Novel Mix-Family Homeobox Genes in Zebrafish and Their Differential Regulation

Hirata, Tsutomu; Yamanaka, Yojiro; Ryu, Seung-Lim; Shimizu, Takashi; Yabe, Taijiro; Hibi, Masahiko; Hirano, Toshio

doi:10.1006/bbrc.2000.2672

Cited by 23 publications

(25 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We found that an MO designed to knock down the 124H4 clone caused heart malformations and subsequently determined that the 124H4 clone is identical to the previously reported transcription factor gene mtx1 (Hirata et al, 2000). mtx1 is a Mix-type homeobox gene that is expressed exclusively in the YSL from the oblong stage (3.7 hpf) until 80% epiboly (8.3 hpf) (Hirata et al, 2000) (data not shown). No mtx1 transcripts can be detected after gastrula stage, or in any embryonic tissues (Hirata et al, 2000).…”

Section: Resultssupporting

confidence: 59%

“…Several zebrafish mix-family genes, such as bonnie and clyde (bon), mtx1 (mxtx1 -Zebrafish Information Network), and mtx2 (mxtx2 -Zebrafish Information Network), are expressed in the YSL Hirata et al, 2000;Kikuchi et al, 2000). bon and mtx2 are expressed in the marginal mesendodermal cells and the YSL, while mtx1 is expressed exclusively in the YSL during blastula and gastrula stages Hirata et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

“…bon and mtx2 are expressed in the marginal mesendodermal cells and the YSL, while mtx1 is expressed exclusively in the YSL during blastula and gastrula stages Hirata et al, 2000). In higher vertebrates, mix-family genes such as mixer and Mixl1 play important roles in endoderm and axial mesoderm development (Henry and Melton, 1998;Hart et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The yolk syncytial layer regulates myocardial migration by influencing extracellular matrix assembly in zebrafish

et al. 2006

View full text Add to dashboard Cite

The roles of extra-embryonic tissues in early vertebrate body patterning have been extensively studied, yet we know little about their function during later developmental events. Here, we analyze the function of the zebrafish extra-embryonic yolk syncytial layer (YSL) specific transcription factor, Mtx1, and find that it plays an essential role in myocardial migration. Downregulating the function of Mtx1 in the YSL leads to cardia bifida, a phenotype in which the myocardial cells fail to migrate to the midline. Mtx1 in the extra-embryonic YSL appears to regulate the embryonic expression of fibronectin, a gene previously implicated in myocardial migration. We further show dosage-sensitive genetic interactions between mtx1 and fibronectin. Based on these data, we propose that the extra-embryonic YSL regulates myocardial migration, at least in part by influencing fibronectin expression and subsequent assembly of the extracellular matrix in embryonic tissues.

show abstract

Section: Resultssupporting

confidence: 59%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The yolk syncytial layer regulates myocardial migration by influencing extracellular matrix assembly in zebrafish

et al. 2006

View full text Add to dashboard Cite

show abstract

“…For example, in Xenopus embryos, mesoderm specification involves over twenty-five functionally redundant copies of the mesoderm inducer Nodal (Takahashi et al 2006), and seven copies of the transcription factor Mix (Hellsten et al 2010). Teleost embryos also express multiple copies of nodal and mix (Hirata et al 2000, Trinh et al 2003, Fan & Dougan 2007. However, this is not the basal state for chordates, and it is not conserved in amphibians.…”

Section: Pluripotency Is Conserved In Chordatesmentioning

confidence: 99%

Evolution of the germ line–soma relationship in vertebrate embryos

Johnson¹,

Richardson²,

Bachvarova³

et al. 2011

Reproduction

111

View full text Add to dashboard Cite

The germ line and soma together maintain genetic lineages from generation to generation: the germ line passes genetic information between generations; the soma is the vehicle for germ line transmission, and is shaped by natural selection. The germ line and somatic lineages arise simultaneously in early embryos, but how their development is related depends on how primordial germ cells (PGC) are specified. PGCs are specified by one of two means. Epigenesis describes the induction of PGCs from pluripotent cells by signals from surrounding somatic tissues. In contrast, PGCs in many species are specified cell-autonomously by maternally derived molecules, known as germ plasm, and this is called preformation. Germ plasm inhibits signaling to PGCs; thus, they are specified cell-autonomously. Germ plasm evolved independently in many animal lineages, suggesting convergent evolution, and therefore it would be expected to convey a selective advantage. But, what this is remains unknown. We propose that the selective advantage that drives the emergence of germ plasm in vertebrates is the disengagement of germ line specification from somatic influences. This liberates the evolution of gene regulatory networks (GRNs) that govern somatic development, and thereby enhances species evolvability, a well-recognized selective advantage. We cite recent evidence showing that frog embryos, which contain germ plasm, have modified GRNs that are not conserved in axolotls, which represent more basal amphibians and employ epigenesis. We also present the correlation of preformation with enhanced species radiations, and we discuss the mutually exclusive trajectories influenced by germ plasm or pluripotency, which shaped chordate evolution.

show abstract

“…Mtx2 Expression and the F-actin Ring in YSL Are Altered in apoa2 Morphants-The proper organization of YSL has been shown to be essential for initiation and progression of epiboly in teleosts (21,31). Apoa2 is dominantly expressed in the YSL and performs a function in zebrafish embryonic gastrulation.…”

Section: Apoa2 Is Required For Cell Convergence During Gastrulation Amentioning

confidence: 99%

ApoA-II Directs Morphogenetic Movements of Zebrafish Embryo by Preventing Chromosome Fusion during Nuclear Division in Yolk Syncytial Layer

Zhang

Yao

Wang

et al. 2011

Journal of Biological Chemistry

View full text Add to dashboard Cite

The high density lipoprotein (HDL) represents a class of lipidand protein-containing particles and consists of two major apolipoproteins apoA-I and apoA-II. ApoA-II has been shown to be involved in the pathogenesis of insulin resistance, adiposity, diabetes, and metabolic syndrome. In embryo, apoa2 mRNAs are abundant in the liver, brain, lung, placenta, and in fish yolk syncytial layer (YSL), suggesting that apoa2 may perform a function during embryonic development. Here we find out that apoa2 modulates zebrafish embryonic development by regulating the organization of YSL. Disruption of apoa2 function in zebrafish caused chromosome fusing, which strongly blocked YSL nuclear division, inducing disorders in YSL organization and finally disturbing the embryonic epiboly. Purified native human apoA-II was able specifically to rescue the defects and induced nuclear division in zebrafish embryos and in human HeLa cells. The C terminus of apoA-II was required for the proper chromosome separation during nuclear division of YSL in zebrafish embryos and in human HeLa cells. Our data indicate that organization of YSL is required for blastoderm patterning and morphogenesis and suggest that apolipoprotein apoA-II is a novel factor of nuclear division in YSL involved in the regulation of early zebrafish embryonic morphogenesis and in mammalian cells for proliferation.Apolipoproteins, including apoA-I, apoA-II, apoA-IV, apoB, apoC-I, apoC-II, apoC-III, apoC-IV, and apoE, are macromolecular complexes synthesized mainly in liver and intestine and play essential roles in lipid uptake and transport in vertebrates (1-3). They bind to lipids to form chylomicrons, very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL) 3 and transport lipid to various tissues through the circulation system. In addition to their function in lipid metabolism, several apolipoproteins play critical roles in embryonic and ontogenic development and tissue regeneration (4, 5).The fish lipoprotein HDL is highly similar to most mammalian HDLs and contain two major apolipoproteins: the 28 kDa apolipoprotein and 14 kDa apolipoprotein (6 -8). The 14 kDa apolipoprotein is identified as a second major component of HDL from Japanese eel, common carp, pufferfish, orange-spotted grouper, grass carp, and fathead minnow (9). Recent data show that fish 14 kDa apolipoprotein is orthologous to mammalian HDL apoA-II (10), which has been shown to involve pathogenesis of insulin resistance, adiposity, diabetes, and metabolic syndrome. The apoa2 mRNAs are abundant in the liver, lung, placenta, brain (6, 11, 12) in embryos. In some fish species, apoa2 also expresses in heart. In addition, apoa2 has been found to express in YSL in embryos (9), suggesting that apoa2 may perform functions during embryonic gastrulation. The previous data indicate that yolk lipids are taken up by the fish YSL, where they are assembled into lipoproteins for releasing into the perisyncytial space (13). Apolipoprotein gene expression and lipoprotein secr...

show abstract

Novel Mix-Family Homeobox Genes in Zebrafish and Their Differential Regulation

Cited by 23 publications

References 34 publications

The yolk syncytial layer regulates myocardial migration by influencing extracellular matrix assembly in zebrafish

The yolk syncytial layer regulates myocardial migration by influencing extracellular matrix assembly in zebrafish

Evolution of the germ line–soma relationship in vertebrate embryos

ApoA-II Directs Morphogenetic Movements of Zebrafish Embryo by Preventing Chromosome Fusion during Nuclear Division in Yolk Syncytial Layer

Contact Info

Product

Resources

About