Repression of Zygotic Gene Expression in the Putative Germline Cells in Ascidian Embryos

Tomioka, Masahiro; Miya, Takahito; Nishida, Hiroki

doi:10.2108/zsj.19.49

Cited by 31 publications

(22 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, there is a correlation between loss of PP and the activation of zygotic transcription. This correlation has been thoroughly documented in the ascidian Halocynthia roretzi (31).…”

Section: Discussionmentioning

confidence: 81%

Evolutionary origins of the vertebrate heart: Specification of the cardiac lineage in Ciona intestinalis

Davidson

Levine

2003

Proc. Natl. Acad. Sci. U.S.A.

120

115

View full text Add to dashboard Cite

Here we exploit the extensive cell lineage information and streamlined genome of the ascidian, Ciona intestinalis, to investigate heart development in a basal chordate. Several cardiac genes were analyzed, including the sole Ciona ortholog of the Drosophila tinman gene, and tissue-specific enhancers were isolated for some of the genes. Conserved sequence motifs within these enhancers facilitated the isolation of a heart enhancer for the Ciona Hand-like gene. Altogether, these studies provide a regulatory framework for the differentiation of the cardiac mesoderm, beginning at the 110-cell stage, and extending through the fusion of cardiac progenitors during tail elongation. The cardiac lineage shares a common origin with the germ line, and zygotic transcription is first detected in the heart progenitors only after its separation from the germ line at the 64-cell stage. We propose that germ-line determinants influence the specification of the cardiac mesoderm, both by inhibiting inductive signals required for the development of noncardiac mesoderm lineages, and by providing a localized source of Wnt-5 and other signals required for heart development. We discuss the possibility that the germ line also influences the specification of the vertebrate heart.

show abstract

“…Therefore, there is a correlation between loss of PP and the activation of zygotic transcription. This correlation has been thoroughly documented in the ascidian Halocynthia roretzi (31).…”

Section: Discussionmentioning

confidence: 81%

Evolutionary origins of the vertebrate heart: Specification of the cardiac lineage in Ciona intestinalis

Davidson

Levine

2003

Proc. Natl. Acad. Sci. U.S.A.

120

115

View full text Add to dashboard Cite

show abstract

“…The origin of the germ line in urochordates is best understood in solitary ascidians like Halocynthia roretzi, in which detailed cell lineage studies have paved the way for contemporary molecular studies (Nishida, 1987;Nishida and Satoh, 1983;Nishida and Satoh, 1985), and Ciona intestinalis, which has recently joined the ranks of the 'genomic' Metazoa (Dehal et al, 2002). Some descriptive evidence (such as vasa mRNA and protein localisation, transcriptional repression of somatic genes) has suggested that two small blastomeres (B7.6 cells) at the 64-cell stage of C. intestinalis and H. roretzi are the pPGCs (Fujimura and Takamura, 2000;Takamura et al, 2002;Tomioka et al, 2002). An organelle whose ultrastructure resembles that of germ plasm, called the centrosome-attracting body (CAB), has been identified in H. roretzi embryos (Iseto and Nishida, 1999;Nishikata et al, 1999).…”

Section: Pgcs In the Chordatesmentioning

confidence: 99%

Mechanisms of germ cell specification across the metazoans: epigenesis and preformation

Extavour¹,

Akam²

2003

Development

730

751

View full text Add to dashboard Cite

Germ cells play a unique role in gamete production, heredity and evolution. Therefore, to understand the mechanisms that specify germ cells is a central challenge in developmental and evolutionary biology. Data from model organisms show that germ cells can be specified either by maternally inherited determinants (preformation) or by inductive signals (epigenesis). Here we review existing data on 28 metazoan phyla, which indicate that although preformation is seen in most model organisms, it is actually the less prevalent mode of germ cell specification, and that epigenetic germ cell specification may be ancestral to the Metazoa.

show abstract

“…We therefore examined the effects of Cipem-1 KD on zygotic gene expression in cleavage stage embryos. Upon the cleavage of a parental germline blastomere, the postplasm-free daughter cell begins the zygotic transcription of many genes, but the other, postplasm-containing, daughter, does not (Di Gregorio et al, 2001;Imai et al, 2002;Imai et al, 2004;Kumano et al, 2006;Lamy et al, 2006;Miya and Nishida, 2003;Tomioka et al, 2002;Olsen and Jeffery, 1997;Yagi et al, 2004). Ci-FoxA-a and Ci-SoxB1 are expressed in this manner from the eight-cell stage, the earliest stage of zygotic gene expression so far 2875 RESEARCH ARTICLE Ci-Pem-1 represses germline transcription detected (Imai et al, 2004;Lamy et al, 2006;Miya and Nishida, 2003).…”

Section: Ci-pem-1 Represses Zygotic Gene Expression In the Germline Bmentioning

confidence: 99%

“…For example, although the postplasmic/PEM RNA that encodes a transcriptional factor for muscle cell fate determination, macho-1, is distributed with the postplasm during the cleavage stages, its target genes, such as ADMP, are never expressed in the germline blastomeres (Tomioka et al, 2002;Yagi et al, 2004). In addition, a comprehensive in situ hybridization analysis of C. intestinalis embryos in the ghost database (http://ghost.zool.kyoto-u.ac.jp/indexr1.html) suggested that very few zygotic genes are transcribed in germline blastomeres during the cleavage stages (Imai et al, 2004;Nishikata et al, 2001;Satou et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Ci-Pem-1 localizes to the nucleus and represses somatic gene transcription in the germline of Ciona intestinalis embryos

Shirae-Kurabayashi¹,

Matsuda²,

Nakamura³

2011

Development

View full text Add to dashboard Cite

In many animal embryos, germ-cell formation depends on maternal factors located in the germ plasm. To ensure the development of germ cells, germline progenitors must be prevented from differentiating inappropriately into somatic cells. A common mechanism for this appears to be the active repression of somatic gene transcription. Species-specific germ-plasm components, such as Pgc in Drosophila and PIE-1 in C. elegans, establish germline transcriptional quiescence by inhibiting general transcriptional machineries. In the ascidian Ciona intestinalis, although transcriptional repression in the germline has been proposed, the factors and mechanisms involved have been unknown. We found that the protein products of Ci-pem-1 RNA, which is an ascidian-specific component of the postplasm (the germ plasm equivalent in ascidians), localized to the nucleus of germline blastomeres, as well as to the postplasm. Morpholino oligonucleotide-mediated Ci-pem-1 knockdown resulted in the ectopic expression of several somatic genes that are usually silent in the germline. In the Ci-pem-1 knockdown embryos, the expression of both β-catenin- and GATAa-dependent genes was derepressed in the germline blastomeres, suggesting that Ci-Pem-1 broadly represses germline mRNA transcription. Immunoprecipitation assays showed that Ci-Pem-1 could interact with two C. intestinalis homologs of Groucho, which is a general co-repressor of mRNA transcription. These results suggest that Ci-pem-1 is the C. intestinalis version of a germ-plasm RNA whose protein product represses the transcription of somatic genes during specification of the germ-cell fate, and that this repression may be operated through interactions between Ci-Pem-1 and Groucho co-repressors.

show abstract

Repression of Zygotic Gene Expression in the Putative Germline Cells in Ascidian Embryos

Cited by 31 publications

References 25 publications

Evolutionary origins of the vertebrate heart: Specification of the cardiac lineage in Ciona intestinalis

Evolutionary origins of the vertebrate heart: Specification of the cardiac lineage in Ciona intestinalis

Mechanisms of germ cell specification across the metazoans: epigenesis and preformation

Ci-Pem-1 localizes to the nucleus and represses somatic gene transcription in the germline of Ciona intestinalis embryos

Contact Info

Product

Resources

About