ZAG2 has been identified as a maternally expressed imprinted gene in maize endosperm.Our study revealed that paternally inherited ZAG2 alleles were imprinted in maize endosperm and embryo at 14 days after pollination(...ZAG2 has been identified as a maternally expressed imprinted gene in maize endosperm.Our study revealed that paternally inherited ZAG2 alleles were imprinted in maize endosperm and embryo at 14 days after pollination(DAP), and consistently imprinted in endosperm at 10, 12, 16, 18, 20, 22, 24, 26, and 28 DAP in reciprocal crosses between B73 and Mo17. ZAG2 alleles were also imprinted in reciprocal crosses between Zheng 58 and Chang7-2 and between Huang C and 178. ZAG2 alleles exhibited differential imprinting in hybrids of 178 × Huang C and B73 × Mo17, while in other hybrids ZAG2 alleles exhibited binary imprinting. The tissue-specific expression pattern of ZAG2 showed that ZAG2 was expressed at a high level in immature ears, suggesting that ZAG2 plays important roles in not only kernel but ear development.展开更多
The function of the 3 040 bp sequence at the upstream translation starting site （ATG） of the ZAG2 gene, isolated from the maize genome, was studied. The sequence analysis showed that the sequence contained a typical...The function of the 3 040 bp sequence at the upstream translation starting site （ATG） of the ZAG2 gene, isolated from the maize genome, was studied. The sequence analysis showed that the sequence contained a typical class C MADS-box gene regulatory element. The 5′ UTR region of the gene contains a 1 299-bp intron that might have important regulatory functions. To study the sequence function, deletion derivatives of promoter-reporter （uidA） gene fusions were generated and transformed into tobaccos. The GUS staining and fluorescence quantification results showed that the GUS activity was detected only in the third and fourth whorl floral organs of the transgenic tobaccos under driving the promoter including the first intron, while detected in all the organs and was stronger under driving the promoter without the first intron. However, the GUS activity was just detected in one whorl of the fourth or third floral organs under driving of the 35S promoter. These results suggested that the first intron of the ZAG2 gene contains functional regulatory elements, which turned out to be important for gene expression in the heterologous systems. Moreover, the GUS activity was decreased when the reporter gene driven by the promoters with 5′-deletions, respectively, from -1 606 to -951 and -951 to -426 nts, which indicates that positive regulatory elements are present in these two sequence stretches.展开更多
基金supported by the Fundamental Research Funds for the Central Universities (XDJK2013C023)the Chongqing Postdoctoral Science Foundation (Xm201344)+2 种基金the China Postdoctoral Science Foundation (2014M552303)the Research Fund for the Doctoral Program of Southwest University (SWU112037)the Research Fund for the Doctoral Program of Higher Education (2011182120011)
文摘ZAG2 has been identified as a maternally expressed imprinted gene in maize endosperm.Our study revealed that paternally inherited ZAG2 alleles were imprinted in maize endosperm and embryo at 14 days after pollination(DAP), and consistently imprinted in endosperm at 10, 12, 16, 18, 20, 22, 24, 26, and 28 DAP in reciprocal crosses between B73 and Mo17. ZAG2 alleles were also imprinted in reciprocal crosses between Zheng 58 and Chang7-2 and between Huang C and 178. ZAG2 alleles exhibited differential imprinting in hybrids of 178 × Huang C and B73 × Mo17, while in other hybrids ZAG2 alleles exhibited binary imprinting. The tissue-specific expression pattern of ZAG2 showed that ZAG2 was expressed at a high level in immature ears, suggesting that ZAG2 plays important roles in not only kernel but ear development.
基金supported by the National Major Project for Transgenic Organism Breeding, China (2011ZX08003-001)
文摘The function of the 3 040 bp sequence at the upstream translation starting site （ATG） of the ZAG2 gene, isolated from the maize genome, was studied. The sequence analysis showed that the sequence contained a typical class C MADS-box gene regulatory element. The 5′ UTR region of the gene contains a 1 299-bp intron that might have important regulatory functions. To study the sequence function, deletion derivatives of promoter-reporter （uidA） gene fusions were generated and transformed into tobaccos. The GUS staining and fluorescence quantification results showed that the GUS activity was detected only in the third and fourth whorl floral organs of the transgenic tobaccos under driving the promoter including the first intron, while detected in all the organs and was stronger under driving the promoter without the first intron. However, the GUS activity was just detected in one whorl of the fourth or third floral organs under driving of the 35S promoter. These results suggested that the first intron of the ZAG2 gene contains functional regulatory elements, which turned out to be important for gene expression in the heterologous systems. Moreover, the GUS activity was decreased when the reporter gene driven by the promoters with 5′-deletions, respectively, from -1 606 to -951 and -951 to -426 nts, which indicates that positive regulatory elements are present in these two sequence stretches.
