Comparative floral ontogeny of single-flowered and double-flowered phenotypes of Alcea rosea (Malvaceae)

2014 ◽  
Vol 62 (3) ◽  
pp. 217 ◽  
Author(s):  
Somayeh Naghiloo ◽  
Zahra Esmaillou ◽  
Mohammad Reza Dadpour
Keyword(s):  
Light Microscopy ◽  
Free Space ◽  
Developmental Pathways ◽  
Partial Replacement ◽  
Floral Ontogeny ◽  
Spiral Sequence ◽  
Proliferation And Differentiation ◽  
Floral Differentiation ◽  
Mutant Phenotypes ◽  
Alcea Rosea

A comparative study of floral ontogeny in single- and double-flowered Alcea rosea L. was conducted using epi-illumination light microscopy. In both floral types, floral differentiation starts with the appearance of three epicalyx lobes, which subsequently subdivide to produce a 7–10-parted epicalyx. Five sepals appear then in a unidirectional or possibly spiral sequence. In single flowers, a corolla-androecium common primordium is formed and subsequently differentiated into five androecial sectors (= primary androecial primordia). Petals are developed at the base of the androecial sectors and secondary androecial primordia are initiated centrifugally in two rows on each sector. Later, tertiary androecial primordia are formed by the subdivision of secondary androecial primordia, which then differentiate into androecial units. Three types of double flowers were identified regarding androecial development. The first type of double flowers shows a more or less disorganised nature. However, 10 proliferation zones can be indentified in the proximal and distal tips of the androecial sectors. In the second and third types of double flowers, androecial development follows similar developmental pathways to that of single flowers. However, in second-type double flowers, the secondary androecial primordia differentiate into petals and the stamens then develop from the free space between the two rows of secondary androecial primordia. In third-type double flowers, after complete primordial partitioning, some primordia on the marginal parts of each androecial sector develop into petaloids or intermediate appendages. The gynoecium appears similarly in both floral types as numerous congenitally united carpel primordia. The double-flowered phenotypes of Alcea appear to fit the criteria for homoheterotopy with complete or partial replacement of stamens with petals, as well as for neoheterotopy, with the formation of stamens in a new position. Based on mutant phenotypes, it is suggested that different functions possibly contribute to the proliferation and differentiation of common primordia.

Inflorescence and floral ontogeny in Jasminum fruticans (Oleaceae)

2011 ◽  
Vol 59 (5) ◽  
pp. 498 ◽  
Author(s):  
Mohammad Reza Dadpour ◽  
Somayeh Naghiloo ◽  
Somayeh Faridi Neycharan
Keyword(s):  
Light Microscopy ◽  
Distal Portion ◽  
Common Pathway ◽  
Floral Ontogeny ◽  
Floral Organs ◽  
The Common

The inflorescence and floral ontogeny of the oleaceous tropical bush, Jasminum fruticans L. were studied using epi-illumination light microscopy and compared with other Oleaceae. The flowers are arranged in a thyrsoid inflorescence with a determinate pattern of development. Deviations from the common pathway of floral ontogeny in Oleaceae observed in J. fruticans are characterised by pentamery in calyx and corolla, diagonal position of sepals, some deviation from acropetal and simultaneous initiation of floral organs. Sepals are helically initiated, beginning with the abaxial sepal. Formation of petal lobes from the ring meristem also is not simultaneous with the initiation of three petals before the others. Concurrently with the formation of corolla ring, two stamens are initiated sequentially. Two median carpels are the last organs to be initiated. Unusual features of organ enlargement include the quincuncial-imbricate aestivation of the corolla and formation of trichomes on the distal portion of petals and stamens.

Comparative development of perianth and androecial primordia of the single flower and the homeotic double-flowered mutant in Hibiscus rosa-sinensis (Malvaceae)

1996 ◽  
Vol 74 (12) ◽  
pp. 1871-1882 ◽  
Author(s):  
Judith P. Maclntyre ◽  
Christian R. Lacroix
Keyword(s):  
Floral Development ◽  
Developmental Pathways ◽  
Partial Replacement ◽  
Double Flower ◽  
Flower Petal ◽  
Hibiscus Rosa Sinensis ◽  
Stamen Primordia ◽  
Staminal Tube ◽  
Mature Flower ◽  
Single Flower

The double-flowered variety of Hibiscus rosa-sinensis L. (Malvaceae) displays a divergent floral morphology that appears to fit the criteria for homeosis. A comprehensive definition defines homeosis as the complete or partial replacement of one part of an organism with another part. The corolla of the single flower is pentamerous. The mature flower has a staminal tube bearing 60 – 70 stamens that surrounds an exserted synstylous gynoecium with five fused stigmas. In double flowers, the outermost whorl of petals is similar in appearance to that of the single flower. The remaining floral appendages have a morphology that is intermediate between petals and stamens, to varying degrees. No two double flowers are exactly the same, even on the same plant. As with other members of the Malvaceae, floral development in both floral types is unusual: once the calyx has been initiated, a ring meristem is formed from which both petal and stamen primordia are initiated. In the single flower, petal primordia are initiated on the flank of the ring, and then stamen primordia arise in five distinct and orderly clusters. In the double flower, petal primordia are also initated on the abaxial flank, but the remainder of the ring initiates primordia that form a mixture of petals, petal – stamen intermediates, and stamens. A common ring meristem that has two different developmental pathways provides a novel opportunity to study homeosis from the perspective of comparative developmental morphology. Keywords: homeosis, Hibiscus rosa-sinensis, androecium, intermediates, ring meristem, floral development.

Application of Epi-Illumination Light Microscopy for Study of Floral Ontogeny in Fruit Trees

2007 ◽  
Vol 4 (1) ◽  
pp. 49-55 ◽  
Author(s):  
M.R. Dadpour ◽  
W. Grigorian ◽  
A. Nazemieh ◽  
M. Valizadeh
Keyword(s):  
Light Microscopy ◽  
Fruit Trees ◽  
Floral Ontogeny

Cerebral cavernous malformations: from genes to proteins to disease

2012 ◽  
Vol 116 (1) ◽  
pp. 122-132 ◽  
Author(s):  
Daniel D. Cavalcanti ◽  
M. Yashar S. Kalani ◽  
Nikolay L. Martirosyan ◽  
Justin Eales ◽  
Robert F. Spetzler ◽  
...  
Keyword(s):  
Chromosomal Abnormalities ◽  
The Body ◽  
Developmental Pathways ◽  
Cerebral Cavernous Malformations ◽  
Cavernous Malformations ◽  
Past Half Century ◽  
Autosomal Dominant Fashion ◽  
Proliferation And Differentiation ◽  
Past Half ◽  
Shed Light

Over the past half century molecular biology has led to great advances in our understanding of angio- and vasculogenesis and in the treatment of malformations resulting from these processes gone awry. Given their sporadic and familial distribution, their developmental and pathological link to capillary telangiectasias, and their observed chromosomal abnormalities, cerebral cavernous malformations (CCMs) are regarded as akin to cancerous growths. Although the exact pathological mechanisms involved in the formation of CCMs are still not well understood, the identification of 3 genetic loci has begun to shed light on key developmental pathways involved in CCM pathogenesis. Cavernous malformations can occur sporadically or in an autosomal dominant fashion. Familial forms of CCMs have been attributed to mutations at 3 different loci implicated in regulating important processes such as proliferation and differentiation of angiogenic precursors and members of the apoptotic machinery. These processes are important for the generation, maintenance, and pruning of every vessel in the body. In this review the authors highlight the latest discoveries pertaining to the molecular genetics of CCMs, highlighting potential new therapeutic targets for the treatment of these lesions.

Msx homeobox genes inhibit differentiation through upregulation ofcyclin D1

Development ◽  
2001 ◽  
Vol 128 (12) ◽  
pp. 2373-2384 ◽  
Author(s):  
Gezhi Hu ◽  
Hansol Lee ◽  
Sandy M. Price ◽  
Michael M. Shen ◽  
Cory Abate-Shen
Keyword(s):  
Cell Cycle ◽  
Cyclin D1 ◽  
Cellular Proliferation ◽  
Homeobox Genes ◽  
Mammary Epithelium ◽  
Cell Types ◽  
Proliferation And Differentiation ◽  
Tumor Virus ◽  
Mutant Phenotypes ◽  
Mmtv Ltr

During development, patterning and morphogenesis of tissues are intimately coordinated through control of cellular proliferation and differentiation. We describe a mechanism by which vertebrate Msx homeobox genes inhibit cellular differentiation by regulation of the cell cycle. We show that misexpression of Msx1 via retroviral gene transfer inhibits differentiation of multiple mesenchymal and epithelial progenitor cell types in culture. This activity of Msx1 is associated with its ability to upregulate cyclin D1 expression and Cdk4 activity, while Msx1 has minimal effects on cellular proliferation. Transgenic mice that express Msx1 under the control of the mouse mammary tumor virus long terminal repeat (MMTV LTR) display impaired differentiation of the mammary epithelium during pregnancy, which is accompanied by elevated levels of cyclin D1 expression. We propose that Msx1 gene expression maintains cyclin D1 expression and prevents exit from the cell cycle, thereby inhibiting terminal differentiation of progenitor cells. Our model provides a framework for reconciling the mutant phenotypes of Msx and other homeobox genes with their functions as regulators of cellular proliferation and differentiation during embryogenesis.

The strawberry notch gene functions with Notch in common developmental pathways

Development ◽  
1993 ◽  
Vol 119 (2) ◽  
pp. 377-395 ◽  
Author(s):  
C.A. Coyle-Thompson ◽  
U. Banerjee
Keyword(s):  
Notch Pathway ◽  
Developmental Pathways ◽  
Wild Type ◽  
Phenotypic Analysis ◽  
Extra Copy ◽  
Its Gene ◽  
Gene Functions ◽  
Specific Manner ◽  
Notch Gene ◽  
Mutant Phenotypes

Genetic and phenotypic analysis of strawberry notch suggests that its gene product is required during embryogenesis and oogenesis, and for the development of the eye, wing and leg. Several lines of evidence suggest that strawberry notch participates together with Notch in many common pathways. A number of strawberry notch mutant phenotypes are similar to those of Notch mutants and can be rescued by an extra copy of wild-type Notch. In addition, mutations in strawberry notch interact strongly with Notch mutants in a tissue-specific manner. Mutations in the strawberry notch and Notch loci also show very similar interactions with genes like Hairless, Delta, groucho, Serrate, and deltex that have all been proposed to participate in Notch related pathways. The genetic evidence presented here suggests that strawberry notch participates with members of the Notch pathway in facilitating developmentally relevant cell-cell communications.

scholarly journals Different ways to obtain similar results: the development of the corolla and epipetaly in Rubieae (Rubioideae, Rubiaceae)

2020 ◽  
Vol 153 (3) ◽  
pp. 466-486
Author(s):  
Alexander Vrijdaghs ◽  
Erik Smets ◽  
Petra De Block
Keyword(s):  
Light Microscopy ◽  
19Th Century ◽  
Floral Development ◽  
Corolla Tube ◽  
Sensu Stricto ◽  
Herbaceous Plants ◽  
Floral Ontogeny ◽  
Developmental Processes ◽  
Postgenital Fusion ◽  
Scanning Electron

Background and aims – Rubieae is a tribe in the subfamily Rubioideae characterised by herbaceous plants with verticillate leaves and flowers with a rudimentary or absent calyx and a short, cup-shaped corolla. This is in contrast to the flowers of most other Rubiaceae, in which the tubular corolla is longer than the corolla lobes. Also, the description by Payer, a French 19th century pioneer of floral ontogenetic research, of the floral development in Asperula, Galium, and Rubia deviates from recent insights about the development of tubular corollas, which are based on investigations of flowers of tropical Rubiaceae. Tubular corollas are currently considered as resulting from the development of underlying annular intercalary meristems, whereas Payer explained the tubular corollas in the three taxa by postgenital fusion. We therefore tested both hypotheses in six Rubieae genera, including the three taxa studied by Payer.Methods – Floral ontogeny of ten species in six Rubieae genera based on scanning electron (SEM) and light microscopy (LM). Conclusions – Our results suggest that, in all species studied, the mature phenotype of the corolla as well as the epipetaly of the stamens is caused by a combination of three developmental processes (the development of a stamen-corolla tube, the development of a corolla tube sensu stricto, and postgenital fusion), and the relative moment of activation of each of these processes during floral development (plastochron variation or heterochrony).

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

The Broad Applications of the Scanning Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 20-21
Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscopy ◽  
Surface Topography ◽  
Great Depth ◽  
Resolving Power ◽  
Depth Of Field ◽  
Pictorial Representations ◽  
Scanning Electron

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.

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