Signal evolution
Dotaz
Zobrazit nápovědu
elektronický časopis
- MeSH
- biologická evoluce MeSH
- druhová specificita MeSH
- fylogeneze MeSH
- genetický kód MeSH
- sekvence nukleotidů MeSH
- Konspekt
- Obecná genetika. Obecná cytogenetika. Evoluce
- NLK Obory
- biologie
- genetika, lékařská genetika
- biologie
- NLK Publikační typ
- elektronické časopisy
Plants and fungi use light and other signals to regulate development, growth, and metabolism. The fruiting bodies of the fungus Phycomyces blakesleeanus are single cells that react to environmental cues, including light, but the mechanisms are largely unknown [1]. The related fungus Mucor circinelloides is an opportunistic human pathogen that changes its mode of growth upon receipt of signals from the environment to facilitate pathogenesis [2]. Understanding how these organisms respond to environmental cues should provide insights into the mechanisms of sensory perception and signal transduction by a single eukaryotic cell, and their role in pathogenesis. We sequenced the genomes of P. blakesleeanus and M. circinelloides and show that they have been shaped by an extensive genome duplication or, most likely, a whole-genome duplication (WGD), which is rarely observed in fungi [3-6]. We show that the genome duplication has expanded gene families, including those involved in signal transduction, and that duplicated genes have specialized, as evidenced by differences in their regulation by light. The transcriptional response to light varies with the developmental stage and is still observed in a photoreceptor mutant of P. blakesleeanus. A phototropic mutant of P. blakesleeanus with a heterozygous mutation in the photoreceptor gene madA demonstrates that photosensor dosage is important for the magnitude of signal transduction. We conclude that the genome duplication provided the means to improve signal transduction for enhanced perception of environmental signals. Our results will help to understand the role of genome dynamics in the evolution of sensory perception in eukaryotes.
- MeSH
- duplikace genu * MeSH
- genetická transkripce účinky záření MeSH
- genom fungální * MeSH
- molekulární evoluce * MeSH
- Mucor genetika účinky záření MeSH
- multigenová rodina MeSH
- percepce MeSH
- Phycomyces genetika účinky záření MeSH
- signální transdukce genetika MeSH
- světlo MeSH
- Publikační typ
- časopisecké články MeSH
Macmillan series in physical anthropology
XII, 322 s. : il. ; 24 cm
The evolution of phenotypes is highly understudied in protists, due to the dearth of morphological characters, missing fossil record, and/or unresolved phylogeny in the majority of taxa. The chrysophyte genus Mallomonas (Stramenopiles) forms species-specific silica scales with extraordinary diversity of their ornamentation. In this paper, we molecularly characterized three additional species to provide an updated phylogeny of 43 species, and combined this with evaluations of 24 morphological traits. Using phylogenetic comparative methods, we evaluated phylogenetic signal in traits, reconstructed the trait evolution, and compared the overall phylogenetic and morphological diversity. The majority of traits showed strong phylogenetic signal and mostly dynamic evolution. Phylogenetic relatedness was often reflected by the phenotypic similarity. Both V-rib and dome are very conservative structures that are presumably involved in precise scale overlap and bristle attachment, respectively. Based on modern species, it seems the dome firstly appeared on apical and/or caudal scales, and only later emerged on body scales. Bristle was presumably present in the common ancestor and gradually elongated ever since. However, most other morphological traits readily changed during the evolution of Mallomonas.
Strigolactones (SLs) are a relatively recent addition to the list of plant hormones that control different aspects of plant development. SL signalling is perceived by an α/β hydrolase, DWARF 14 (D14). A close homolog of D14, KARRIKIN INSENSTIVE2 (KAI2), is involved in perception of an uncharacterized molecule called karrikin (KAR). Recent studies in Arabidopsis identified the SUPPRESSOR OF MAX2 1 (SMAX1) and SMAX1-LIKE 7 (SMXL7) to be potential SCF-MAX2 complex-mediated proteasome targets of KAI2 and D14, respectively. Genetic studies on SMXL7 and SMAX1 demonstrated distinct developmental roles for each, but very little is known about these repressors in terms of their sequence features. In this study, we performed an extensive comparative analysis of SMXLs and determined their phylogenetic and evolutionary history in the plant lineage. Our results show that SMXL family members can be sub-divided into four distinct phylogenetic clades/classes, with an ancient SMAX1. Further, we identified the clade-specific motifs that have evolved and that might act as determinants of SL-KAR signalling specificity. These specificities resulted from functional diversities among the clades. Our results suggest that a gradual co-evolution of SMXL members with their upstream receptors D14/KAI2 provided an increased specificity to both the SL perception and response in land plants.
- MeSH
- Arabidopsis genetika metabolismus MeSH
- laktony metabolismus MeSH
- molekulární evoluce * MeSH
- multigenová rodina * MeSH
- proteiny huseníčku genetika metabolismus MeSH
- regulátory růstu rostlin metabolismus MeSH
- signální transdukce MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
... The Structure of Adaptive Landscapes Underlying Protein Evolution, 121 -- Adaptive Maturation of the ... ... Immune Response, 122 Evolution of Novel Catalytic Functions, 142 -- Applied Molecular Evolution: Direct ... ... - PART III ORDER AND ONTOGENY, 407 -- 11 The Architecture of Genetic Regulatory Circuits and Its Evolution ... ... , 411 -- Independence of the Molecular Evolutionary Clock and Morphological Evolution, 412 -- CONTENTS ...
1st ed. 709 s. : il.
- Klíčová slova
- Biologie, Evoluce, Fylogeneze,
- MeSH
- biologická evoluce MeSH
- biologie MeSH
- fylogeneze MeSH
- molekulární evoluce MeSH
- původ života MeSH
A high degree of morphological variability is expressed between the ornately sculptured siliceous scales formed by species in the chrysophycean genus, Synura. In this study, we aimed to uncover the general principles and trends underlying the evolution of scale morphology in this genus. We assessed the relationships among thirty extant Synura species using a robust molecular analysis that included six genes, coupled with morphological characterization of the species-specific scales. The analysis was further enriched with addition of morphological information from fossil specimens and by including the unique modern species, Synura punctulosa. We inferred the phylogenetic position of the morphologically unique S. punctulosa, to be an ancient Synura lineage related to S. splendida in the section Curtispinae. Some morphological traits, including development of a keel or a labyrinth ribbing pattern on the scale, appeared once in evolution, whereas other structures, such as a hexagonal meshwork pattern, originated independently several times over geologic time. We further uncovered numerous construction principles governing scale morphology and evolution, as follows: (i) scale roundness and pore diameter decreased during evolution; (ii) elongated scales became strengthened by a higher number of struts or ribs; (iii) as a consequence of scale biogenesis, scales with spines possessed smaller basal holes than scales with a keel and; and (iv) the keel area was proportional to scale area, indicating its potential value in strengthening the scale against breakage.
