Characterization of RNA species synthesized during early development of sea urchins

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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Characterization of N-Myristoyltransferases in Vertebrate Embryos by Using Zebrafish: Appearance of Low Molecular Weight N-Myristoyltransferase 1 in Early Development

Journal of Glycomics & Lipidomics ◽

10.4172/2153-0637.1000120 ◽

2014 ◽

Vol 04 (03) ◽

Author(s):

Hajime Nakatani Natsuki Nukada

Keyword(s):

Molecular Weight ◽

Early Development ◽

Low Molecular Weight ◽

Vertebrate Embryos

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Divergence of gene regulatory network linkages during specification of ectoderm and mesoderm in early development of sea urchins

10.1101/044149 ◽

2016 ◽

Author(s):

Eric M. Erkenbrack ◽

Eric H. Davidson

Keyword(s):

Early Development ◽

Regulatory Networks ◽

Evolutionary Dynamics ◽

Sea Urchins ◽

Regulatory Genes ◽

Geological Time ◽

Appreciable Change ◽

Comparative Analyses ◽

Temporal Gene Expression ◽

Gene Regulatory

AbstractDevelopmental gene regulatory networks (GRNs) are assemblages of gene regulatory interactions that direct ontogeny of animal body plans. Studies of GRNs operating in early development of euechinoid sea urchins has revealed that little appreciable change has occurred since their divergence approximately 90 million years ago (mya). These observations suggest that strong conservation of GRN architecture has been maintained in early development of the sea urchin lineage. To test whether this is true for all sea urchins, comparative analyses of echinoid taxa that diverged deeper in geological time must be conducted. Recent studies highlighted extensive divergence of skeletogenic mesoderm specification in the sister clade of euechinoids, the cidaroids, suggesting that comparative analyses of cidaroid GRN architecture may confer a greater understanding of the evolutionary dynamics of developmental GRNs. Here, we report spatiotemporal patterning of 55 regulatory genes and perturbation analyses of key regulatory genes involved in euechinoid oral-aboral patterning of non-skeletogenic mesodermal and ectodermal domains in early development of the cidaroid Eucidaris tribuloides. Our results indicate that developmental GRNs directing mesodermal and ectodermal specification have undergone marked alterations since the divergence of cidaroids and euechinoids. Notably, statistical and clustering analyses of echinoid temporal gene expression datasets indicate that regulation of mesodermal genes has diverged more markedly than regulation of ectodermal genes. Although research on indirect-developing euechinoid sea urchins suggests strong conservation of GRN circuitry during early embryogenesis, this study indicates that since the divergence of cidaroids and euechinoids developmental GRNs have undergone significant divergence.

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Counterproductive transcriptional and translational regulation of elongation factor 1-α synthesis during early development in sea urchins

Developmental Biology ◽

10.1016/0012-1606(90)90371-o ◽

1990 ◽

Vol 142 (2) ◽

pp. 486-488 ◽

Cited By ~ 7

Author(s):

Margaret Truschel Peeler ◽

Leslie Kelso-Winemiller ◽

Ming-Fan Wu ◽

James K. Skipper ◽

Matthew M. Winkler

Keyword(s):

Early Development ◽

Translational Regulation ◽

Sea Urchins ◽

Elongation Factor ◽

Elongation Factor 1 ◽

Transcriptional And Translational Regulation

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Sequencing and characterization of tomato genes putatively involved in fruit set and early development

Sexual Plant Reproduction ◽

10.1007/s00497-001-0122-4 ◽

2002 ◽

Vol 14 (5) ◽

pp. 269-277 ◽

Cited By ~ 16

Author(s):

Giuseppe Testa ◽

Riccardo Caccia ◽

Francesca Tilesi ◽

Gian Soressi ◽

Andrea Mazzucato

Keyword(s):

Early Development ◽

Fruit Set

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Characterization of the early development of specific hypaxial muscles from the ventrolateral myotome

Development ◽

10.1242/dev.126.19.4305 ◽

1999 ◽

Vol 126 (19) ◽

pp. 4305-4315 ◽

Cited By ~ 10

Author(s):

Y. Cinnamon ◽

N. Kahane ◽

C. Kalcheim

Keyword(s):

Confocal Microscopy ◽

Early Development ◽

Early Generation ◽

Intercostal Muscles ◽

Fundamental Component ◽

Vital Dyes ◽

First Time ◽

Second Wave ◽

Longitudinal Cell

We have previously found that the myotome is formed by a first wave of pioneer cells generated along the medial epithelial somite and a second wave emanating from the dorsomedial lip (DML), rostral and caudal edges of the dermomyotome (Kahane, N., Cinnamon, Y. and Kalcheim, C. (1998a) Mech. Dev. 74, 59–73; Kahane, N., Cinnamon, Y. and Kalcheim, C. (1998b) Development 125, 4259–4271). In this study, we have addressed the development and precise fate of the ventrolateral lip (VLL) in non-limb regions of the axis. To this end, fluorescent vital dyes were iontophoretically injected in the center of the VLL and the translocation of labeled cells was followed by confocal microscopy. VLL-derived cells colonized the ventrolateral portion of the myotome. This occurred following an early longitudinal cell translocation along the medial boundary until reaching the rostral or caudal dermomyotome lips from which fibers emerged into the myotome. Thus, the behavior of VLL cells parallels that of their DML counterparts which colonize the opposite, dorsomedial portion of the myotome. To precisely understand the way the myotome expands, we addressed the early generation of hypaxial intercostal muscles. We found that intercostal muscles were formed by VLL-derived fibers that intermingled with fibers emerging from the ventrolateral aspect of both rostral and caudal edges of the dermomyotome. Notably, hypaxial intercostal muscles also contained pioneer myofibers (first wave) showing for the first time that lateral myotome-derived muscles contain a fundamental component of fibers generated in the medial domain of the somite. In addition, we show that during myotome growth and evolution into muscle, second-wave myofibers progressively intercalate between the pioneer fibers, suggesting a constant mode of myotomal expansion in its dorsomedial to ventrolateral extent. This further suggests that specific hypaxial muscles develop following a consistent ventral expansion of a ‘compound myotome’ into the somatopleure.

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Example: Early Pattern Formation in Amphibia

Morphogenesis and Evolution ◽

10.1093/oso/9780195049121.003.0007 ◽

1988 ◽

Author(s):

Keith Stewart Thomson

Keyword(s):

Pattern Formation ◽

Early Development ◽

Sea Urchins ◽

Vitelline Membrane ◽

Causal Processes ◽

Phases Of Development ◽

Primary Induction ◽

The Subject ◽

Axis Of Symmetry ◽

Early Phases

The Amphibia has been one of the most important animal groups for the study of developmental biology, and a huge descriptive and experimental literature has accumulated over the years. While sea urchins, molluscs, and nematodes, and more recently, Drosophila, have each become an important vehicle for the study of different aspects of development, the Amphibia and chordates in general have been especially important as the vehicle for the study of inductive regulative mechanisms. The early development of all chordates is marked by two revolutions in the control of early pattern formation: dorsalization at the blastula stage and gastrulation—primary induction caused by the “organizer” —which was studied in great detail in Amphibia by Spemann and his coworkers and continues to be the subject of intense scrutiny. The early phases of development in Amphibia exemplify rather well some of the problems in discovering the causal processes in development, whether in the egg, at fertilization, in the blastula, or in gastrulation itself. The short discussion of early development in Amphibia that follows is meant to exemplify rather than catalogue these questions. The oocyte in amphibians is radially symmetrical. A first axis of symmetry is established between a more heavily pigmented animal hemisphere and a less pigmented vegetal hemisphere. Before fertilization the egg is covered with a transparent vitelline membrane. When fertilization occurs, the vitelline membrane lifts from the surface of the egg and the egg is then free to rotate inside it so that the animal hemisphere lies uppermost and the vegetal hemisphere is lowermost. This rotation is apparently a response to gravity, which means that the vegetal hemisphere is heavier, almost certainly a result of the concentration of more and larger yolk granules in the vegetal hemisphere. Therefore, if the egg rotates to a new orientation with the yolk down and the animal hemisphere up, it must be the case that at this point the yolk and other egg contents are not free to be redistributed within the egg but are secured in place. The animal vegetal axis now marks the future anteroposterior axis of the embryo.

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