In many metazoan species, germ cell formation requires the germ plasm, a specialized cytoplasm which often con-tains electron dense structures. Genes required for germ cell formation in Drosophila have been isolated p...In many metazoan species, germ cell formation requires the germ plasm, a specialized cytoplasm which often con-tains electron dense structures. Genes required for germ cell formation in Drosophila have been isolated predominantlyin screens for maternal-effect mutations. One such gene is tudor (tud); without proper tud function germ cell formationdoes not occur. Unlike other genes involved in Drosophila germ cell specification tud is dispensable for other somaticfunctions such as abdominal patterning. It is not known how TUD contributes at a molecular level to germ cell forma-tion but in tud mutants, polar granule formation is severely compromised, and mitochondrially encoded ribosomal RNAsdo not localize to the polar granule. TUD is composed of 11 repeats of the protein motif called the Tudor domain. Thereare similar proteins to TUD in the germ line of other metazoan species including mice. Probable vertebrate orthologuesof Drosophila genes involved in germ cell specification will be discussed.展开更多
Cilia depend on their highly differentiated structure, a 9 ＋ 2 arrangement, to remove particles from the lung and to transport reproductive cells. Immortalized cells could potentially be of great use in cilia researc...Cilia depend on their highly differentiated structure, a 9 ＋ 2 arrangement, to remove particles from the lung and to transport reproductive cells. Immortalized cells could potentially be of great use in cilia research. Immortalization of cells with cilia structure containing the 9 ＋ 2 arrangement might be able to generate cell lines with such cilia structure. How- ever, whether immortalized cells can retain such a highly differentiated structure remains unclear. Here we demonstrate that （1） using Ela gene transfection, tracheal cells are immortalized; （2） interestingly, in a gel culture the immortalized cells form spherical aggregations within which a lumen is developed; and （3） surprisingly, inside the aggregation, cilia containing a 9 ＋ 2 arrangement grow from the cell＇s apical pole and protrude into the lumen. These results may influence future research in many areas such as understanding the mechanisms of cilia differentiation, cilia generation in other existing cell lines, cilia disorders, generation of other highly differentiated structures besides cilia using the gel culture, immortalization of other ciliated cells with the Ela gene, development of cilia motile function, and establishment of a research model to provide uniform ciliated cells.展开更多
Some germ cell marker genes, such as vasa, nanos, and dead end( dnd), have been identified in fish. Recently, lymphocyte antigen 75(Ly75/CD205) has been identified as a mitotic germ cell-specific cell-surface marker i...Some germ cell marker genes, such as vasa, nanos, and dead end( dnd), have been identified in fish. Recently, lymphocyte antigen 75(Ly75/CD205) has been identified as a mitotic germ cell-specific cell-surface marker in several fish species. In this study, the Japanese flounder Paralichthys olivaceus ly75 homolog( ly75) was cloned and its expression pattern in gonads was analyzed. The full-length c DNA of ly75 was 7 346 bp, with an open reading frame(ORF) of 5 229 bp. The ORF encoded a protein containing 1 742 amino acids with a predicted molecular mass of 196.89 k Da. In adult tissues, ly75 transcripts were detected in all analyzed tissues but abundantly in the testis. In in-situ hybridization analyses, ly75 mRNA was predominantly localized in oocytes in the ovary and spermatogonia in the testis, but ly75 mRNA was not detected in oogonia, spermatocytes, spermatids, or spermatozoa. These results indicated that ly75 could be a potential germ cell-specific marker in P. olivaceus, as in other fishes.展开更多
The genus Echeveria has about 143 species that are unique to the Americas, 117 of which are presented in the Mexican Republic, mainly in the states of Hidalgo, Puebla and Oaxaca. Propagation can be done by cuttings, l...The genus Echeveria has about 143 species that are unique to the Americas, 117 of which are presented in the Mexican Republic, mainly in the states of Hidalgo, Puebla and Oaxaca. Propagation can be done by cuttings, leaf cuttings or seeds, but these methods are insufficient to avoid the predation of many species. NOM-059-ECOL-2001 shows Echeveria elegans as species reported endangered. The objectives in this study were achieved in vitro propagation from axillary buds, as an alternative to multiplication and preservation species. We evaluated different concentrations and combinations of two growth regulators, 6-BAP （2.22, 4.44, 6.66 and 8.88 μM） and u-NAA （1.35 and 2.70 μM） on shoot formation from axillary buds and two culture media with different concentrations of MS salts, to achieve root plants grown in vitro. It was found by combining 6.66 μM of 6-BAP and 1.35μM of α-NAA favored the formation and development of new shoots. In the rooting stage, the best results are achieved with the treatment containing 50% of MS salts. Then the plants were transplanted into greenhouses and achieved a successful acclimatization. During this last phase of development, there were no phenotypic changes or presence of somaclonal variants.展开更多
The rapid developments of science and technology in China over recent decades, particularly in biomedical research, have brought forward serious challenges regarding ethical governance. Recently, Jian-kui HE, a Chines...The rapid developments of science and technology in China over recent decades, particularly in biomedical research, have brought forward serious challenges regarding ethical governance. Recently, Jian-kui HE, a Chinese scientist, claimed to have "created" the first gene-edited babies, designed to be naturally immune to the human immunodeficiency virus(HIV). The news immediately triggered widespread criticism, denouncement, and debate over the scientific and ethical legitimacy of HE’s genetic experiments. China’s guidelines and regulations have banned germline genome editing on human embryos for clinical use because of scientific and ethical concerns, in accordance with the international consensus. HE’s human experimentation has not only violated these Chinese regulations, but also breached other ethical and regulatory norms. These include questionable scientific value, unreasonable risk-benefit ratio, illegitimate ethics review, invalid informed consent, and regulatory misconduct. This series of ethical failings of HE and his team reveal the institutional failure of the current ethics governance system which largely depends on scientist’s self-regulation. The incident highlights the need for urgent improvement of ethics governance at all levels, the enforcement of technical and ethical guidelines, and the establishment of laws relating to such bioethical issues.展开更多
文摘In many metazoan species, germ cell formation requires the germ plasm, a specialized cytoplasm which often con-tains electron dense structures. Genes required for germ cell formation in Drosophila have been isolated predominantlyin screens for maternal-effect mutations. One such gene is tudor (tud); without proper tud function germ cell formationdoes not occur. Unlike other genes involved in Drosophila germ cell specification tud is dispensable for other somaticfunctions such as abdominal patterning. It is not known how TUD contributes at a molecular level to germ cell forma-tion but in tud mutants, polar granule formation is severely compromised, and mitochondrially encoded ribosomal RNAsdo not localize to the polar granule. TUD is composed of 11 repeats of the protein motif called the Tudor domain. Thereare similar proteins to TUD in the germ line of other metazoan species including mice. Probable vertebrate orthologuesof Drosophila genes involved in germ cell specification will be discussed.
文摘Cilia depend on their highly differentiated structure, a 9 ＋ 2 arrangement, to remove particles from the lung and to transport reproductive cells. Immortalized cells could potentially be of great use in cilia research. Immortalization of cells with cilia structure containing the 9 ＋ 2 arrangement might be able to generate cell lines with such cilia structure. How- ever, whether immortalized cells can retain such a highly differentiated structure remains unclear. Here we demonstrate that （1） using Ela gene transfection, tracheal cells are immortalized; （2） interestingly, in a gel culture the immortalized cells form spherical aggregations within which a lumen is developed; and （3） surprisingly, inside the aggregation, cilia containing a 9 ＋ 2 arrangement grow from the cell＇s apical pole and protrude into the lumen. These results may influence future research in many areas such as understanding the mechanisms of cilia differentiation, cilia generation in other existing cell lines, cilia disorders, generation of other highly differentiated structures besides cilia using the gel culture, immortalization of other ciliated cells with the Ela gene, development of cilia motile function, and establishment of a research model to provide uniform ciliated cells.
基金Supported by the National Natural Science Foundation of China(Nos.31372514,31472264,31572602)the China Agriculture Research System(No.CARS-47)+1 种基金the Scientific and Technological Innovation Project Financially Supported by Qingdao National Laboratory for Marine Science and Technology(Nos.2015ASKJ02,2015ASKJ02-03-03)the Youth Innovation Promotion Association CAS and Chinese Academy of Science and Technology Service Network Planning(No.KFJ-EW-STS-060)
文摘Some germ cell marker genes, such as vasa, nanos, and dead end( dnd), have been identified in fish. Recently, lymphocyte antigen 75(Ly75/CD205) has been identified as a mitotic germ cell-specific cell-surface marker in several fish species. In this study, the Japanese flounder Paralichthys olivaceus ly75 homolog( ly75) was cloned and its expression pattern in gonads was analyzed. The full-length c DNA of ly75 was 7 346 bp, with an open reading frame(ORF) of 5 229 bp. The ORF encoded a protein containing 1 742 amino acids with a predicted molecular mass of 196.89 k Da. In adult tissues, ly75 transcripts were detected in all analyzed tissues but abundantly in the testis. In in-situ hybridization analyses, ly75 mRNA was predominantly localized in oocytes in the ovary and spermatogonia in the testis, but ly75 mRNA was not detected in oogonia, spermatocytes, spermatids, or spermatozoa. These results indicated that ly75 could be a potential germ cell-specific marker in P. olivaceus, as in other fishes.
文摘The genus Echeveria has about 143 species that are unique to the Americas, 117 of which are presented in the Mexican Republic, mainly in the states of Hidalgo, Puebla and Oaxaca. Propagation can be done by cuttings, leaf cuttings or seeds, but these methods are insufficient to avoid the predation of many species. NOM-059-ECOL-2001 shows Echeveria elegans as species reported endangered. The objectives in this study were achieved in vitro propagation from axillary buds, as an alternative to multiplication and preservation species. We evaluated different concentrations and combinations of two growth regulators, 6-BAP （2.22, 4.44, 6.66 and 8.88 μM） and u-NAA （1.35 and 2.70 μM） on shoot formation from axillary buds and two culture media with different concentrations of MS salts, to achieve root plants grown in vitro. It was found by combining 6.66 μM of 6-BAP and 1.35μM of α-NAA favored the formation and development of new shoots. In the rooting stage, the best results are achieved with the treatment containing 50% of MS salts. Then the plants were transplanted into greenhouses and achieved a successful acclimatization. During this last phase of development, there were no phenotypic changes or presence of somaclonal variants.
基金Project supported by the National Natural Science Foundation of China(No.L1824000)
文摘The rapid developments of science and technology in China over recent decades, particularly in biomedical research, have brought forward serious challenges regarding ethical governance. Recently, Jian-kui HE, a Chinese scientist, claimed to have "created" the first gene-edited babies, designed to be naturally immune to the human immunodeficiency virus(HIV). The news immediately triggered widespread criticism, denouncement, and debate over the scientific and ethical legitimacy of HE’s genetic experiments. China’s guidelines and regulations have banned germline genome editing on human embryos for clinical use because of scientific and ethical concerns, in accordance with the international consensus. HE’s human experimentation has not only violated these Chinese regulations, but also breached other ethical and regulatory norms. These include questionable scientific value, unreasonable risk-benefit ratio, illegitimate ethics review, invalid informed consent, and regulatory misconduct. This series of ethical failings of HE and his team reveal the institutional failure of the current ethics governance system which largely depends on scientist’s self-regulation. The incident highlights the need for urgent improvement of ethics governance at all levels, the enforcement of technical and ethical guidelines, and the establishment of laws relating to such bioethical issues.
