Embryology of Barley II: Synergids and Egg Cell, Zygote and Embryo Development

Author(s):  
Kirsten Engell
Keyword(s):  
2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Thomas Dresselhaus ◽  
Gerd Jürgens

Following fertilization in flowering plants (angiosperms), egg and sperm cells unite to form the zygote, which generates an entire new organism through a process called embryogenesis. In this review, we provide a comparative perspective on early zygotic embryogenesis in flowering plants by using the Poaceae maize and rice as monocot grass and crop models as well as Arabidopsis as a eudicot model of the Brassicaceae family. Beginning with the activation of the egg cell, we summarize and discuss the process of maternal-to-zygotic transition in plants, also taking recent work on parthenogenesis and haploid induction into consideration. Aspects like imprinting, which is mainly associated with endosperm development and somatic embryogenesis, are not considered. Controversial findings about the timing of zygotic genome activation as well as maternal versus paternal contribution to zygote and early embryo development are highlighted. The establishment of zygotic polarity, asymmetric division, and apical and basal cell lineages represents another chapter in which we also examine and compare the role of major signaling pathways, cell fate genes, and hormones in early embryogenesis. Except for the model Arabidopsis, little is known about embryo patterning and the establishment of the basic body plan in angiosperms. Using available in situ hybridization, RNA-sequencing, and marker data, we try to compare how and when stem cell niches are established. Finally, evolutionary aspects of plant embryo development are discussed. Expected final online publication date for the Annual Review of Plant Biology, Volume 72 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2005 ◽  
Vol 56 (10) ◽  
pp. 1101 ◽  
Author(s):  
A. G. Mavromatis ◽  
S. K. Kantartzi ◽  
D. N. Vlachostergios ◽  
I. N. Xynias ◽  
G. N. Skarakis ◽  
...  

The possibility of inducing embryo development after pollination of F1 interspecific cotton hybrids (Gossypium barbadense × Gossypium hirsutum) and their reciprocals with pollen from Hibiscus cannabinus was investigated. For this, flowers of F1 plants from 4 G. barbadense × G. hirsutum interspecific hybrids (B403 × Acala Sindos, Carnak × 4S, B403 × Coker 310, and Carnak × Acala Sindos) and their reciprocals grown in the field were pollinated with pollen from Hibiscus cannabinus. From the 443 pollinated flowers, 276 were left on the plant to grow naturally, and 167 were collected 5 days after pollination. Young ovules from the collected buds were cultured in vitro for embryo development. It was observed that, from the buds left to grow naturally on the mother plant, 21 bolls reached maturity. The mature bolls originated only from the 4 G. barbadense × G. hirsutum hybrids and contained 82 mature seeds. Finally, 38 plants (Pa0) were produced. From the in-ovule culture method, 10 young embryos were isolated from both G. barbadense × G. hirsutum and G. hirsutum × G. barbadense hybrids and finally 3 plants were produced. The plants produced from both approaches originated only from the G. barbadense × G. hirsutum hybrids. These plants exhibited morphological traits from both cotton species and they were partially fertile. No signs of H. cannabinus morphological traits were observed in the plants produced. Root-tip chromosome counts revealed that chromosome number among cells of the Pa0 plants ranged from 27 to 42 and the difference in chromosome number observed among cells of the same plant ranged from 1 to 3. The chromosome number, however, was increased progressively from generation to generation and in Pa3 it ranged from 46 to 52. Plants with 52 chromosomes were identified even from the Pa1 generation. In addition, flow cytometric analysis indicated that the parental plants had a similar DNA profile to the F1 and F2 interspecific hybrids but a different one from the Pa0 plants. Thus, alien pollination of cotton flowers from interspecific (G. barbadense × G. hirsutum and reciprocals) hybrids with pollen from H. cannabinus most likely induced parthenogenetic (Pa) egg cell development which, after a progressive chromosome increase, produced fully fertile plants with most of the cells at the tetraploid or near-tetraploid level. It was concluded that a combination of the in situ boll development with an optimised in vitro ovule culture technique could establish the ‘cannabinus method’ in cotton, as a method for the production of genotype-independent partial interspecific lines.


2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Tony Setia Dharma

<p><em>Silver pompano is a prospective high value commodity to be developed in mariculture. The aims of this research were to understand the development of embryo and absorption pattern of endogenous nutrient at the time of changing from using endogenous to exogenous nutrient. This research was conducted in Institute for Mariculture Research and Development, Gondol, Singaraja, Bali using fertilized eggs which were stocked in concrete tanks 3 m<sup>3</sup>, filled with 2 m<sup>3 </sup>of seawater, in a density of 25 eggs/l. Temperature at the time of hatching was 28-30<sup>o</sup>C. The observation of embryo development and its morphology was performed after hatching by collecting larvae as many as 10. Parameters measured were total length of larvae (TL), yolk sac volume (VK), oil globule volume (VM) and larvae development. The results showed that embryo of silver pompano had a normal development, consisted of several phases i.e., fertilized egg, cell division, neurola, gastrula, complete embryo and hatching as larvae. Newly hatched larvae had endogenous nutrient as yolk sac and oil globule with volume of 2.27.10<sup>-1</sup> mm<sup>3</sup> ± 0.06 and 5.57.10<sup>-1</sup> mm<sup>3</sup> ± 0.02, respectively. Yolk sac was completely absorbed after 35:30 to 46:30 hours and oil globule after 52:30 to 64:30 hours. Initial feeding was given when yolk sac was completely absorbed but before oil globule was completely absorbed. The average total length of larvae was 2.40 ± 0.10 mm.</em></p> <p><em> </em></p> <strong><em>Keywords:</em></strong><em> embryo, larvae, absorption, yolk sac, silver pampano</em>


2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Tony Setia Dharma

Silver pompano is a prospective high value commodity to be developed in mariculture. The aims of this research were to understand the development of embryo and absorption pattern of endogenous nutrient at the time of changing from using endogenous to exogenous nutrient. This research was conducted in Institute for Mariculture Research and Development, Gondol, Singaraja, Bali using fertilized eggs which were stocked in concrete tanks 3 m3, filled with 2 m3 of seawater, in a density of 25 eggs/l. Temperature at the time of hatching was 28-30oC. The observation of embryo development and its morphology was performed after hatching by collecting larvae as many as 10. Parameters measured were total length of larvae (TL), yolk sac volume (VK), oil globule volume (VM) and larvae development. The results showed that embryo of silver pompano had a normal development, consisted of several phases i.e., fertilized egg, cell division, neurola, gastrula, complete embryo and hatching as larvae. Newly hatched larvae had endogenous nutrient as yolk sac and oil globule with volume of 2.27.10-1 mm3 ± 0.06 and 5.57.10-1 mm3 ± 0.02, respectively. Yolk sac was completely absorbed after 35:30 to 46:30 hours and oil globule after 52:30 to 64:30 hours. Initial feeding was given when yolk sac was completely absorbed but before oil globule was completely absorbed. The average total length of larvae was 2.40 ± 0.10 mm. Keywords: embryo, larvae, absorption, yolk sac, silver pampano


Author(s):  
G.L. Decker ◽  
M.C. Valdizan

A monoclonal antibody designated MAb 1223 has been used to show that primary mesenchyme cells of the sea urchin embryo express a 130-kDa cell surface protein that may be directly involved in Ca2+ uptake required for growth of skeletal spicules. Other studies from this laboratory have shown that the 1223 antigen, although in relatively low abundance, is also expressed on the cell surfaces of unfertilized eggs and on the majority of blastomeres formed prior to differentiation of the primary mesenchyme cells.We have studied the distribution of 1223 antigen in S. purpuratus eggs and embryos and in isolated egg cell surface complexes that contain the cortical secretory vesicles. Specimens were fixed in 1.0% paraformaldehyde and 1.0% glutaraldehyde and embedded in Lowicryl K4M as previously reported. Colloidal gold (8nm diameter) was prepared by the method of Mulpfordt.


2014 ◽  
Author(s):  
Xing Duan ◽  
Zhen-Bo Wang ◽  
Xiang-Shun Cui ◽  
Nam-Hyung Kim ◽  
Shao-Chen Sun

2008 ◽  
Vol 36 (1) ◽  
pp. 43-51 ◽  
Author(s):  
S. Prodanovic ◽  
F. Matzk ◽  
D. Zoric

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