Zebrafish（Danio rerio） Z-OTU,containing OTU and TUDOR domains,was predicted to be a member of OTU-related protease,a family of the deubiquitylating enzymes（DUBs）.A previous report from our laboratory clearly descr...Zebrafish（Danio rerio） Z-OTU,containing OTU and TUDOR domains,was predicted to be a member of OTU-related protease,a family of the deubiquitylating enzymes（DUBs）.A previous report from our laboratory clearly describes the expression patterns of z-otu mRNA.Here,we characterized the Z-OTU protein during zebrafish oogenesis and early embryogenesis.After prokaryotic expression,the recombinant protein of the OTU domain and GST was purified and injected into rabbits to obtain the polyclonal antibody-anti-Z-OTU,which was used for immunohistochemistry in zebrafish ovaries and embryos.Interestingly,obvious differences existed between the expression patterns of z-otu mRNA and its protein during oogenesis and early embryogenesis.In stage I oocytes,z-otu mRNA was detected in cytoplasm while its protein existed in the germinal vesicle.In addition,its protein was distributed during entire oogenesis,while mRNA was not detected in oocytes at stage IV or mature oocytes.The z-otu mRNA disappeared after midblastula transition（MBT） and its protein gradually decreased after this stage.We inferred that Z-OTU protein,like other OTU-related protease with DUB activity,was required for germinal vesicle breakdown of oocytes during meiosis,germinal vesicle migration,and embryo cleavage maintenance.展开更多
Estradiol, or 17-β-estradiol （E2）, the most potent naturally occurring estrogen, is involved in the hormone-immune system interaction in both mammals and fish. However, in vivo studies are largely limited, and litt...Estradiol, or 17-β-estradiol （E2）, the most potent naturally occurring estrogen, is involved in the hormone-immune system interaction in both mammals and fish. However, in vivo studies are largely limited, and little is known about whether E2 exerts similar effects on both female and male zebrafish （Danio rerio）. Here, we show exposure of both sexes ofD. rerio to 20 nmol/L E2 resulted in a significant increase in Vgl expression, but caused little damage to the hepatocytes, suggesting that this is the optimum E2 concentration. Also, exposure to 20 nmol/L E2 for 20 days caused a marked increase in plasma IgM levels, but had little influence on the peripheral leukocyte density, providing the first evidence of a hormone-immune system interaction in this species.展开更多
Apolipoprotein C1 （Apocl） is associated with lipoprotein metabolism, but its physiological role during embryogenesis is largely unknown. We reveal a new function of Apoclb, a transcript isoform of Apocl, in epiboly ...Apolipoprotein C1 （Apocl） is associated with lipoprotein metabolism, but its physiological role during embryogenesis is largely unknown. We reveal a new function of Apoclb, a transcript isoform of Apocl, in epiboly during zebrafish gastrulation. Apoclb is expressed in yolk syncytial layers and in deep cells of the ventral and lateral region of the embryos. It displays a ra- dial gradient with high levels in the interior layer and low levels in the superficial layer. Knockdown of Apoclb by injecting antisense morpholino （MO） caused the epiboly arrest in deep cells. Moreover, we show that the radial intercalation and the ra- dial gradient distribution of E-cadherin are disrupted both in Apoclb knockdown and overexpressed embryos. Therefore, Apoc 1 b controls epiboly via E-cadherin-mediated radial intercalation in a gradient-dependent manner.展开更多
Development of animal embryos before zygotic genome activation at the mid blastula transition （MBT） is essentially supported by eggderived maternal products. Nodal proteins are crucial signals for mesoderm and endod...Development of animal embryos before zygotic genome activation at the mid blastula transition （MBT） is essentially supported by eggderived maternal products. Nodal proteins are crucial signals for mesoderm and endoderm induction after the MBT. It remains unclear which maternal factors activate zygotic expression of nodal genes in the ventrotateral blastodermal margin of the zebrafish blastulas. In this study, we show that loss of maternal Eomesodermin a （Eomesa）, a T-box transcription factor, impairs zygotic expression of the nodal genes ndr1 and ndr2 as well as mesodermal and endodermal markers, indicating an involvement in mesendoderm induction. Maternal Eomesa is also required for timely zygotic expression of the transcription factor gene mxtx2, a regulator of nodal gene expression. Eomesa directly binds to the Eomes-binding sites in the promoter or enhancer of ndr1, ndr2, and rnxtx2 to activate their transcrip- tion. Furthermore, human and mouse Nodal genes are also regulated by Eomes. Transfection of zebrafish eomesa into murine embryonic stem cells promotes mesendodermal differentiation with constant higher levels of endogenous Nodal expression, suggesting a conserved function of Eomes. Taken together, our findings reveal a conserved rote of maternal T-box transcription factors in regulating nodal gene expression and mesendoderm induction in vertebrate embryos.展开更多
基金supported by grants from the ICGEB (International Center for Genetic Engineering and Biotechnology) (CRP/CHN02-01) (SONG Ping)the National Basic Research Program of China (2004CB117400) (SONG Ping)+1 种基金the National Natural Science Foundation of China (30150005 30270675) (SONG Ping)
文摘Zebrafish（Danio rerio） Z-OTU,containing OTU and TUDOR domains,was predicted to be a member of OTU-related protease,a family of the deubiquitylating enzymes（DUBs）.A previous report from our laboratory clearly describes the expression patterns of z-otu mRNA.Here,we characterized the Z-OTU protein during zebrafish oogenesis and early embryogenesis.After prokaryotic expression,the recombinant protein of the OTU domain and GST was purified and injected into rabbits to obtain the polyclonal antibody-anti-Z-OTU,which was used for immunohistochemistry in zebrafish ovaries and embryos.Interestingly,obvious differences existed between the expression patterns of z-otu mRNA and its protein during oogenesis and early embryogenesis.In stage I oocytes,z-otu mRNA was detected in cytoplasm while its protein existed in the germinal vesicle.In addition,its protein was distributed during entire oogenesis,while mRNA was not detected in oocytes at stage IV or mature oocytes.The z-otu mRNA disappeared after midblastula transition（MBT） and its protein gradually decreased after this stage.We inferred that Z-OTU protein,like other OTU-related protease with DUB activity,was required for germinal vesicle breakdown of oocytes during meiosis,germinal vesicle migration,and embryo cleavage maintenance.
基金Supported by the Natural Science Foundation of Shandong Province (No. 2007ZRB02238)the Natural Science Foundation of Qingdao Municipality (No. 06-2-2-15-jch)
文摘Estradiol, or 17-β-estradiol （E2）, the most potent naturally occurring estrogen, is involved in the hormone-immune system interaction in both mammals and fish. However, in vivo studies are largely limited, and little is known about whether E2 exerts similar effects on both female and male zebrafish （Danio rerio）. Here, we show exposure of both sexes ofD. rerio to 20 nmol/L E2 resulted in a significant increase in Vgl expression, but caused little damage to the hepatocytes, suggesting that this is the optimum E2 concentration. Also, exposure to 20 nmol/L E2 for 20 days caused a marked increase in plasma IgM levels, but had little influence on the peripheral leukocyte density, providing the first evidence of a hormone-immune system interaction in this species.
基金supported by grants from the National Basic Research Program of China(2010CB126300)the National High Technology Research and Development Program of China(2012AA092201-3)+1 种基金Ministry of Agriculture of China within the special Fund for Agro-scientific Research in the Public Interest(200903045)the National Natural Science Foundation of China(30971414)
文摘Apolipoprotein C1 （Apocl） is associated with lipoprotein metabolism, but its physiological role during embryogenesis is largely unknown. We reveal a new function of Apoclb, a transcript isoform of Apocl, in epiboly during zebrafish gastrulation. Apoclb is expressed in yolk syncytial layers and in deep cells of the ventral and lateral region of the embryos. It displays a ra- dial gradient with high levels in the interior layer and low levels in the superficial layer. Knockdown of Apoclb by injecting antisense morpholino （MO） caused the epiboly arrest in deep cells. Moreover, we show that the radial intercalation and the ra- dial gradient distribution of E-cadherin are disrupted both in Apoclb knockdown and overexpressed embryos. Therefore, Apoc 1 b controls epiboly via E-cadherin-mediated radial intercalation in a gradient-dependent manner.
基金Acknowledgements We thank Drs Alex Schier and Susan Mango （Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA） for discussion and suggestions, Dr David Kimelman （Department of Biochemistry, University of Washington, Seattle, WA, USA） for myc-eomesa construct, and members of the Meng lab for discussion and technical assistance. This work was financially supported by grants from the Major Science Research Programs of China （2011CB943800） and the National Natural Science Foundation of China （31221064）.
文摘Development of animal embryos before zygotic genome activation at the mid blastula transition （MBT） is essentially supported by eggderived maternal products. Nodal proteins are crucial signals for mesoderm and endoderm induction after the MBT. It remains unclear which maternal factors activate zygotic expression of nodal genes in the ventrotateral blastodermal margin of the zebrafish blastulas. In this study, we show that loss of maternal Eomesodermin a （Eomesa）, a T-box transcription factor, impairs zygotic expression of the nodal genes ndr1 and ndr2 as well as mesodermal and endodermal markers, indicating an involvement in mesendoderm induction. Maternal Eomesa is also required for timely zygotic expression of the transcription factor gene mxtx2, a regulator of nodal gene expression. Eomesa directly binds to the Eomes-binding sites in the promoter or enhancer of ndr1, ndr2, and rnxtx2 to activate their transcrip- tion. Furthermore, human and mouse Nodal genes are also regulated by Eomes. Transfection of zebrafish eomesa into murine embryonic stem cells promotes mesendodermal differentiation with constant higher levels of endogenous Nodal expression, suggesting a conserved function of Eomes. Taken together, our findings reveal a conserved rote of maternal T-box transcription factors in regulating nodal gene expression and mesendoderm induction in vertebrate embryos.
