Biomedical subjects

Xiao-Yan Ding

Publications and source records attributed to Xiao-Yan Ding.

6 recordsLinked to original sources

PubMed2006

Optimized adaptor polymerase chain reaction method for efficient genomic walking.

Genomic walking is one of the most useful approaches in genome-related research. Three kinds of PCR-based methods are available for this purpose. However, none of them has been generally applied because they are either insensitive or inefficient. Here we present an efficient PCR protocol, an optimized adaptor PCR method for genomic walking. Using a combination of a touchdown PCR program and a special adaptor, the optimized adaptor PCR protocol achieves high sensitivity with low background noise. By applying this protocol, the insertion sites of a gene trap mouse line and two gene promoters from the incompletely sequenced Xenopus laevis genome were successfully identified with high efficiency. The general application of this protocol in genomic walking was promising.

Animals↗

PubMed2006

Cloning and analyzing of Xenopus Mespo promoter in retinoic acid regulated Mespo expression.

During vertebrate embryogenesis, presomitic mesoderm cells enter a segmental program to generate somite, a process termed somitogenesis. Mespo, a member of the bHLH transcription factor family, plays important roles in this process. However, how Mespo expression is regulated remains unclear. To address this question, we isolated a genomic DNA sequence containing 4317 bp of Mespo 5' flanking region in Xenopus. Luciferase assays show that this upstream sequence has transcription activity. Transgenic assay shows that this genomic contig is sufficient to recapitulate the dynamic stage- and tissue-specific expression pattern of endogenous Mespo from the gastrula to the tailbud stage. We further mapped a 326 bp DNA sequence responding to retinoic acid signaling. These results shed light on how Mespo expression is regulated, and suggest that retinoic acid signaling pathways play roles in somitogenesis through regulating Mespo.

Animals↗

PubMed2005

[Progress in the investigation of Avian sex determination and sex identification].

Avian sex determination is a multiple gene regulation cascade. Genes such as the Z chromosome-linked DMRT1 gene, W chromosome-linked PKCIW gene and other factors have been demonstrated to be involved in this process. In this paper, we review the recent progress in this field. The investigation of functions of sex determinate genes and methods of sexing identification in birds are also discussed.

Animals↗

PubMed2004

Multiple signaling pathways control Tbx6 expression during Xenopus myogenesis.

Tbx6 is critical for somite specification and myogenesis initiation. It has been shown that Activin/Nodal, VegT/Nodal, FGF, and BMP signaling pathways are involved early in specifying mesoderm or later in patterning mesoderm, and Xnot plays roles in setting up the boundary between notochord and paraxial mesoderm. In this study, we introduce the dominant negative form of above genes into embryos to evaluate if they are responsible for regulating Tbx6 expression. The results show that: (1) Activin/Nodal and VegT/Nodal signals are necessary for both initiation and maintenance of Tbx6 expression, and Nodal is sufficient to induce ectopic Tbx6 expression; (2) FGF signal is necessary for the initiation and maintenance of Tbx6, but it is not sufficient to induce Tbx6 expression; (3) BMP is also necessary for the expression of Tbx6, and the induction of Tbx6 expression by BMP is dose dependent; (4) Xnot has no effect on the expression of Tbx6. Our results suggest that several signaling pathways are involved in regulating Tbx6 expression, and pave the route to reveal the molecular mechanism of initiating myogenesis.

Animals↗

PubMed1999

The Regulation of Xmyf-5 Gene, a Muscle Determinant, Expression in Xenopus Laevis.

Xmyf-5 gene is a member of the myogenic regulatory genes important for Xenopus muscle cell commitment and differentiation. To analyze the mechanism involved in regulating Xmyf-5 gene activity in the process of myogenesis, the 4.9 kb 5' upstream sequence of Xmyf-5 was identified. LacZ gene could be activated in the presomitic mesoderm in stage 14 embryos and myotomes in stage 25 embryos when it was driven by the 4.9 kb sequence and introduced into embryos at 2 cell stage. The Luciferase reporter gene activities driven by deletion constructs suggested that there are at least one enhancer between 4.9 kb and 3.5 kb of Xmyf-5 5' upstream DNA and one negatively regulative factor between 2.0 kb and 0.9 kb of the Xmyf-5 5' upstream DNA. In addition, sequence analysis indicated that a 100 bp fragment 5' upstream of Xmyf-5 contained conserved regulative elements such as OLS which were found in other vertebrates.

Journal Article↗

PubMed1999

In Situ Hybridization of RA Induced P19 Cells.

P19 EC cells can be induced to differentiate into neurons in vitro when they were treated with 1x10(-6) mol/L retinoic acid. In the process of neuronal differentiation, P19 cells gradually migrate and form aggregates. Aggregated cells weakly adhered to the surface of cell culture dishes are usually dropped of during the procedure of in situ hybridization. To keep cells on the coverslips, we modified the procedure by using 1 g/L gelatin solution to cover the cells and substituting proteinase K treatment with pepsin treatment which digested cellular proteins mildly. With the treatment of pepsin, RNA probe can easily go through cell membrane and bind to its target, without loss of cell from coverslips.

Journal Article↗