Promoter analysis meets pattern formation: transcriptional regulatory genes in sea urchin embryogenesis

Maxson, Rob; Tan, Hongying

doi:10.1016/0959-437x(94)90134-o

Cited by 4 publications

(3 citation statements)

References 63 publications

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“…Although dominant negative interference and misexpression experiments clearly establish that these factors play important developmental roles, to date in the cases of only two factors (SpEts4 and SpSoxB1) have downstream target genes of these maternal regulators been identified, i.e., the hatching enzyme gene (SpHE, HE) and the tolloid-related gene, SpAN. In contrast, very detailed analyses of the regulatory elements of genes encoding terminal differentiation products of major cell types have identified a large number of trans-acting factors (reviewed in Coffman and Davidson, 1992;Maxson and Tan, 1994;Kirchhamer et al, 1996). The sea urchin embryo presents a remarkably tractable and powerful system for analysis of gene regulatory networks in early embryogenesis (Arnone and Davidson, 1997;Yuh et al, 1998).…”

Section: New Questionsmentioning

confidence: 99%

Animal–Vegetal Axis Patterning Mechanisms in the Early Sea Urchin Embryo

Angerer

2000

Developmental Biology

118

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We discuss recent progress in understanding how cell fates are specified along the animal-vegetal axis of the sea urchin embryo. This process is initiated by cell-autonomous, maternally directed, mechanisms that establish three unique gene-regulatory domains. These domains are defined by distinct sets of vegetalizing (beta-catenin) and animalizing transcription factor (ATF) activities and their region of overlap in the macromeres, which specifies these cells as early mesendoderm. Subsequent signaling among cleavage-stage blastomeres further subdivides fates of macromere progeny to yield major embryonic tissues. Zygotically produced Wnt8 reinforces maternally regulated levels of nuclear beta-catenin in vegetal derivatives to down regulate ATF activity and further promote mesendoderm fates. Signaling through the Notch receptor from the vegetal micromere lineages diverts adjacent mesendoderm to secondary mesenchyme fates. Continued Wnt signaling expands the vegetal domain of beta-catenin's transcriptional regulatory activity and competes with animal signaling factors, including BMP2/4, to specify the endoderm-ectoderm border within veg(1) progeny. This model places new emphasis on the importance of the ratio of maternally regulated vegetal and animal transcription factor activities in initial specification events along the animal-vegetal axis.

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Section: New Questionsmentioning

confidence: 99%

Animal–Vegetal Axis Patterning Mechanisms in the Early Sea Urchin Embryo

Angerer

2000

Developmental Biology

118

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“…Some characterization of two other PMC‐specific genes, PM27 and msp130 (Raman et al 1993; Klueg et al 1997), has also been carried out. Meanwhile, other genes have been intensively studied in terms of their regulatory mechanisms, such as those expressed specifically in the aboral ectoderm, in the gut, or universally during the course of development (Maxson & Tan 1994; Kirchhamer et al 1996). Hence, by comparison with other genes, it will be possible to explore the common and disparate regulatory architecture in genes that are uniquely active in the PMC lineage and contribute to differentiation of the skeleton.…”

Section: Introductionmentioning

confidence: 99%

Functional organization of DNA elements regulating SM30α, a spicule matrix gene of sea urchin embryos

Yamasu

Wilt

1999

Dev Growth Differ

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The SM30a gene encodes a protein in the embryonic endoskeleton of the sea urchin Strongylocentrotus purpuratus, and is specifically expressed in the skeletogenic primary mesenchyme cell lineage. To clarify the mechanism for the differentiation of this cell lineage, which proceeds rather autonomously in the embryo, regulation of the SM30alpha gene was investigated previously and it was shown that the distal DNA region upstream of this gene from - 1.6 to - 1.0 kb contained numerous negative regulatory elements that suppressed the ectopic expression of the gene in the gut. Here we study the influence of the proximal region from - 303 to + 104 bp. Analysis of the expression of reporter constructs indicated that a strong positive enhancer element existed in the region from -142 to -105bp. This element worked both in forward and reverse orientations and additively when placed tandemly upstream to the reporter gene. In addition, other weaker positive and negative regulatory sites were also detected throughout the proximal region. Electrophoretic gel mobility shift analyses showed that multiple nuclear proteins were bound to the putative strong enhancer region. One of the proteins binding to this region was present in ear y blastulae, a time when the SM30 gene was still silent, but it was not in prism embryos actively expressing the gene. The binding region for this blastula-specific protein was narrowed down to the region from - 132 to -122 bp, which included the consensus binding site for the mammalian proto-oncogene product, Ets. Two possible SpGCF1 binding sites were identified in the vicinity of the enhancer region. This information was used to make a comparison of the general regulatory architecture of genes that contribute to the formation of the skeletal spicule.

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“…Nevertheless, the gene families in these divergent years as a convenient system to analyze the transcriptional sea urchin species appear to have distinct DNA elements concontrol of cell lineage-specific genes (for reviews, see Coffman trolling their transcription. Positive control of the S. purpuraand Davidson, 1992;Maxson and Tan, 1994). Monitoring re-tus Spec genes is mediated by an aboral/mesenchyme cell-speporter gene activity in microinjected embryos has led to the cific enhancer that contains multiple binding sites for the sea identification of a number of DNA-regulatory elements impor-urchin homeobox protein, SpOtx (Gan and Klein, 1993;Mao tant for the regulation of genes expressed in the major embry-et al, 1994; Gan et al, 1995).…”

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confidence: 99%

A G/C-Rich DNA-Regulatory Element Controls Positive Expression of the Sea UrchinLytechinus pictusAboral Ectoderm-SpecificLpS1Gene

Wang

Klein²

1996

DNA and Cell Biology

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The LpS1 beta gene of Lytechinus pictus is activated at the late cleavage stage about 12 hr after fertilization. LpS1 beta transcripts accumulate exclusively in aboral ectoderm lineages. LpS1 beta is thus a classic example of a gene whose expression is tightly controlled both temporally and spatially during early development. Previous studies on the LpS1 beta promoter identified two G-string DNA elements, one proximal and one distal to the LpS1 beta transcriptional start site, which bind to an ectoderm-enriched nuclear factor. In this report, we show that the ectoderm G-string factor binds to a G/C-rich region larger than the G-string itself and that the binding of the G-string factor requires sequences immediately downstream from the G-string. These downstream sequences are essential for full promoter activity. Two regions of 5'-flanking DNA are required for positive control of LpS1 beta, region I from base pairs -762 to -511, and region II, which includes the G/C-rich element, from base pairs -108 to -61. Region I also contains a mesenchyme cell repressor element. The results indicate that LpS1 beta expression is regulated positively in ectoderm cells and negatively in mesenchyme cells. Similar positive and negative control mechanisms regulate the expression of the related Spec genes of Strongylocentrotus purpuratus, but in this gene family the DNA elements are entirely different. We hypothesize that cis-regulatory elements are evolutionarily dynamic and that many different combinations of DNA elements are capable of given rise to aboral ectoderm-specific expression.

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Promoter analysis meets pattern formation: transcriptional regulatory genes in sea urchin embryogenesis

Cited by 4 publications

References 63 publications

Animal–Vegetal Axis Patterning Mechanisms in the Early Sea Urchin Embryo

Animal–Vegetal Axis Patterning Mechanisms in the Early Sea Urchin Embryo

Functional organization of DNA elements regulating SM30α, a spicule matrix gene of sea urchin embryos

A G/C-Rich DNA-Regulatory Element Controls Positive Expression of the Sea UrchinLytechinus pictusAboral Ectoderm-SpecificLpS1Gene

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