Gene expression in the dimorphic sperm cells of Plumbago zeylanica: transcript profiling, diversity, and relationship to cell type
Gene expression in the dimorphic sperm cells of Plumbago zeylanica: transcript profiling, diversity, and relationship to cell type
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DOI：
10.1111/j.1365-313x.2009.03934.x
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发表时间：
2009-10-01
期刊：
影响因子：
7.2
通讯作者：
Russell, Scott D.
中科院分区：
文献类型：
--
作者：
Gou, Xiaoping;Yuan, Tong;Russell, Scott D.
白花丹在受精过程中产生以卵和中央细胞为目标的胞质二型精子。在成熟花粉中，较大的精细胞含有大量线粒体，与营养核（S-vn）相连，并优先与中央细胞融合，形成胚乳。另一个是富含质体的精细胞（S-ua），它与卵细胞融合，形成受精卵和胚胎。使用从每种精子类型产生的EST研究精子表达基因;通过抑制性消减杂交、定制微阵列、实时RT-PCR和原位杂交验证差异表达。二型精子细胞的表达谱反映了基因的多样性和广泛的互补性，包括高比例的保守和未知基因，以及不同的表达模式。许多基因在雄性生殖系中高度上调，包括一些在S-ua或S-vn中差异表达的基因。在卵靶向的S-ua中差异上调的基因在转录和翻译类别中表现出增加的表达，而中央细胞靶向的S-vn在激素生物合成类别中表现出扩大的表达。有趣的是，在精细胞中表达的上调基因似乎反映了未来胚胎和胚乳的预期融合后概况。由于已知该植物在受精过程中传递精子细胞质，因此精子贡献的mRNA可能在受精过程中被运输，这可能影响早期胚胎和胚乳发育。
Plumbago zeylanica produces cytoplasmically dimorphic sperm cells that target the egg and central cell during fertilization. In mature pollen, the larger sperm cell contains numerous mitochondria, is associated with the vegetative nucleus (S-vn), and fuses preferentially with the central cell, forming endosperm. The other, plastid-enriched sperm cell (S-ua) fuses with the egg cell, forming the zygote and embryo. Sperm expressed genes were investigated using ESTs produced from each sperm type; differential expression was validated through suppression subtractive hybridization, custom microarrays, real-time RT-PCR and in situ hybridization. The expression profiles of dimorphic sperm cells reflect a diverse and broad complement of genes, including high proportions of conserved and unknown genes, as well as distinct patterns of expression. A number of genes were highly up-regulated in the male germ line, including some genes that were differentially expressed in either the S-ua or the S-vn. Differentially up-regulated genes in the egg-targeted S-ua showed increased expression in transcription and translation categories, whereas the central cell-targeted S-vn displayed expanded expression in the hormone biosynthesis category. Interestingly, the up-regulated genes expressed in the sperm cells appeared to reflect the expected post-fusion profiles of the future embryo and endosperm. As sperm cytoplasm is known to be transmitted during fertilization in this plant, sperm-contributed mRNAs are probably transported during fertilization, which could influence early embryo and endosperm development.