Somatic embryogenesis is a very efficient way to propagate economically important plants;however, not all genotypes within a species can be propagated using this method, as a combined effect of both genetic and epigen...Somatic embryogenesis is a very efficient way to propagate economically important plants;however, not all genotypes within a species can be propagated using this method, as a combined effect of both genetic and epigenetic mechanisms may be involved in the response. The aim of the present study was to perform a comparative analysis of the genetic differences through amplified fragment length polymorphism (AFLP) and the epigenetic differences through methylation-sensitive amplified polymorphism (MSAP) of two Agave fourcroydes clonal lines, one highly embryogenic (K33) and the other non-embryogenic (K7). Genetic and epigenetic variabilities existed within each clonal line;however, the polymorphic profiles from the two marker systems allowed us to clearly distinguish the two clonal lines before somatic embryogenesis induction. During the induction, the changes detected were mainly 1) unmethylated fragments in the initial explants that were methylated during induction (methylation events) and 2) fragments with different methylation states in the initial explant that were unmethylated in some stages of the process (demethylation events). K33 showed greater dynamism in relation to methylation/demethylation events, while K7 presented the methylation events in a more constant range and at higher levels during all process.展开更多
During the course of malignant transformation of mammalian cells in vitro,a regular varia-tion in chromosome number and structure is usually found.In order to elucidate the rela-tionship between chromosomal changes an...During the course of malignant transformation of mammalian cells in vitro,a regular varia-tion in chromosome number and structure is usually found.In order to elucidate the rela-tionship between chromosomal changes and maligannt expression,we isolated fire clonesfrom a malignant transformed Syrian hamster fibroblast cell line and analyzed their biologicalcharacteristics,as well as chromosomal changes.A positive correlation betweetn chromosomeNo 15 monosomy and the transformed and malignant phenotype was observed.We suggestthat a suppression gene may be located on chromosome No 15,and its deletion or the lossof the chromosome may result in expression of the malignant phenotype.展开更多
Objective: The purpose of the study was to investigate the effects of parathyroid hormone and parathyroid hormone receptor monoclonal antibody on in vitro growth and proliferation of human medullary thyroid carcinoma ...Objective: The purpose of the study was to investigate the effects of parathyroid hormone and parathyroid hormone receptor monoclonal antibody on in vitro growth and proliferation of human medullary thyroid carcinoma cell lines. Methods: The medullary thyroid carcinoma cell line was cultured in vitro, with parathyroid hormone and parathyroid hormone receptor monoclonal antibody treatment intervention, the growth of the cells was observed under an inverted contrast microscope, the MTT assay was used to detect the cell growth inhibition rate. Results: Under the inverted contrast microscope, the cells changed significantly, the parathyroid hormone and parathyroid hormone receptor monoclonal antibodies can effectively inhibit the proliferation of medullary thyroid cancer cells in a time and dose dependent. When parathyroid hormone concentration reached a concentration of 2.0 μmol/L, the parathyroid hormone receptor monoclonal antibody reached a concentration of 1.0 μmol/L, the cell growth was most significantly inhibited(P < 0.05). Conclusion: Parathyroid hormone and parathyroid hormone receptor monoclonal antibody were able to inhibit the proliferation of medullary thyroid carcinoma cells and significantly reduce the proliferation index.展开更多
文摘Somatic embryogenesis is a very efficient way to propagate economically important plants;however, not all genotypes within a species can be propagated using this method, as a combined effect of both genetic and epigenetic mechanisms may be involved in the response. The aim of the present study was to perform a comparative analysis of the genetic differences through amplified fragment length polymorphism (AFLP) and the epigenetic differences through methylation-sensitive amplified polymorphism (MSAP) of two Agave fourcroydes clonal lines, one highly embryogenic (K33) and the other non-embryogenic (K7). Genetic and epigenetic variabilities existed within each clonal line;however, the polymorphic profiles from the two marker systems allowed us to clearly distinguish the two clonal lines before somatic embryogenesis induction. During the induction, the changes detected were mainly 1) unmethylated fragments in the initial explants that were methylated during induction (methylation events) and 2) fragments with different methylation states in the initial explant that were unmethylated in some stages of the process (demethylation events). K33 showed greater dynamism in relation to methylation/demethylation events, while K7 presented the methylation events in a more constant range and at higher levels during all process.
文摘During the course of malignant transformation of mammalian cells in vitro,a regular varia-tion in chromosome number and structure is usually found.In order to elucidate the rela-tionship between chromosomal changes and maligannt expression,we isolated fire clonesfrom a malignant transformed Syrian hamster fibroblast cell line and analyzed their biologicalcharacteristics,as well as chromosomal changes.A positive correlation betweetn chromosomeNo 15 monosomy and the transformed and malignant phenotype was observed.We suggestthat a suppression gene may be located on chromosome No 15,and its deletion or the lossof the chromosome may result in expression of the malignant phenotype.
基金Supported by a grant from the Science and Technology Plan Projects of Lanzhou(No.2013-3-38)
文摘Objective: The purpose of the study was to investigate the effects of parathyroid hormone and parathyroid hormone receptor monoclonal antibody on in vitro growth and proliferation of human medullary thyroid carcinoma cell lines. Methods: The medullary thyroid carcinoma cell line was cultured in vitro, with parathyroid hormone and parathyroid hormone receptor monoclonal antibody treatment intervention, the growth of the cells was observed under an inverted contrast microscope, the MTT assay was used to detect the cell growth inhibition rate. Results: Under the inverted contrast microscope, the cells changed significantly, the parathyroid hormone and parathyroid hormone receptor monoclonal antibodies can effectively inhibit the proliferation of medullary thyroid cancer cells in a time and dose dependent. When parathyroid hormone concentration reached a concentration of 2.0 μmol/L, the parathyroid hormone receptor monoclonal antibody reached a concentration of 1.0 μmol/L, the cell growth was most significantly inhibited(P < 0.05). Conclusion: Parathyroid hormone and parathyroid hormone receptor monoclonal antibody were able to inhibit the proliferation of medullary thyroid carcinoma cells and significantly reduce the proliferation index.
