scholarly journals Effect of Chemical Composition of Nutritive Medium and Explant Size Over Androgenetic Response in Microspore Culture of Brassica oleracea L.

2020 ◽  
Vol 71 (10) ◽  
pp. 131-136
Author(s):  
Tina Oana Cristea ◽  
Gabriel-Alin Iosob ◽  
Creola Brezeanu ◽  
Petre Marian Brezeanu
Keyword(s):  
Brassica Oleracea ◽  
Double Haploid ◽  
Developmental Stages ◽  
Microspore Culture ◽  
Morphological Characteristics ◽  
Homogeneous Population ◽  
Nutritive Medium ◽  
Stage Of Development ◽  
Bud Size ◽  
Haploid Plants

The dimension of the bud is a key factor for the orientation of microspore culture and the success of obtaining double haploid plants as it is a strong correlation between bud size and the developmental stages of microspores, and it is specific for each plant species and genotype. Our study was focused to determine the correlation between morphological characteristics, namely floral bud size and specific microspore developmental stages in order to determine the proper size, suitable for a successful protocol of obtaining double haploid plants in Brassica oleracea var. italica. Thus, we tested four bud sizes ranging from 2.0 to 4.0 mm measured from the base to the tip of the bud. After the statistical analysis of the results it can be emphasized that the best results were obtained in the case of using as a source of microspores the flower buds with the size between 3.1-3.5 mm. At this dimension, the share of microspores in the uninucleate stage, predominantly in the late uninucleate stage, is 90%, thus ensuring a homogeneous population of microspores in the optimum stage of development. Their evolution is predominantly embryogenic, the percentage of microspores following the gametophytic pathway is reduced, by only 9.12%.

Electron Microscopy of California Isolate of Cat Leukemia Virus

1968 ◽  
Vol 26 ◽  
pp. 24-25
Author(s):  
T. G. Kawakami ◽  
G. H. Theilen ◽  
R. J. Munn
Keyword(s):  
Plasma Membrane ◽  
Developmental Stages ◽  
Leukemia Virus ◽  
Morphological Characteristics ◽  
Host Cells ◽  
Stage Of Development ◽  
Viral Particles ◽  
The Difference ◽  
Vacuolar Membranes ◽  
Electron Lucent

Although “C”-type viral particles have been observed in oats with feline leukemia, the developmental stages, morphological characteristics and sites of replication have not been fully described. The isolation of an agent from a cat with spontaneous leukemia and transmission of the disease with cell-free preparations to newborn kittens presented an opportunity for an extensive eleotron mioroscopic examination of the feline leukemogenic agent.The agent apparently undergoes development by budding from the plasma or vacuolar membranes of infected host cells. The earliest stage of development is recognizable in thin section by a crescent-shaped electron-dense zone beneath the plasma membrane (Fig. 1a). This structure or bud enlarges progressively into a sphere which is resolvable into two concentric components and concomitantly causes a protrusion of the plasma membrane. Later stages are independent of the host cell proper. The immature forms (Fig. 1b), one recently detached from the plasma membrane, still maintain the internal morphology of the later stages of budding but is completely surrounded by a protein coat. The mature forms (Fig. 2) which develop by reorganization of the dense shells possess either a central electron-dense or central electron-lucent nucleoid. The difference between mature electron-lucent and immature forms appears to be an absence of the organized concentric shell in the former.

scholarly journals Crayfish hemocytes develop along the granular cell lineage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fang Li ◽  
Zaichao Zheng ◽  
Hongyu Li ◽  
Rongrong Fu ◽  
Limei Xu ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Cell Lineage ◽  
Granular Cell ◽  
Marker Genes ◽  
Hematopoietic Tissue ◽  
Differentiated Cells ◽  
Stage Of Development ◽  
Almost All ◽  
Relationship Of

AbstractDespite the central role of hemocytes in crustacean immunity, the process of hemocyte differentiation and maturation remains unclear. In some decapods, it has been proposed that the two main types of hemocytes, granular cells (GCs) and semigranular cells (SGCs), differentiate along separate lineages. However, our current findings challenge this model. By tracking newly produced hemocytes and transplanted cells, we demonstrate that almost all the circulating hemocytes of crayfish belong to the GC lineage. SGCs and GCs may represent hemocytes of different developmental stages rather than two types of fully differentiated cells. Hemocyte precursors produced by progenitor cells differentiate in the hematopoietic tissue (HPT) for 3 ~ 4 days. Immature hemocytes are released from HPT in the form of SGCs and take 1 ~ 3 months to mature in the circulation. GCs represent the terminal stage of development. They can survive for as long as 2 months. The changes in the expression pattern of marker genes during GC differentiation support our conclusions. Further analysis of hemocyte phagocytosis indicates the existence of functionally different subpopulations. These findings may reshape our understanding of crustacean hematopoiesis and may lead to reconsideration of the roles and relationship of circulating hemocytes.

scholarly journals Association between floral bud size and developmental stage in soybean microspores

2003 ◽  
Vol 46 (4) ◽  
pp. 515-520 ◽  
Author(s):  
Mozart da Silva Lauxen ◽  
Eliane Kaltchuk- Santos ◽  
Ching -yeh Hu ◽  
Sidia Maria Callegari- Jacques ◽  
Maria Helena Bodanese-Zanettini
Keyword(s):  
Developmental Stage ◽  
Anther Culture ◽  
Developmental Stages ◽  
Size Group ◽  
Soybean Cultivars ◽  
Advanced Stages ◽  
Bud Size ◽  
Microspore Stage ◽  
Floral Bud

This study was carried out to establish the association between floral bud size and the corresponding microspore developmental stages for Brazilian soybean cultivars. Microspore developmental stage distributions were examined in young buds from cv Década, IAS5 and RS7. The data indicated that for a given bud-size group, the microspores of different cultivars were at different developmental stages, with cv RS7 and Década distributed at the youngest and cv IAS5 at the most advanced stages. Microspore stages distribution were also compared among the ten anthers of the same bud of the above cultivars. The ten anthers from a given bud were clearly distributed at different developmental stages. Caution should be exercised when adopting the standard anther culture practice of using the microspore stage of one anther to represent the entire bud.

Haploid Culture and Double Haploid Induction in Medicago sativa L. cv. XinJiangDaYe

2020 ◽  
Author(s):  
Bo Xu ◽  
Rina Wu ◽  
Fang Tang ◽  
Cuiping Gao ◽  
Xia Gao ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Medicago Sativa ◽  
Double Haploid ◽  
Haploid Plant ◽  
Regeneration System ◽  
Forage Crops ◽  
Improvement Programs ◽  
Medicago Sativa L ◽  
Cultivation Methods ◽  
Haploid Plants

Background: Alfalfa (Medicago Sativa), a perennial cross-pollinated plant, is one of the most important forage crops in the world with commercial value and ecological significance. However, due to the complexity of its genome, varietal improvement is difficult. Therefore, generating genetically homozygous materials have greater significance for breeding. In the current study, we aimed to identify the best tissue culture conditions to obtain haploid plants and double haploid plants.Methods: In this study, the haploid plants of alfalfa were obtained by combining tissue culture regeneration system with Flow cytometry. Different concentrations of colchicine were applied to the haploid plants using solid and liquid cultivation methods to determine the optimum conditions to obtain double haploid plants of Medicago Sativa L. cv. ‘XinJiangDaYe’. Result: Among the two colchicine cultivation methods tested, the doubling rate of regenerated plants obtained by liquid cultivation method was higher and the leaves developed under this system have the best doubling effect among the three explants tested. Optimal doubling conditions for alfalfa haploid (Medicago Sativa L. cv. ‘XinJiangDaYe’) were identified. The double haploid plant material generated from the current study could serve as a genetic resource for developing the hybrid combinations and for analyzing genetic linkage in alfalfa improvement programs.

Spatial- and temporal-restricted pattern for amelogenin gene expression during mouse molar tooth organogenesis

Development ◽  
1988 ◽  
Vol 104 (1) ◽  
pp. 77-85 ◽  
Author(s):  
M.L. Snead ◽  
W. Luo ◽  
E.C. Lau ◽  
H.C. Slavkin
Keyword(s):  
Gene Expression ◽  
In Situ Hybridization ◽  
Gene Transcription ◽  
Developmental Stages ◽  
Three Dimensional ◽  
Molar Tooth ◽  
Specific Expression ◽  
Amelogenin Gene ◽  
Stage Of Development

Position- and time-restricted amelogenin gene transcription was analysed in developing tooth organs using in situ hybridization with asymmetric complementary RNA probes produced from a cDNA specific to the mouse 26 × 10(3) Mr amelogenin. In situ analysis was performed on developmentally staged fetal and neonatal mouse mandibular first (M1) and maxillary first (M1) molar tooth organs using serial sections and three-dimensional reconstruction. Amelogenin mRNA was first detected in a cluster of ameloblasts along one cusp of the M1 molar at the newborn stage of development. In subsequent developmental stages, amelogenin transcripts were detected within foci of ameloblasts lining each of the five cusps comprising the molar crown form. The number of amelogenin transcripts appeared to be position-dependent, being more abundant on one cusp surface while reduced along the opposite surface. Amelogenin gene transcription was found to be bilaterally symmetric between the developing right and left M1 molars, and complementary between the M1 and M1 developing molars; indicating position-restricted gene expression resulting in organ stereoisomerism. The application of in situ hybridization to forming tooth organ geometry provides a novel strategy to define epithelial-mesenchymal signal(s) which are believed to be responsible for organ morphogenesis, as well as for temporal- and spatial-restricted tissue-specific expression of enamel extracellular matrix.

scholarly journals The Influence of pH on Microspore Embryogenesis of White Cabbage (Brassica oleracea L.)

2013 ◽  
Vol 5 (4) ◽  
pp. 485-489 ◽  
Author(s):  
Tina Oana CRISTEA
Keyword(s):  
Brassica Oleracea ◽  
Microspore Culture ◽  
Microspore Embryogenesis ◽  
Critical Factor ◽  
Cellular Level ◽  
Strong Base ◽  
White Cabbage ◽  
In Vitro Microspore Culture ◽  
Influence Of Ph

In vitro microspore culture is one of the top techniques utilised now-a-days for the obtaining of double haploid plants in many plant species, including Brassica. The pH of the medium is a critical factor for the success of In vitro microspore culture as it influences the invertase enzyme activity, translated at cellular level through an acceleration or reduction of sucrose cleavage. The results published until now shows rather contradictory findings, as the response of microspores have been proved to be highly depending on genotypes, most of them being focused on Brassica napus. Thus, in the present study, the effect of different NLN liquid medium pH, ranging between 5.0 to 7.0 were tested in order to establish the most suitable pH for the expression of embryogenic competences of microspores cultivated on medium In vitro and ultimately for the obtaining of microspore-derived embryos. Among the 11 values of pH tested, the best results were obtained on variants with pH 5.8 and 6.0, both in what concern the maintaining of microspores viability and the number of microspore-derived embryos. The findings of the present study provide a strong base for the establishment of an efficient protocol for the In vitro culture of microspore at Brassica oleracea L. genotypes with Romanian origin.

scholarly journals Prenatal development in pterosaurs and its implications for their postnatal locomotory ability

2019 ◽  
Vol 286 (1904) ◽  
pp. 20190409 ◽  
Author(s):  
David Michael Unwin ◽  
D. Charles Deeming
Keyword(s):  
Vertebral Column ◽  
Egg Size ◽  
Developmental Stages ◽  
Prenatal Development ◽  
Limb Bones ◽  
Stage Of Development ◽  
Full Development ◽  
Absolute Requirement ◽  
Near Term ◽  
First Time

Recent fossil finds in China and Argentina have provided startling new insights into the reproductive biology and embryology of pterosaurs, Mesozoic flying reptiles. Nineteen embryos distributed among four species representing three distinct clades have been described and all are assumed to be at, or near, term. We show here how the application of four contrasting quantitative approaches allows a more precise identification of the developmental status of embryos revealing, for the first time to our knowledge, the presence of middle and late developmental stages as well as individuals that were at term. We also identify a predicted relationship between egg size and shape and the developmental stage of embryos contained within. Small elongate eggs contain embryos at an earlier stage of development than larger rounder eggs which contain more fully developed embryos. Changes in egg shape and size probably reflect the uptake of water, consistent with a pliable shell reported for several pterosaurs. Early ossification of the vertebral column, limb girdles and principal limb bones involved some heterochronic shifts in appearance times, most notably of manus digit IV, and facilitated full development of the flight apparatus prior to hatching. This is consistent with a super-precocial flight ability and, while not excluding the possibility of parental care in pterosaurs, suggests that it was not an absolute requirement.

Patterns of polyembryony and frequency of surviving multiple embryos of the Brazilian pine Araucaria angustifolia

2011 ◽  
Vol 59 (8) ◽  
pp. 749 ◽  
Author(s):  
Sarah Zanon Agapito-Tenfen ◽  
Neusa Steiner ◽  
Miguel Pedro Guerra ◽  
Rubens Onofre Nodari
Keyword(s):  
Microsatellite Markers ◽  
Developmental Stages ◽  
Rare Event ◽  
Morphological Characteristics ◽  
Immature Embryos ◽  
Araucaria Angustifolia ◽  
Embryo Survival ◽  
Major Mechanism ◽  
Novel Approach ◽  
Nuclear Microsatellite

The development of polyembryony is a common reproductive strategy in conifers. Multiple embryos are observed during early seed developmental stages. However, upon seed maturation, only the dominant embryo survives, with few exceptions. Although programmed cell death has been reported as the major mechanism responsible for elimination of subordinate embryos, the genetics of surviving embryos and the probabilities of survival remain unclear. The aim of this study is to determine patterns of polyembryony and survival frequency in Araucaria angustifolia (Bert) O. Ktze. Thus, we investigate the morphogenetic parameters that might be related to embryo survival using nuclear microsatellite markers and morphological characteristics of immature embryos and seedlings. Our novel approach couples genotype frequency analysis with the number of surviving embryos, presence of embryo dominance and number of cotyledons present within a single seed. Polyembryonic seedling frequency was low (0.022%) and 91% of surviving embryos were monozygotic. From all monozygotic embryos, 98% showed differences in growth rate (height) in relation to each other. Concrescent tissues were common in the monozygotic polyembryony patterns observed (80%) but not for those with polyzygotic polyembryony. We demonstrate that the survival of multiple embryos is a rare event in A. angustifolia seeds. To the best of our knowledge this study represents the first evidence of cleavage polyembryony in immature embryos and seedlings from A. angustifolia. Our novel approach using a combined set of morphological parameters and microsatellite markers was successful in investigating polyembryony patterns and survival.

154 COMPARISON OF DIFFERENT CULTURE MEDIA AND INCUBATION METHODS ON CULTURING MURINE EMBRYOS IN VITRO USING STRAW AS A RECEPTACLE

2017 ◽  
Vol 29 (1) ◽  
pp. 185
Author(s):  
L. R. Madzhie ◽  
M. A. Raseona ◽  
L. P. Nethenzheni ◽  
O. Ajao ◽  
M. L. Mphaphathi ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Culture Media ◽  
Uv Light ◽  
Fertilization Rate ◽  
Blastocyst Stage ◽  
Blastocyst Formation ◽  
Vitro Fertilization ◽  
Stage Of Development ◽  
Murine Embryos

In vitro fertilization in the straw system might increase the efficiency of fertilization and the quality of blastocyst formation as compared with micro-drops-IVF systems. The aim of the study was to in vitro fertilize mouse oocytes and culture the resulting zygotes in bi-gas incubator and in a goat vagina and compare the in vitro embryo developmental stages in TCM-199 and Ham’s F10 culture media until the blastocyst-stage of development. F1 generations (Balb C × C57) were used to harvest oocytes and spermatozoa. The fresh sperm were capacitated in different incubation methods (bi-gas incubator and in the vagina of a goat). A volume of 2–4 µL of Ham’s F10 containing capacitated sperm (~8 × 106 per mL) were placed into Ham’s F10 fertilization drops under the oil, containing 10 oocytes and penicillamine, hypotaurine, and epinephrine for enhancing sperm motility and penetration of oocytes. The same procedure was used with the TCM-199 medium and IVF drops without oil (both TCM-199 and Ham’s F10) for straw filling. The presumptive embryos in Ham’s F10 and TCM-199 were divided into different groups: first group were cultured in micro-drops, second group the embryos were aspirated in semen straws and placed in the incubator (incubator straws) for culture, and other straws were covered with a sponge and inserted in the vagina of a goat (vaginal straws) for culture. The resulted blastocysts were stained using Hoechst 33528 solution and blastomeres were counted on a fluorescent UV light inverted microscope at 400× magnification (Nikon Eclipse TI, Narishige Co., Ltd., Amityville, NY, USA). The results were analysed by 2 × 2 factorial designs and Student’s t-test was used to separate the mean. There was no statistical difference (P > 0.05) between the media and incubators on the stage of murine embryo development. The overall fertilization rate was 94 to 99%. The incubator straws with Ham’s F10 (80.5%) had the highest rate of embryos that reached the blastocyst stage, followed by incubator straws with TCM-199 (77.0%), and vaginal straws with Ham’s F10 (60.0%) had the lowest rate of embryos that reached the blastocyst stage. The overall mean number of blastomeres in the blastocyst stage of the embryos ranged from 85 ± 9 to 90 ± 9 cells in all receptacles and incubators. It was concluded that the fertilization and culturing of murine embryos are possible in straws incubated in a bi-gas incubator and in the goat vagina as an alternative method of fertilizing oocytes and culturing murine embryos. In addition, Ham’s F10 and TCM-199 can both be used to fertilize oocytes and culture murine embryos until blastocyst formation embryo in vitro, incubated in a bi-gas incubator or in the vagina.

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