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Topic Review
Molluscivorous and Vermivorous Conus Species
It is generally believed that more than 700 Conus species have evolved during the last 50 million years. With the highest species abundance occurring in southeast Asia, most Conus can be found in the shallow waters of tropical and subtropical oceans. Conus is widely distributed in rocky shores, sandy beaches, coral reefs and intertidal waters, with depths reaching up to over 600 m. Nowadays, Conus species are generally overexploited, and some species are now endangered. Exploring these waters of potentially high species diversity could enrich our understanding of their population’s genetic structure and provide the missing pieces for clarifying Conus evolution. As the conotoxin compounds vary greatly throughout the growth stages and across geolocations within the same species, further investigation of these species-specific regional distribution differences may provide crucial insights for artificial breeding and harvesting specific bioactive compounds in the future.
  • 1.7K
  • 18 Feb 2022
Topic Review
Invasion of African Clarias gariepinus in Bangladesh
The African catfish Clarias gariepinus has been introduced for aquaculture in Bangladesh due to the scarcity of indigenous C. batrachus fingerlings. The African catfish Clarias gariepinus is a highly carnivorous species and predates small indigenous freshwater fishes when escaping into natural water bodies. However, the government of Bangladesh has banned the farming of C. gariepinus due to the carnivorous nature of this species. The introduction of C. gariepinus caused native biodiversity loss due to its predatory nature.
  • 1.7K
  • 25 Feb 2022
Topic Review
Microchromosome Organization in Birds
Interchromosomal rearrangements involving microchromosomes are rare events in birds. To date, they have been found mostly in Neognathae and Neoaves (e.g., Psittaciformes, Falconiformes, and Cuculiformes), although only a few orders have been analyzed. Hence, cytogenomic studies focusing on microchromosomes in species belonging to different bird orders are essential to shed more light on the avian chromosome and karyotype evolution. Relevant hypothetical Neognathae, Neoaves and other ancestral karyotypes can be reconstructed to trace these rearrangements. In a more recent study, a comparative chromosome mapping for chicken microchromosomes 10 to 28 was performed using interspecies BAC-based FISH hybridization in five species, representing four Neoaves orders (Caprimulgiformes, Piciformes, Suliformes, and Trogoniformes). These results suggest that the ancestral microchromosomal syntenies are conserved in Pteroglossus inscriptus (Piciformes), Ramphastos tucanus tucanus (Piciformes), and Trogon surrucura surrucura (Trogoniformes). On the other hand, chromosome reorganization in Phalacrocorax brasilianus (Suliformes) and Hydropsalis torquata (Caprimulgiformes) included fusions involving both macro- and microchromosomes. Fissions in macrochromosomes were observed in P. brasilianus and H. torquata. No interchromosomal rearrangement involving microchromosomes were found to be shared between avian orders where rearrangements were detected. These findings suggest that convergent evolution involving microchromosomal change is a rare event in birds and may be appropriate in cytotaxonomic inferences in orders where these rearrangements occurred.
  • 1.7K
  • 21 Oct 2022
Topic Review
Novel Animal Vitamin C Biosynthesis Pathways
Vitamin C (VC) is a water-soluble compound that, at physiological pH, is mainly found in a reduced ionizable form (L-ascorbate). The potential applications of VC have been the subject of research since it was first synthesized in 1933 to the present day, in many areas relevant to mankind, such as human nutrition, animal feed supplementation, agricultural and industrial waste management, and sustainable nanomaterial synthesis. This nutrient gained further relevance as a potential therapeutic agent for COVID-19 prevention and treatment.
  • 1.5K
  • 04 Nov 2022
Topic Review
Photosynthesis and Rubisco: An Evolutionary Perspective
When oxygenic photosynthesis evolved around 2.4 billion years ago, it is believed that all the oxygen-evolving organisms used the ribulose bisphosphate carboxylase-oxygenase (Rubisco)- photosynthetic carbon reduction cycle (PCRC) despite there being five other major CO2 assimilation pathways. Rubisco-PCRC was dominant, with the highest specific activity in presence of carbon dioxide at high concentrations without the presence of oxygen. 
  • 1.5K
  • 13 Apr 2022
Topic Review
Development of SARS-CoV-2 Variants
A novel coronavirus (SARS-CoV-2) emerged towards the end of 2019 that caused a severe respiratory disease in humans called COVID-19. It led to a pandemic with a high rate of morbidity and mortality that is ongoing and threatening humankind. Most of the mutations occurring in SARS-CoV-2 are synonymous or deleterious, but a few of them produce improved viral functions. The first known mutation associated with higher transmissibility, D614G, was detected in early 2020. Since then, the virus has evolved; new mutations have occurred, and many variants have been described. Depending on the genes affected and the location of the mutations, they could provide altered infectivity, transmissibility, or immune escape. To date, mutations that cause variations in the SARS-CoV-2 spike protein have been among the most studied because of the protein’s role in the initial virus–cell contact and because it is the most variable region in the virus genome. Some concerning mutations associated with an impact on viral fitness have been described in the Spike protein, such as D614G, N501Y, E484K, K417N/T, L452R, and P681R, among others. To understand the impact of the infectivity and antigenicity of the virus, the mutation landscape of SARS-CoV-2 has been under constant global scrutiny. The virus variants are defined according to their origin, their genetic profile (some characteristic mutations prevalent in the lineage), and the severity of the disease they produce, which determines the level of concern. If they increase fitness, new variants can outcompete others in the population. The Alpha variant was more transmissible than previous versions and quickly spread globally. The Beta and Gamma variants accumulated mutations that partially escape the immune defenses and affect the effectiveness of vaccines. Nowadays, the Delta variant, identified around March 2021, has spread and displaced the other variants, becoming the most concerning of all lineages that have emerged. The Delta variant has a particular genetic profile, bearing unique mutations, such as T478K in the spike protein and M203R in the nucleocapsid. This entry summarizes the current knowledge of the different mutations that have appeared in SARS-CoV-2, mainly on the spike protein. It analyzes their impact on the protein function and, subsequently, on the level of concern of different variants and their importance in the ongoing pandemic. 
  • 1.5K
  • 28 Dec 2021
Topic Review Video Peer Reviewed
The Domestication of Humans
The domestication of humans is not an issue of domesticity but of the effects of the domestication syndrome on a hominin species and its genome. These effects are well expressed in the ‘anatomically modern humans’, in their physiology, behavior, genetic defects, neuropathology, and distinctive neoteny. The physiological differences between modern (gracile) humans and their ancestors, robust Homo sapiens types, are all accounted for by the domestication syndrome. From deductions we can draw about early human behavior, it appears that modifications are attributable to the same cause. The domestication hypothesis ascribes the initiation of the changes to selective breeding introduced by the consistent selection of neotenous features. That would trigger genetic pleiotropy, causing the changes that are observed.
  • 1.4K
  • 31 Jul 2023
Topic Review
Circum-Saharan Prehistory through the Lens of mtDNA Diversity
African history has been significantly influenced by the Sahara, which has represented a barrier for migrations of all living beings, including humans. Major exceptions were the gene flow events that took place between North African and sub-Saharan populations during the so-called African Humid Periods, especially in the Early Holocene (11.5 to 5.5 thousand years ago), and more recently in connection with trans-Saharan commercial routes. The research indicates that maternal gene flow must have been important in this circum-Saharan space, not only within North Africa and the Sahel/Savannah belt but also between these two regions.
  • 1.4K
  • 25 Mar 2022
Topic Review
Self-Incompatibility in Orchids
Self-incompatibility (SI) refers to the inability of hermaphroditic angiosperms to self-pollinate, which promotes outcrossing or hybridization. 
  • 1.4K
  • 13 Dec 2021
Topic Review
Virtual Anthropology and Paleoneurology
Advances in neuroscience have made it possible to obtain increasing information on the anatomy of the brain, at ever-higher resolutions, with different imaging techniques, on ever-larger samples. At the same time, paleoanthropology has to deal with partial reflections on the shape of the brain, on fragmentary specimens and small samples in an attempt to approach the morphology of the brain of past human species. Paleoanthropology has much to gain from interacting more with the field of neuroimaging. Improving our understanding of the morphology of the endocast necessarily involves studying the external surface of the brain and the link it maintains with the internal surface of the skull. The contribution of neuroimaging will allow us to better define the relationship between brain and endocast. Models of intra- and inter-species variability in brain morphology inferred from large neuroimaging databases will help make the most of the rare endocasts of extinct species. Moreover, exchanges between these two disciplines will also be beneficial to our knowledge of the Homo sapiens brain. Documenting the anatomy among other human species and including the variation over time within our own species are approaches that offer us a new perspective through which to appreciate what really characterizes the brain of humanity today. 
  • 1.3K
  • 09 Nov 2021
Topic Review
Sex Determination and Differentiation in Southern Swordtail Fishes
Southern swordtail fishes, which belong to the viviparous teleosts called Xiphophorus, are unique models for studies of evolution of sex chromosomes. Monofactorial sex-determining systems, with either the male or the female being the heterogametic sex, as well as sex determination involving more than two sex chromosomes, are found in swordtails and related species. Some swordtail species seem to have originated by crossing between two closely related species. Although the sword has disappeared in many Xiphophorus species during evolution, females of non-sworded species still prefer sworded males, demonstrating a discrepancy between natural and sexual selection. Natural sex change has not been documented sufficiently convincingly in swordtails, but, at least in some subspecies, two or more male phenotypes exist.
  • 1.3K
  • 14 Aug 2023
Topic Review
Bird’s-Eye View of Chromosomic Evolution in Class Aves
Birds (Aves) are the most speciose of terrestrial vertebrates, displaying Class-specific characteristics yet incredible external phenotypic diversity. Critical to agriculture and as model organisms, birds have adapted to many habitats. The only extant examples of dinosaurs, birds emerged ~150 mya and >10% are currently threatened with extinction.
  • 1.2K
  • 28 Feb 2024
Topic Review
Cenancestor
Cenancestor, the last universal cellular ancestor (LUCA), is assumed to exist on the basis of extensive sharing of inferred homologous characters among representatives of living cellular organisms. These characteristics include the nearly universal genetic code, the concordance of phylogenetic trees from different genes, the sharing of fundamental biochemical processes, and numerous transitional fossils. A cenancestor would be a logical necessity if the cellular structure originated only once, given the cell theory stating that new cells are created by old cells dividing into two. The recent empirical search for the cenancestor started with the prediction that eukaryotes could not possibly have evolved from the common ancestor of extant bacterial species. This led to the discovery of Archaebacteria and the three domains of life. Archaebacteria was found to be "archae" only to eukaryotes and consequently renamed to Archaea. The molecular substantiation of the endosymbiotic hypothesis of mitochondrial and chloroplast origin led to the hypothesis that the nucleus in eukaryotes is also an organelle originating from endosymbiosis or cell fusion, followed by massive horizontal gene transfer (HGT) between an engulfing host and engulfed guests which serve as mitochondrial and chloroplast progenitors. The cenancestor is expected to coexist with a variety of viruses that may mediate HGT to bring heterogeneous genomes together. This virus-mediated and plasmid-mediated genomic assembly and exchange could abolish one major difficulty in creating endosymbiotic genomes, i.e., the need for primitive cells to engulf each other – a difficult feat if they had cell walls.
  • 1.1K
  • 07 Dec 2024
Topic Review
Egyptian Carob Pods (Ceratonia siliqua L.) Aqueous Extract
Ceratonia siliqua (Carob) is an evergreen Mediterranean tree, and carob pods are potentially nutritive and have medicinal value. 
  • 1.1K
  • 15 Dec 2021
Topic Review
Growth of Biological Complexity from Prokaryotes to Hominids
The growth of complexity in evolution is a most intriguing phenomenon. Using gene phylostratigraphy, we showed this growth (as reflected in regulatory mechanisms) in the human genome, tracing the path from prokaryotes to hominids. Generally, the different regulatory gene families expanded at different times, yet only up to the Euteleostomi (bony vertebrates). The only exception was the expansion of transcription factors (TF) in placentals; however, we argue that this was not related to increase in general complexity. Surprisingly, although TF originated in the Prokaryota while chromatin appeared only in the Eukaryota, the expansion of epigenetic factors predated the expansion of TF. Signaling receptors, tumor suppressors, oncogenes, and aging- and disease-associated genes (indicating vulnerabilities in terms of complex organization and strongly enrichment in regulatory genes) also expanded only up to the Euteleostomi. The complexity-related gene properties (protein size, number of alternative splicing mRNA, length of untranslated mRNA, number of biological processes per gene, number of disordered regions in a protein, and density of TF–TF interactions) rose in multicellular organisms and declined after the Euteleostomi, and possibly earlier. At the same time, the speed of protein sequence evolution sharply increased in the genes that originated after the Euteleostomi. Thus, several lines of evidence indicate that molecular mechanisms of complexity growth were changing with time, and in the phyletic lineage leading to humans, the most salient shift occurred after the basic vertebrate body plan was fixed with bony skeleton. The obtained results can be useful for evolutionary medicine. 
  • 1.1K
  • 05 Nov 2021
Topic Review
Dehydrin Genes in Model Brachypodium Grasses
Dehydration proteins (dehydrins, DHNs) confer tolerance to water-stress deficit in plants. We performed a comparative genomics and evolutionary study of DHN genes in four model Brachypodium grass species. Ten dehydrins have been describe within Brachypodium species. Due to limited knowledge on dehydrin expression under water deprivation stress in Brachypodium, we also performed a drought-induced gene expression analysis in 32 ecotypes of the genus’ flagship species B. distachyon showing different hydric requirements. Bdhn1 - Bdhn2, Bdhn3 and Bdhn7 genes, orthologs of wheat, barley, rice, sorghum, and maize genes, were more highly expressed in plants under drought conditions.
  • 1.1K
  • 13 Dec 2021
Topic Review
Evolution of 14-3-3 Proteins in Angiosperm Plants
14-3-3 proteins are key regulatory factors in plants and are involved in a broad range of physiological processes. We focused on the evolutionary history of 14-3-3s from 46 angiosperm species, including basal angiosperm Amborella and major lineage of monocotyledons and eudicotyledons. 
  • 1.1K
  • 20 Dec 2021
Topic Review
Relationship between Latent-Toxoplasmosis and Depression
Latent infection of the globally spread parasite Toxoplasma gondii in humans has been associated with changes in personality and behavior. Numerous studies have investigated the effect of toxoplasmosis on depression, but their results are inconsistent. Our study focused on the effect of latent toxoplasmosis on depression in men and women in association with their fertility. In 2016–2018, we recruited clients (677 men and 664 women) of the Center for Assisted Reproduction and asked them to complete a standardized Beck Depression Inventory-II. In women without fertility problems, we found higher depression scores in Toxoplasma-positive than in Toxoplasma-negative (p = 0.010, Cohen’s d = 0.48). Toxoplasma-positive infertile men, on the other hand, had lower depression scores than Toxoplasma-negative infertile men (p ≤ 0.001, Cohen’s d = 0.48). Our results are consistent with the previously described effects of latent toxoplasmosis, which seem to go in opposite directions regarding the effect on personality and behavior of men and women. Our results could be explained by gender-contrasting reactions to chronic stress associated with lifelong infection. This suggests that due to gender differences in the impact of latent toxoplasmosis, future studies ought to perform separate analyses for women and men. 
  • 1.1K
  • 26 Aug 2021
Topic Review
Grapevine Relevance and Grapevine in near East Origins
The origins of the main cultivar groups of Vitis vinifera, their relationships with wild grapevine populations, and the use of other Vitaceae are relevant issues for the improvement and conservation of Vitis diversity. Morphometric studies, domestication indices, multivariate analyses, and Bayesian hypothesis testing have been used. 
  • 1.0K
  • 28 Jul 2023
Topic Review
Laccases
Laccase (p-diphenol, EC1.10.3.2) is a copper-containing glycoprotein oxidase. Plant laccase is a ubiquitous multifunctional protein that encodes a large gene family. 
  • 1.0K
  • 07 Feb 2022
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