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1.
Front Psychiatry ; 15: 1396556, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38938458

RESUMO

[This corrects the article DOI: 10.3389/fpsyt.2024.1287096.].

2.
Protoplasma ; 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38822209

RESUMO

Alicia anisopetala and Callaeum psilophyllum are two closely related species that belong to the christianelloid clade of the family Malpighiaceae. Both species are pollinated by oil-collecting bees and exhibit variations at specimen and population level in the number of elaiophores per flower. These floral glands that secrete non-volatile oils constitute an ancestral trait for the family. There is evidence that the observed variations in the number of elaiophores can be the result of processes of connation or reduction associated with differences in their vascularization. In order to identify which process occurs in each species, we conducted an anatomical study in natural populations of both species distributed along a wide range of their geographical distributions in Argentina. We collected flowers of different individuals, counted the number of elaiophores per flower, carried out exomorphological observations, and used conventional histological techniques to examine the vascularization of these glands. The floral anatomy of both species does not show any modifications in other whorls related to the fusion or reduction of elaiophores. Our results indicate that the process of loss of elaiophores in A. anisopetala is caused by incomplete connation and in C. psilophyllum by reduction, suggesting that the processes that lead to the loss of elaiophores in Malpighiaceae are homoplastic and would not reflect phylogenetic signals.

3.
Front Psychiatry ; 15: 1287096, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38317766

RESUMO

Introduction: Societal perceptions and lack of understanding of autism spectrum disorder can be stigmatizing for autistic individuals and their families. This may be particularly the case for individuals who meet criteria for profound autism. Despite the considerable service needs of this marginalized group, there is little data on the prevalence of profound autism, nor on the experiences of those with profound autism and their families. Methods: The current study leveraged a mixed-methods approach to address these gaps. First, the prevalence of profound autism was examined in six samples-three from the United States and three from Western Europe. Second, inductive thematic analysis was used to code interviews from 20 caregivers of profoundly autistic adults. Results: The prevalence of profound autism varied widely across the six samples-from 11% to 48%. There were also notable differences between samples in prevalence by gender, race, and ethnicity. Two overarching themes were identified via inductive thematic analysis: Community Perceptions of Autism and Family Support Needs and Advocacy Challenges. Though caregivers were not directly asked about stigmatization during interviews, 85% of caregivers reported at least one instance of perceived stigma. Discussion: Future research should continue to examine the unique needs and stigmatization experiences of profoundly autistic individuals and their families across the life course.

4.
Protoplasma ; 261(4): 725-733, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38286848

RESUMO

Ovule morphology, megasporogenesis, and megagametogenesis processes were examined in Hydrocleys nymphoides, Alisma plantago-aquatica, and Sagittaria montevidensis. Each of these species belongs to a different clade within the Alismataceae family. It is worth mentioning that the genus Hydrocleys previously belonged to the Limnocharitaceae family but is now classified within the Alismataceae. Flowers in different developmental stages were processed following classical histological methods for their observation with bright-field microscope. The three species present an anatropous and bitegmic mature ovule. This is tenuinucellate in A. plantago-aquatica and S. montevidensis and pseudo-crassinucellate in H. nymphoides. Although all three species have the same type of megasporogenesis, they differ in the megagametogenesis and in the total number of nuclei and cells that form the mature gametophyte. H. nymphoides has a female gametophyte composed of four cells and four nuclei, while A. plantago-aquatica and S. montevidensis have a female gametophyte of five cells and six nuclei. The results are discussed according to the phylogenetic position of each of the species. Moreover, new types of megagametophyte development are described: Hydrocleys and Sagittaria types. The reduction of the female gametophyte with respect to the Polygonum type is found in families belonging to the ANA grade and in other aquatic families within the order Alismatales. We infer that the reduction in the number of cells and nuclei in the female gametophyte is characteristic of species that inhabit aquatic environments. Future studies in aquatic species belonging to other families would be necessary to confirm this hypothesis.


Assuntos
Sagittaria , Sagittaria/citologia , Óvulo Vegetal/citologia , Alisma/química , Alisma/citologia , Alismataceae/citologia
5.
Protoplasma ; 261(1): 3-13, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37338648

RESUMO

Ceropegia lenewtonii (Plowes) Bruyns (=Huernia keniensis), currently belonging to the Huernia section of the genus Ceropegia, is a stapeliad species distributed in Africa and the Arabian Peninsula; but it is widely cultivated as ornamental in most parts of the world. This species of stapeliad presents "carrion flowers" associated with a sapromyophilous pollination syndrome since the flowers emit an unpleasant odor. In this work, we describe the floral morphology and anatomy of the calyx, corolla, and corona of this species based on bright-field and scanning electron microscope techniques. We detected the presence of diverse floral secretor tissues, and based on different histochemical tests, the principal component of the secreted substance was identified. We interpret the functions of the glands and compare with other related species of stapeliads. Our results indicate that flowers of C. lenewtonii present colleters in sepals, osmophores in corolla, and primary and secondary nectaries in corona. All these floral glands have specific functions that involve the processes of pollination and reproduction of this species, as well as protection and defense mechanisms.


Assuntos
Apocynaceae , Flores/química , Polinização , Odorantes
6.
Planta ; 257(6): 100, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37084157

RESUMO

MAIN CONCLUSION: The appearance of new cellular structures and characteristics in the tapetum suggests that there is still much to discover that would help to better understand the tapetum functions. The ultrastructure of the tapetum provides important information for the understanding of the functions performed by this tissue. Since there are no reviews on the subject, we aim to collect all the detailed information about the tapetum ultrastructure present until this moment in order to lay the foundations for future research. Detailed information on the tapetal ultrastructure of 80 species from 45 different families: 2 species with invasive non-syncytial tapetum, 11 with plasmodial and 67 with a secretory tapetum was collected. These studies allowed to establish (a) the most usual cytological characteristics of this tissue, (b) unique characteristics and/or cellular structures in tapetum cells, (c) the ultrastructural changes that occur in different types of tapetum, during the progress of microsporogenesis and microgametogenesis, and (d) the most recognized ultrastructural traits of the tapetum that cause androsterility. The structure of these cells is related to their function in each developmental stage. Since most species present their particular ultrastructure and may sometimes, share some traits within families, there is not a model plant on tapetum ultrastructure. However, knowing the general cytological aspect of the tapetum may help distinguish between patterns of cytoplasmic disorganization due to tapetum degeneration from technical failures of the preparation. Moreover, as the amount of species analyzed increases, unknown tapetal organelles or traits may be identified that might be associated to particular functions of this tissue. On the other hand, different ultrastructural changes may be related to the metabolisms and the regulation of normal/abnormal tapetum development.


Assuntos
Magnoliopsida , Plantas , Citoplasma
7.
Planta ; 257(1): 3, 2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36418498

RESUMO

MAIN CONCLUSIONS: Transmitting tissue cells of Luehea divaricata present a thick middle lamella and prominent convex lens-shaped thickenings of the cell wall that act as reservoir of energy for pollen tube growth. Luehea Milld. is a Neotropical genus with 18 species. This paper reports the study of the structure and the ultrastructure of the stigma and the style of Luehea divaricata Milld. using bright-field microscope and transmission electron microscope. Multiseriate papillae are observed in the stigma. The papillae cells are large with a content that stains intensively and the sub-stigmatic tissue resembles the style's transmitting tissue. L. divaricata has a closed style with an epidermis that presents raised stomata and multicellular trichomes. Numerous organelles and a large nucleus are present in the dense cytoplasm of the transmitting tissue cells. A relevant feature is that the cells of this tissue in the species studied present a very thick middle lamella with two zones of different electron density in the angle of contact between cells, and convex lens-shaped thickenings of the cell wall are prominent mainly also in these angles of contact. The growth of the pollen tube is initiated on the stigmatic papillae surface and continues growing in the middle lamella of the sub-stigmatic tissue and the transmitting tissue, mainly at the contact angle between cells. The present work is the first contribution to the knowledge of structure and ultrastructure of the stigma and style in the genus Luehea, as well as to the subfamily Grewioideae (Malvaceae).


Assuntos
Malvaceae , Núcleo Celular , Citoplasma , Tubo Polínico , Coloração e Rotulagem
9.
Protoplasma ; 258(5): 1091-1102, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33619655

RESUMO

Catasetum fimbriatum is a dioecious species whose flowers fully adapted to an euglossinophilic mode of pollination. Euglossini male bees collect the volatile fragrances which are produced in osmophores on the flowers. In order to understand the mechanism of scent secretion and floral interaction with the pollinator, we describe the location, histochemistry, anatomy, and ultrastructure of osmophores in pistillate and staminate flowers of this species. Fresh flowers were submerged in neutral red solution to locate the position of the osmophores. Other histochemical test performed includes the NADI reaction to detect terpenoids, Sudan IV for lipids, and Lugol's iodine solution to detect starch. Anatomical and ultrastructural traits were studied with bright field and transmission electron microscopes, respectively. The location of osmophores differs between pistillate and staminate flowers. In pistillate flowers, secretory tissues were observed on the ribbed adaxial surface of the labellum, but not on its margins, whereas in staminate flowers, they were found throughout the adaxial surface of the labellum and especially in the fimbriae. Anatomy and ultrastructure of the osmophores in the labellum of both types of flowers were similar. They present characteristics of metabolically active cells, such as abundant mitochondria, rough endoplasmic reticulum, vesicles, plastids with starch grains, and lipid globules. Granulocrine secretion and cycles of cytoplasmic contraction and expansion appear to allow the release of products without involving the rupture of the cuticle. Individuals of Eufriesea auriceps and Euglossa sp. were captured in staminate and pistillate flowers but, it seems likely, that only the former pollinates this orchid species.


Assuntos
Orchidaceae , Animais , Abelhas , Flores , Odorantes , Polinização , Terpenos
10.
An Acad Bras Cienc ; 92(suppl 2): e20181382, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33174909

RESUMO

The aim of this paper is to investigate the ultrastructural events that occur during pollen grains development, with emphasis in pollen grain wall and tapetum ontogeny in Ziziphus jujuba, Z. mucronata, Paliurus spina-christi (Paliureae) and Gouania ulmifolia (Gouanieae). Anthers at different developmental stages were processed according to classic techniques for transmission electron microscopy. Differences in the number of endothecium layers and in the number of tapetal cell nuclei were found. Tapetal cells present an anastomosing tubular network and large vesicles with fibrillar content in the cytoplasm. Pollen grain development and ontogeny of pollen grain wall are similar in the four species. The number of endothecium layers, the number of nuclei of the tapetal cells and tapetal cells ultrastructure of the four species support the phylogenetic relationships previously published for the Rhamnaceae family. Tapetal vesicles with fibrillar or polysaccharide content seem to be an exclusive characteristic of the tribes Paliureae and Gouanieae. Some ultrastructural characters of the pollen grain wall development are common to other species of Rhamnaceae, such as the primexine matrix present at the microspore mother cell stage, the aperture entirely built up during the tetrad stage, the thick and fibrillar intine, and the granular infractectum.


Assuntos
Rhamnaceae , Ziziphus , Microscopia Eletrônica de Transmissão , Filogenia , Pólen
11.
Protoplasma ; 257(4): 1109-1121, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32152721

RESUMO

Although the presence of scent was described for several species of Rhamnaceae, localization, morphology and structure of osmophores were unknown. We studied different species of the tribes Rhamneae (Rhamnoids clade), Pomaderreae, Colletieae, Paliureae (Ziziphoids clade) and the species Alphitonia excelsa (unknown tribe, Ziziphoids clade). We expect to have a better comprehension of these structures and provide information on which morphological and anatomical characters may support the phylogeny of the family. We localized the osmophores in the margins and top of the sepals using neutral red. Histochemical tests were made on transverse hand-cut sections of fresh sepals. Observations were made with stereoscopic and bright field microscopes, scanning and transmission electron microscopes. Papillae were observed in the zones with positive reaction to reagents. Different kinds of hairs are present in the sepal epidermis besides papillae. Epidermal cells present a striate cuticle with canals and cavities. Druses are abundant in most species. The ultrastructure of epidermal and subepidermal cells shows high metabolic activity: there are vesicles, mitochondria, endoplasmic reticulum, dictyosomes, plastids with lipids and starch. The vascularization is well developed and reaches the top of the sepal where the principal area of volatile components production is localized. The location and abundance of papillae are the most important traits that allow us recognize and characterize the osmophores in Rhamnaceae. There are no clear anatomical and morphological features exclusive of one clade or tribe. Therefore, in contrast to other sporophytic structures of this family, osmophores do not seem to have any systematic value.


Assuntos
Microscopia Eletrônica de Varredura/métodos , Rhamnaceae/anatomia & histologia , Rhamnaceae/ultraestrutura
12.
Protoplasma ; 256(4): 1133-1144, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30953173

RESUMO

We analyzed the gynoecium morphology and anatomy of Tricomaria usillo in young and mature flowers from diverse populations in order to analyze the differentiation of structure and function of the parts of the carpel. We also aimed to find the potential pollinators and associate the morphology of the gynoecium with its role. We compare the characteristics of the gynoecium of T. usillo and discuss the carpel dimorphism with other genera within the Carolus clade in relation with their pollination syndromes. Carpels were processed according to classic techniques for scanning electron microscopy and bright field microscopy. We conducted field observation in different populations of T. usillo and captured the insects that were identified to specific level. The gynoecium of T. usillo shows inter-population and intra-individual variability. Some have three well-developed carpels, while most of them present two posterior carpels with differentiated styles and stigmas and the anterior one with a shorter style with or without stigma. The ovary has three locules with one ovule each. A compitum is formed and all ovules may be fecundated. However, fruits have generally one seed that develops in the anterior locule. Centris brethesi is the potential pollinator. The gynoecium of T. usillo reflects part of the variation in the carpel dimorphism that probably arose in the branch of the Carolus clade, and evolved in diverse ways in the lineages of this group. Tricomaria usillo seems to represent a recent transition towards reaching a stable form of carpel dimorphism and definitive division of labors of the carpels.


Assuntos
Flores/anatomia & histologia , Malpighiaceae/anatomia & histologia , Flores/fisiologia , Malpighiaceae/fisiologia , Microscopia Eletrônica de Varredura , Óvulo Vegetal/anatomia & histologia , Óvulo Vegetal/fisiologia , Polinização
13.
Protoplasma ; 255(5): 1433-1442, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29594351

RESUMO

The family Malpighiaceae, particularly in the Neotropic, shows a similar floral morphology. Although floral attraction and rewards to pollinators are alike, stigmas and styles show more diversity. The stigmas were described covered with a thin and impermeable cuticle that needs to be ruptured by the mechanical action of the pollinators. However, this characteristic was only mentioned for a few species and the anatomy and ultrastructure of the stigmas were not explored. In this work, we analyze the morphology, anatomy, and ultrastructure of the stigma and style of Callaeum psilophyllum. Moreover, we identify the potential pollinators in order to evaluate how the disposition of the stigmas is related with their size and its role in the exposure of the receptive stigmatic surface. Our observations indicate that Centris flavifrons, C. fuscata, C. tarsata, and C. trigonoides are probably efficient pollinators of C. psilophyllum. The three stigmas are covered by a cuticle that remained intact in bagged flowers. The flowers exposed to visitors show the cuticle broken, more secretion in the intercellular spaces between sub-stigmatic cells and abundant electron-dense components inside vacuoles in stigmatic papillae. This indicates that the stigmas prepares in similar ways to receive pollen grains, but the pollinator action is required to break the cuticle, and once pollen tubes start growing, stigmatic and sub-stigmatic cells release more secretion by a granulocrine process.


Assuntos
Malpighiaceae/fisiologia , Flores/metabolismo , Flores/fisiologia , Flores/ultraestrutura , Malpighiaceae/metabolismo , Malpighiaceae/ultraestrutura , Polinização/fisiologia
14.
Protoplasma ; 255(2): 501-515, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28913647

RESUMO

The ultrastructure of the style and pollen tube pathway before, during and after anthesis were studied in 13 species belonging to the tribes Pomaderreae, Paliureae, Colletieae and Gouanieae (Ziziphoid clade) and Rhamneae (Rhamnoid clade) using light microscopy and transmission electron microscopy. The aim of this study is to provide new morphological characters useful for phylogenetic analysis at suprageneric level in Rhamnaceae. The patterns of pollen tube growth and the ultrastructural changes undergone by cells of the style were also described. Species of Rhamneae (Scutia buxifolia and Condalia buxifolia) have a solid style, with the transmitting tissue forming three independent strands (S. buxifolia) or a central, single horseshoe-shaped strand as seen in transversal section (C. buxifolia) which could derive from the fusion of formerly independent strands. In contrast, Pomaderreae, Gouanieae and Paliureae showed semi-solid styles, while in Colletieae, as previously reported, the style is hollow with two or three stylar canals. The style anatomy and the ultrastructure of the pollen tube pathway show that there is a tendency towards a solid style with a single strand of transmitting tissue within the family. The three-canalled hollow style could be the plesiomorphic state of the character "type of style" in the family, the semi-solid style the synapomorphic state and the solid style with three strands of transmitting tissue the apomorphic state, with the solid style with a single strand of transmitting tissue as the most derived state. Therefore, Colletieae would be the most basal tribe of the Ziziphoid clade.


Assuntos
Tubo Polínico/anatomia & histologia , Rhamnaceae/anatomia & histologia , Fertilização , Tubo Polínico/citologia , Tubo Polínico/crescimento & desenvolvimento , Tubo Polínico/ultraestrutura , Rhamnaceae/citologia , Rhamnaceae/ultraestrutura
15.
Protoplasma ; 253(4): 1125-33, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26277353

RESUMO

Despite that there is some literature on pollen morphology of Rhamnaceae, studies addressing general aspects of the microsporogenesis, microgametogenesis, and anther development are rare. The aim of this paper is to describe the ultrastructure of pollen grain ontogeny with special attention to tapetum cytology in Hovenia dulcis. Anthers at different stages of development were processed for transmission and scanning electron microscopy, bright-field microscopy, and fluorescence microscopy. Different histochemical reactions were carried out. The ultrastructural changes observed during the development of the tapetal cells and pollen grains are described. Large vesicles containing carbohydrates occur in the tapetal cell cytoplasm during the early stages of pollen development. Its origin and composition are described and discussed. This is the first report on the ontogeny and ultrastructure of the pollen grain and related sporophytic structures of H. dulcis.


Assuntos
Gametogênese Vegetal , Pólen/crescimento & desenvolvimento , Rhamnaceae/crescimento & desenvolvimento , Vesículas Citoplasmáticas/fisiologia , Vesículas Citoplasmáticas/ultraestrutura , Pólen/metabolismo , Pólen/ultraestrutura , Polissacarídeos/metabolismo , Rhamnaceae/metabolismo , Rhamnaceae/ultraestrutura
16.
Ann Bot ; 99(4): 755-63, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17353203

RESUMO

BACKGROUND AND AIMS: Although orbicular functions are still a matter of debate, they are considered by most authors to be exclusively formed by a secretory tapetum. However, the presence of orbicules on a peritapetal membrane associated with a plasmodial tapetum has been described for Abutilon pictum (Malvaceae) in a previous study. Thus, studies on other species of Malvaceae are necessary to corroborate the presence of such bodies in other members of the family. Pollen and microsporangium development of Modiolastrum malvifolium has been studied in this work. METHODS: Anthers at different stages of development were processed for transmission electron microscopy and light microscopy. Membranes and pollen walls resistant to acetolysis were isolated from whole anthers. KEY RESULTS: Microspore tetrads have a tetrahedral arrangement. Pollen grains are shed at the bicellular stage. The tapetum is invasive, non-syncytial and a peritapetal membrane with orbicules is formed. CONCLUSIONS: This is the first report of the presence of orbicules on a peritapetal membrane in a species with a tapetum of an invasive, non-syncytial type. Taking into consideration all the information on the subject, it can be concluded that the presence of orbicules is not a stable criterion to differentiate between a secretory or plasmodial, or intermediate invasive, non-syncytial tapetum.


Assuntos
Malvaceae/crescimento & desenvolvimento , Malvaceae/ultraestrutura , Pólen/crescimento & desenvolvimento , Malvaceae/anatomia & histologia , Microscopia Eletrônica de Transmissão , Pólen/anatomia & histologia , Pólen/ultraestrutura
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