A.V. Sivaprasad's scientific contributionswhile affiliated with University of Adelaide (Adelaide, Australia) and other places

Publications (10)

Publications citing this author (112)

    • The remaining early genes consist of an operon of 9, 12 and 11 genes in P2, 186, and HP1 respectively (Bertani and Bertani, 1971)(Portelli et al., 1998)(Nilsson and Haggård-Ljungquist, 2006)(Esposito et al. 1996)(Table 1). The expression of this operon initiates the lytic cycle mainly by enabling excision from the bacterial genome (through Cox in P2 and through Apl in 186) and through the initiation of replication (through A in P2 and through rep in 186) (Esposito and Scocca, 1997)(Liu et al., 1993)(Sivaprasad et al., 1990). Fig 7 Gene
    Article · Jan 2012 · Nutrition Research Reviews
    • Using transgenic methods, the quality, length, strength, fineness and crimp of the wool and hair fiber from sheep and goats can be manipulated [7] for better returns. To alleviate the need for hand shearing of fiber producing animals, transgenesis technology can be used, to induce sheep to shed their wool at specific times.
    [Show abstract] [Hide abstract] ABSTRACT: Transgenic animals are those animals which have been genetically engineered to carry one or more foreign genes. The foreign DNA is present in all tissue of the animal and transmitted to its offspring. The production of transgenic animals is one of several new and developing technologies that will have a profound impact on the genetic improvement of livestock. Improvement in livestock by this technology has been done through modification of milk quality and quantity, heat tolerant breeds, enhancement in carcass composition and growth traits, disease resistance, reproductive performance and fecundity in litter bearing animals, improving hair and fiber. Remarkable achievements have been made with this technology but due to the unavailability of simple, efficient and economic methods to produce transgenic animals, as well as our inability to identify appropriate genes to manipulate the livestock species, the utility of this technology in producing livestock is limited to meet consumer and market demand.
    Full-text · Article · Feb 2017 · Nutrition Research Reviews
    • Brie¯y, these show that twenty-eight transgenic sheep with the genes encoding cysteine biosynthesis have been produced. These animals contain the bacterial coding sequences for the enzymes SAT and OAS, isolated either from E. coli or from Salmonella typhimurium (Sivaprasad et al. 1992) and regulated by three different eukaryotic promoters. However, no useful expression of the genes has been obtained in any of these animals, although some low-level expression has been detected ( Bawden et al. 1995;Ward et al. 1998).
    [Show abstract] [Hide abstract] ABSTRACT: Improved domestic animal productivity is necessary in order to provide for an increasing world population over the next two to three decades and such improvement would be aided by an increase in the efficiency of nutrient utilization. This can be achieved by conventional genetic selection protocols but progress by this approach is slow. A more rapid but as yet largely unproven technique is the direct modification of the genome which can be achieved by the transfer of recombinant DNA to the nuclei of early embryos. This new technology is potentially powerful because it allows the direct transfer of genes without regard to inter-species barriers to breeding. However, it raises a new set of problems associated with the integration and expression of the foreign genetic information in the new genome. In this review the application of the technology to increasing nutrient utilization and increased productivity are discussed. Two areas have received substantial attention in the 15 years since the technique was first applied to domestic animals. First, the current status of the modification of growth hormone levels to improve productivity and feed utilization efficiency is reviewed, with current results suggesting that several of the projects may soon be approaching field trial status. Second, the introduction of novel biochemical pathways to domestic animals to provide them with different sources of the substrates required for growth and production is discussed. Recent results obtained in the introduction of a cysteine biosynthetic pathway to animals is reviewed. While this line of research remains some distance from commercial application, it provides a useful example of the powerful possibilities inherent in the new technology. However, it also serves to highlight some of the difficulties that might be expected as new genes are expressed to produce enzymes that must fit compatibly with existing animal biochemistry.
    Article · Jul 1999
    • On the other hand, few genetically modified sheep models developed using pronuclear microinjection have been reported. The preferred target for sheep is to enhance meat or wool production (Murray et al., 1989;Rexroad et al., 1989;Bawden et al., 1995;Damak et al., 1996;Adams et al., 2002), or generate disease resistant models (Clements et al., 1994). In addition, some models of human diseases have been also developed in sheep (Jacobsen et al., 2010).
    [Show abstract] [Hide abstract] ABSTRACT: This review summarizes the main achievements with the use of transgenesis and genome editing technologies in sheep and goats. Transgenesis, also referred to as recombinant DNA (rDNA) technology, made possible by the first time 30 years ago the addition of novel traits from a given species into a different one. On the other hand, more recently genome editing appears a much more precise method of making changes to the genome of a plant, animal, or other living organism, allowing for the addition, substitution, or deletion of specific nucleotides in an organism's genome. With transgenesis, the introduction of new DNA into an organism's genome was generally without control of the site of the genome in which the insertion of that rDNA construct would occur. With genome editing in contrast, researchers and developers of products can make specific changes in precise locations of the genome. This concept was absolutely improved with the novel CRISPR/Cas system, making genome edition cheaper, more efficient, easier and affordable for every Laboratory around the world. This revolution that originally emerged from molecular biology and passed to biomedicine, has recently been applied to livestock and agriculture. In addition, the application of this technology in sheep, goats, pigs and cattle, also has been possible by the advance of assisted reproductive technologies for embryo production, micromanipulation, cryopreservation and transfer. In general, multidisciplinary approaches including basic research and technical improvements, participation of private actors and adequate regulation should be merged to take advantage of this potent biotechnology in different countries.
    Full-text · Article · Mar 2017 · Nutrition Research Reviews