scholarly journals (Epi)Genetic Mechanisms Underlying the Evolutionary Success of Eusocial Insects

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 498
Author(s):  
Kayli R. Sieber ◽  
Taylor Dorman ◽  
Nicholas Newell ◽  
Hua Yan
Keyword(s):  
Genetic Regulation ◽  
Environmental Cues ◽  
Epigenetic Mechanisms ◽  
Eusocial Insects ◽  
Reproductive Ability ◽  
Genetic Mechanisms ◽  
Evolutionary Success ◽  
Non Coding Rnas ◽  
And Behavior ◽  
Caste Structure

Eusocial insects, such as bees, ants, and wasps of the Hymenoptera and termites of the Blattodea, are able to generate remarkable diversity in morphology and behavior despite being genetically uniform within a colony. Most eusocial insect species display caste structures in which reproductive ability is possessed by a single or a few queens while all other colony members act as workers. However, in some species, caste structure is somewhat plastic, and individuals may switch from one caste or behavioral phenotype to another in response to certain environmental cues. As different castes normally share a common genetic background, it is believed that much of this observed within-colony diversity results from transcriptional differences between individuals. This suggests that epigenetic mechanisms, featured by modified gene expression without changing genes themselves, may play an important role in eusocial insects. Indeed, epigenetic mechanisms such as DNA methylation, histone modifications and non-coding RNAs, have been shown to influence eusocial insects in multiple aspects, along with typical genetic regulation. This review summarizes the most recent findings regarding such mechanisms and their diverse roles in eusocial insects.

Epigenetics, Nuclear Organization & Gene Function

2019 ◽  
Author(s):  
John C. Lucchesi
Keyword(s):  
Gene Function ◽  
Genetic Regulation ◽  
Genetic Material ◽  
Three Dimensional ◽  
Therapeutic Interventions ◽  
Human Disorders ◽  
Genetic Mechanisms ◽  
Non Coding Rnas ◽  
Increased Susceptibility

Epigenetics is the study of heritable changes in gene function that do not involve changes in the DNA sequence. Epigenetic changes, consisting principally of DNA methylation, histone modifications and non-coding RNAs, maintain and modulate the initial impact of regulatory factors that recognize and associate with particular genomic sequences. This book’s primary goal is to establish a framework that can be used to understand the basis of epigenetic regulation and to appreciate both its derivation from genetics and its interdependence with genetic mechanisms. A further aim is to highlight the role played by the three-dimensional organization of the genetic material itself (the complex of DNA, histones and non-histone proteins referred to as chromatin) and its distribution within a functionally compartmentalized nucleus. Dysfunctions at any level of genetic regulation have the potential to result in an increased susceptibility to disease or actually give rise to overt pathologies. As illustrated in this book, research is continuously uncovering the role of epigenetics in a variety of human disorders, providing new avenues for therapeutic interventions and advances in regenerative medicine.

scholarly journals Nuclear genetic regulation of the human mitochondrial transcriptome

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Aminah T Ali ◽  
Lena Boehme ◽  
Guillermo Carbajosa ◽  
Vlad C Seitan ◽  
Kerrin S Small ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mitochondrial Genome ◽  
Complex Disease ◽  
Genetic Regulation ◽  
Cell Types ◽  
Tissue Cell ◽  
Cellular Processes ◽  
Genetic Mechanisms ◽  
Cell Type Specific ◽  
Nuclear Loci

Mitochondria play important roles in cellular processes and disease, yet little is known about how the transcriptional regime of the mitochondrial genome varies across individuals and tissues. By analyzing >11,000 RNA-sequencing libraries across 36 tissue/cell types, we find considerable variation in mitochondrial-encoded gene expression along the mitochondrial transcriptome, across tissues and between individuals, highlighting the importance of cell-type specific and post-transcriptional processes in shaping mitochondrial-encoded RNA levels. Using whole-genome genetic data we identify 64 nuclear loci associated with expression levels of 14 genes encoded in the mitochondrial genome, including missense variants within genes involved in mitochondrial function (TBRG4, MTPAP and LONP1), implicating genetic mechanisms that act in trans across the two genomes. We replicate ~21% of associations with independent tissue-matched datasets and find genetic variants linked to these nuclear loci that are associated with cardio-metabolic phenotypes and Vitiligo, supporting a potential role for variable mitochondrial-encoded gene expression in complex disease.

Epigenetics

2019 ◽  
pp. 56-70
Author(s):  
Edward Hookway ◽  
Nicholas Athanasou ◽  
Udo Oppermann
Keyword(s):  
Gene Expression ◽  
Histone Deacetylases ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Tumour Suppressor Genes ◽  
Epigenetic Mechanisms ◽  
Therapeutic Approaches ◽  
Control Of Gene Expression ◽  
Non Coding Rnas ◽  
Epigenetic Processes

Epigenetics is a term that refers to a collection of diverse mechanisms that are important in both the control of gene expression and the transmission of this information during cell division. Epigenetic processes are deranged in many cancers, leading to a combination of inappropriate silencing of tumour suppressor genes and overexpression of oncogenes. In this chapter, the molecular mechanisms that underpin the major epigenetic processes of DNA methylation, histone modification, and non-coding RNAs will be described in both their normal physiological roles and in the context of cancer. The challenge of understanding the complexity of the interactions between different epigenetic mechanisms and the limitations of our current knowledge will be highlighted. Therapeutic approaches towards targeting deranged epigenetic processes will also be described, such as the use of small molecule inhibitors of histone deacetylases.

Understanding the Genetic Basis of C4 Kranz Anatomy with a View to Engineering C3 Crops

2018 ◽  
Vol 52 (1) ◽  
pp. 249-270 ◽  
Author(s):  
Olga V. Sedelnikova ◽  
Thomas E. Hughes ◽  
Jane A. Langdale
Keyword(s):  
Genetic Basis ◽  
Genetic Regulation ◽  
Crop Productivity ◽  
Research Field ◽  
Leaf Cell ◽  
Cell Type ◽  
Kranz Anatomy ◽  
Genetic Mechanisms ◽  
Metabolic Reactions ◽  
Type Specification

One of the most remarkable examples of convergent evolution is the transition from C3 to C4 photosynthesis, an event that occurred on over 60 independent occasions. The evolution of C4 is particularly noteworthy because of the complexity of the developmental and metabolic changes that took place. In most cases, compartmentalized metabolic reactions were facilitated by the development of a distinct leaf anatomy known as Kranz. C4 Kranz anatomy differs from ancestral C3 anatomy with respect to vein spacing patterns across the leaf, cell-type specification around veins, and cell-specific organelle function. Here we review our current understanding of how Kranz anatomy evolved and how it develops, with a focus on studies that are dissecting the underlying genetic mechanisms. This research field has gained prominence in recent years because understanding the genetic regulation of Kranz may enable the C3-to-C4 transition to be engineered, an endeavor that would significantly enhance crop productivity.

Eusocial Insects as a Model for Understanding Altruism, Cooperation, and Levels of Selection

2020 ◽  
Author(s):  
Heikki Helanterä
Keyword(s):  
Natural Selection ◽  
Division Of Labor ◽  
Social Insect ◽  
Social Evolution ◽  
Inclusive Fitness ◽  
Family Structures ◽  
Major Transitions ◽  
Eusocial Insects ◽  
Insect Societies ◽  
Evolutionary Success

If the logic of natural selection is applied strictly at the level of individual production of offspring, sterile workers in insect societies are enigmatic. How can natural selection ever produce individuals that refrain from reproduction, and how are traits of such individuals that never produce offspring scrutinized and changed through natural selection? The solution to both questions is found in the family structures of insect societies. That is, the sterile helper individuals are evolutionary altruists that give up their own reproduction and instead are helping their kin reproduce and proliferate shared genes in the offspring of the fertile queen. Selection in such cases is not just a matter of individual’s direct reproduction, and instead of own offspring, the currency of the evolutionary success of sterile individuals is inclusive fitness. The concept of inclusive fitness and the process of kin selection are key to understanding the magnificent cooperation we see in insect societies, and reciprocally, insect societies are key case studies of inclusive fitness logic. In extreme cases, such as the highly advanced and sophisticated societies of ants, honeybees, and termites, the division of labor and interdependence of colony members is so complete, that it is justified to talk about a new level of evolutionary individuality. Such increases in the hierarchical complexity of life are called major transitions in evolution. We see adaptations of the colony, rather than individuals, in, e.g., their communication and group behaviors. The division of labor between morphologically differentiated queens and workers is analogous to germline-soma separation of a multicellular organism, justifying the term superorganism for the extreme cases of social lifestyle. Alongside these extreme cases, there is enormous diversity in the social lifestyles across social insect taxa, which provides a window into the balance of cooperation and conflict, and individual reproduction and helping others, in social evolution. Over the last decades, social insect research has been an area where the theoretical and empirical understanding have been developed hand in hand, together with examples of wonderful natural history, and has tremendously improved our understanding of evolution.

scholarly journals Epigenetic modifications associated with in utero exposure to endocrine disrupting chemicals BPA, DDT and Pb

2019 ◽  
Vol 34 (4) ◽  
pp. 309-325 ◽  
Author(s):  
Chinonye Doris Onuzulu ◽  
Oluwakemi Anuoluwapo Rotimi ◽  
Solomon Oladapo Rotimi
Keyword(s):  
Endocrine Disruptors ◽  
Endocrine Disrupting Chemicals ◽  
Endocrine System ◽  
Environmental Chemicals ◽  
Epigenetic Mechanisms ◽  
Epigenetic Alterations ◽  
Endocrine Disrupting ◽  
Non Coding Rnas ◽  
Hormone System ◽  
Developmental Windows

Abstract Endocrine disrupting chemicals (EDCs) are xenobiotics which adversely modify the hormone system. The endocrine system is most vulnerable to assaults by endocrine disruptors during the prenatal and early development window, and effects may persist into adulthood and across generations. The prenatal stage is a period of vulnerability to environmental chemicals because the epigenome is usually reprogrammed during this period. Bisphenol A (BPA), lead (Pb), and dichlorodiphenyltrichloroethane (DDT) were chosen for critical review because they have become serious public health concerns globally, especially in Africa where they are widely used without any regulation. In this review, we introduce EDCs and describe the various modes of action of EDCs and the importance of the prenatal and developmental windows to EDC exposure. We give a brief overview of epigenetics and describe the various epigenetic mechanisms: DNA methylation, histone modifications and non-coding RNAs, and how each of them affects gene expression. We then summarize findings from previous studies on the effects of prenatal exposure to the endocrine disruptors BPA, Pb and DDT on each of the previously described epigenetic mechanisms. We also discuss how the epigenetic alterations caused by these EDCs may be related to disease processes.

scholarly journals MicroRNAs in Daphnia magna identified and characterized by deep sequencing, genome mapping and manual curation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Dag H. Coucheron ◽  
Marcin W. Wojewodzic ◽  
Thomas Bøhn
Keyword(s):  
Daphnia Magna ◽  
Deep Sequencing ◽  
Rna Silencing ◽  
Genome Mapping ◽  
Regulation Of Gene Expression ◽  
Environmental Cues ◽  
Water Flea ◽  
Manual Curation ◽  
Non Coding Rnas ◽  
Post Transcriptional Regulation

Abstract MicroRNAs (miRNAs) are small non-coding RNAs that function in RNA silencing and post-transcriptional regulation of gene expression in most organisms. The water flea, Daphnia magna is a key model to study phenotypic, physiological and genomic responses to environmental cues and miRNAs can potentially mediate these responses. By using deep sequencing, genome mapping and manual curations, we have characterised the miRNAome of D. magna. We identified 66 conserved miRNAs and 13 novel miRNAs; all of these were found in the three studied life stages of D. magna (juveniles, subadults, adults), but with variation in expression levels between stages. Forty-one of the miRNAs were clustered into 13 genome clusters also present in the D. pulex genome. Most miRNAs contained sequence variants (isomiRs). The highest expressed isomiRs were 3′ template variants with one nucleotide deletion or 3′ non-template variants with addition of A or U at the 3′ end. We also identified offset RNAs (moRs) and loop RNAs (loRs). Our work extends the base for further work on all species (miRNA, isomiRs, moRNAs, loRNAs) of the miRNAome of Daphnia as biomarkers in response to chemical substances and environment cues, and underline age dependency.

scholarly journals Emerging epigenetic mechanisms of long non-coding RNAs

Neuroscience ◽  
2014 ◽  
Vol 264 ◽  
pp. 25-38 ◽  
Author(s):  
K. Schaukowitch ◽  
T.-K. Kim
Keyword(s):  
Epigenetic Mechanisms ◽  
Non Coding Rnas

scholarly journals Natural CMT2 variation is associated with genome-wide methylation changes and temperature seasonality

2014 ◽  
Author(s):  
Xia Shen ◽  
Jennifer De Jonge ◽  
Simon Forsberg ◽  
Mats Pettersson ◽  
Zheya Sheng ◽  
...  
Keyword(s):  
Genetic Regulation ◽  
Genome Wide Association ◽  
Genome Wide ◽  
Public Data ◽  
Wide Range ◽  
The World ◽  
Genetic Mechanisms ◽  
Novel Method ◽  
Major Allele ◽  
Temperature Seasonality

As Arabidopsis thaliana has colonized a wide range of habitats across the world it is an attractive model for studying the genetic mechanisms underlying environmental adaptation. Here, we used public data from two collections of A. thaliana accessions to associate genetic variability at individual loci with differences in climates at the sampling sites. We use a novel method to screen the genome for plastic alleles that tolerate a broader climate range than the major allele. This approach reduces confounding with population structure and increases power compared to standard genome-wide association methods. Sixteen novel loci were found, including an association between Chromomethylase 2 (CMT2) and temperature seasonality where the genome-wide CHH methylation was different for the group of accessions carrying the plastic allele. Cmt2 mutants were shown to be more tolerant to heat-stress, suggesting genetic regulation of epigenetic modifications as a likely mechanism underlying natural adaptation to variable temperatures, potentially through differential allelic plasticity to temperature-stress.

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