scholarly journals Housing microbial symbionts: evolutionary origins and diversification of symbiotic organs in animals

2020 ◽  
Vol 375 (1808) ◽  
pp. 20190603 ◽  
Author(s):  
Angela E. Douglas
Keyword(s):  
Genetic Changes ◽  
Evolutionary Origins ◽  
Genetic Technologies ◽  
Host Genetic ◽  
Microbial Symbionts ◽  
Developmental Programme ◽  
Taxonomic Groups ◽  
Evo Devo ◽  
Host Evolution

In many animal hosts, microbial symbionts are housed within specialized structures known as symbiotic organs, but the evolutionary origins of these structures have rarely been investigated. Here, I adopt an evolutionary developmental (evo-devo) approach, specifically to apply knowledge of the development of symbiotic organs to gain insights into their evolutionary origins and diversification. In particular, host genetic changes associated with evolution of symbiotic organs can be inferred from studies to identify the host genes that orchestrate the development of symbiotic organs, recognizing that microbial products may also play a key role in triggering the developmental programme in some associations. These studies may also reveal whether higher animal taxonomic groups (order, class, phylum, etc.) possess a common genetic regulatory network for symbiosis that is latent in taxa lacking symbiotic organs, and activated at the origination of symbiosis in different host lineages. In this way, apparent instances of convergent evolution of symbiotic organs may be homologous in terms of a common genetic blueprint for symbiosis. Advances in genetic technologies, including reverse genetic tools and genome editing, will facilitate the application of evo-devo approaches to investigate the evolution of symbiotic organs in animals. This article is part of the theme issue ‘The role of the microbiome in host evolution’.

scholarly journals Evolutionary Origins of the Oligodendrocyte Cell Type and Adaptive Myelination

2021 ◽  
Vol 15 ◽  
Author(s):  
Jacob H. Hines
Keyword(s):  
Neural Plasticity ◽  
Core Gene ◽  
Neural Function ◽  
Cell Type ◽  
Genetic Changes ◽  
Working Models ◽  
Evolutionary Origins ◽  
The Many ◽  
Additional Form

Oligodendrocytes are multifunctional central nervous system (CNS) glia that are essential for neural function in gnathostomes. The evolutionary origins and specializations of the oligodendrocyte cell type are among the many remaining mysteries in glial biology and neuroscience. The role of oligodendrocytes as CNS myelinating glia is well established, but recent studies demonstrate that oligodendrocytes also participate in several myelin-independent aspects of CNS development, function, and maintenance. Furthermore, many recent studies have collectively advanced our understanding of myelin plasticity, and it is now clear that experience-dependent adaptations to myelination are an additional form of neural plasticity. These observations beg the questions of when and for which functions the ancestral oligodendrocyte cell type emerged, when primitive oligodendrocytes evolved new functionalities, and the genetic changes responsible for these evolutionary innovations. Here, I review recent findings and propose working models addressing the origins and evolution of the oligodendrocyte cell type and adaptive myelination. The core gene regulatory network (GRN) specifying the oligodendrocyte cell type is also reviewed as a means to probe the existence of oligodendrocytes in basal vertebrates and chordate invertebrates.

scholarly journals Microbiome-mediated plasticity directs host evolution along several distinct time scales

2020 ◽  
Vol 375 (1808) ◽  
pp. 20190589 ◽  
Author(s):  
Oren Kolodny ◽  
Hinrich Schulenburg
Keyword(s):  
Phenotypic Plasticity ◽  
Time Scales ◽  
Generation Time ◽  
Experimental Tests ◽  
Theme Issue ◽  
Baldwin Effect ◽  
Host Genetic ◽  
Host Evolution ◽  
The Baldwin Effect

Host-associated microbiomes influence their host's fitness in myriad ways and can be viewed as a source of phenotypic plasticity. This plasticity may allow the host to accommodate novel environmental challenges and thus influence the host's evolutionary adaptation. As with other modalities of phenotypic plasticity in phenomena such as the Baldwin effect and genetic assimilation, the microbiome-mediated plasticity may influence host genetic adaptation by facilitating and accelerating it, by slowing it down, or even by preventing it. The dynamics involved are likely more complex than those of previously studied phenomena related to phenotypic plasticity, and involve different processes on each time scale, such as acquired recognition of newly associated microbes by the host's immune system on single- and multiple-generation time scales, or selection on transmission dynamics of microbes between hosts, acting on longer time scales. To date, it is unclear if and how any of these processes shape host evolution. This opinion piece article provides a conceptual framework for considering the processes by which microbiome-mediated plasticity directs host evolution and concludes with suggestions for key experimental tests of the presented ideas. This article is part of the theme issue ‘The role of the microbiome in host evolution’.

scholarly journals Coral evolutionary responses to microbial symbioses

2020 ◽  
Vol 375 (1808) ◽  
pp. 20190591 ◽  
Author(s):  
Madeleine J. H. van Oppen ◽  
Mónica Medina
Keyword(s):  
Coral Holobiont ◽  
Immunity Genes ◽  
Ecological Success ◽  
Microbial Symbionts ◽  
Microbial Symbiosis ◽  
The Right ◽  
Host Evolution ◽  
The Impact ◽  
Microbial Symbioses

This review explores how microbial symbioses may have influenced and continue to influence the evolution of reef-building corals (Cnidaria; Scleractinia). The coral holobiont comprises a diverse microbiome including dinoflagellate algae (Dinophyceae; Symbiodiniaceae), bacteria, archaea, fungi and viruses, but here we focus on the Symbiodiniaceae as knowledge of the impact of other microbial symbionts on coral evolution is scant. Symbiosis with Symbiodiniaceae has extended the coral's metabolic capacity through metabolic handoffs and horizontal gene transfer (HGT) and has contributed to the ecological success of these iconic organisms. It necessitated the prior existence or the evolution of a series of adaptations of the host to attract and select the right symbionts, to provide them with a suitable environment and to remove disfunctional symbionts. Signatures of microbial symbiosis in the coral genome include HGT from Symbiodiniaceae and bacteria, gene family expansions, and a broad repertoire of oxidative stress response and innate immunity genes. Symbiosis with Symbiodiniaceae has permitted corals to occupy oligotrophic waters as the algae provide most corals with the majority of their nutrition. However, the coral–Symbiodiniaceae symbiosis is sensitive to climate warming, which disrupts this intimate relationship, causing coral bleaching, mortality and a worldwide decline of coral reefs. This article is part of the theme issue ‘The role of the microbiome in host evolution’.

scholarly journals Reconstruction of Microbial Haplotypes by Integration of Statistical and Physical Linkage in Scaffolding

2021 ◽  
Author(s):  
Chen Cao ◽  
Jingni He ◽  
Lauren Mak ◽  
Deshan Perera ◽  
Devin Kwok ◽  
...  
Keyword(s):  
Single Molecule ◽  
Human Genetics ◽  
Real Data ◽  
Sequencing Technologies ◽  
Bacterial Genomics ◽  
Physical Linkage ◽  
Pooled Sequencing ◽  
Computational Reconstruction ◽  
Host Genetic ◽  
Host Evolution

Abstract DNA sequencing technologies provide unprecedented opportunities to analyze within-host evolution of microorganism populations. Often, within-host populations are analyzed via pooled sequencing of the population, which contains multiple individuals or “haplotypes.” However, current next-generation sequencing instruments, in conjunction with single-molecule barcoded linked-reads, cannot distinguish long haplotypes directly. Computational reconstruction of haplotypes from pooled sequencing has been attempted in virology, bacterial genomics, metagenomics, and human genetics, using algorithms based on either cross-host genetic sharing or within-host genomic reads. Here, we describe PoolHapX, a flexible computational approach that integrates information from both genetic sharing and genomic sequencing. We demonstrated that PoolHapX outperforms state-of-the-art tools tailored to specific organismal systems, and is robust to within-host evolution. Importantly, together with barcoded linked-reads, PoolHapX can infer whole-chromosome-scale haplotypes from 50 pools each containing 12 different haplotypes. By analyzing real data, we uncovered dynamic variations in the evolutionary processes of within-patient HIV populations previously unobserved in single position-based analysis.

scholarly journals Small Noncoding RNAs in Knee Osteoarthritis: The Role of MicroRNAs and tRNA-Derived Fragments

2021 ◽  
Vol 22 (11) ◽  
pp. 5711
Author(s):  
Julian Zacharjasz ◽  
Anna M. Mleczko ◽  
Paweł Bąkowski ◽  
Tomasz Piontek ◽  
Kamilla Bąkowska-Żywicka
Keyword(s):  
Knee Osteoarthritis ◽  
Noncoding Rnas ◽  
Pathological Process ◽  
Joint Disease ◽  
Limited Information ◽  
Genetic Changes ◽  
Small Noncoding Rnas ◽  
Knee Oa ◽  
Cartilage Homeostasis

Knee osteoarthritis (OA) is a degenerative knee joint disease that results from the breakdown of joint cartilage and underlying bone, affecting about 3.3% of the world's population. As OA is a multifactorial disease, the underlying pathological process is closely associated with genetic changes in articular cartilage and bone. Many studies have focused on the role of small noncoding RNAs in OA and identified numbers of microRNAs that play important roles in regulating bone and cartilage homeostasis. The connection between other types of small noncoding RNAs, especially tRNA-derived fragments and knee osteoarthritis is still elusive. The observation that there is limited information about small RNAs different than miRNAs in knee OA was very surprising to us, especially given the fact that tRNA fragments are known to participate in a plethora of human diseases and a portion of them are even more abundant than miRNAs. Inspired by these findings, in this review we have summarized the possible involvement of microRNAs and tRNA-derived fragments in the pathology of knee osteoarthritis.

scholarly journals Molecular Genetics in Epstein–Barr Virus-Associated Malignancies

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 593
Author(s):  
Srikanth Umakanthan ◽  
Maryann M Bukelo
Keyword(s):  
Epstein Barr Virus ◽  
Diagnostic Tools ◽  
Main Role ◽  
Genetic Changes ◽  
Barr Virus ◽  
Cancer Pathogenesis ◽  
Genomic Studies ◽  
Epstein Barr ◽  
Oncogenic Form

Global genomic studies have detected the role of genomic alterations in the pathogenesis of Epstein–Barr virus (EBV)-associated tumors. EBV oncoproteins cause a vital shift of EBV from an infectious virus to an oncogenic form during the latent and lytic phase within the lymphoid B cells and epithelial cells. This epigenetic alteration modulates the virus and host genomes and inactivates and disrupts numerous tumor suppressors and signaling pathways. Genomic profiling has played the main role in identifying EBV cancer pathogenesis and its related targeted therapies. This article reviews the role of genetic changes in EBV-associated lymphomas and carcinomas. This includes the prolific molecular genesis, key diagnostic tools, and target-specific drugs that have been in recent clinical use.

scholarly journals Insects in the City: Does Remnant Native Habitat Influence Insect Order Distributions?

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 148
Author(s):  
Mani Shrestha ◽  
Jair E. Garcia ◽  
Freya Thomas ◽  
Scarlett R. Howard ◽  
Justin H. J. Chua ◽  
...  
Keyword(s):  
Urban Areas ◽  
Rapid Expansion ◽  
Ecological Value ◽  
Native Habitat ◽  
Insect Order ◽  
Insect Pollinator ◽  
Pollinating Insects ◽  
Study Sites ◽  
Taxonomic Groups

There is increasing interest in developing urban design principles that incorporate good ecological management. Research on understanding the distribution and role of beneficial pollinating insects, in particular, is changing our view of the ecological value of cities. With the rapid expansion of the built environment comes a need to understand how insects may be affected in extensive urban areas. We therefore investigated insect pollinator capture rates in a rapidly growing and densely urbanized city (Melbourne, Australia). We identified a remnant native habitat contained within the expansive urban boundary, and established study sites at two nearby populated urban areas. We employed standard pan trap sampling techniques to passively sample insect orders in the different environments. Our results show that, even though the types of taxonomic groups of insects captured are comparable between locations, important pollinators like bees and hoverflies were more frequently captured in the remnant native habitat. By contrast, beetles (Coleoptera) and butterflies/moths (Lepidoptera) were more frequently observed in the urban residential regions. Our results suggest that the maintenance of native habitat zones within cities is likely to be valuable for the conservation of bees and the ecosystem services they provide.

scholarly journals Further twists in gastropod shell evolution

2008 ◽  
Vol 4 (2) ◽  
pp. 179-182 ◽  
Author(s):  
Reuben Clements ◽  
Thor-Seng Liew ◽  
Jaap Jan Vermeulen ◽  
Menno Schilthuizen
Keyword(s):  
Evolutionary Biology ◽  
Logarithmic Spiral ◽  
Spiral Growth ◽  
Evolutionary Perspective ◽  
Gastropod Shell ◽  
Form And Function ◽  
Evolutionary Origins ◽  
Taxonomic Groups ◽  
And Function ◽  
Shell Coiling

The manner in which a gastropod shell coils has long intrigued laypersons and scientists alike. In evolutionary biology, gastropod shells are among the best-studied palaeontological and neontological objects. A gastropod shell generally exhibits logarithmic spiral growth, right-handedness and coils tightly around a single axis. Atypical shell-coiling patterns (e.g. sinistroid growth, uncoiled whorls and multiple coiling axes), however, continue to be uncovered in nature. Here, we report another coiling strategy that is not only puzzling from an evolutionary perspective, but also hitherto unknown among shelled gastropods. The terrestrial gastropod Opisthostoma vermiculum sp. nov. generates a shell with: (i) four discernable coiling axes, (ii) body whorls that thrice detach and twice reattach to preceding whorls without any reference support, and (iii) detached whorls that coil around three secondary axes in addition to their primary teleoconch axis. As the coiling strategies of individuals were found to be generally consistent throughout, this species appears to possess an unorthodox but rigorously defined set of developmental instructions. Although the evolutionary origins of O. vermiculum and its shell's functional significance can be elucidated only once fossil intermediates and live individuals are found, its bewildering morphology suggests that we still lack an understanding of relationships between form and function in certain taxonomic groups.

scholarly journals Bacterial influence on the maintenance of symbiotic yeast through Drosophila metamorphosis

2020 ◽  
Author(s):  
Robin Guilhot ◽  
Antoine Rombaut ◽  
Anne Xuéreb ◽  
Kate Howell ◽  
Simon Fellous
Keyword(s):  
Young Adults ◽  
Drosophila Melanogaster ◽  
Life Cycle ◽  
Symbiotic Bacteria ◽  
Bacterial Symbionts ◽  
Tripartite Symbiosis ◽  
Summary Statement ◽  
Key Features ◽  
Microbial Symbionts

AbstractInteractions between microbial symbionts of metazoan hosts are emerging as key features of symbiotic systems. Little is known about the role of such interactions on the maintenance of symbiosis through host’s life cycle. We studied the influence of symbiotic bacteria on the maintenance of symbiotic yeast through metamorphosis of the fly Drosophila melanogaster. To this end we mimicked the development of larvae in natural fruit. In absence of bacteria yeast was never found in young adults. However, yeast could maintain through metamorphosis when larvae were inoculated with symbiotic bacteria isolated from D. melanogaster faeces. Furthermore, an Enterobacteriaceae favoured yeast transstadial maintenance. Because yeast is a critical symbiont of D. melanogaster flies, bacterial influence on host-yeast association may have consequences for the evolution of insect-yeast-bacteria tripartite symbiosis and their cooperation.Summary statementBacterial symbionts of Drosophila influence yeast maintenance through fly metamorphosis, a novel observation that may have consequences for the evolution of insect-yeast-bacteria interactions.

Sign in / Sign up

Export Citation Format

Share Document