Se estudió la arquitectura de raíces y vástagos de Vismia baccifera y raíces de V. macrophylla (C... more Se estudió la arquitectura de raíces y vástagos de Vismia baccifera y raíces de V. macrophylla (Clusiaceae). Los sistemas de raíces de ambas especies presentan características similares en los ejes. V. macrophylla tiene un orden jerárquico menos que V. baccifera y su unidad arquitectónica se completa más rápidamente. V. baccifera presenta el modelo arquitectónico de Attims mientras V. macrophylla exhibe el modelo de Troll. No se encontró coincidencia ni simultaneidad entre las etapas de desarrollo de raíces y de vástagos. En ambas especies se encontró un mayor número de ejes en las raíces con respecto a los vástagos. Con respecto a otras especies del género estudiadas anteriormente, se encontraron diferencias en la arquitectura caulinar principalmente en lo referente a la plagiotropía secundaria, los monopodios inestables y la localización de las inflorescencias.
Acyl-CoA-binding protein (ACBP) was first identified in mammals as a neuropeptide, and was demons... more Acyl-CoA-binding protein (ACBP) was first identified in mammals as a neuropeptide, and was demonstrated to belong to an important house-keeping protein family that extends across eukaryotes and some prokaryotes. In plants, the Arabidopsis ACBP family consists of six AtACBPs (AtACBP1 to AtACBP6), and has been investigated using gene knock-out mutants and overexpression lines. Herein, recent findings on the AtACBPs are examined to provide an insight on their functions in various plant developmental processes, such as embryo and seed development, seed dormancy and germination, seedling development and cuticle formation, as well as their roles under various environmental stresses. The significance of the AtACBPs in acyl-CoA/lipid metabolism, with focus on their interaction with long to very-long-chain (VLC) acyl-CoA esters and their potential role in the formation of lipid droplets in seeds and vegetative tissues are discussed. In addition, recent findings on the rice ACBP family are pr...
RESUMEN Se estudió la arquitectura de raíces y vástagos de Vismia baccifera y raíces de V. macrop... more RESUMEN Se estudió la arquitectura de raíces y vástagos de Vismia baccifera y raíces de V. macrophylla (Clusiaceae). Los sistemas de raíces de ambas especies presentan características similares en los ejes. V. macrophylla tiene un orden jerárquico menos que V. baccifera y su unidad arquitectónica se completa más rápidamente. V. baccifera presenta el modelo arquitectónico de Attims mientras V. macrophylla
Polyploidy, or whole-genome duplication (WGD), is a recurrent mutation both in cell lineages and ... more Polyploidy, or whole-genome duplication (WGD), is a recurrent mutation both in cell lineages and over evolutionary time. By globally changing the relationship between gene copy number and other cellular entities, it can induce dramatic changes at the cellular and phenotypic level. Perhaps surprisingly, then, the insights that these events can bring to understanding other cellular features are not as well appreciated as they could be. In this review, we draw on examples of polyploidy from animals, plants and yeast to explore how investigations of polyploid cells have improved our understanding of the cell cycle, biological network complexity, metabolic phenotypes and tumor biology. We argue that the study of polyploidy across organisms, cell types, and time scales serves not only as a window into basic cell biology, but also as a basis for a predictive biology with applications ranging from crop improvement to treating cancer.
The vast majority of fl owering plant seeds contain a triploid endosperm formed by fertilization ... more The vast majority of fl owering plant seeds contain a triploid endosperm formed by fertilization of a monosporic, Polygonumtype female gametophyte. However, evolutionary transitions to six other genetic constructs of endosperm are widespread, and six of seven known patterns are found in the order Piperales. Within Piperaceae, Manekia has not been described, and we report its female gametophyte to be tetrasporic and 16-nucleate at maturity. Manekia ontogeny is generally characterized by early establishment of a bipolar or weakly bipolar body plan and a binucleate central cell at maturity (Drusa-type pattern); however, ca. 16% of early stages had distinctly tetrapolar organization, and ca. 21% of mature specimens had a tetranucleate central cell (Penaea-type pattern, not previously reported in Piperaceae). An evolutionary developmental analysis indicates heterochrony, heterotopy, novelties, and sequence deletions have each played roles in modulating variation within Piperales. Our data suggest the common ancestor of Piperaceae was tetrasporic and retained a plesiomorphic bipolar body plan, producing a " functionally bisporic " form of triploid endosperm derived from the lineal descendants of two megaspores and a sperm. Developmental modifi cations of this tetrasporic, bipolar ontogeny can account for the origin of all three other known " true " tetrasporic endosperm genetic constructs, formed from derivatives of all four megaspores and a sperm. These derived endosperms in turn have higher ploidy, higher potential heterozygosity, and reduced genetic confl icts.
The biogeography, chromosome number evolution, pollination biology and evolutionary history of th... more The biogeography, chromosome number evolution, pollination biology and evolutionary history of the plant family Araceae have recently become much clearer . However, phylogenetic ambiguity near the root of the tree precludes answering questions about the early evolution of the family. We use Illumina sequencing technology and reference based assembly to resolve the remaining questions in the deep phylogeny of Araceae. We sampled 32 genera and obtained 7 from GenBank (including an outgroup), representing 42 of 44 major clades described in . A subsequent phylogenomic analysis based on mitochondrial data was performed to test congruence between plastid and mitochondrial data for phylogenetic inference. Plastid sequences produced strongly supported phylogenies. In contrast, mitochondrial phylogenies were weakly supported and incongruent with chloroplast data (Templeton test, p 6 0.0001), although several smaller clades were recovered. New strongly-supported clades seen here are: (1) Anubias and Montrichardia, excluding Calla, form a clade that is sister to the Zantedeschia clade; (2) the South African genus Zantedeschia is sister to the Old World Anchomanes clade; and (3) within the Zantedeschia clade, Philodendron is sister to the rest. Calla and Schismatoglottis form a clade at the base of one of two major clades in Aroideae based on complete chloroplast sequences. Although statistical support is weak, morphological and cytological features support this topology.
Se estudió la arquitectura de raíces y vástagos de Vismia baccifera y raíces de V. macrophylla (C... more Se estudió la arquitectura de raíces y vástagos de Vismia baccifera y raíces de V. macrophylla (Clusiaceae). Los sistemas de raíces de ambas especies presentan características similares en los ejes. V. macrophylla tiene un orden jerárquico menos que V. baccifera y su unidad arquitectónica se completa más rápidamente. V. baccifera presenta el modelo arquitectónico de Attims mientras V. macrophylla exhibe el modelo de Troll. No se encontró coincidencia ni simultaneidad entre las etapas de desarrollo de raíces y de vástagos. En ambas especies se encontró un mayor número de ejes en las raíces con respecto a los vástagos. Con respecto a otras especies del género estudiadas anteriormente, se encontraron diferencias en la arquitectura caulinar principalmente en lo referente a la plagiotropía secundaria, los monopodios inestables y la localización de las inflorescencias.
Acyl-CoA-binding protein (ACBP) was first identified in mammals as a neuropeptide, and was demons... more Acyl-CoA-binding protein (ACBP) was first identified in mammals as a neuropeptide, and was demonstrated to belong to an important house-keeping protein family that extends across eukaryotes and some prokaryotes. In plants, the Arabidopsis ACBP family consists of six AtACBPs (AtACBP1 to AtACBP6), and has been investigated using gene knock-out mutants and overexpression lines. Herein, recent findings on the AtACBPs are examined to provide an insight on their functions in various plant developmental processes, such as embryo and seed development, seed dormancy and germination, seedling development and cuticle formation, as well as their roles under various environmental stresses. The significance of the AtACBPs in acyl-CoA/lipid metabolism, with focus on their interaction with long to very-long-chain (VLC) acyl-CoA esters and their potential role in the formation of lipid droplets in seeds and vegetative tissues are discussed. In addition, recent findings on the rice ACBP family are pr...
RESUMEN Se estudió la arquitectura de raíces y vástagos de Vismia baccifera y raíces de V. macrop... more RESUMEN Se estudió la arquitectura de raíces y vástagos de Vismia baccifera y raíces de V. macrophylla (Clusiaceae). Los sistemas de raíces de ambas especies presentan características similares en los ejes. V. macrophylla tiene un orden jerárquico menos que V. baccifera y su unidad arquitectónica se completa más rápidamente. V. baccifera presenta el modelo arquitectónico de Attims mientras V. macrophylla
Polyploidy, or whole-genome duplication (WGD), is a recurrent mutation both in cell lineages and ... more Polyploidy, or whole-genome duplication (WGD), is a recurrent mutation both in cell lineages and over evolutionary time. By globally changing the relationship between gene copy number and other cellular entities, it can induce dramatic changes at the cellular and phenotypic level. Perhaps surprisingly, then, the insights that these events can bring to understanding other cellular features are not as well appreciated as they could be. In this review, we draw on examples of polyploidy from animals, plants and yeast to explore how investigations of polyploid cells have improved our understanding of the cell cycle, biological network complexity, metabolic phenotypes and tumor biology. We argue that the study of polyploidy across organisms, cell types, and time scales serves not only as a window into basic cell biology, but also as a basis for a predictive biology with applications ranging from crop improvement to treating cancer.
The vast majority of fl owering plant seeds contain a triploid endosperm formed by fertilization ... more The vast majority of fl owering plant seeds contain a triploid endosperm formed by fertilization of a monosporic, Polygonumtype female gametophyte. However, evolutionary transitions to six other genetic constructs of endosperm are widespread, and six of seven known patterns are found in the order Piperales. Within Piperaceae, Manekia has not been described, and we report its female gametophyte to be tetrasporic and 16-nucleate at maturity. Manekia ontogeny is generally characterized by early establishment of a bipolar or weakly bipolar body plan and a binucleate central cell at maturity (Drusa-type pattern); however, ca. 16% of early stages had distinctly tetrapolar organization, and ca. 21% of mature specimens had a tetranucleate central cell (Penaea-type pattern, not previously reported in Piperaceae). An evolutionary developmental analysis indicates heterochrony, heterotopy, novelties, and sequence deletions have each played roles in modulating variation within Piperales. Our data suggest the common ancestor of Piperaceae was tetrasporic and retained a plesiomorphic bipolar body plan, producing a " functionally bisporic " form of triploid endosperm derived from the lineal descendants of two megaspores and a sperm. Developmental modifi cations of this tetrasporic, bipolar ontogeny can account for the origin of all three other known " true " tetrasporic endosperm genetic constructs, formed from derivatives of all four megaspores and a sperm. These derived endosperms in turn have higher ploidy, higher potential heterozygosity, and reduced genetic confl icts.
The biogeography, chromosome number evolution, pollination biology and evolutionary history of th... more The biogeography, chromosome number evolution, pollination biology and evolutionary history of the plant family Araceae have recently become much clearer . However, phylogenetic ambiguity near the root of the tree precludes answering questions about the early evolution of the family. We use Illumina sequencing technology and reference based assembly to resolve the remaining questions in the deep phylogeny of Araceae. We sampled 32 genera and obtained 7 from GenBank (including an outgroup), representing 42 of 44 major clades described in . A subsequent phylogenomic analysis based on mitochondrial data was performed to test congruence between plastid and mitochondrial data for phylogenetic inference. Plastid sequences produced strongly supported phylogenies. In contrast, mitochondrial phylogenies were weakly supported and incongruent with chloroplast data (Templeton test, p 6 0.0001), although several smaller clades were recovered. New strongly-supported clades seen here are: (1) Anubias and Montrichardia, excluding Calla, form a clade that is sister to the Zantedeschia clade; (2) the South African genus Zantedeschia is sister to the Old World Anchomanes clade; and (3) within the Zantedeschia clade, Philodendron is sister to the rest. Calla and Schismatoglottis form a clade at the base of one of two major clades in Aroideae based on complete chloroplast sequences. Although statistical support is weak, morphological and cytological features support this topology.
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