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Current Biology : CB Jan 2019Hybridogenesis is an unusual form of reproduction that is found in hybrids between different species. It involves the selective transmission of one of the parental...
Hybridogenesis is an unusual form of reproduction that is found in hybrids between different species. It involves the selective transmission of one of the parental genomes, while the other one is renewed by mating with the corresponding species. It is seen as a form of sexual parasitism, in which the hybridogenetic genome gains a twofold transmission advantage and exploits the reproductive effort of another species.
Topics: Animals; Anura; Biological Evolution; Fishes; Genome; Hybridization, Genetic; Insecta; Reproduction
PubMed: 30620918
DOI: 10.1016/j.cub.2018.11.046 -
The International Journal of... 2021The axial skeleton of the has undergone an evolutionary reduction of its bone elements. This structural plan is strongly preserved throughout the order and would have... (Review)
Review
The axial skeleton of the has undergone an evolutionary reduction of its bone elements. This structural plan is strongly preserved throughout the order and would have emerged as a highly specialized anatomical adaptation to its locomotor jumping pattern. The development programs that direct the vertebral morphogenesis of the anurans are poorly described and the molecular bases that have caused their pattern to differ from other tetrapods are completely unknown. In this work, we review the ontogeny of the spinal column of the anurans and explore the genetic mechanisms that could explain the morphological difference and the maintenance of the body plan during evolution. Here, we propose that the absence of caudal osseous elements, as a consequence of the inability of sclerotomes to form cartilaginous condensations in frogs, could be due to changes in both pattern and expression levels of , , and genes along the anteroposterior axis. The anteriorised expression of the genes together with the reduction in the expression levels of , and in the posterior somites could explain, at least partly, the loss of caudal vertebrae in the anurans during evolution.
Topics: Animals; Anura; Bone and Bones; Gene Expression Regulation, Developmental; Genes, Homeobox; Skeleton; Somites
PubMed: 32930370
DOI: 10.1387/ijdb.200230ss -
Current Biology : CB Nov 2015Stynoski et al. introduce the dendrobatids, a charismatic group of frogs known for their colourful and often poisonous skin.
Stynoski et al. introduce the dendrobatids, a charismatic group of frogs known for their colourful and often poisonous skin.
Topics: Animals; Anura; Female; Male; Poisons; Skin; Skin Pigmentation; Toxins, Biological
PubMed: 26528739
DOI: 10.1016/j.cub.2015.06.044 -
Genetics and Molecular Research : GMR Aug 2014This article reviews the polyploidy events that have long been demonstrated to play a role in the evolution of Anura, while also discussing the importance of epigenetic... (Review)
Review
This article reviews the polyploidy events that have long been demonstrated to play a role in the evolution of Anura, while also discussing the importance of epigenetic control of gene expression and diversity. Findings on Brazilian autopolyploid anurans, mainly of the genus Odontophrynus, obtained in previous studies on their cytogenetics, chromatin ultrastructure, and molecular gene regulation are discussed here. Our data on genome duplication and on epigenetic events were analyzed here regarding phylogenetic trees, including the classic 2R model for vertebrate evolution and the growing evidence of similar epigenetic mechanisms in animal and allopolyploid plants. We propose that polyploidy and epigenetic events led to rapid Anura diversity and speciation. Also, recent advances in molecular studies in other organisms led us to revisit some controversial models of evolution.
Topics: Amphibians; Animals; Anura; Brazil; Chromosomes, Plant; Epigenesis, Genetic; Epigenomics; Evolution, Molecular; Gene Expression Regulation, Plant; Hybridization, Genetic; Phylogeny; Phylogeography; Polymorphism, Genetic; Polyploidy
PubMed: 25117358
DOI: 10.4238/2014.August.7.15 -
Current Biology : CB Sep 2020David and Karin Pfennig introduce character displacement, the divergent evolution of traits in overlapping species.
David and Karin Pfennig introduce character displacement, the divergent evolution of traits in overlapping species.
Topics: Animals; Anura; Biological Evolution; Phenotype; Selection, Genetic; Species Specificity
PubMed: 32961151
DOI: 10.1016/j.cub.2020.07.021 -
Genes Mar 2021Frogs are ideal organisms for studying sex chromosome evolution because of their diversity in sex chromosome differentiation and sex-determination systems. We review 222... (Review)
Review
Frogs are ideal organisms for studying sex chromosome evolution because of their diversity in sex chromosome differentiation and sex-determination systems. We review 222 anuran frogs, spanning ~220 Myr of divergence, with characterized sex chromosomes, and discuss their evolution, phylogenetic distribution and transitions between homomorphic and heteromorphic states, as well as between sex-determination systems. Most (~75%) anurans have homomorphic sex chromosomes, with XY systems being three times more common than ZW systems. Most remaining anurans (~25%) have heteromorphic sex chromosomes, with XY and ZW systems almost equally represented. There are Y-autosome fusions in 11 species, and no W-/Z-/X-autosome fusions are known. The phylogeny represents at least 19 transitions between sex-determination systems and at least 16 cases of independent evolution of heteromorphic sex chromosomes from homomorphy, the likely ancestral state. Five lineages mostly have heteromorphic sex chromosomes, which might have evolved due to demographic and sexual selection attributes of those lineages. Males do not recombine over most of their genome, regardless of which is the heterogametic sex. Nevertheless, telomere-restricted recombination between ZW chromosomes has evolved at least once. More comparative genomic studies are needed to understand the evolutionary trajectories of sex chromosomes among frog lineages, especially in the ZW systems.
Topics: Animals; Anura; Evolution, Molecular; Female; Male; Phylogeny; Sex Chromosomes; Sex Determination Processes
PubMed: 33810524
DOI: 10.3390/genes12040483 -
Hearing Research Mar 2011The frog inner ear contains three regions that are sensitive to airborne sound and which are functionally distinct. (1) The responses of nerve fibres innervating the... (Comparative Study)
Comparative Study Review
The frog inner ear contains three regions that are sensitive to airborne sound and which are functionally distinct. (1) The responses of nerve fibres innervating the low-frequency, rostral part of the amphibian papilla (AP) are complex. Electrical tuning of hair cells presumably contributes to the frequency selectivity of these responses. (2) The caudal part of the AP covers the mid-frequency portion of the frog's auditory range. It shares the ability to generate both evoked and spontaneous otoacoustic emissions with the mammalian cochlea and other vertebrate ears. (3) The basilar papilla functions mainly as a single auditory filter. Its simple anatomy and function provide a model system for testing hypotheses concerning emission generation. Group delays of stimulus-frequency otoacoustic emissions (SFOAEs) from the basilar papilla are accounted for by assuming that they result from forward and reverse transmission through the middle ear, a mechanical delay due to tectorial membrane filtering and a rapid forward and reverse propagation through the inner ear fluids, with negligible delay.
Topics: Animals; Anura; Biomechanical Phenomena; Ear, Inner; Evoked Potentials, Auditory; Hearing; Sensory Receptor Cells
PubMed: 20149854
DOI: 10.1016/j.heares.2010.02.004 -
Journal of Biological Physics Sep 2021Vertebrate hearts have undergone marked morphological and structural changes to adapt to different environments and lifestyles as part of the evolutionary process....
Vertebrate hearts have undergone marked morphological and structural changes to adapt to different environments and lifestyles as part of the evolutionary process. Amphibians were the first vertebrates to migrate to land. Transition from aquatic to terrestrial environments required the ability to circulate blood against the force of gravity. In this study, we investigated the passive mechanical properties and histology of the ventricles of three species of Anura (frogs and toads) from different habitats, Xenopus laevis (aquatic), Pelophylax nigromaculatus (semiaquatic), and Bufo japonicus formosus (terrestrial). Pressure-loading tests demonstrated stiffer ventricles of P. nigromaculatus and B. j. formosus compared X. laevis ventricles. Histological analysis revealed a remarkable difference in the structure of cardiac tissue: thickening of the compact myocardium layer of P. nigromaculatus and B. j. formosus and enrichment of the collagen fibers of B. j. formosus. The amount of collagen fibers differed among the species, as quantitatively confirmed by second-harmonic generation light microscopy. No significant difference was observed in cardiomyocytes isolated from each animal, and the sarcomere length was almost the same. The results indicate that the ventricles of Anura stiffen during adaptation to life on land.
Topics: Animals; Anura; Biological Evolution; Bufonidae; Ecosystem; Xenopus laevis
PubMed: 34515919
DOI: 10.1007/s10867-021-09579-4 -
Proceedings. Biological Sciences Apr 2019Frogs and toads (Anura) exhibit some of the most diverse parental strategies in vertebrates. Identifying the evolutionary origins of parenting is fundamental to...
Frogs and toads (Anura) exhibit some of the most diverse parental strategies in vertebrates. Identifying the evolutionary origins of parenting is fundamental to understanding the relationships between sexual selection, social evolution and parental care systems of contemporary Anura. Moreover, parenting has been hypothesized to allow the invasion of terrestrial habitats by the ancestors of terrestrial vertebrates. Using comprehensive phylogenetic analyses of frogs and toads based on data from over 1000 species that represent 46 out of 55 Anura families, we test whether parental care is associated with terrestrial reproduction and several life-history traits. Here, we show that both the duration of care and offspring protection by males and females have coevolved with terrestrial reproduction. Sexual size dimorphism is also related to care, because the large male size relative to female size is associated with increased paternal care. Furthermore, increased egg size and reduced clutch volume are associated with increased care in bivariate but not in multivariate analyses, suggesting that the relationships between care, egg size and clutch volume are mediated by terrestrial reproduction. Taken together, our results suggest that parenting by males and females has coevolved, and complex parenting traits have evolved several times independently in Anura in response to breeding in terrestrial environments.
Topics: Animals; Anura; Biological Evolution; Female; Life History Traits; Male; Maternal Behavior; Paternal Behavior
PubMed: 30966991
DOI: 10.1098/rspb.2018.2737 -
Proceedings. Biological Sciences Aug 2021The eyes of frogs and toads (Anura) are among their most fascinating features. Although several pupil shapes have been described, the diversity, evolution, and...
The eyes of frogs and toads (Anura) are among their most fascinating features. Although several pupil shapes have been described, the diversity, evolution, and functional role of the pupil in anurans have received little attention. Studying photographs of more than 3200 species, we surveyed pupil diversity, described their morphological variation, tested correlation with adult habits and diel activity, and discuss major evolutionary patterns considering iris anatomy and visual ecology. Our results indicate that the pupil in anurans is a highly plastic structure, with seven main pupil shapes that evolved at least 116 times during the history of the group. We found no significant correlation between pupil shape, adult habits, and diel activity, with the exception of the circular pupil and aquatic habits. The vertical pupil arose at least in the most-recent common ancestor of Anura + Caudata, and this morphology is present in most early-diverging anuran clades. Subsequently, a horizontal pupil, a very uncommon shape in vertebrates, evolved in most neobatrachian frogs. This shape evolved into most other known pupil shapes, but it persisted in a large number of species with diverse life histories, habits, and diel activity patterns, demonstrating a remarkable functional and ecological versatility.
Topics: Animals; Anura; Biological Evolution; Bufonidae; Phylogeny; Pupil
PubMed: 34403634
DOI: 10.1098/rspb.2021.1402