Isolation of molecular markers from the barley endosperm coenocyte and the surrounding nucellus cell layers
Isolation of molecular markers from the barley endosperm coenocyte and the surrounding nucellus cell layers
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DOI：
10.1007/bf00019474
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发表时间：
1996-07-01
影响因子：
5.1
通讯作者：
Olsen, OA
中科院分区：
文献类型：
--
作者：
Doan, DNP;Linnestad, C;Olsen, OA
谷类胚乳通过核质结构域的形成和这些核质结构域之间的细胞壁沉积，从核细胞发育为细胞储存器官。在胚乳发育的早期阶段，胚乳与珠心密切接触，珠心是形成大配子体的孢子体组织。由于这两个组织位于卵巢深处，这两种细胞类型都不容易进行分子研究。本文首次报道了大麦胚乳、核和珠心细胞分子标记的克隆。通过对授粉后5d子房的cDNA文库进行差异筛选，从人工解剖的贴珠层和种皮细胞层的胚囊中分离到新的END1和NUC1cDNAs，从果皮中分离到一个阴性探针。原位杂交和Northern杂交结果表明，END1转录本在胚乳胞质中呈不对称分布，仅限于珠心突起上的区域。在细胞胚乳中，END1转录本存在于改良糊粉细胞和几层腹面淀粉状胚乳细胞中。第二个克隆NUC1在受精前在珠心细胞中与转录产物杂交，受精后在珠心细胞中与自溶珠心细胞杂交。在后期，在珠心消失后，NUC1转录本存在于珠心表皮和珠心突起的侧细胞中。这项工作为进一步阐明胚乳组织发生的基因提供了工具。
The cereal endosperm develops from a coenocyte to a cellular storage organ through formation of nucleo-cytoplasmic domains and cell wall deposition in the interzones between these domains. During its early stages, the endosperm develops in close contact with nucellus, the sporophytic tissue which gives rise to the megagametophyte. Owing to the positioning of the two tissues deeply within the ovary, neither cell types have been easily accessible for molecular studies. In this paper we report for the first time the cloning of molecular markers for the barley endosperm coenocyte and the nucellus. The novel END1 and NUC1 cDNAs were isolated by differential screening of a cDNA library from 5 DAP (days after pollination) ovaries using a positive probe from hand-dissected embryo sacs with adhering nucellus and testa cell layers, and a negative probe from pericarp. In situ and northern blot hybridization data show that END1 transcripts are asymmetrically distributed in the endosperm coenocyte limited to an area over the nucellar projection. In the cellular endosperm, END1 transcripts are present in modified aleurone cells and a few layers of ventral starchy endosperm cells. The second clone, NUC1, hybridizes to transcripts in the nucellus before fertilization and in autolyzing nucellus cells after fertilization. At later stages, after the disappearance of nucellus, NUC1 transcripts are present in the nucellar epidermis and in the lateral cells of the nucellar projection. This work provide tools for future elucidation of the genes specifying endosperm histogenesis.