Transgenic farm animals get off the ground

Transgenic Research -     

MicroRNAs in farm animals

MicroRNAs (miRNAs) are a class of ∼22 nucleotide-long small noncoding RNAs that target mRNAs for translational repression or degradation. miRNAs target mRNAs by base-pairing with the 3′-untranslated regions (3′-UTRs) of mRNAs. miRNAs are present in various species, from animals to plants. In this review, we summarize the identification, expression, and function of miRNAs in four important farm animal species: cattle, chicken, pig and sheep. In each of these species, hundreds of miRNAs have been identified through homology search, small RNA cloning and next generation sequencing. Real-time RT-PCR and microarray experiments reveal that many miRNAs are expressed in a tissue-specific or spatiotemporal-specific manner in farm animals. Limited functional studies suggest that miRNAs have important roles in muscle development and hypertrophy, adipose tissue growth, oocyte maturation and early embryonic development in farm animals. Increasing evidence suggests that single-nucleotide polymorphisms in miRNA target sites or miRNA gene promoters may contribute to variation in production or health traits in farm animals.     

浅谈转基因克隆动物技术

根据现有理论和技术发展趋势,提出了转基因克隆动物的概念,即将克隆动物与转基因克隆动物技术有机地结合起来,认为转基因克隆动物制作 技术将有望成为下一世纪创建遗传工程动物的主导性技术。     

Giardia infection in farm animals

Giardia infection is prevalent in farm animals from an early age. Despite the wide occurrence of the infection and recent understanding of its epidemiology, many aspects of giardiasis of farm animals remain unclear. In this article, Lihua Xiao discusses the prevalence, patterns, sources and clinical importance of Giardia infection in a variety of farm animals.     

Transgenic animals and nutrition research

Transgenic animals are useful tools for the study of biological functions of proteins and secondary gene products synthesized by the action of protein catalysts. Research in nutrition and allied fields is benefiting from their use as models to contrast normal and altered metabolism. Although food, nutritional products, and ingredients from transgenic animals have not yet reached consumers, the technologies for their production are maturing and yielding exciting results in experimental and farm animals. Regulatory governmental bodies are already issuing guidelines and legislation in anticipation of the advent of these products and ingredients. This review summarizes available technology for the production of transgenic animals, discusses their scientific and commercial potential, and examines ancillary issues relevant to the field of nutrition.     

Comparative mapping in farm animals.

This paper summarises the current status of comparative mapping in farm animals. For most of the major farm animal species, a wide range of genomic tools are now available to create high-resolution genetic and physical maps of the genome. For many farm animals, the use of radiation hybrid panels and sequence data from expressed sequence tag (EST) projects has accelerated the development of high-resolution comparative maps, with human--the model species for farm animals. These tools and comparative maps are being used to map and identify the genes at the loci for simple and complex traits. The development of detailed physical maps in farm animals based on radiation hybrid panels and bacterial artificial chromosome (BAC) contigs provides a direct link between the 'information-poor' maps of farm animals and the 'information-rich' genomes of human and other model organisms.     

Control of ovulation in farm animals

Examination of hormonal changes occurring in farm species at the onset of puberty, during the follicular phase of the oestrous cycle, and at those times when ovarian activity is re-established after periods of seasonal or lactational anoestrus, provides circumstantial evidence that the final phases of follicular development are dependent on a pattern of tonic (episodic) LH secretion. A suppression of episodic LH secretion is associated with periods of anovulation. Stimulation of tonic LH secretion by repeated injections of small doses of synthetic Gn-RH or purified LH restores normal reproductive function in all but deeply anoestrous animals. Continuous infusion of Gn-RH is as effective as repeated injections. It is suggested that an additional inadequacy, possibly endocrine, contributes to the anovulatory state in deep anoestrus.     

Lice of farm animals in Libya

Abstract. This first report on the lice of farm animals in Libya lists a total of fifteen species, as follows: Haematopinus quadripertusus and Linognathus vituli from cattle, Bovicola ovis, Linognathus pedalis, L.afrlcanus and L.ovillus from sheep, L.stenopsis, L.africanus and Bovicola caprae from goats. Poultry harboured Lipeurus caponis, L.heterographus, Menacanthus stramineus, Menopon gallinae, Goniocotes gallinae, Goniodes gigas and G.dissimilis.     

A note on behavioural responses of farm animals to ultrasound

Ultrasound emission is a method used to eliminate rats from buildings. This study was aimed at establishing whether immediate and strong behavioural reactions could be noticed in farm animals when exposed to ultrasonic sound from a device used for rat eradication.Behavioural reactions were recorded in horses, cattle, swine, sheep and poultry. The character of the behaviour reactions observed suggests that the animals experienced the pulsating ultrasound as a disturbance. It is concluded that ultrasound can not be regarded as suitable for rat eradication in stables for horses, cattle, sheep, swine or laying hens.     

Comparative analysis of variability of various genetic systems in farm animals]

The particularities of the genetic structure formings of the different genetic systems (biochemical and immunogenetic markers) in the breeds, interbreed crosses of sheep and groups of cattle in connections with the locus, breed and the way of the productivity trait selections were described. The uniqueness of the characteristics and forming mechanisms of the genetic structure related with these factors and the inadequacy of the suppositions about them on the genealogical data were discussed.     

Transgenic animals in inflammatory disease models

Inflammatory diseases affect a significant portion of the population worldwide and have been intensely studied for several decades. The advent of transgenic technology has allowed researchers to study individual gene contributions to the pathogenesis of these diseases. This has been done using standard inflammatory disease models in transgenic animals and by identifying novel models through the spontaneous generation of disease in the transgenic animal. Recent advances have been made in the understanding of rheumatoid arthritis, pulmonary inflammation, multiple sclerosis and inflammatory bowel disease through the use of transgenic animals in models of human inflammatory disease.     

Transgenic animals in biomedical research.

The advent of transgenic technology, in which foreign genetic information is stably introduced into the mammalian germ line, has dramatically enhanced our basic knowledge of physiologic and pathologic processes. Transgenic animals created by these genetic manipulations are being used to provide insights into gene regulation, development, pathogenesis, and the treatment of disease. Furthermore, transgenic biotechnology holds great promise for the creation of genetically superior livestock and the industrial production of precious pharmaceuticals. It is evident now that the study and use of transgenic animals will significantly improve the human condition.