ABSTRACT
The International Society of Differentiation was born from the First International Conference on Cell Differentiation conceived by D.V. and held in Nice, France in 1971. The conference also resulted in the creation of the journal of the Society named Differentiation. The Society advocates for the field of differentiation through the journal Differentiation, organizing and supporting international scientific conferences, honoring scientific achievements, and supporting trainees.
Subject(s)
Cell Differentiation , Societies, Scientific , Societies, Scientific/historyABSTRACT
The sequences of two frog herpesviruses, Ranid herpesvirus 1 and Ranid herpesvirus 2, were determined. They are respectively 220 859 and 231 801 bp in size and contain 132 and 147 predicted genes. The genomes are related most closely in the central regions, where 40 genes are conserved convincingly. Nineteen of these genes are also conserved in a fish herpesvirus, Ictalurid herpesvirus 1. The terminal regions of the genomes are largely not conserved and contain many of the 15 families of related genes present in each genome. The frog herpesviruses are unique among sequenced herpesviruses in that the three exons of the gene encoding the putative ATPase subunit of terminase are not specified by the same DNA strand and in that they encode a putative DNA (cytosine-5-)-methyltransferase and have extensively methylated genomes.
Subject(s)
DNA, Viral/chemistry , Genome, Viral , Herpesviridae/genetics , Adenosine Triphosphatases/genetics , Animals , Base Sequence , Conserved Sequence , DNA (Cytosine-5-)-Methyltransferases/genetics , DNA Methylation , DNA, Viral/genetics , Endodeoxyribonucleases/genetics , Exons , Genes, Viral , Molecular Sequence Data , Open Reading Frames , Ranidae/virology , Sequence Analysis, DNA , Sequence HomologySubject(s)
Cloning, Organism/history , Ploidies , Rana pipiens/genetics , Reproduction/genetics , Animals , History, 20th CenturyABSTRACT
May 2002 marked the golden anniversary of the first cloned tadpoles. We celebrate this anniversary, as nuclear transplantation of frog cells into enucleated eggs became the prototype for cloning insects, fish, and mammals. We briefly review the salient results from amphibian cloning. Extension of these studies to mammalian species led to cloning adult cells, important advances in understanding nuclear reprogramming, and the construction of transgenic clones for biomedical applications. In addition, murine cloning clarified two problems unresolved in frog cloning: the unequivocal demonstration that nuclei of fully differentiated cells can direct the formation of fertile adults, and that abnormal expression of genes was responsible for the endoderm and neural syndromes in Rana clones.
Subject(s)
Cloning, Organism/history , Animals , Cloning, Organism/ethics , History, 20th Century , History, 21st Century , Larva , Mice , Sheep , XenopusABSTRACT
Animal cloning by nuclear transplantation was first developed in the northern leopard frog, Rana pipiens. It was soon extended to other amphibian species and within time, to various mammalian species. The production of a cloned sheep (Dolly) from an adult nuclear donor reawakened interest in human cloning. Nuclear transfer for the production of animal clones has served experimental biology well. Nonetheless, the potential burden of developmental hazards, scientists and funds diverted from more needy causes, as well as the potential assault on the concept of family has led the author to oppose human cloning.
