scholarly journals Negative Geotaxis in Sea Urchin Larvae: A Possible Role of Mechanoreception in the Late Stages of Development

1988 ◽  
Vol 137 (1) ◽  
pp. 141-156 ◽  
Author(s):  
Yoshihiro Mogami ◽  
Chieko Oobayashi ◽  
Tomoko Yamaguchi ◽  
Yumi Ogiso ◽  
Shoji A. Baba
Keyword(s):  
Control Systems ◽  
Sea Urchin ◽  
Developmental Stages ◽  
Dark Field ◽  
Physiological Control ◽  
Swimming Direction ◽  
Early Stages ◽  
Late Stages ◽  
Pluteus Stage

Negative geotactic behaviour of sea urchin larvae at various developmental stages from blastula to pluteus was analysed by means of time-exposure dark-field photography of the swimming behaviour of individual larvae. Significant differences in the patterns of behaviour, such as swimming direction and speed, were demonstrated between the early stages (up to the gastrula) and the pluteus, although larvae at any developmental stage showed negative geotactic migration. Larvae in the early stages swam at speeds that varied as a function of the swimming direction with respect to gravity, faster downwards and slower upwards. This might be predicted from the assumption that vertical locomotion is determined by constant propulsion affected passively by gravity. In the pluteus stage, however, larvae swam at a constant speed in any direction, suggesting that the propulsive activity of swimming plutei is actively controlled depending on the swimming direction. This change in the negative geotactic behaviour of sea urchin larvae in the course of embryogenesis indicates development of physiological control systems for propulsive activity at the pluteus stage.

scholarly journals Blocking the Bromodomains Function Contributes to Disturbances in Alga Chara vulgaris Spermatids Differentiation

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1352
Author(s):  
Agnieszka Wojtczak
Keyword(s):  
Endoplasmic Reticulum ◽  
Essential Role ◽  
Developmental Stages ◽  
Chromatin Condensation ◽  
Ultrastructural Level ◽  
Prolonged Treatment ◽  
Chara Vulgaris ◽  
Cellular Processes ◽  
Early Stages

Bromodomain containing (BRD) proteins play an essential role in many cellular processes. The aim of this study was to estimate activity of bromodomains during alga Chara vulgaris spermatids differentiation. The effect of a bromodomain inhibitor, JQ1 (100 μM), on the distribution of individual stages of spermatids and their ultrastructure was studied. The material was Feulgen stained and analysed in an electron microscope. JQ1 caused shortening of the early stages of spermiogenesis and a reverse reaction at the later stages. Additionally, in the same antheridium, spermatids at distant developmental stages were present. On the ultrastructural level, chromatin fibril system disorders and significantly distended endoplasmic reticulum (ER) cisternae already at the early stages were observed. Many autolytic vacuoles were also visible. The ultrastructural disturbances intensified after prolonged treatment with JQ1. The obtained data show that JQ1 treatment led to changes in the spermatid number and disturbances in chromatin condensation and to cytoplasm reduction. The current studies show some similarities between C. vulgaris and mammals spermiogenesis. Taken together, these results suggest that JQ1 interferes with the spermatid differentiation on many interdependent levels and seems to induce ER stress, which leads to spermatid degeneration. Studies on the role of bromodomains in algae spermiogenesis have not been conducted so far.

Molecular cloning of five individual stage- and tissue-specific mRNA sequences from sea urchin pluteus embryos

1983 ◽  
Vol 3 (6) ◽  
pp. 1021-1031
Author(s):  
N Fregien ◽  
G J Dolecki ◽  
M Mandel ◽  
T Humphreys
Keyword(s):  
Molecular Cloning ◽  
Sea Urchin ◽  
Developmental Stages ◽  
Blastula Stage ◽  
Developmentally Regulated ◽  
Cell Layers ◽  
Rare Class ◽  
Specific Sequences ◽  
Pluteus Stage ◽  
Specific Mrna

Five developmentally regulated sea urchin mRNA sequences which increase in abundance between the blastula and pluteus stages of development were isolated by molecular cloning of cDNA. The regulated sequences all appeared in moderately abundant mRNA molecules of pluteus cells and represented 4% of the clones tested. There were no regulated sequences detected in the 40% of the clones which hybridized to the most abundant mRNA, and the screening procedures were inadequate to detect possible regulation in the 20 to 30% of the clones presumably derived from rare-class mRNA. The reaction of 32P[cDNA] from blastula and pluteus mRNA to dots of the cloned DNAs on nitrocellulose filters indicated that the mRNAs complementary to the different cloned pluteus-specific sequences were between 3- and 47-fold more prevalent at the pluteus stage than at the blastula stage. Polyadenylated RNA from different developmental stages was transferred from electrophoretic gels to nitrocellulose filters and reacted to the different cloned sequences. The regulated mRNAs were undetectable in the RNA of 3-h embryos, became evident at the hatching blastula stage, and reached a maximum in abundance by the gastrula or pluteus stage. Certain of the clones reacted to two sizes of mRNA which did not vary coordinately with development. Transfers of RNA isolated from each of the three cell layers of pluteus embryos that were reacted to the cloned sequences revealed that two of the sequences were found in the mRNA of all three layers, two were ectoderm specific, and one was endoderm specific. Four of the regulated sequences were complementary to one or two major bands and one to at least 50 bands on Southern transfers of restriction endonuclease-digested total sea urchin DNA.

scholarly journals Molecular cloning of five individual stage- and tissue-specific mRNA sequences from sea urchin pluteus embryos.

1983 ◽  
Vol 3 (6) ◽  
pp. 1021-1031 ◽  
Author(s):  
N Fregien ◽  
G J Dolecki ◽  
M Mandel ◽  
T Humphreys
Keyword(s):  
Molecular Cloning ◽  
Sea Urchin ◽  
Developmental Stages ◽  
Blastula Stage ◽  
Developmentally Regulated ◽  
Cell Layers ◽  
Rare Class ◽  
Specific Sequences ◽  
Pluteus Stage ◽  
Specific Mrna

Five developmentally regulated sea urchin mRNA sequences which increase in abundance between the blastula and pluteus stages of development were isolated by molecular cloning of cDNA. The regulated sequences all appeared in moderately abundant mRNA molecules of pluteus cells and represented 4% of the clones tested. There were no regulated sequences detected in the 40% of the clones which hybridized to the most abundant mRNA, and the screening procedures were inadequate to detect possible regulation in the 20 to 30% of the clones presumably derived from rare-class mRNA. The reaction of 32P[cDNA] from blastula and pluteus mRNA to dots of the cloned DNAs on nitrocellulose filters indicated that the mRNAs complementary to the different cloned pluteus-specific sequences were between 3- and 47-fold more prevalent at the pluteus stage than at the blastula stage. Polyadenylated RNA from different developmental stages was transferred from electrophoretic gels to nitrocellulose filters and reacted to the different cloned sequences. The regulated mRNAs were undetectable in the RNA of 3-h embryos, became evident at the hatching blastula stage, and reached a maximum in abundance by the gastrula or pluteus stage. Certain of the clones reacted to two sizes of mRNA which did not vary coordinately with development. Transfers of RNA isolated from each of the three cell layers of pluteus embryos that were reacted to the cloned sequences revealed that two of the sequences were found in the mRNA of all three layers, two were ectoderm specific, and one was endoderm specific. Four of the regulated sequences were complementary to one or two major bands and one to at least 50 bands on Southern transfers of restriction endonuclease-digested total sea urchin DNA.

scholarly journals Profiling of circulating chromosome 21-encoded microRNAs, miR-155 and Let-7c, in Down Syndrome People

2020 ◽  
Author(s):  
Jesús Manuel Pérez-Villareal ◽  
Katia Aviña-Padilla ◽  
Evangelina Beltrán López ◽  
Alma Marlene Guadrón-Llanos ◽  
Esther López-Bayghen ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Cognitive Impairment ◽  
Lipid Metabolism ◽  
Target Genes ◽  
Genetic Material ◽  
Hdl Cholesterol ◽  
Chromosome 21 ◽  
Early Stages ◽  
Late Stages

AbstractDown syndrome (DS), or Trisomy 21 (Ts21), is the most common chromosomal survival aneuploidy. Nevertheless, people with DS have compromised health, and the increase in their life expectancy further heightens the risk of developing chronic degenerative diseases such as obesity, dyslipidemias and diabetes mellitus associated with higher morbidity, and mortality for cardiovascular disease from an early age. DS is also accompanied by a higher risk of neurodegeneration. The extra genetic material that characterizes DS causes an imbalance in the genetic dosage, including overexpression of miR-155 and Let-7c miRNAs, both associated with cognitive impairment and dementia in adults. The dynamics of expression of their putative target genes in the early stages of the development of DS and their clinical associations, however, remain to be ascertained. This study aimed to evaluate the relative expression of miR-155 and Let-7c in young and adult individuals with DS and its possible association with biochemical indicators of lipid metabolism. The anthropometric, clinical, biochemical, and gene expression features of miR-155 and Let-7c were analyzed in a population of 52 control and 50 DS subjects divided into groups of 20 years of age or younger and 21 years or older. Expression changes for miR-155 were not significant. Nevertheless, a negative correlation for HDL-Cholesterol concentrations and miR-155 expression was identified. Notably, Let-7c was overexpressed in DS from young and old ages. Overall, our results suggest that Let-7c is related from early stages to cognitive impairment in DS, while a similar role of miR-155 in late stages could be mediated by alterations in lipid metabolism. Further studies with both miRNAs will shed light on their potential as therapeutic targets to prevent or delay cognitive impairment in DS.

scholarly journals Genes ScBx1 and ScIgl—Competitors or Cooperators?

Genes ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 223 ◽  
Author(s):  
Anna Wlazło ◽  
Magdalena Święcicka ◽  
Marek D. Koter ◽  
Tomasz Krępski ◽  
Leszek Bolibok ◽  
...  
Keyword(s):  
Plant Development ◽  
In Silico ◽  
Developmental Stages ◽  
Biosynthesis Pathway ◽  
Glycerol Phosphate ◽  
Promoter Sequences ◽  
Early Stages

Two genes, Bx1 and Igl, both encoding indole-3-glycerol phosphate lyase (IGL), are believed to control the conversion of indole-3-glycerol phosphate (IGP) to indole. The first of these has generally been supposed to be regulated developmentally, being expressed at early stages of plant development with the indole being used in the benzoxazinoid (BX) biosynthesis pathway. In contrast, it has been proposed that the second one is regulated by stresses and that the associated free indole is secreted as a volatile. However, our previous results contradicted this. In the present study, we show that the ScIgl gene takes over the role of ScBx1 at later developmental stages, between the 42nd and 70th days after germination. In the majority of plants with silenced ScBx1 expression, ScIgl was either expressed at a significantly higher level than ScBx1 or it was the only gene with detectable expression. Therefore, we postulate that the synthesis of indole used in BX biosynthesis in rye is controlled by both ScBx1 and ScIgl, which are both regulated developmentally and by stresses. In silico and in vivo analyses of the promoter sequences further confirmed our hypothesis that the roles and modes of regulation of the ScBx1 and ScIgl genes are similar.

scholarly journals Comparative transcriptome analysis of mulberry reveals anthocyanin biosynthesis mechanisms in black (Morus atropurpurea Roxb) and white (Morus alba L) fruit genotypes

2020 ◽  
Author(s):  
Gaiqun Huang ◽  
Yichun Zeng ◽  
Ling Wei ◽  
Yongquan Yao ◽  
Jie Dai ◽  
...  
Keyword(s):  
Transcriptome Analysis ◽  
Developmental Stages ◽  
Anthocyanin Biosynthesis ◽  
Morus Alba ◽  
Comparative Transcriptome ◽  
Comparative Transcriptome Analysis ◽  
Early Stages ◽  
New Genes ◽  
Mulberry Fruit ◽  
Late Stages

Abstract To better understand anthocyanin biosynthesis in mulberry fruit, we analyzed the transcriptome of Da 10 (Morus atropurpurea Roxb, black fruit) and Baisang (Morus alba L., white fruit). Although Da 10 had high levels of cyanidin 3-O-glucoside (Cy) and pelargonidin 3-O-glucoside (Pg), Baisang contained only Cy, at low levels. Comparative transcriptome analysis resulted in the annotation of more than 27,085 genes (including 1,735 new genes). Differentially expressed genes (DEGs) were detected at three developmental stages—S1 (4,256 genes, 10 DPA), S2 (5,612 genes, 19 DPA), and S3 (5,226 genes, 28 DPA)—when comparing Da 10 and Baisang. Anthocyanin biosynthesis was associated with the expression of 15 core genes and 5 transcription factors. Relative to Baisang, Da 10 showed significant upregulation of the genes involved in the early stages (production of the intermediate compounds, chalcone and dihydroflavonol) and late stages (production of Cy and Pg) of anthocyanin biosynthesis. Baisang showed significant downregulation of the genes involved in the early stages of anthocyanin biosynthesis, and overexpression of flavanone 3-hydroxylase, resulting in the generation of quercetin and/or myricetin but not anthocyanins. Anthocyanin biosynthesis in mulberry fruit was fueled by the precursor, phenylalanine, the intermediates, chalcone and dihydroflavonol, and the products, Cy and Pg, involving the anthocyanin biosynthesis pathways.

Sign in / Sign up

Export Citation Format

Share Document