Development in vitro of surgically halved stamen primordia of tobacco

1972 ◽  
Vol 50 (11) ◽  
pp. 2396-2400 ◽  
Author(s):  
G. S. Hicks

Tobacco stamen primordia at different developmental stages were surgically bisected and cultured while still attached to the floral meristem. The youngest incised primordia frequently regenerated two stamen primordia each with the characteristic four anther lobes. No regeneration was observed from the oldest stamen rudiments bisected and these formed only half-stamens. It is suggested that normally a stamen rudiment passes through a labile phase and that the pattern of the organ is subsequently fixed in the primordium.

2020 ◽  
Author(s):  
Zhen Gu ◽  
Jia Guo ◽  
Jinglei Zhai ◽  
Guihai Feng ◽  
Xianning Wang ◽  
...  

Abstract The mammalian embryo must undergo dramatic morphogenetic changes to invade the uterine endometrium and achieve implantation. Thus, recapitulation of implantation using in vitro systems is crucial for revealing the mechanisms controlling early development and the main problems compromising human fertility. Experimental systems based on two-dimensional (2D) platforms cannot fully recapitulate the in vivo 3D microenvironments of the embryo. Therefore, here we use collagen grafted onto polydimethylsiloxane (PDMS) based on the uterine mechanics and microstructure to establish a uterus-inspired 3D niche (U3N). Our U3N enables mouse embryos to form egg cylinders at high rate and reach the developmental stages of heartbeat. Moreover, a unique interface forms between the embryo and collagen, showing the invasion of trophoblasts into collagen fires, which simulate the developmental process of implantation. Our findings highlight embryo-substrate interaction as a key characteristic of post-implantation development in vitro and as an important design parameter of 3D conditions for embryo culture.


Botany ◽  
2017 ◽  
Vol 95 (1) ◽  
pp. 89-99 ◽  
Author(s):  
Gui-Fang Yang ◽  
Feng-Xia Xu

Species of Myristicaceae have diverse morphology and structure of their synandria, making them an interesting group for androecium evolution research. To clarify the morphology, structure, and origin of the synandrium, scanning electron microscopy and histology were performed on staminate flowers of Horsfieldia pandurifolia H.H.Hu, H. tetratepala C.Y.Wu & W.T.Wang, and Myristica fragrans Houtt. at different developmental stages. A whorl of stamen primordia was rapidly initiated around the margin of the floral apex in groups of two in H. pandurifolia and groups of three in M. fragrans. Each stamen primordium grew longitudinally, producing a pair of anther lobes and four microsporangia, accompanying one vascular bundle in H. pandurifolia and M. fragrans. In H. tetratepala, three stamen primordia groups were formed, and each group with several anthers was supported by one vascular bundle, indicating a secondary increase of stamen. Three types of synandrium origin were observed: in M. fragrans, the central sterile column tissues originated from the elongate receptacle; in H. pandurifolia and H. tetratepala they were derived from a combination of floral meristem and fused connectives, and a combination of receptacular tissue and stamen groups. The diverse origins of the central sterile column suggest that the synandrium develops differently and independently in different genera and species of Myristicaceae.


Zygote ◽  
1993 ◽  
Vol 1 (3) ◽  
pp. 225-229 ◽  
Author(s):  
Francesca Vidal ◽  
Juan Hidalgo

The effect of zinc and copper on the in vitro development of mouse preimplantation embryos and on metallothionein (MT) levels was studied by exposing the embryos to 100 μM concentrations of the metals for 24 h at the 1-cell,2-cell, 6-8-cell, morula and blastocyst stages. Zinc affected embryo development in the early but not in the late stages, whereas copper affected it more generally. The combined presence of both metals caused a stronger embryotoxicity. MT levels were measured by radioimmunoassay and were found to be similar at all developmental stages, though possibly higher at the blastocyst stage. The exposure of embryos to zinc and copper increased MT levels significantly only at the blastocyst stage, supporting previously published results on MT mRNA levels.


Author(s):  
J. P. Revel

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.


2014 ◽  
Author(s):  
Hitomi Obata ◽  
Maki Kamoshita ◽  
Tsubasa Kato ◽  
Junya Ito ◽  
Naomi Kashiwazaki
Keyword(s):  

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 776
Author(s):  
Shipra Kumari ◽  
Bashistha Kumar Kanth ◽  
Ju young Ahn ◽  
Jong Hwa Kim ◽  
Geung-Joo Lee

Genome-wide transcriptome analysis using RNA-Seq of Lilium longiflorum revealed valuable genes responding to biotic stresses. WRKY transcription factors are regulatory proteins playing essential roles in defense processes under environmental stresses, causing considerable losses in flower quality and production. Thirty-eight WRKY genes were identified from the transcriptomic profile from lily genotypes, exhibiting leaf blight caused by Botrytis elliptica. Lily WRKYs have a highly conserved motif, WRKYGQK, with a common variant, WRKYGKK. Phylogeny of LlWRKYs with homologous genes from other representative plant species classified them into three groups- I, II, and III consisting of seven, 22, and nine genes, respectively. Base on functional annotation, 22 LlWRKY genes were associated with biotic stress, nine with abiotic stress, and seven with others. Sixteen unique LlWRKY were studied to investigate responses to stress conditions using gene expression under biotic and abiotic stress treatments. Five genes—LlWRKY3, LlWRKY4, LlWRKY5, LlWRKY10, and LlWRKY12—were substantially upregulated, proving to be biotic stress-responsive genes in vivo and in vitro conditions. Moreover, the expression patterns of LlWRKY genes varied in response to drought, heat, cold, and different developmental stages or tissues. Overall, our study provides structural and molecular insights into LlWRKY genes for use in the genetic engineering in Lilium against Botrytis disease.


Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 91
Author(s):  
Verena Schultz ◽  
Stephanie L. Cumberworth ◽  
Quan Gu ◽  
Natasha Johnson ◽  
Claire L. Donald ◽  
...  

Understanding how Zika virus (Flaviviridae; ZIKV) affects neural cells is paramount in comprehending pathologies associated with infection. Whilst the effects of ZIKV in neural development are well documented, impact on the adult nervous system remains obscure. Here, we investigated the effects of ZIKV infection in established mature myelinated central nervous system (CNS) cultures. Infection incurred damage to myelinated fibers, with ZIKV-positive cells appearing when myelin damage was first detected as well as axonal pathology, suggesting the latter was a consequence of oligodendroglia infection. Transcriptome analysis revealed host factors that were upregulated during ZIKV infection. One such factor, CCL5, was validated in vitro as inhibiting myelination. Transferred UV-inactivated media from infected cultures did not damage myelin and axons, suggesting that viral replication is necessary to induce the observed effects. These data show that ZIKV infection affects CNS cells even after myelination—which is critical for saltatory conduction and neuronal function—has taken place. Understanding the targets of this virus across developmental stages including the mature CNS, and the subsequent effects of infection of cell types, is necessary to understand effective time frames for therapeutic intervention.


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