Development of pigment-cup eyes in the polychaetePlatynereis dumeriliiand evolutionary conservation of larval eyes in Bilateria

Development ◽  
2002 ◽  
Vol 129 (5) ◽  
pp. 1143-1154 ◽  
Author(s):  
Detlev Arendt ◽  
Kristin Tessmar ◽  
Maria-Ines Medeiros de Campos-Baptista ◽  
Adriaan Dorresteijn ◽  
Joachim Wittbrodt
Keyword(s):  
Visual System ◽  
Early Development ◽  
Developmental Stages ◽  
Photoreceptor Cells ◽  
Evolutionary Conservation ◽  
Early Developmental Stages ◽  
Platynereis Dumerilii ◽  
Differentiation Marker ◽  
Early Developmental

The role of Pax6 in eye development in insects and vertebrates supports the view that their eyes evolved from simple pigment-cup ocelli present in their last common ancestors (Urbilateria). The cerebral eyes in errant polychaetes represent prototype invertebrate pigment-cup ocelli and thus resemble the presumed ancestral eyes. We have analysed expression of conserved eye specification genes in the early development of larval and adult pigment-cup eyes in Platynereis dumerilii (Polychaeta, Annelida, Lophotrochozoa). Both larval and adult eyes form in close vicinity of the optic anlagen on both sides of the developing brain ganglia. While pax6 is expressed in the larval, but not in the developing, adult eyes, expression of six1/2 from trochophora stages onwards specifically outlines the optic anlagen and thus covers both the developing larval and adult eyes. Using Platynereis rhabdomeric opsin as differentiation marker, we show that the first pair of adult eye photoreceptor cells is detected within bilateral clusters that transitorily express ath, the Platynereis atonal orthologue, thus resembling proneural sensory clusters. Our data indicate that – similar to insects, but different from the vertebrates – polychaete six1/2 expression outlines the entire visual system from early developmental stages onwards and ath-positive clusters generate the first photoreceptor cells to appear. We propose that pax6-, six1/2- and ath-positive larval eyes, as found in today’s trochophora, were present already in Urbilateria.

scholarly journals Zebrafish lipid droplets regulate embryonic ATP homeostasis to power early development

Open Biology ◽  
2017 ◽  
Vol 7 (7) ◽  
pp. 170063 ◽  
Author(s):  
Asmita Dutta ◽  
Deepak Kumar Sinha
Keyword(s):  
Fatty Acids ◽  
Early Development ◽  
Lipid Droplets ◽  
Developmental Stages ◽  
Fatty Acyl ◽  
Zebrafish Embryos ◽  
Early Developmental Stages ◽  
Successful Execution ◽  
Acyl Coenzyme A ◽  
Early Developmental

In zebrafish embryos, the maternally supplied pool of ATP is insufficient to power even the earliest of developmental events (0–3 hpf) such as oocyte-to-embryo transition (OET). The embryos generate an additional pulse (2.5 h long) of ATP (1.25–4 hpf) to achieve the embryonic ATP homeostasis. We demonstrate that the additional pulse of ATP is needed for successful execution of OET. The maternally supplied yolk lipids play a crucial role in maintaining the embryonic ATP homeostasis. In this paper, we identify the source and trafficking routes of free fatty acids (FFAs) that feed the mitochondria for synthesis of ATP. Interestingly, neither the maternally supplied pool of yolk-FFA nor the yolk-FACoA (fatty acyl coenzyme A) is used for ATP homeostasis during 0–5 hpf in zebrafish embryos. With the help of lipidomics, we explore the link between lipid droplet (LD)-mediated lipolysis and ATP homeostasis in zebrafish embryos. Until 5 hpf, the embryonic LDs undergo extensive lipolysis that generates FFAs. We demonstrate that these newly synthesized FFAs from LDs are involved in the maintenance of embryonic ATP homeostasis, rather than the FFAs/FACoA present in the yolk. Thus, the LDs are vital embryonic organelles that maintain the ATP homeostasis during early developmental stages (0–5 hpf) in zebrafish embryos. Our study highlights the important roles carried on by the LDs during the early development of the zebrafish embryos.

Liriodenine, Early Antimicrobial Defence in Annona diversifolia

2011 ◽  
Vol 66 (7-8) ◽  
pp. 377-384 ◽  
Author(s):  
Iván De la Cruz-Chacón ◽  
Alma Rosa González-Esquinca ◽  
Patricia Guevara Fefer ◽  
Luis Felipe Jímenez Garcia
Keyword(s):  
High Performance ◽  
Positive Relationship ◽  
Developmental Stages ◽  
Rhizopus Stolonifer ◽  
Seed Deterioration ◽  
Aspergillus Glaucus ◽  
Early Developmental Stages ◽  
Alkaloid Extracts ◽  
Early Developmental

Annonaceae aporphine alkaloids, of which liriodenine is the most abundant, have not been extensively studied from a biological standpoint. The goal of this study was to investigate the role of liriodenine in antimicrobial defense during early developmental stages in Annona diversifolia. The fungi Rhizopus stolonifer and Aspergillus glaucus, which are responsible for seed deterioration, were isolated during imbibition, and their antifungal activity was determined by diffusion, macrodilution, and metabolic inhibition assays using purified liriodenine and alkaloid extracts obtained from embryos, radicles, and roots at early developmental stages. The presence of liriodenine in extracts was quantified by high-performance liquid chromatography. Purified liriodenine and alkaloidal extracts inhibited both fungi, and there was a positive relationship between extract activity and amount of liriodenine contained therein. The quantity of liriodenine present in extracts suggests its importance in controlling other phytopathogens.

Paedomorphosis and cryptogenesis in trilobites

1981 ◽  
Vol 118 (6) ◽  
pp. 591-602 ◽  
Author(s):  
H. B. Whittington
Keyword(s):  
Type Species ◽  
World Wide ◽  
Developmental Stages ◽  
Upper Cambrian ◽  
Early Developmental Stages ◽  
Early Developmental ◽  
Early Upper

SummaryStubblefield suggested that proparian trilobites may have arisen by paedomorphosis. Examples of the role of paedomorphosis in the evolution of species and of particular organs are reviewed. The cryptogenetic renewal of trilobites after the Cambrian resulted in distinctive major taxa, but their relationships to each other and to older groups remain unsolved. Similarities between early developmental stages should be re-assessed as a possible guide to relationships. The early Upper Cambrian, type species of the proparian Schmalenseeia is re-described. It was small, possibly world-wide in distribution, the exoskeleton thin, the parts not articulated, apparently forming a more or less rigid shield. It may have been a paedomorphic, planktic species, but its origin and relationships are obscure.

scholarly journals Stage-Specific Effects of Ionizing Radiation during Early Development

2020 ◽  
Vol 21 (11) ◽  
pp. 3975 ◽  
Author(s):  
Yasuko Honjo ◽  
Tatsuo Ichinohe
Keyword(s):  
Ionizing Radiation ◽  
Early Development ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Embryonic Cells ◽  
Specific Effects ◽  
Early Developmental Stages ◽  
Similarities And Differences ◽  
Radio Sensitivity ◽  
Early Developmental

Early embryonic cells are sensitive to genotoxic stressors such as ionizing radiation. However, sensitivity to these stressors varies depending on the embryonic stage. Recently, the sensitivity and response to ionizing radiation were found to differ during the preimplantation period. The cellular and molecular mechanisms underlying the change during this period are beginning to be elucidated. In this review, we focus on the changes in radio-sensitivity and responses to ionizing radiation during the early developmental stages of the preimplantation (before gastrulation) period in mammals, Xenopus, and fish. Furthermore, we discuss the underlying cellular and molecular mechanisms and the similarities and differences between species.

Dynamics of gene expression patterns during early development of the European seabass (Dicentrarchus labrax)

2015 ◽  
Vol 47 (5) ◽  
pp. 158-169 ◽  
Author(s):  
E. Kaitetzidou ◽  
J. Xiang ◽  
E. Antonopoulou ◽  
C. S. Tsigenopoulos ◽  
E. Sarropoulou
Keyword(s):  
Gene Expression ◽  
Early Development ◽  
Developmental Stages ◽  
Expression Patterns ◽  
Dicentrarchus Labrax ◽  
Larval Rearing ◽  
Poor Growth ◽  
European Seabass ◽  
Early Developmental Stages ◽  
Early Developmental

Larval and embryonic stages are the most critical period in the life cycle of marine fish. Key developmental events occur early in development and are influenced by external parameters like stress, temperature, salinity, and photoperiodism. Any failure may cause malformations, developmental delays, poor growth, and massive mortalities. Advanced understanding of molecular processes underlying marine larval development may lead to superior larval rearing conditions. Today, the new sequencing and bioinformatic methods allow transcriptome screens comprising messenger (mRNA) and microRNA (miRNA) with the scope of detecting differential expression for any species of interest. In the present study, we applied Illumina technology to investigate the transcriptome of early developmental stages of the European seabass ( Dicentrarchus labrax). The European seabass, in its natural environment, is a euryhaline species and has shown high adaptation processes in early life phases. During its embryonic and larval phases the European seabass lives in a marine environment and as a juvenile it migrates to coastal zones, estuaries, and lagoons. Investigating the dynamics of gene expression in its early development may shed light on factors promoting phenotypic plasticity and may also contribute to the improvement and advancement of rearing methods of the European seabass, a species of high economic importance in European and Mediterranean aquaculture. We present the identification, characterization, and expression of mRNA and miRNA, comprising paralogous genes and differentially spliced transcripts from early developmental stages of the European seabass. We further investigated the detection of possible interactions of miRNA with mRNA.

Review of early developmental stages of trilobites and agnostids from the Barrandian area (Czech Republic)

2017 ◽  
Vol 186 (1) ◽  
pp. 103-112
Author(s):  
Lukáš Laibl ◽  
Oldřich Fatka
Keyword(s):  
Czech Republic ◽  
Developmental Stages ◽  
History Of Research ◽  
Early Developmental Stages ◽  
History Of ◽  
Barrandian Area ◽  
Early Developmental

This contribution briefly summarizes the history of research, modes of preservation and stratigraphic distribution of 51 trilobite and five agnostid taxa from the Barrandian area, for which the early developmental stages have been described.

scholarly journals The Effect of an Anthropogenic Magnetic Field on the Early Developmental Stages of Fishes—A Review

2021 ◽  
Vol 22 (3) ◽  
pp. 1210
Author(s):  
Krzysztof Formicki ◽  
Agata Korzelecka-Orkisz ◽  
Adam Tański
Keyword(s):  
Magnetic Fields ◽  
Developmental Stages ◽  
Negative Influence ◽  
Pigment Cells ◽  
Egg Activation ◽  
Industrial Equipment ◽  
Positive Effects ◽  
Early Developmental Stages ◽  
Species Specific ◽  
Early Developmental

The number of sources of anthropogenic magnetic and electromagnetic fields generated by various underwater facilities, industrial equipment, and transferring devices in aquatic environment is increasing. These have an effect on an array of fish life processes, but especially the early developmental stages. The magnitude of these effects depends on field strength and time of exposure and is species-specific. We review studies on the effect of magnetic fields on the course of embryogenesis, with special reference to survival, the size of the embryos, embryonic motor function, changes in pigment cells, respiration hatching, and directional reactions. We also describe the effect of magnetic fields on sperm motility and egg activation. Magnetic fields can exert positive effects, as in the case of the considerable extension of sperm capability of activation, or have a negative influence in the form of a disturbance in heart rate or developmental instability in inner ear organs.

scholarly journals Mitochondrial Processes during Early Development of Dictyostelium discoideum: From Bioenergetic to Proteomic Studies

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 638
Author(s):  
Monika Mazur ◽  
Daria Wojciechowska ◽  
Ewa Sitkiewicz ◽  
Agata Malinowska ◽  
Bianka Świderska ◽  
...  
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Coupling Efficiency ◽  
Slime Mold ◽  
Intact Cells ◽  
Life Cycle Stages ◽  
Early Developmental Stages ◽  
Proteomic Study ◽  
And Function ◽  
Early Developmental

The slime mold Dictyostelium discoideum’s life cycle includes different unicellular and multicellular stages that provide a convenient model for research concerning intracellular and intercellular mechanisms influencing mitochondria’s structure and function. We aim to determine the differences between the mitochondria isolated from the slime mold regarding its early developmental stages induced by starvation, namely the unicellular (U), aggregation (A) and streams (S) stages, at the bioenergetic and proteome levels. We measured the oxygen consumption of intact cells using the Clarke electrode and observed a distinct decrease in mitochondrial coupling capacity for stage S cells and a decrease in mitochondrial coupling efficiency for stage A and S cells. We also found changes in spare respiratory capacity. We performed a wide comparative proteomic study. During the transition from the unicellular stage to the multicellular stage, important proteomic differences occurred in stages A and S relating to the proteins of the main mitochondrial functional groups, showing characteristic tendencies that could be associated with their ongoing adaptation to starvation following cell reprogramming during the switch to gluconeogenesis. We suggest that the main mitochondrial processes are downregulated during the early developmental stages, although this needs to be verified by extending analogous studies to the next slime mold life cycle stages.

Sign in / Sign up

Export Citation Format

Share Document