Ling Gu

Northeast Institute of Geography and Agroecology, Beijing, Beijing Shi, China

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Publications (5)16.81 Total impact

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    ABSTRACT: Histone modifications are associated with many fundamental biological processes in cells. An emerging notion from recent studies is that meiosis stage-dependent histone modifications are crucial for the oocyte development in mammals. In this paper, we review the changes and regulation as well as functions of histone modifications during meiotic maturation of mammalian oocyte, with particular emphasis on histone acetylation, phosphorylation and methylation. In general, dynamic and differential modification patterns have been revealed during oocyte maturation, indicative of functional requirement. Disruption of histone modifications leads to defective chromosome condensation and segregation, delayed maturation progression and even oocyte aging. Although several histone-modifying enzymes have been identified in mammalian oocytes, more works are necessary to determine how they direct histone modifications globally and individually in oocytes. Studies on chromatin modification during oocyte development will have implications for our understanding of the mechanisms controlling nuclear architecture and genomic stability in female germ line.
    Cell cycle (Georgetown, Tex.) 05/2010; 9(10):1942-50. · 5.24 Impact Factor
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    ABSTRACT: Phenol oxidase (PO), a copper-containing enzyme with oxygenase activity, can convert mono- or diphenol into quinone and plays an important role in the arthropod melanization reaction. Here, we report a new property of PO from Musca domestica larvae: a thermotolerant endonuclease activity, by which PO can degrade plasmid DNA even after being heated to 80 degrees C for 20 min. We cloned PO cDNA, constructed the expression vector pVAX1-PO, and expressed it in HeLa cells. The expression product showed the same properties as purified PO. Our data indicate that PO is a bifunctional enzyme, exhibiting both oxygenase and endonuclease activity, suggesting new roles for this important molecule in the innate responses of M. domestica.
    Biological Bulletin 09/2008; 215(1):108-14. · 1.23 Impact Factor
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    ABSTRACT: Heterochromatin protein 1 (HP1) is closely associated with diverse chromatin organization and function in mitosis. However, we almost know nothing about HP1 in mammalian oocyte. Here, we investigated the subcellular distribution of HP1alpha and its spatial relationship to histone modifications during mouse oocyte maturation. Dynamic migration of HP1alpha was observed in germinal vesicle with non-surrounded nucleolus (NSN) to surrounded nucleolus (SN) oocytes, which may be essential for the transition of chromatin conformation during the development of antral oocytes. In meiosis, HP1alpha was clearly detectable at the periphery of chromosomes from pre-metaphase I stage to anaphase-telophase I stage. Spatial correlation between HP1alpha and histone modifications is highly variable around the time of meiotic resumption. In germinal vesicle oocytes, HP1alpha almost colocalized with all histone modifications examined in this study except for phosphorylation of serine 28 on histone H3. However, with the breakdown of germinal vesicle, HP1alpha was detected mostly in the chromosomal domains with strong phosphorylation of serine 10 and 28 on histone H3, and they also partially associated with methylated histones. These results presented the functional implication of histone modifications in the regulation of HP1alpha during oocyte maturation. In addition, we also showed that blocking the function of HP1alpha by microinjecting anti-HP1alpha antibody caused the delay of GVBD, however, this effect may not be achieved through modifying histones.
    Cell cycle (Georgetown, Tex.) 03/2008; 7(4):513-20. · 5.24 Impact Factor
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    ABSTRACT: Phosphorylation modification of core histones is correlated well with diverse chromatin-based cell activities. However, its distribution pattern and primary roles during mammalian oocyte meiosis are still in dispute. In this study, by performing immunofluorescence and Western blotting, spatial distribution and temporal expression of phosphorylated serine 10 or 28 on histone H3 during porcine oocyte meiotic maturation were examined and distinct subcellular distribution patterns between them were presented. Low expression of phosphorylated H3/ser10 was detected in germinal vesicle. Importantly, following gradual dephosphorylation from germinal vesicle (GV) to late germinal vesicle (L-GV) stage, a transient phosphorylation at the periphery of condensed chromatin was re-established at early germinal vesicle breakdown (E-GVBD) stage, and then the dramatically increased signals covered whole chromosomes from pre-metaphase I (Pre-MI) to metaphase II (MII). Similarly, hypophosphorylation of serine 28 on histone H3 was also monitored from GV to E-GVBD, indicating dephosphorylation of histone H3 maybe involved in the regulation of meiotic resumption. Moreover, the rim staining on the chromosomes and high levels of H3/ser28 phosphorylation were observed in Pre-MI, MI, and MII stage oocytes. Based on above results, such stage-dependent dynamics of phosphorylation of H3/ser 10 and 28 may play specific roles during mammalian oocyte maturation.
    Molecular Reproduction and Development 02/2008; 75(1):143-9. · 2.81 Impact Factor
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    ABSTRACT: We established a rapid procedure for obtaining transgenic mice by directly injecting an enhanced green fluorescent protein (EGFP)-expressing plasmid (pIRES-EGFP) into the ovaries of fertile mice. The frequency of transgenic mouse production was determined by pair-mating, and by polymerase chain reaction (PCR) and sequence analysis of DNA taken from the tails of the offspring. The mice that received the EGFP gene transmitted it to their offspring (F(1)). Genetic and PCR analyses of F(1) progeny confirmed that the inserted EGFP was stably inherited. Of six female F(1) mice, all were able to pass the foreign DNA on to the next generation (F(2)). In situ hybridization using paraffin-embedded sections of ovarian and testicular tissues from the F(1) and F(2) progeny showed that the introduced gene was expressed in the gonads of the animals. The chromosomal location of the injected DNA was determined by fluorescence in situ hybridization, and the frequency of multiple site versus single site insertions is 85.71% (18/21) analyzed by FISH. We anticipate great progress in murine genetic engineering using this technique.
    Biochemical and Biophysical Research Communications 07/2007; 358(1):266-71. · 2.28 Impact Factor

Publication Stats

31 Citations
16.81 Total Impact Points


  • 2010
    • Northeast Institute of Geography and Agroecology
      • State Key Laboratory of Reproductive Biology
      Beijing, Beijing Shi, China
  • 2008
    • China Agricultural University
      • College of Biological Sciences
      Beijing, Beijing Shi, China