background: over the past several years, mammals have been successfully cloned by either the splitting of an early stage embryo or nuclear transfer of adult somatic cells (nt) into oocytes. although it has been 15 years since the generation of the first cloned mammals from somatic cells by nt, the success rate for producing live offspring by this technique is low regardless of the cell type and...

The announcement that Sir John Gurdon had been awarded the 2012 Nobel Prize for Medicine or Physiology was received with great joy by developmental biologists. It was a very special occasion because of his total dedication to science and turning the Golden Rule of western civilization - love your neighbor as yourself - into a reality in our field. This essay attempts to explain how John became ...

The ability to obtain genetically identical offspring in cattle (clones) is useful for research and for potential applications to breeding schemes. Experimental possibilities for generating such animals have evolved considerably in the last two decades. Embryo splitting has become a relatively simple technique but is limited to twinning. Embryonic nuclear transfer has improved and is associated...

DNA methylation patterns are dynamic in cleavage-stage embryos of a number of mammalian species. A failure to properly recapitulate preimplantation DNA methylation patterns in embryos derived by nuclear transfer may contribute to the low efficiency of nuclear transfer in producing live offspring.

the industrial growth of any developing country largely depends on the availability of abundant energy resources. according to the energy survey carried out by international atomic energy agency, (1) the contribution which nuclear energy will make towards the total energy requirements of the developed countries of the world by the end of the century will be about 50%. in iran by the year 1992 t...

isotopic and nuclear techniques play an important role in food and agriculture, health and industry. in the agricultural sciences and food technology sectors, recent research has elucidated the new potential application of radiation for microbial decontamination, food preservation, improve the nutritional quality of  foods  and effectively utilise its potential as human food or animal feed. the...

INTRODUCTION A METHOD by which nuclei can be successfully transplanted into Amphibian eggs was first worked out by Briggs & King (1952) for the eggs of Ranapipiens. Xenopus laevis is an atypical Anuran since its eggs can be obtained throughout the year, and the resulting embryos can be reared to maturity within 12 months under laboratory conditions. Because of these advantages we have used Xeno...

There are many ways to genetically modify fish including inbreeding, gynogenesis, androgenesis, selection, intraspecific crossbreeding, interspecific hybridization, polyploidy, sex reversal and breeding, nuclear transplantation and transgenesis. Cloned populations have been produced via gynogenesis and androgenesis (Dunham 2004 in press), but direct cloning of an individual fish of interest has...

Background: For several years, mammalian cloning by splitting an early embryo or nuclear transfer into oocytes method has been successfully performed. Cloning is now also possible using adult somatic cells. Although it has now been 15 years since the first cloned mammals were generated from somatic cells using nuclear transfer (NT), the success rate for producing live offspring by cloning is lo...

Genetically modified cattle are important for developing new biomedical models and for an improved understanding of the pathophysiology of zoonotic diseases. However, genome editing and genetic engineering based on somatic cell nuclear transfer suffer from a low overall efficiency. Here, we established a highly efficient one-step multiplex gene transfer system into the bovine genome.