Floral development and anatomy of Pentadiplandra (Pentadiplandraceae): a key genus in the identification of floral morphological trends in the core Brassicales

2002 ◽  
Vol 80 (5) ◽  
pp. 443-459 ◽  
Author(s):  
Louis P Ronse De Craene
Keyword(s):  
Molecular Phylogeny ◽  
Floral Development ◽  
Evolutionary Trends ◽  
Close Link ◽  
The Core ◽  
Anatomical Data ◽  
Young Leaves ◽  
Petal Growth ◽  
Basal Position ◽  
Axile Placentation

The development and anatomy of leaves and flowers have been investigated in the monotypic species Pentadiplandra brazzeana to discuss its position relative to the core Brassicales and to clarify floral evolutionary trends within the order. Young leaves are flanked by two large stipules that shrivel at anthesis. Young flowers develop as elliptical primordia on a flattened raceme. Sepal initiation is sequential, starting with the lateral sepals and ending with three median sepals. The petals and diplostemonous androecium arise as regular whorls. Five antesepalous carpels develop into a saccate gynoecium with axile placentation. Petals develop a cushion-like basal appendage covering the extrastaminal nectary. Several ontogenetic and anatomical data of the flower support the basal position of Pentadiplandra in the evolution of the core Brassicales and for the derivation of the order from pentamerous diplostemonous ancestors. A derivation of the tetramerous Capparaceae and Brassicaceae as well as hexamerous Tovariaceae is discussed. A number of synapomorphies are identified: sequential sepal initiation with laterals preceding median sepals, retarded petal growth, a (andro)gynophore, the extrastaminal nectary, and stipulate leaves. The peculiar androecium of the Brassicaceae is caused by the strong median compression of the flower, leading to the loss and displacement of median stamens. The derivation of a parietal placenta from an axile placenta is supported. Evidence supports a close link with either Tovariaceae or Capparaceae, concomitant with macromolecular results.Key words: core Brassicales, Capparaceae, Pentadiplandra brazzeana, Tovariaceae, molecular phylogeny, floral development, anatomy, diplostemony, placentation.

Molecular phylogeny of the subtribe Melinidinae (Poaceae: Panicoideae: Paniceae) and evolutionary trends in the homogenization of inflorescences

2010 ◽  
Vol 56 (1) ◽  
pp. 355-369 ◽  
Author(s):  
Diego L. Salariato ◽  
Fernando O. Zuloaga ◽  
Liliana M. Giussani ◽  
Osvaldo Morrone
Keyword(s):  
Molecular Phylogeny ◽  
Evolutionary Trends

scholarly journals Old and Cosmopolite: Molecular Phylogeny of Tropical–Subtropical Kites (Aves: Elaninae) with Taxonomic Implications

Diversity ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 327
Author(s):  
Ivan J. Starikov ◽  
Michael Wink
Keyword(s):  
Molecular Phylogeny ◽  
Genetic Markers ◽  
Sequence Data ◽  
Cyt B ◽  
Ecological Data ◽  
Dna Sequence Data ◽  
Family Level ◽  
Taxonomic Implications ◽  
Rag 1 ◽  
Basal Position

Kites of the Elaninae group are small and medium-sized, mostly tropical raptors traditionally considered as an early diverged subfamily of the Accipitridae. We used nucleotide sequences of three genetic markers (mitochondrial Cyt b and COI, nuclear RAG-1) to reconstruct the phylogenetic relationships of the Elaninae, other kites, and representatives of different families of diurnal raptors. Our results confirm the basal position of Elaninae, separated the latest in Early Miocene, including Chelictinia riocourii, which was not sequenced before and belongs to this group. Not only DNA data but also cytological, morphological, and ecological data show the singularity of Elaninae. We suggest elevating this group to family level as Elanidae within the order Accipitriformes. It includes Gampsonyx swainsonii as a monotypic subfamily because of distinctive traits and DNA sequence data. Taxonomic implications for other macrogroups of Accipitriformes are discussed.

Molecular phylogeny of Acrobeloides and Cephalobus (Nematoda: Cephalobidae) reveals paraphyletic taxa and recurrent evolution of simple labial morphology

Nematology ◽  
2006 ◽  
Vol 8 (6) ◽  
pp. 819-836 ◽  
Author(s):  
Steven Nadler ◽  
Ashleigh Smythe
Keyword(s):  
Molecular Phylogeny ◽  
Large Subunit ◽  
Taxonomic Revision ◽  
Morphological Characters ◽  
Lateral Field ◽  
The Core ◽  
Morphological Taxonomy ◽  
Dominant Feature ◽  
The Family ◽  
Molecular Phylogenetic

AbstractMembers of the family Cephalobidae (Nematoda) are among the most common and morphologically striking soil nematodes. Many members of Cephalobidae have extensive lip elaborations called probolae, but two taxonomically problematic genera, Acrobeloides and Cephalobus, have simple, low probolae. We sequenced a portion of the nuclear large subunit ribosomal DNA for 33 cultures of Acrobeloides and Cephalobus. A phylogenetic analysis of these data, plus sequences representing other members of Cephalobina, revealed a core clade of 22 closely related taxa, but did not represent Acrobeloides and Cephalobus as monophyletic. The dominant feature used in morphological taxonomy of Cephalobidae, the lip region, was homoplastic according to the molecular phylogenetic hypothesis. Contrary to previous suggestions, taxa with simple probolae have arisen multiple times from taxa with complex probolae. Cultures were also examined for mode of reproduction (presumed parthenogenetic vs sexual) and three morphological characters commonly used in generic diagnoses: the shape of the corpus in profile; the number of lateral incisures; and the terminal extent of the lateral field. Most cultures, including all 22 members of the core clade, lacked males and were presumed to be parthenogenetic, but several independent origins of sexually reproducing taxa were found. Of the morphological characters, only the corpus shape was consistent with the molecular phylogeny, however, the utility of this character is also questioned. Many genera with complex probolae were also paraphyletic, including Nothacrobeles, Zeldia and Cervidellus, indicating the need for more comprehensive phylogenies and a broad taxonomic revision of the family.

scholarly journals γ-Tubulin controls neuronal microtubule polarity independently of Golgi outposts

2014 ◽  
Vol 25 (13) ◽  
pp. 2039-2050 ◽  
Author(s):  
Michelle M. Nguyen ◽  
Christie J. McCracken ◽  
E. S. Milner ◽  
Daniel J. Goetschius ◽  
Alexis T. Weiner ◽  
...  
Keyword(s):  
Golgi Complex ◽  
Loss Of Function ◽  
Microtubule Nucleation ◽  
Close Link ◽  
The Core ◽  
Microtubule Polarity ◽  
Nucleation Sites

Neurons have highly polarized arrangements of microtubules, but it is incompletely understood how microtubule polarity is controlled in either axons or dendrites. To explore whether microtubule nucleation by γ-tubulin might contribute to polarity, we analyzed neuronal microtubules in Drosophila containing gain- or loss-of-function alleles of γ-tubulin. Both increased and decreased activity of γ-tubulin, the core microtubule nucleation protein, altered microtubule polarity in axons and dendrites, suggesting a close link between regulation of nucleation and polarity. To test whether nucleation might locally regulate polarity in axons and dendrites, we examined the distribution of γ-tubulin. Consistent with local nucleation, tagged and endogenous γ-tubulins were found in specific positions in dendrites and axons. Because the Golgi complex can house nucleation sites, we explored whether microtubule nucleation might occur at dendritic Golgi outposts. However, distinct Golgi outposts were not present in all dendrites that required regulated nucleation for polarity. Moreover, when we dragged the Golgi out of dendrites with an activated kinesin, γ-tubulin remained in dendrites. We conclude that regulated microtubule nucleation controls neuronal microtubule polarity but that the Golgi complex is not directly involved in housing nucleation sites.

Reconstruction of intrageneric relationships within the Indo-West Pacific littoral crab genus Metopograpsus (Decapoda, Brachyura, Grapsidae): an alternative speciation order according to a 28S rDNA molecular phylogeny

Crustaceana ◽  
2021 ◽  
Vol 94 (11-12) ◽  
pp. 1313-1325
Author(s):  
Elisabeth Mock ◽  
Christoph D. Schubart
Keyword(s):  
Molecular Phylogeny ◽  
Nuclear Gene ◽  
28S Rrna ◽  
Widespread Species ◽  
West Pacific ◽  
Phylogenetic Reconstructions ◽  
Geographic Coverage ◽  
Morphological Differences ◽  
First Time ◽  
Basal Position

Abstract The genus Metopograpsus H. Milne Edwards, 1853 is widespread throughout the Indo-West Pacific and currently consists of seven species that can only be separated by minor morphological differences. Therefore, it represents a good example for the usefulness of genetic analyses for identification and classification. In order to obtain phylogenetic information at both lower and higher evolutionary levels, it is best to use a combination of mitochondrial and nuclear molecular markers. Here we present for the first time a molecular phylogeny based on a relative long fragment of the 28S rRNA nuclear gene for the genus Metopograpsus, after application of newly developed primers. Our data suggest an alternative intrageneric speciation order, with M. thukuhar and M. cannicci holding a basal position and a monophyletic grouping of M. frontalis, M. oceanicus and M. quadridentatus, which differs from prior phylogenetic reconstructions. Previously recognized intraspecific phylogeographic patterns in M. latifrons and M. quadridentatus could not be confirmed, due to limited variability of this conserved nuclear gene and due to an incomplete geographic coverage of the corresponding species. In contrast, the previously indicated phylogenetic subdivision within the formerly widespread species M. thukuhar, which led to the recent description of M. cannicci, is here supported.

scholarly journals Public Policy for Sustainability and Retail Resilience in Lisbon City Center

2020 ◽  
Vol 12 (22) ◽  
pp. 9433
Author(s):  
Teresa Barata-Salgueiro ◽  
Pedro Guimarães
Keyword(s):  
Public Policy ◽  
International Organizations ◽  
Housing Prices ◽  
Urban Resilience ◽  
City Center ◽  
Public Authorities ◽  
Close Link ◽  
The Core ◽  
The City

International organizations, public authorities and researchers have increasingly been concerned with urban resilience and sustainability. We focus on the triangle retail, urban resilience and city sustainability, aiming to uncover how cities have coped with retail challenges to increase their resilience towards a sustainable path, highlighting the role played by public policy. The case study asks, is Central Lisbon strongly affected by processes of regeneration, touristification and gentrification, simultaneously with changes in retail. The analysis of planning and other policy documents complemented by fieldwork evidence shows a close link between public initiatives and private entrepreneurship and their impacts in the vitality of the core. The text shows that the policy outlined by local authorities to overcome the decline of the city center and to meet the aims of sustainability implies urban resilience. The transformation of retail is aligned with that vision and is supported its achievement, while the commercial fabric suffered an evolution from shopping to consumption spaces, polarized by culture and entertainment, targeting new consumers and lifestyles. However, new social and economic challenges arise due to escalating housing prices, change in retail supply, the excessive dependence of tourism and the danger of losing part of the city’s identity.

scholarly journals What is the nature of petals in Caryophyllaceae? Developmental evidence clarifies their evolutionary origin

2019 ◽  
Vol 124 (2) ◽  
pp. 281-295 ◽  
Author(s):  
Lai Wei ◽  
Louis Ronse De Craene
Keyword(s):  
Electron Microscopy ◽  
Floral Development ◽  
General Tendency ◽  
Ancestral State ◽  
State Reconstruction ◽  
Floral Organs ◽  
The Core ◽  
Petal Development ◽  
Character Mapping ◽  
Scanning Electron

Abstract Background and Aims Floral development is a powerful tool to infer homologies of floral organs and to understand floral evolution. Caryophyllaceae is a major family of core Caryophyllales that possesses petal-like structures (petaloids) with a great diversity in shape. The main purpose of this study is to determine the nature of the second whorl of floral organs in Caryophyllaceae. Mainstream views consider ancestors of Caryophyllaceae as apetalous and interpret petals as centrifugally derived staminodial appendages. This hypothesis, based on morphological similarities of petals with stamens and previous ancestral state reconstruction, is tested here. Methods A floral developmental investigation of five species was carried out using scanning electron microscopy, combined with character optimization of the presence or absence of second-whorl petaloids. Key Results The calyx is always well developed with a quincuncial aestivation. Petaloids either develop by fractionation of common stamen–petal primordia, as in Spergularia, or petaloid development is independent and precedes alternisepalous stamens in Saponaria and Sagina. In Sagina the petaloid whorl is always fully formed but alternisepalous stamens are often reduced or missing. Petaloids are absent in Gymnocarpos and the investigated Cerastium. Conclusions Developmental evidence and character mapping reject the hypothesis that petaloids represent a staminodial whorl and suggest that they are independent structures equivalent to second-whorl petals of most Pentapetalae and present in the basal Caryophyllaceae. Heterochronic shifts, including a delay in petal development and acceleration of androecial growth, are responsible for the amalgamation of petals with the androecium as common stamen–petal primordia and their appearance as stamen-derived appendages. Selective pollinator pressure in Caryophyllaceae led to variable petal expansion or reduction and loss. This trend corresponds largely with the general tendency in the core Caryophyllales for petal loss and perianth reorganization.

scholarly journals Floral development of Hydrocera and Impatiens reveals evolutionary trends in the most early diverged lineages of the Balsaminaceae

2012 ◽  
Vol 109 (7) ◽  
pp. 1285-1296 ◽  
Author(s):  
Steven B. Janssens ◽  
Erik F. Smets ◽  
Alexander Vrijdaghs
Keyword(s):  
Floral Development ◽  
Evolutionary Trends

scholarly journals Phylogeny of Maleae (Rosaceae) Based on Multiple Chloroplast Regions: Implications to Genera Circumscription

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jiahui Sun ◽  
Shuo Shi ◽  
Jinlu Li ◽  
Jing Yu ◽  
Ling Wang ◽  
...  
Keyword(s):  
Molecular Phylogeny ◽  
Phylogenetic Relationships ◽  
Chloroplast Gene ◽  
Generic Level ◽  
Taxonomic Treatment ◽  
The Core ◽  
Data Support ◽  
Basal Clade ◽  
Gene Data

Maleae consists of economically and ecologically important plants. However, there are considerable disputes on generic circumscription due to the lack of a reliable phylogeny at generic level. In this study, molecular phylogeny of 35 generally accepted genera in Maleae is established using 15 chloroplast regions. Gillenia is the most basal clade of Maleae, followed by Kageneckia + Lindleya, Vauquelinia, and a typical radiation clade, the core Maleae, suggesting that the proposal of four subtribes is reasonable. In the core Maleae including 31 genera, chloroplast gene data support that the four Malus-related genera should better be merged into one genus and the six Sorbus-related genera would be classified into two genera, whereas all Photinia-related genera should be accepted as distinct genera. Although the phylogenetic relationships among the genera in Maleae are much clearer than before, it is still premature to make a formal taxonomic treatment for these genera.

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