How the sperm triggers development of the egg: what have we learned and what can we expect in the next millennium?

Zygote ◽  
1999 ◽  
Vol 8 (S1) ◽  
pp. S7-S8
Author(s):  
David Epel
Keyword(s):  
Sea Urchin ◽  
Cell Biology ◽  
Control Cell ◽  
Rapid Evolution ◽  
Cell Activity ◽  
Turn Of The Century ◽  
Direct Demonstration ◽  
Creative Research ◽  
Contemporary Work ◽  
Species Specific

The problem of how the sperm activates the egg has captivated the attention of cell and developmental biologists since the turn of the century. An early focus concerned species-specific fertilisation and the pioneering work of Lilly and Tyler (Tyler & Tyler, 1966) used immunological analogies to provide explanations of species-specific fertilisation. Contemporary work has focused on the identity of unique receptors on the sperm and the egg as exemplified in the work of Lennarz (Ohlendieck & Lennarz, 1996), Vacquier (Vacquier, et al., 1995) and Wasserman (1999). Lately, this approach has provided unexpected insights on how speciation might occur. Speciation requires reproductive isolation and creative research from the Vacquier laboratory has demonstrated how reproductive barriers might occur through rapid evolution of sperm/egg recognition systems (Lee et al., 1995).Studies on the cell biology of activation received a major impetus in the 1930s with Mazia's observation of a calcium increase in eggs of the sea urchin following fertilisation (Mazia, 1937). His discovery, however, was a premature one in that there was no satisfactory model at that time for explaining how a calcium increase could affect cell activity. It took almost 40 years to develop a paradigm, and this came from studies on muscle and nerve which revealed how calcium increases could somehow control cell activity. Work in the 1970s rapidly established a similar role for calcium in activation of the egg at fertilisation. The first break-through was the direct demonstration by Steinhardt & Epel (1974) that calcium was involved in egg activation, through manipulation of calcium levels in sea urchin oocytes by use of calcium ionophores.

Adenosine Analogues as Opposite Modulators of the Cisplatin Resistance of Ovarian Cancer Cells

2019 ◽  
Vol 19 (4) ◽  
pp. 473-486 ◽  
Author(s):  
Katarzyna Bednarska-Szczepaniak ◽  
Damian Krzyżanowski ◽  
Magdalena Klink ◽  
Marek Nowak
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Cell Biology ◽  
Immune Cell ◽  
Immunosuppressive Agents ◽  
Cell Activity ◽  
Ovarian Cancer Cells ◽  
Adenosine Analogues

Background: Adenosine released by cancer cells in high amounts in the tumour microenvironment is one of the main immunosuppressive agents responsible for the escape of cancer cells from immunological control. Blocking adenosine receptors with adenosine analogues and restoring immune cell activity is one of the methods considered to increase the effectiveness of anticancer therapy. However, their direct effects on cancer cell biology remain unclear. Here, we determined the effect of adenosine analogues on the response of cisplatinsensitive and cisplatin-resistant ovarian cancer cells to cisplatin treatment. Methods: The effects of PSB 36, DPCPX, SCH58261, ZM 241385, PSB603 and PSB 36 on cisplatin cytotoxicity were determined against A2780 and A2780cis cell lines. Quantification of the synergism/ antagonism of the compounds cytotoxicity was performed and their effects on the cell cycle, apoptosis/necrosis events and cisplatin incorporation in cancer cells were determined. Results: PSB 36, an A1 receptor antagonist, sensitized cisplatin-resistant ovarian cancer cells to cisplatin from low to high micromolar concentrations. In contrast to PSB 36, the A2AR antagonist ZM 241385 had the opposite effect and reduced the influence of cisplatin on cancer cells, increasing their resistance to cisplatin cytotoxicity, decreasing cisplatin uptake, inhibiting cisplatin-induced cell cycle arrest, and partly restoring mitochondrial and plasma membrane potentials that were disturbed by cisplatin. Conclusion: Adenosine analogues can modulate considerable sensitivity to cisplatin of ovarian cancer cells resistant to cisplatin. The possible direct beneficial or adverse effects of adenosine analogues on cancer cell biology should be considered in the context of supportive chemotherapy for ovarian cancer.

EFFECTS OF CRYSTAL SIZE AND ORIENTATION OF SUBSTRATES ON CELL ADHESION: IMPLICATION FOR MEDICAL IMPLANTS

2008 ◽  
Vol 22 (18n19) ◽  
pp. 3069-3081 ◽  
Author(s):  
SHAHAB FAGHIHI ◽  
HOJATOLLAH VALI ◽  
MARYAM TABRIZIAN
Keyword(s):  
Cellular Response ◽  
High Pressure Torsion ◽  
Control Cell ◽  
Cell Activity ◽  
Titanium Implants ◽  
Polycrystalline Materials ◽  
Substrate Interactions ◽  
Cell Substrate ◽  
Substrate Engineering ◽  
And Control

The aim of this study is to investigate the effect of atomic structure of polycrystalline materials on cell-substrate interactions. Samples are prepared from rods and sheets of Ti -6 Al -4 V substrates with predominately two distinct crystallographic orientations as well as nano-structured and annealed titanium fabricated through high-pressure torsion and heat treatment processes. The degree of preosteoblast attachment and rate of growth, which are regulated through the activity and interaction of proteins present in the extracellular matrix, are notably increased on the nano-structured titanium and substrate having predominant [Formula: see text] orientation. The improved cell activity is attributed to the nano-structured feature of these substrates consisting of ultra-fine crystals (< 50 nm) and specific atomic order of [Formula: see text] substrate which provide higher degree of surface wettability. These findings demonstrate the advantages of nano-structured titanium over the conventional and coated titanium implants, as both mechanical properties and cellular response are improved. Furthermore, crystal orientation of the substrates can influence cell responses and, therefore, substrate engineering can be used to improve and control cell-substrate interactions.

Calcium and cell cycle control

Development ◽  
1990 ◽  
Vol 108 (4) ◽  
pp. 525-542 ◽  
Author(s):  
M. Whitaker ◽  
R. Patel
Keyword(s):  
Cell Cycle ◽  
Sea Urchin ◽  
Mammalian Cells ◽  
Cell Cycle Regulation ◽  
Sea Urchins ◽  
Cell Cycle Control ◽  
Control Point ◽  
Control Cell ◽  
Free Calcium ◽  
Cycle Regulation

The cell division cycle of the early sea urchin embryo is basic. Nonetheless, it has control points in common with the yeast and mammalian cell cycles, at START, mitosis ENTRY and mitosis EXIT. Progression through each control point in sea urchins is triggered by transient increases in intracellular free calcium. The Cai transients control cell cycle progression by translational and post-translational regulation of the cell cycle control proteins pp34 and cyclin. The START Cai transient leads to phosphorylation of pp34 and cyclin synthesis. The mitosis ENTRY Cai transient triggers cyclin phosphorylation. The motosis EXIT transient causes destruction of phosphorylated cyclin. We compare cell cycle regulation by calcium in sea urchin embryos to cell cycle regulation in other eggs and oocytes and in mammalian cells.

scholarly journals Cause and Effectors: Whole-Genome Comparisons Reveal Shared but Rapidly Evolving Effector Sets among Host-Specific Plant-Castrating Fungi

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
William C. Beckerson ◽  
Ricardo C. Rodríguez de la Vega ◽  
Fanny E. Hartmann ◽  
Marine Duhamel ◽  
Tatiana Giraud ◽  
...  
Keyword(s):  
Positive Selection ◽  
Plant Pathogens ◽  
Pfam Domain ◽  
Rapid Evolution ◽  
Host Specialization ◽  
Secreted Proteins ◽  
Smut Fungi ◽  
Core Proteins ◽  
Genes Encoding ◽  
Species Specific

ABSTRACT Plant pathogens utilize a portfolio of secreted effectors to successfully infect and manipulate their hosts. It is, however, still unclear whether changes in secretomes leading to host specialization involve mostly effector gene gains/losses or changes in their sequences. To test these hypotheses, we compared the secretomes of three host-specific castrating anther smut fungi (Microbotryum), two being sister species. To address within-species evolution, which might involve coevolution and local adaptation, we compared the secretomes of strains from differentiated populations. We experimentally validated a subset of signal peptides. Secretomes ranged from 321 to 445 predicted secreted proteins (SPs), including a few species-specific proteins (42 to 75), and limited copy number variation, i.e., little gene family expansion or reduction. Between 52% and 68% of the SPs did not match any Pfam domain, a percentage that reached 80% for the small secreted proteins, indicating rapid evolution. In comparison to background genes, we indeed found SPs to be more differentiated among species and strains, more often under positive selection, and highly expressed in planta; repeat-induced point mutations (RIPs) had no role in effector diversification, as SPs were not closer to transposable elements than background genes and were not more RIP affected. Our study thus identified both conserved core proteins, likely required for the pathogenic life cycle of all Microbotryum species, and proteins that were species specific or evolving under positive selection; these proteins may be involved in host specialization and/or coevolution. Most changes among closely related host-specific pathogens, however, involved rapid changes in sequences rather than gene gains/losses. IMPORTANCE Plant pathogens use molecular weapons to successfully infect their hosts, secreting a large portfolio of various proteins and enzymes. Different plant species are often parasitized by host-specific pathogens; however, it is still unclear whether the molecular basis of such host specialization involves species-specific weapons or different variants of the same weapons. We therefore compared the genes encoding secreted proteins in three plant-castrating pathogens parasitizing different host plants, producing their spores in plant anthers by replacing pollen. We validated our predictions for secretion signals for some genes and checked that our predicted secreted proteins were often highly expressed during plant infection. While we found few species-specific secreted proteins, numerous genes encoding secreted proteins showed signs of rapid evolution and of natural selection. Our study thus found that most changes among closely related host-specific pathogens involved rapid adaptive changes in shared molecular weapons rather than innovations for new weapons.

scholarly journals Bioelectrical understanding and engineering of cell biology

2020 ◽  
Vol 17 (166) ◽  
pp. 20200013 ◽  
Author(s):  
Zoe Schofield ◽  
Gabriel N. Meloni ◽  
Peter Tran ◽  
Christian Zerfass ◽  
Giovanni Sena ◽  
...  
Keyword(s):  
Systems Biology ◽  
Cell Biology ◽  
Genetic Basis ◽  
Control Cell ◽  
Status Quo ◽  
Cell Behaviour ◽  
Cellular Processes ◽  
Mechanical Responses ◽  
Predictive Understanding ◽  
Biology Research

The last five decades of molecular and systems biology research have provided unprecedented insights into the molecular and genetic basis of many cellular processes. Despite these insights, however, it is arguable that there is still only limited predictive understanding of cell behaviours. In particular, the basis of heterogeneity in single-cell behaviour and the initiation of many different metabolic, transcriptional or mechanical responses to environmental stimuli remain largely unexplained. To go beyond the status quo , the understanding of cell behaviours emerging from molecular genetics must be complemented with physical and physiological ones, focusing on the intracellular and extracellular conditions within and around cells. Here, we argue that such a combination of genetics, physics and physiology can be grounded on a bioelectrical conceptualization of cells. We motivate the reasoning behind such a proposal and describe examples where a bioelectrical view has been shown to, or can, provide predictive biological understanding. In addition, we discuss how this view opens up novel ways to control cell behaviours by electrical and electrochemical means, setting the stage for the emergence of bioelectrical engineering.

scholarly journals Variable Rates of Simple Satellite Gains across the Drosophila Phylogeny

2018 ◽  
Vol 35 (4) ◽  
pp. 925-941 ◽  
Author(s):  
Kevin H -C Wei ◽  
Sarah E Lower ◽  
Ian V Caldas ◽  
Trevor J S Sless ◽  
Daniel A Barbash ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Rapid Evolution ◽  
Single Mutation ◽  
Closely Related Species ◽  
Interspecific Differences ◽  
Limited Sampling ◽  
Drosophila Phylogeny ◽  
Males And Females ◽  
Species Specific ◽  
Turn Over

Abstract Simple satellites are tandemly repeating short DNA motifs that can span megabases in eukaryotic genomes. Because they can cause genomic instability through nonallelic homologous exchange, they are primarily found in the repressive heterochromatin near centromeres and telomeres where recombination is minimal, and on the Y chromosome, where they accumulate as the chromosome degenerates. Interestingly, the types and abundances of simple satellites often vary dramatically between closely related species, suggesting that they turn over rapidly. However, limited sampling has prevented detailed understanding of their evolutionary dynamics. Here, we characterize simple satellites from whole-genome sequences generated from males and females of nine Drosophila species, spanning 40 Ma of evolution. We show that PCR-free library preparation and postsequencing GC-correction better capture satellite quantities than conventional methods. We find that over half of the 207 simple satellites identified are species-specific, consistent with previous descriptions of their rapid evolution. Based on a maximum parsimony framework, we determined that most interspecific differences are due to lineage-specific gains. Simple satellites gained within a species are typically a single mutation away from abundant existing satellites, suggesting that they likely emerge from existing satellites, especially in the genomes of satellite-rich species. Interestingly, unlike most of the other lineages which experience various degrees of gains, the lineage leading up to the satellite-poor D. pseudoobscura and D. persimilis appears to be recalcitrant to gains, providing a counterpoint to the notion that simple satellites are universally rapidly evolving.

scholarly journals Pseudo-DUBs as allosteric activators and molecular scaffolds of protein complexes

2018 ◽  
Vol 46 (2) ◽  
pp. 453-466 ◽  
Author(s):  
Miriam Walden ◽  
Safi Kani Masandi ◽  
Krzysztof Pawłowski ◽  
Elton Zeqiraj
Keyword(s):  
Cell Biology ◽  
Protein Complexes ◽  
Cell Signalling ◽  
Control Cell ◽  
Mechanisms Of Action ◽  
Molecular Scaffolds ◽  
Polyubiquitin Chains ◽  
Macromolecular Complexes ◽  
Cellular Life ◽  
Almost All

The ubiquitin (Ub) proteasome system and Ub signalling networks are crucial to cell biology and disease development. Deubiquitylases (DUBs) control cell signalling by removing mono-Ub and polyubiquitin chains from substrates. DUBs take part in almost all processes that regulate cellular life and are frequently dysregulated in disease. We have catalogued 99 currently known DUBs in the human genome and sequence conservation analyses of catalytic residues suggest that 11 lack enzyme activity and are classed as pseudo-DUBs. These pseudoenzymes play important biological roles by allosterically activating catalytically competent DUBs as well as other active enzymes. Additionally, pseudoenzymes act as assembly scaffolds of macromolecular complexes. We discuss how pseudo-DUBs have lost their catalytic activity, their diverse mechanisms of action and their potential as therapeutic targets. Many known pseudo-DUBs play crucial roles in cell biology and it is likely that unstudied and overlooked pseudo-DUB genes will have equally important functions.

scholarly journals A Review on Biomaterials for 3D Conductive Scaffolds for Stimulating and Monitoring Cellular Activities

2019 ◽  
Vol 9 (5) ◽  
pp. 961 ◽  
Author(s):  
Muhammad Khan ◽  
Edoardo Cantù ◽  
Sarah Tonello ◽  
Mauro Serpelloni ◽  
Nicola Lopomo ◽  
...  
Keyword(s):  
Control Cell ◽  
Cell Activity ◽  
Three Dimensional ◽  
Specific Cell ◽  
Conductive Materials ◽  
Non Invasive ◽  
Interesting Approach ◽  
Practical Guidelines ◽  
Cell Monitoring ◽  
Cell Growth And Differentiation

During the last years, scientific research in biotechnology has been reporting a considerable boost forward due to many advances marked in different technological areas. Researchers working in the field of regenerative medicine, mechanobiology and pharmacology have been constantly looking for non-invasive methods able to track tissue development, monitor biological processes and check effectiveness in treatments. The possibility to control cell cultures and quantify their products represents indeed one of the most promising and exciting hurdles. In this perspective, the use of conductive materials able to map cell activity in a three-dimensional environment represents the most interesting approach. The greatest potential of this strategy relies on the possibility to correlate measurable changes in electrical parameters with specific cell cycle events, without affecting their maturation process and considering a physiological-like setting. Up to now, several conductive materials has been identified and validated as possible solutions in scaffold development, but still few works have stressed the possibility to use conductive scaffolds for non-invasive electrical cell monitoring. In this picture, the main objective of this review was to define the state-of-the-art concerning conductive biomaterials to provide researchers with practical guidelines for developing specific applications addressing cell growth and differentiation monitoring. Therefore, a comprehensive review of all the available conductive biomaterials (polymers, carbon-based, and metals) was given in terms of their main electric characteristics and range of applications.

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