals Organization of the sea urchin egg endoplasmic reticulum and its reorganization at fertilization.

1991 ◽  
Vol 114 (5) ◽  
pp. 929-940 ◽  
Author(s):  
M Terasaki ◽  
L A Jaffe
Keyword(s):  
Sea Urchin ◽  
Time Lapse ◽  
Sperm Nucleus ◽  
Temporal Organization ◽  
Calcium Wave ◽  
Zygote Nucleus ◽  
Lytechinus Pictus ◽  
Sea Urchin Egg ◽  
A Cell ◽  
Sperm Aster

The ER of eggs of the sea urchin Lytechinus pictus was stained by microinjecting a saturated solution of the fluorescent dicarbocyanine DiIC18(3) (DiI) in soybean oil; the dye spread from the oil drop into ER membranes throughout the egg but not into other organelles. Confocal microscopy revealed large cisternae extending throughout the interior of the egg and a tubular membrane network at the cortex. Since diffusion of DiI is confined to continuous bilayers, the spread of the dye supports the concept that the ER is a cell-wide, interconnected compartment. In time lapse observations, the internal cisternae were seen to be in continuous motion, while the cortical ER was stationary. After fertilization, the internal ER appeared to become more finely divided, beginning as a wave apparently coincident with the calcium wave and becoming most marked by 2-3 min. By 5-8 min the ER returned to an organization similar to that of the unfertilized egg. The cortical network also changed at fertilization; it became disrupted and eventually recovered. DiI labeling allowed continuous observations of the ER during pronuclear migration and mitosis. DiI-stained membranes accumulated in the region of the microtubule array surrounding the sperm nucleus and centriole (the sperm aster) as it migrated to the center of the egg; this accumulation persisted near the centrosomes and zygote nucleus throughout pronuclear fusion and the first two mitotic cycles. We have used a new method to observe the spatial and temporal organization of the ER in a living cell, and we have demonstrated a striking reorganization of the ER at fertilization.

scholarly journals Organization and evolution of the actin gene family in sea urchins.

1983 ◽  
Vol 3 (10) ◽  
pp. 1824-1833 ◽  
Author(s):  
P J Johnson ◽  
D R Foran ◽  
G P Moore
Keyword(s):  
Sea Urchin ◽  
Sequence Homology ◽  
Copy Number ◽  
Sea Urchins ◽  
Intron Position ◽  
Actin Gene ◽  
Genomic Libraries ◽  
Lytechinus Pictus ◽  
Transcriptional Orientation ◽  
Actin Genes

Genomic libraries of the sea urchins Strongylocentrotus franciscanus and Lytechinus pictus were screened with an actin cDNA clone from Strongylocentrotus purpuratus. Four nonoverlapping clones were isolated and characterized from the S. franciscanus library; three were isolated and characterized from the L. pictus library. Linked genes having the same transcriptional orientation were found on all S. franciscanus clones. Three clones contained two actin genes each; the other clone contained three. In contrast, the L. pictus clones contained only one actin gene. Comparison of actin genomic clones from these three species indicated a difference in the genomic organization of sea urchin actin genes in that the genes appear to be more highly clustered in S. franciscanus than in S. purpuratus and L. pictus. Genomic dot blots and reassociation kinetics demonstrated that the copy number of actin genes in all three species is 15 to 20. Nucleotide sequence homology of actin genes within and among the species was measured by thermal elution. These experiments indicated that there is a high degree of interspecies actin gene sequence homology but that, within each species, actin gene sequences may differ by as much as 30%. Sequencing of two S. franciscanus actin genes revealed introns at the same amino acid positions, 121 and 204, reported for S. purpuratus actin genes. These data demonstrated that the genomic copy number, the transcriptional orientation of linked genes, and, to the extent studied, the intron position of actin genes have evolved similarly in these three species. In contrast, significant change has occurred in the chromosomal arrangement of sea urchin actin genes.

Involvement of l(–)-rhamnose in sea urchin gastrulation. Part II: α-l-Rhamnosidase

Zygote ◽  
2015 ◽  
Vol 24 (3) ◽  
pp. 371-377 ◽  
Author(s):  
Jing Liang ◽  
Heghush Aleksanyan ◽  
Stan Metzenberg ◽  
Steven B. Oppenheimer
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Competitive Inhibitor ◽  
Innate Immune ◽  
Lytechinus Pictus ◽  
Sea Urchin Embryo ◽  
Low Concentrations ◽  
Health And Disease ◽  
Dose Dependent ◽  
Dose Dependent Effect

SummaryThe sea urchin embryo is recognized as a model system to reveal developmental mechanisms involved in human health and disease. In Part I of this series, six carbohydrates were tested for their effects on gastrulation in embryos of the sea urchin Lytechinus pictus. Only l-rhamnose caused dramatic increases in the numbers of unattached archenterons and exogastrulated archenterons in living, swimming embryos. It was found that at 30 h post-fertilization the l-rhamnose had an unusual inverse dose-dependent effect, with low concentrations (1–3 mM) interfering with development and higher concentrations (30 mM) having little to no effect on normal development. In this study, embryos were examined for inhibition of archenteron development after treatment with α-l-rhamnosidase, an endoglycosidase that removes terminal l-rhamnose sugars from glycans. It was observed that the enzyme had profound effects on gastrulation, an effect that could be suppressed by addition of l-rhamnose as a competitive inhibitor. The involvement of l-rhamnose-containing glycans in sea urchin gastrulation was unexpected, since there are no characterized biosynthetic pathways for rhamnose utilization in animals. It is possible there exists a novel l-rhamnose-containing glycan in sea urchins, or that the enzyme and sugar interfere with the function of rhamnose-binding lectins, which are components of the innate immune system in many vertebrate and invertebrate species.

scholarly journals Exogenous hyalin and sea urchin gastrulation. Part III: Biological activity of hyalin isolated from Lytechinus pictus embryos

Zygote ◽  
2008 ◽  
Vol 16 (4) ◽  
pp. 355-361 ◽  
Author(s):  
Azalia Contreras ◽  
John Vitale ◽  
Virginia Hutchins-Carroll ◽  
Edward J. Carroll ◽  
Steven B. Oppenheimer
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
National Institutes Of Health ◽  
Cellular Interactions ◽  
General Role ◽  
Lytechinus Pictus ◽  
Sea Urchin Embryo ◽  
Repeat Domain ◽  
Health And Disease ◽  
Adhesive Interactions

SummaryHyalin is a large glycoprotein, consisting of the hyalin repeat domain and non-repeated regions, and is the major component of the hyaline layer in the early sea urchin embryo of Strongylocentrotus purpuratus. The hyalin repeat domain has been identified in proteins from organisms as diverse as bacteria, sea urchins, worms, flies, mice and humans. While the specific function of hyalin and the hyalin repeat domain is incompletely understood, many studies suggest that it has a functional role in adhesive interactions. In part I of this series, we showed that hyalin isolated from the sea urchin S. purpuratus blocked archenteron elongation and attachment to the blastocoel roof occurring during gastrulation in S. purpuratus embryos, (Razinia et al., 2007). The cellular interactions that occur in the sea urchin, recognized by the U.S. National Institutes of Health as a model system, may provide insights into adhesive interactions that occur in human health and disease. In part II of this series, we showed that S. purpuratus hyalin heterospecifically blocked archenteron–ectoderm interaction in Lytechinus pictus embryos (Alvarez et al., 2007). In the current study, we have isolated hyalin from the sea urchin L. pictus and demonstrated that L. pictus hyalin homospecifically blocks archenteron–ectoderm interaction, suggesting a general role for this glycoprotein in mediating a specific set of adhesive interactions. We also found one major difference in hyalin activity in the two sea urchin species involving hyalin influence on gastrulation invagination.

scholarly journals The mouse thymidylate synthase promoter: essential elements are in close proximity to the transcriptional initiation sites.

1989 ◽  
Vol 9 (9) ◽  
pp. 4079-4082 ◽  
Author(s):  
T Deng ◽  
Y Li ◽  
K Jolliff ◽  
L F Johnson
Keyword(s):  
Thymidylate Synthase ◽  
Promoter Region ◽  
Promoter Activity ◽  
Initiation Site ◽  
Essential Elements ◽  
Site Directed Mutagenesis ◽  
Upstream Stimulatory Factor ◽  
Transcriptional Initiation ◽  
Close Proximity ◽  
Stimulatory Factor

The promoter region of the mouse thymidylate synthase gene was analyzed by deletion and site-directed mutagenesis. Elimination of an upstream Sp1 element reduced expression threefold, whereas elimination of an adenovirus upstream stimulatory factor element had little effect. All of the upstream elements that are essential for promoter activity are located within 22 nucleotides of the first transcriptional initiation site.

scholarly journals Carbohydrate specificity of sea urchin sperm bindin: a cell surface lectin mediating sperm-egg adhesion.

1982 ◽  
Vol 94 (1) ◽  
pp. 123-128 ◽  
Author(s):  
C G Glabe ◽  
L B Grabel ◽  
V D Vacquier ◽  
S D Rosen
Keyword(s):  
Sea Urchin ◽  
Potent Inhibitor ◽  
Sea Urchins ◽  
Structural Features ◽  
Carbohydrate Specificity ◽  
Lectin Activity ◽  
A Cell ◽  
Surface Polysaccharide ◽  
Adhesion Activity ◽  
Sea Urchin Sperm

We have examined the carbohydrate specificity of bindin, a sperm protein responsible for the adhesion of sea urchin sperm to eggs, by investigating the interaction of a number of polysaccharides and glycoconjugates with isolated bindin. Several of these polysaccharides inhibit the agglutination of eggs by bindin particles. An egg surface polysaccharide was found to be the most potent inhibitor of bindin-mediated egg agglutination. Fucoidin, a sulfated fucose heteropolysaccharide, was the next most potent inhibitor, followed by the egg jelly fucan, a sulfated fucose homopolysaccharide, and xylan, a beta(1 leads to 4) linked xylose polysaccharide. A wide variety of other polysaccharides and glycoconjugates were found to have no effect on egg agglutination. We also report that isolated bindin has a soluble lectinlike activity which is assayed by agglutination of erythrocytes. The bindin lectin activity is inhibited by the same polysaccharides that inhibit egg agglutination by particulate bindin. This suggests that the egg adhesion activity of bindin is directly related to its lectin activity. We have established that fucoidin binds specifically to bindin particles with a high apparent affinity (Kd = 5.5 X 10(-8) M). The other polysaccharides that inhibit egg agglutination also inhibit the binding of 125I-fucoidin to bindin particles, suggesting that they compete for the same site on bindin. The observation that polysaccharides of different composition and linkage type interact with bindin suggests that the critical structural features required for binding may reside at a higher level of organization. Together, these findings strengthen the hypothesis that sperm-egg adhesion in sea urchins is mediated by a lectin-polysaccharide type of interaction.

scholarly journals Substituting mouse transcription factor Pou4f2 with a sea urchin orthologue restores retinal ganglion cell development

2016 ◽  
Vol 283 (1826) ◽  
pp. 20152978 ◽  
Author(s):  
Chai-An Mao ◽  
Cavit Agca ◽  
Julie A. Mocko-Strand ◽  
Jing Wang ◽  
Esther Ullrich-Lüter ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Sea Urchin ◽  
Ganglion Cells ◽  
Sea Urchins ◽  
Photoreceptor Cells ◽  
Retinal Ganglion ◽  
Mammalian Retina ◽  
Morphological Differences ◽  
And Function ◽  
Tube Feet

Pou domain transcription factor Pou4f2 is essential for the development of retinal ganglion cells (RGCs) in the vertebrate retina. A distant orthologue of Pou4f2 exists in the genome of the sea urchin (class Echinoidea) Strongylocentrotus purpuratus ( SpPou4f1/2 ), yet the photosensory structure of sea urchins is strikingly different from that of the mammalian retina. Sea urchins have no obvious eyes, but have photoreceptors clustered around their tube feet disc. The mechanisms that are associated with the development and function of photoreception in sea urchins are largely unexplored. As an initial approach to better understand the sea urchin photosensory structure and relate it to the mammalian retina, we asked whether SpPou4f1/2 could support RGC development in the absence of Pou4f2 . To answer this question, we replaced genomic Pou4f2 with an SpPou4f1/2 cDNA. In Pou4f2 -null mice, retinas expressing SpPou4f1/2 were outwardly identical to those of wild-type mice. SpPou4f1/2 retinas exhibited dark-adapted electroretinogram scotopic threshold responses, indicating functionally active RGCs. During retinal development, SpPou4f1/2 activated RGC-specific genes and in S. purpuratus , SpPou4f2 was expressed in photoreceptor cells of tube feet in a pattern distinct from Opsin4 and Pax6. Our results suggest that SpPou4f1/2 and Pou4f2 share conserved components of a gene network for photosensory development and they maintain their conserved intrinsic functions despite vast morphological differences in mouse and sea urchin photosensory structures.

Organization and evolution of the actin gene family in sea urchins

1983 ◽  
Vol 3 (10) ◽  
pp. 1824-1833
Author(s):  
P J Johnson ◽  
D R Foran ◽  
G P Moore
Keyword(s):  
Sea Urchin ◽  
Sequence Homology ◽  
Copy Number ◽  
Sea Urchins ◽  
Intron Position ◽  
Actin Gene ◽  
Genomic Libraries ◽  
Lytechinus Pictus ◽  
Transcriptional Orientation ◽  
Actin Genes

Genomic libraries of the sea urchins Strongylocentrotus franciscanus and Lytechinus pictus were screened with an actin cDNA clone from Strongylocentrotus purpuratus. Four nonoverlapping clones were isolated and characterized from the S. franciscanus library; three were isolated and characterized from the L. pictus library. Linked genes having the same transcriptional orientation were found on all S. franciscanus clones. Three clones contained two actin genes each; the other clone contained three. In contrast, the L. pictus clones contained only one actin gene. Comparison of actin genomic clones from these three species indicated a difference in the genomic organization of sea urchin actin genes in that the genes appear to be more highly clustered in S. franciscanus than in S. purpuratus and L. pictus. Genomic dot blots and reassociation kinetics demonstrated that the copy number of actin genes in all three species is 15 to 20. Nucleotide sequence homology of actin genes within and among the species was measured by thermal elution. These experiments indicated that there is a high degree of interspecies actin gene sequence homology but that, within each species, actin gene sequences may differ by as much as 30%. Sequencing of two S. franciscanus actin genes revealed introns at the same amino acid positions, 121 and 204, reported for S. purpuratus actin genes. These data demonstrated that the genomic copy number, the transcriptional orientation of linked genes, and, to the extent studied, the intron position of actin genes have evolved similarly in these three species. In contrast, significant change has occurred in the chromosomal arrangement of sea urchin actin genes.

The mouse thymidylate synthase promoter: essential elements are in close proximity to the transcriptional initiation sites

1989 ◽  
Vol 9 (9) ◽  
pp. 4079-4082
Author(s):  
T Deng ◽  
Y Li ◽  
K Jolliff ◽  
L F Johnson
Keyword(s):  
Thymidylate Synthase ◽  
Promoter Region ◽  
Promoter Activity ◽  
Initiation Site ◽  
Essential Elements ◽  
Site Directed Mutagenesis ◽  
Upstream Stimulatory Factor ◽  
Transcriptional Initiation ◽  
Close Proximity ◽  
Stimulatory Factor

The promoter region of the mouse thymidylate synthase gene was analyzed by deletion and site-directed mutagenesis. Elimination of an upstream Sp1 element reduced expression threefold, whereas elimination of an adenovirus upstream stimulatory factor element had little effect. All of the upstream elements that are essential for promoter activity are located within 22 nucleotides of the first transcriptional initiation site.

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