Floral morphogenesis and proliferation in Poa labillardieri (Poaceae)

2009 ◽  
Vol 57 (7) ◽  
pp. 602 ◽  
Author(s):  
Nabil M. Ahmad ◽  
Peter M. Martin ◽  
John M. Vella
Keyword(s):  
Developmental Stages ◽  
Early Stage ◽  
Perennial Grass ◽  
Variable Number ◽  
Unknown Factor ◽  
In The Wild ◽  
Vegetative Shoot Apex ◽  
Stage 1 ◽  
Vegetative Propagules ◽  
Short Type

Inflorescence and spikelet development in Poa labillardieri Steud. were investigated by scanning electron microscopy. Thirteen developmental stages were described in detail, starting with the vegetative shoot apex which was shown to be of the short type (stage zero), followed by a conversion from vegetative to floral meristem at Stage 1 and ending at Stage 12, with a mature panicle consisting of a variable number of florets at anthesis within each spikelet. The occurrence of short-type vegetative apices in this perennial grass adds further support to the view that there is no correlation between life span and the apex type. The branches of the P. labillardieri panicle are formed in acropetal succession; however, it is the upper branches that first bear rudiments of the spikelets, starting at the tip of the branches. In contrast differentiation of florets within each spikelet occurs in acropetal succession, so that the basal floret is farthest advanced and each successively upper floret less advanced. P. labillardieri occasionally produces inflorescences containing spikelets in which some or all of the florets are replaced by a plantlet that is structurally similar to a vegetative tiller. Proliferous development ranged from a situation where all florets were converted to vegetative propagules that can be detached and rooted readily in soil, to cases where proliferation extended only as far as an enlargement of the lemma, with either functional or non-functional sexual organs in its axil. Under greenhouse conditions, there was a shift from occasional cases of partially proliferating spikelets that occur in the wild to complete vigorous proliferation stimulated by unknown factor(s). Departure from the normal sexual pattern took place from early Stage 5 (initiation of spikelet primordial) to late Stage 6 (differentiation of florets).

Observation of Aneurobracon philippinensis (Hymenoptera: Braconidae) Immatures Shows How Koinobiont Offspring Flexibly Adjust Their Development to Host Growth

2019 ◽  
Vol 112 (5) ◽  
pp. 490-496 ◽  
Author(s):  
Haruka Aoyama ◽  
Issei Ohshima
Keyword(s):  
Developmental Stages ◽  
Early Stage ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
First Instar ◽  
Leaf Mining ◽  
Wild Host ◽  
Host Growth ◽  
In The Wild ◽  
The Ideal

AbstractKoinobionts are parasitoids that allow their hosts to grow after infection, and they finally kill their host individuals at parasitoid-specific host stages. Since fatal accidents of host organisms directly result in the deaths of parasitizing koinobionts, a longer parasitization period in vulnerable hosts is likely to increase the mortality of the koinobionts. However, for hosts inhabiting concealed environments in their later developmental stages, koinobionts should begin parasitization in early-stage hosts to make use of the grown hosts. A koinobiont parasitoid, Aneurobracon philippinensis (Muesebeck), mainly uses a leaf-mining moth, Acrocercops transecta Meyrick (Lepidoptera: Gracillariidae) as a host. Due to the three-dimensional structure of the mines constructed by later instars of A. transecta, females of A. philippinensis seldomly oviposit into later instar hosts, whereas feeding on final instar hosts is essential for A. philippinensis larvae. This implies that oviposition targets in the wild are shifted to early instars, though the final instar is the ideal target to shorten the parasitization period. The dissection of wild host larvae demonstrated that no eggs were observed in the final instar, supporting the above expectation. Laboratory parasitization experiments revealed that A. philippinensis eggs hatched approximately 80 h after oviposition, and hatched larvae stayed in the first instar until the host larvae completed making cocoons. These results suggest that the first-instar period of the parasitoid larvae functions as an adjusting period to synchronize the parasitoid and host developmental stages and that koinobiosis plays an important role in utilizing the final instar of A. transecta as a resource.

Alterations in the number of motoneurons containing immunoreactive calcitonin gene-related peptide(CGRP)& choline acetyltransferase(ChAT) in the cervical spinal cord of the wobbler mouse during the development of the motoneuron disease

1995 ◽  
Vol 53 ◽  
pp. 970-971
Author(s):  
L. Vacca-Galloway ◽  
Y.Q. Zhang ◽  
P. Bose ◽  
S.H. Zhang
Keyword(s):  
Spinal Cord ◽  
Early Stage ◽  
Cervical Spinal Cord ◽  
Wild Type Mouse ◽  
Reflex Response ◽  
Mouse Strains ◽  
Behavioral Tests ◽  
Wobbler Mouse ◽  
Stage 4 ◽  
Stage 1

The Wobbler mouse (wr) has been studied as a model for inherited human motoneuron diseases (MNDs). Using behavioral tests for forelimb power, walking, climbing, and the “clasp-like reflex” response, the progress of the MND can be categorized into early (Stage 1, age 21 days) and late (Stage 4, age 3 months) stages. Age-and sex-matched normal phenotype littermates (NFR/wr) were used as controls (Stage 0), as well as mice from two related wild-type mouse strains: NFR/N and a C57BI/6N. Using behavioral tests, we also detected pre-symptomatic Wobblers at postnatal ages 7 and 14 days. The mice were anesthetized and perfusion-fixed for immunocytochemical (ICC) of CGRP and ChAT in the spinal cord (C3 to C5).Using computerized morphomety (Vidas, Zeiss), the numbers of IR-CGRP labelled motoneurons were significantly lower in 14 day old Wobbler specimens compared with the controls (Fig. 1). The same trend was observed at 21 days (Stage 1) and 3 months (Stage 4). The IR-CGRP-containing motoneurons in the Wobbler specimens declined progressively with age.

scholarly journals Temporal changes of quantitative CT findings from 102 patients with COVID-19 in Wuhan, China: A longitudinal study

2021 ◽  
Vol 29 ◽  
pp. 297-309
Author(s):  
Xiaohui Chen ◽  
Wenbo Sun ◽  
Dan Xu ◽  
Jiaojiao Ma ◽  
Feng Xiao ◽  
...  
Keyword(s):  
Lung Diseases ◽  
Early Stage ◽  
Temporal Changes ◽  
Time Interval ◽  
Lesion Area ◽  
Quantitative Ct ◽  
Diagnosis And Prognosis ◽  
Ct Findings ◽  
Stage 4 ◽  
Stage 1

BACKGROUND: Computed tomography (CT) imaging combined with artificial intelligence is important in the diagnosis and prognosis of lung diseases. OBJECTIVE: This study aimed to investigate temporal changes of quantitative CT findings in patients with COVID-19 in three clinic types, including moderate, severe, and non-survivors, and to predict severe cases in the early stage from the results. METHODS: One hundred and two patients with confirmed COVID-19 were included in this study. Based on the time interval between onset of symptoms and the CT scan, four stages were defined in this study: Stage-1 (0 ∼7 days); Stage-2 (8 ∼ 14 days); Stage-3 (15 ∼ 21days); Stage-4 (> 21 days). Eight parameters, the infection volume and percentage of the whole lung in four different Hounsfield (HU) ranges, ((-, -750), [-750, -300), [-300, 50) and [50, +)), were calculated and compared between different groups. RESULTS: The infection volume and percentage of four HU ranges peaked in Stage-2. The highest proportion of HU [-750, 50) was found in the infected regions in non-survivors among three groups. CONCLUSIONS: The findings indicate rapid deterioration in the first week since the onset of symptoms in non-survivors. Higher proportion of HU [-750, 50) in the lesion area might be a potential bio-marker for poor prognosis in patients with COVID-19.

scholarly journals Influence of Parenting Styles and Developmental Stages on Identity Formation among Adolescents

2017 ◽  
Vol 4 (3) ◽  
Author(s):  
Ahmad Rezvan ◽  
H. M. Ramakrishne Gowda ◽  
Lancy D’Souza
Keyword(s):  
Identity Formation ◽  
Parenting Styles ◽  
Collective Identity ◽  
Rural Areas ◽  
Developmental Stages ◽  
Early Stage ◽  
Personality Development ◽  
Late Adolescents ◽  
Authoritarian Parenting ◽  
Significant Difference

Paternal attitudes, beliefs and behaviors that appear as family pattern or parenting styles play a key role in personality development and stabilizing the identity of adolescents. The present study assesses parenting styles and identity formation status of adolescents studying in and around Mysore city. A total of 400 adolescents (200 early and 200 late adolescents) were randomly selected covering Mysore city and nearby rural areas, of which equal number among were male and female adolescents and also equal number of them were from urban and rural areas. They were provided with Parental authority questionnaire (PAQ) developed by Buri (1991) and Aspects of Identity Questionnaire – IV (AIQ – IV) developed by Sampson (1978). PAQ measured perceived parenting styles. The AIQ scale measured personal, Relational Social and Collective areas of identity formation. The collected data were, coded and analyzed using SPSS software. The data was analyzed by Two-way ANOVA to find significant difference if any, in the developmental stages, area of living as well as gender of the participants. Results revealed that, adolescents with authoritarian Parenting styles had higher personal identity formation than adolescents with permissive and authoritarian parenting styles. Developmental stage showed significant influence on all components of identity-Personal, Relational, Social and Collective, where in early stage adolescents had higher identity than adolescents at later stage. In general, this study showed that the developmental stages had considerable effect on the collective identity formation in both early and late adolescents.

scholarly journals Cnidome and Morphological Features of Pelagia noctiluca (Cnidaria: Scyphozoa) Throughout the Different Life Cycle Stages

2021 ◽  
Vol 8 ◽  
Author(s):  
Ainara Ballesteros ◽  
Carina Östman ◽  
Andreu Santín ◽  
Macarena Marambio ◽  
Mridvika Narda ◽  
...  
Keyword(s):  
Life Cycle ◽  
Developmental Stages ◽  
Later Life ◽  
Life Stages ◽  
Accurate Identification ◽  
Early Stages ◽  
Pelagia Noctiluca ◽  
Life Cycle Stages ◽  
Advanced Stages ◽  
Stage 1

Pelagia noctiluca is considered the most important jellyfish in the Mediterranean Sea, due to its abundance and the severity of its stings. Despite its importance in marine ecosystems and the health problems caused by its massive arrival in coastal areas, little is known about its early life stages and its cnidome has never been described. This study of the morphological and anatomical features throughout the life cycle identifies four early stages: two ephyra and two metaephyra stages. Ephyra stage 1, newly developed from a planula, has no velar canals, gastric filaments or nematocyst batteries. Ephyra stage 2, has velar canals, a cruciform-shaped manubrium and gastric filaments. Metaephyra stage 3 has eight tentacle buds and nematocyst clusters for the first time. Lastly, in metaephyra stage 4, the eight primary tentacles grow nearly simultaneously, with no secondary tentacles. Complete nematocyst battery patterns gradually develop throughout the later life stages. Four nematocyst types are identified: a-isorhiza, A-isorhiza, O-isorhiza and eurytele. Of these, a-isorhiza and eurytele are the most important throughout the entire life cycle, while A-isorhiza and O-isorhiza have a more important role in advanced stages. All nematocysts show a positive correlation between increasing capsule volumes and increasing body diameter of the ephyrae, metaephyrae, young medusae and adult medusae. In the early stages, the volumes of euryteles in the gastric filaments are larger than those in the exumbrella, indicating that the capsule volume is critical in the absence of marginal tentacles, specialized for feeding. This study provides updated information, the most extensive description to date, including high-resolution photographs and schematic drawings of all the developmental stages in the life cycle of P. noctiluca. Additionally, the first cnidome characterization is provided for each stage to facilitate accurate identification of this species when collected in the water column, and to raise awareness of the potential for human envenomation.

scholarly journals Plant Developmental Stage Drives the Differentiation in Ecological Role of Plant Bacterial and Fungal Microbiomes

2021 ◽  
Author(s):  
Chao Xiong ◽  
Brajesh K. Singh ◽  
Ji-Zheng He ◽  
Yan-Lai Han ◽  
Pei-Pei Li ◽  
...  
Keyword(s):  
Developmental Stage ◽  
Plant Development ◽  
Late Stage ◽  
Developmental Stages ◽  
Early Stage ◽  
Alpha Diversity ◽  
Microbial Interactions ◽  
Disease Suppression ◽  
Fungal Communities ◽  
Ecological Role

Abstract BackgroundPlants live with diverse microbial communities which profoundly affect multiple facets of host performance such as nutrition acquisition, disease suppression and productivity, but if and how host development impacts the assembly, functions and microbial interactions of crop microbiomes are poorly understood. Here we examined both bacterial and fungal communities across soils (rhizosphere and bulk soil), plant epiphytic and endophytic niches (phylloplane, rhizoplane, leaf and root endosphere), and plastic leaf of fake plant (representing environment-originating microbes) at three developmental stages of maize at two contrasting sites, and further explored the potential function of phylloplane microbiomes based on metagenomics.ResultsOur results suggested that plant developmental stage had a much stronger influence on the microbial diversity, composition and interkingdom networks in plant compartment niches than in soils, with the strongest effect in the phylloplane. Air (represented by fake plants) was an important source of phylloplane microbiomes which were co-shaped by both plant development and seasonal environmental factors. Further, we demonstrated that bacterial and fungal communities in plant compartment niches exhibited contrasting response to host developmental stages, with higher alpha diversity and stronger deterministic assembly within bacterial microbiomes at the early stage but a similar pattern within mycobiomes at the late stage. Moreover, we found that bacterial taxa played a more important role in microbial interkingdom network and crop yield prediction at the early stage, while fungal taxa did so at the late stage. Metagenomic analyses further indicated that phylloplane microbiomes possessed higher functional diversity and functional genes involved in nutrient provision and disease resistance at the early stage than the late stage. ConclusionsOur results suggest that host developmental stage profoundly influences plant microbiome assembly and functions, and the bacterial and fungal microbiomes take a differentiated ecological role at different plant development stages. This study provides empirical evidence for host exerting strong effect on plant microbiomes by deterministic selection to meet the physiological requirement of plant developmental stages. These findings have implications for the development of future tools to manipulate microbiome for sustainable increase in primary productivity.

New Coenogonium species (Ostropales: Coenogoniaceae) from Thailand, new reports and a revised key to the species occurring in the country

Phytotaxa ◽  
2016 ◽  
Vol 283 (2) ◽  
pp. 101 ◽  
Author(s):  
JUTARAT KALB ◽  
KANSRI BOONPRAGOB ◽  
KLAUS KALB
Keyword(s):  
Early Stage ◽  
Stage Of Development ◽  
Dichotomous Key ◽  
Lichen Biota ◽  
Vegetative Propagules

A revision of 159 Coenogonium collections from Thailand preserved in RAMK, herb. K. Kalb and herb. K. & J. Kalb is presented. 18 species (including 1 doubtful) could be delimited, three of which are described as new to science, namely C. convexum which differs from the similar C. nepalense by smaller and convex apothecia already at a very early stage of development, C. subborinquense which has larger apothecia (almost double the size) than the similar C. borinquense and C. verrucimarginatum which differs from C. coronatum by having denticulate-verrucose margins of the apothecia. Coenogonium barbatum, C. epiphyllum, C. frederici, C. leprieurii and C. queenslandicum are new additions to the Thai lichen biota. C. disciforme is synonymized with C. isidiiferum. The peculiar vegetative propagules in this species, hitherto named isidia, are described as thallodiscs. Photographs showing the habitus of the species as well as characteristic structures are given and a dichotomous key for the identification of all species is provided.

A new class of mutations in Arabidopsis thaliana, acaulis1, affecting the development of both inflorescences and leaves

Development ◽  
1993 ◽  
Vol 118 (3) ◽  
pp. 751-764 ◽  
Author(s):  
H. Tsukaya ◽  
S. Naito ◽  
G. P. Redei ◽  
Y. Komeda
Keyword(s):  
Arabidopsis Thaliana ◽  
Apical Meristem ◽  
Developmental Stages ◽  
Temperature Shift ◽  
Wild Type ◽  
New Class ◽  
Group 4 ◽  
Consequent Reduction ◽  
In The Wild ◽  
Specific Temperature

We isolated and analyzed mutants of Arabidopsis thaliana, acaulis, with flower stalks that are almost absent or are much reduced in length. The mutations are divided between two loci, acaulis1 (acl1) and acaulis2 (acl2). The acl1-1 mutation has been assigned to linkage group 4 in the vicinity of locus ap2. The acl1-1 mutant showed premature arrest of the inflorescence meristem after the onset of reproductive development, followed by consequent reduction in the number of flower-bearing phytomers and therefore flowers. The apical meristem of the inflorescences was morphologically normal but its radius was about half that of the wild type. The acl1 mutants are also defective in the development of foliage leaves. Both defects could be rescued by growth at a specific temperature (28°C). The length of the cells in acl1-3 mutant was less than that in the wild type but the numbers of cells in leaves and internodes of acl1 mutants were calculated to be the same as those of the wild type. Thus, the defects in inflorescences and leaves were attributed to defects in the process of elongation (maturation) of these cells. Temperature-shift experiments showed that the Acl1+ product was necessary at all developmental stages. A critical stage was shown to exist for recovery from the cessation of development of inflorescence meristems that was caused by the acl1-1 mutation. Grafting experiments showed that the acl1-1 mutation does not affect diffusible substances. An analysis of double mutants carrying both acl1-1 and one of developmental mutations, ap1, clv1, lfy, or tfl1, showed that ACL1 is a new class of gene.

scholarly journals Diagnosis of Parkinson’s Disease by A Metabolomics-Based Laboratory-Developed Test (LDT)

Diagnostics ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 332 ◽  
Author(s):  
Petr G. Lokhov ◽  
Oxana P. Trifonova ◽  
Dmitry L. Maslov ◽  
Steven Lichtenberg ◽  
Elena E. Balashova
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Early Stage ◽  
Mass Spectrometry Analysis ◽  
Great Effort ◽  
Spectrometry Analysis ◽  
Yahr Scale ◽  
In Vitro Diagnostic ◽  
Stage 1

A laboratory-developed test (LDT) is a type of in vitro diagnostic test that is designed, manufactured and used in the same laboratory (i.e., an in-house test). In this study, a metabolomics-based LDT was developed. This test involves a blood plasma preparation, direct-infusion mass spectrometry analysis with a high-resolution mass spectrometer, alignment and normalization of mass peaks using original algorithms, metabolite annotation by a biochemical context-driven algorithm, detection of overrepresented metabolic pathways and results in a visualization in the form of a pathway names cloud. The LDT was applied to detect early stage Parkinson’s disease (PD)—the diagnosis of which currently requires great effort due to the lack of available laboratory tests. In a case–control study (n = 56), the LDT revealed a statistically sound pattern in the PD-relevant pathways. Usage of the LDT for individuals confirmed its ability to reveal this pattern and thus diagnose PD at the early-stage (1–2.5 stages, according to Hoehn and Yahr scale). The detection of this pattern by LDT could diagnose PD with a specificity of 64%, sensitivity of 86% and an accuracy of 75%. Thus, this LDT can be used for further widespread testing.

The Spermatozoon of Actinia Equina L. Var. Mesembryanthemum

1980 ◽  
Vol 60 (1) ◽  
pp. 193-204 ◽  
Author(s):  
A. U. Larkman ◽  
M. A. Carter
Keyword(s):  
Fine Structure ◽  
Sexual Reproduction ◽  
Recent Work ◽  
Developmental Stages ◽  
Early Stage ◽  
Genetic Material ◽  
Sea Anemones ◽  
Free Living ◽  
Pass Through ◽  
Parent Female

Actinia equina var. mesembryanthemum, the beadlet anemone (Stephenson, 1935), is a very common and widely distributed littoral anthozoan, whose sexual reproduction shows several interesting characteristics. Adult sea anemones of both sexes brood planulae and more advanced developmental stages within the gastrovascular cavity, although earlier embryonic stages are rarely found brooded in this way. Chia & Rostron (1970) suggest that embryos are expelled from the parent female anemone at an early stage and pass through a free-living phase before re-entering anemones of either sex for brooding. However, recent work (Cain, 1974) suggests that juvenile anemones are genetically related to the adult anemones in which they are brooded, and also the distribution of genetic material during sexual reproduction appears to be abnormal (Carter & Thorp, 1979). In an attempt to achieve a better understanding of the unusual sexual reproduction of this species, an ultrastructural investigation of gametogenesis was undertaken. This paper describes the fine structure of the spermatozoon within the testis.

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