Badania cytochemiczne woreczka zalążkowego Lilium regale w różnych fazach rozwoju [Cytochemical investigations of the embryo sac of Lilium regale in various development phases]

During megasporocyte and embryo sac development in <i>Lilium regale</i>, characteristic changes were noted within the cytoplasm. In the course of prophase I there appear parallel systems of endoplasmic reticulum cisternae which further transform to cytoplasmic bodies built of protein and different-sized lipid inclusions. During maturation of the embryo sac the cytoplasmic bodies and lipid inclusions synthesized during prophase I undergo hydrolysis and constitute storage material utilized during maturation of the embryo sac.

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Ultrastructure of the maturating embryo sac of Lilium regale

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1967.053 ◽

2015 ◽

Vol 36 (3) ◽

pp. 555-566 ◽

Cited By ~ 6

Author(s):

E. Mikulska ◽

B. Rodkiewicz

Keyword(s):

Embryo Sac ◽

Lilium Regale

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Practitioners’ Involvement and Challenges, they Encountered in Curriculum Development: The Case of Secondary Schools in Amhara Sayint Woreda, Amhara Region, Ethiopia

Indian Journal of Health and Wellbeing ◽

10.15614/ijhw.v11i01.15 ◽

2020 ◽

Vol 11 (01) ◽

Author(s):

Solomon Melesse ◽

Mulu Melesse

Keyword(s):

Secondary Schools ◽

Curriculum Development ◽

Secondary School Teachers ◽

School Principals ◽

Sampling Technique ◽

Structured Interview ◽

Amhara Region ◽

Vice Principals ◽

Development Phases ◽

Perceived Involvement

The purpose of this study was to assess practitioners’ perceived involvement and challenges they encountered in the process of curriculum development in Secondary schools of Amhara Sayintworeda. Mixed research design was employed to provide answer to the basic questions of this research. The sample consisted of 125 secondary school teachers, 3 school principals, 4 vice principals, and 1 supervisor. Proportional random sampling technique was used to select the sample teachers and comprehensive sampling technique was used to select the sample school principals, vice principals, and the supervisor. The data was collected through questionnaire and semi-structured interview. The collected data was analyzed using percentage, one sample t-test and thematic description. The findings indicated low practitioners’ perceived involvement in all the curriculum development phases other than curriculum implementation. Absence of financial and material incentives and practitioners’ lack of motivation were considered as the major inhibiting factors for practitioners’ involvement in the different phases of the curriculum development process. On the basis of the major findings, relevant recommendations are suggested in the paper.

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Ultrastructural Observation on Embryo Sac Development inPhaius tankervilliae(Aiton)Bl.

Plant Science Journal ◽

10.3724/sp.j.1142.2012.20188 ◽

2012 ◽

Vol 30 (2) ◽

pp. 188 ◽

Cited By ~ 2

Author(s):

Dong-Mei LI ◽

Cheng-Hou WU ◽

Xiu-Lin YE ◽

Cheng-Ye LIANG

Keyword(s):

Embryo Sac ◽

Ultrastructural Observation ◽

Embryo Sac Development

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Somatic variants for seed and fruit set in grapevine

BMC Plant Biology ◽

10.1186/s12870-021-02865-2 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Laura Costantini ◽

Paula Moreno-Sanz ◽

Chinedu Charles Nwafor ◽

Silvia Lorenzi ◽

Annarita Marrano ◽

...

Keyword(s):

Single Nucleotide Polymorphisms ◽

Fruit Set ◽

Climatic Factors ◽

Embryo Sac ◽

Wine Industry ◽

Nucleotide Polymorphisms ◽

Wine Quality ◽

Single Nucleotide ◽

Germplasm Collections

Abstract Background Grapevine reproductive development has direct implications on yield. It also impacts on berry and wine quality by affecting traits like seedlessness, berry and bunch size, cluster compactness and berry skin to pulp ratio. Seasonal fluctuations in yield, fruit composition and wine attributes, which are largely driven by climatic factors, are major challenges for worldwide table grape and wine industry. Accordingly, a better understanding of reproductive processes such as gamete development, fertilization, seed and fruit set is of paramount relevance for managing yield and quality. With the aim of providing new insights into this field, we searched for clones with contrasting seed content in two germplasm collections. Results We identified eight variant pairs that seemingly differ only in seed-related characteristics while showing identical genotype when tested with the GrapeReSeq_Illumina_20K_SNP_chip and several microsatellites. We performed multi-year observations on seed and fruit set deriving from different pollination treatments, with special emphasis on the pair composed by Sangiovese and its seedless variant locally named Corinto Nero. The pollen of Corinto Nero failed to germinate in vitro and gave poor berry set when used to pollinate other varieties. Most berries from both open- and cross-pollinated Corinto Nero inflorescences did not contain seeds. The genetic analysis of seedlings derived from occasional Corinto Nero normal seeds revealed that the few Corinto Nero functional gametes are mostly unreduced. Moreover, three genotypes, including Sangiovese and Corinto Nero, were unexpectedly found to develop fruits without pollen contribution and occasionally showed normal-like seeds. Five missense single nucleotide polymorphisms were identified between Corinto Nero and Sangiovese from transcriptomic data. Conclusions Our observations allowed us to attribute a seedlessness type to some variants for which it was not documented in the literature. Interestingly, the VvAGL11 mutation responsible for Sultanina stenospermocarpy was also discovered in a seedless mutant of Gouais Blanc. We suggest that Corinto Nero parthenocarpy is driven by pollen and/or embryo sac defects, and both events likely arise from meiotic anomalies. The single nucleotide polymorphisms identified between Sangiovese and Corinto Nero are suitable for testing as traceability markers for propagated material and as functional candidates for the seedless phenotype.

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Reproductive biology, embryonic development and matrotrophy in the phylactolaemate bryozoan Plumatella casmiana

Organisms Diversity & Evolution ◽

10.1007/s13127-021-00497-w ◽

2021 ◽

Author(s):

Julian Bibermair ◽

Andrew N. Ostrovsky ◽

Andreas Wanninger ◽

Thomas Schwaha

Keyword(s):

Embryonic Development ◽

Embryo Sac ◽

The Body ◽

Transcellular Transport ◽

Cell Contacts ◽

Transmission Electron ◽

Distal Side ◽

Early Embryos ◽

Mesoderm Formation ◽

Cytoplasmic Processes

AbstractBryozoa is a phylum of aquatic, colonial suspension-feeders within the Lophotrochozoa. In the Phylactolaemata embryonic development occurs in an internal brood sac on the body wall accompanied by extraembryonic nutrition. Owing to previous contradictive descriptions, many aspects of their sexual reproduction require restudy. Consequently, this study analyses embryogenesis of the freshwater bryozoan Plumatella casmiana by serial sections, 3D reconstruction and transmission electron microscopy. Early embryos cleave and soon develop into blastulae with a small central cavity. The mesoderm forms by delamination starting from the distal side towards the proximal end. In later embryos two polypides form on the posterior side that ultimately will be covered by a ciliated mantle in the larva. Embryos increase in size during development and form temporary cell contacts to the embryo sac. Mesodermal cells of the embryo sac show signs of transcellular transport indicating that embryos are nourished by transferring nutrients from the maternal coelom towards the brood cavity. This study clarifies several details such as mesoderm formation and the onset of bud development. Embryos are connected to their respective embryo sacs by a variety of temporary cytoplasmic processes formed by both tissues during embryogenesis, including a ‘placental’ ring zone. Although ultrastructural data of these cell contacts are not entirely conclusive about their function, we suggest that embryos absorb nutrients via the entire surface. The close opposition of embryos to the embryo sac implies placentation as matrotrophic mode in phylactolaemate bryozoans, with embryo sacs acting as placental analogues.

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Variability as normal as apple pie

Linguistics Vanguard ◽

10.1515/lingvan-2020-0034 ◽

2021 ◽

Vol 7 (s2) ◽

Author(s):

Marjolijn Verspoor ◽

Wander Lowie ◽

Kees de Bot

Keyword(s):

Dynamic Systems ◽

Dynamic Systems Theory ◽

Complex Dynamic ◽

Controlled Processes ◽

Complex Dynamic Systems ◽

L2 Development ◽

Limited Degree ◽

Development Phases ◽

Longitudinal Case Studies ◽

Over Time

Abstract In recent studies in second language (L2) development, notably within the focus of Complex Dynamic Systems Theory (CDST), non-systematic variation has been extensively studied as intra-individual variation, which we will refer to as variability. This paper argues that variability is functional and is needed for development. With examples of four longitudinal case studies we hope to show that variability over time provides valuable information about the process of development. Phases of increased variability in linguistic constructions are often a sign that the learner is trying out different constructions, and as such variability can be evidence for change, and change can be learning. Also, a limited degree of variability is inherent in automatic or controlled processes. Conversely, the absence of variability is likely to show that no learning is going on or the system is frozen.

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Longitudinal Characterization of the Gut Bacterial and Fungal Communities in Yaks

Journal of Fungi ◽

10.3390/jof7070559 ◽

2021 ◽

Vol 7 (7) ◽

pp. 559

Author(s):

Yaping Wang ◽

Yuhang Fu ◽

Yuanyuan He ◽

Muhammad Fakhar-e-Alam Kulyar ◽

Mudassar Iqbal ◽

...

Keyword(s):

Natural Aging ◽

Fungal Communities ◽

Significant Shift ◽

Mature Adult ◽

Bacterial Phyla ◽

Development Stages ◽

Composition And Structure ◽

Intestinal Functions ◽

Development Phases

Development phases are important in maturing immune systems, intestinal functions, and metabolism for the construction, structure, and diversity of microbiome in the intestine during the entire life. Characterizing the gut microbiota colonization and succession based on age-dependent effects might be crucial if a microbiota-based therapeutic or disease prevention strategy is adopted. The purpose of this study was to reveal the dynamic distribution of intestinal bacterial and fungal communities across all development stages in yaks. Dynamic changes (a substantial difference) in the structure and composition ratio of the microbial community were observed in yaks that matched the natural aging process from juvenile to natural aging. This study included a significant shift in the abundance and proportion of bacterial phyla (Planctomycetes, Firmicutes, Bacteroidetes, Spirochaetes, Tenericutes, Proteobacteria, and Cyanobacteria) and fungal phyla (Chytridiomycota, Mortierellomycota, Neocallimastigomycota, Ascomycota, and Basidiomycota) across all development stages in yaks. As yaks grew older, variation reduced, and diversity increased as compared to young yaks. In addition, the intestine was colonized by a succession of microbiomes that coalesced into a more mature adult, including Ruminococcaceae_UCG-005, Romboutsia, Prevotellaceae_UCG-004, Blautia, Clostridium_sensu_stricto_1, Ruminococcus_1, Ruminiclostridium_5, Rikenellaceae_RC9_gut_group, Alloprevotella, Acetitomaculum, Lachnospiraceae_NK3A20_group, Bacteroides, Treponema_2, Olsenella, Escherichia-Shigella, Candidatus_Saccharimonas, and fungal communities Mortierella, Lomentospora, Orpinomyces, and Saccharomyces. In addition, microorganisms that threaten health, such as Escherichia-Shigella, Mortierella, Lomentospora and Hydrogenoanaerobacterium, Corynebacterium_1, Trichosporon, and Coprinellus, were enriched in young and old yaks, respectively, although all yaks were healthy. The significant shifts in microflora composition and structure might reflect adaptation of gut microbiome, which is associated with physicochemical conditions changes and substrate availability in the gut across all development periods of yaks.

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