Wool production in transgenic sheep: Results from first‐generation adults and second‐generation lambs

Su, Huafang; Np, Jay; Ts, Gourley; Gw, Kay; Damak, Sami

doi:10.1080/10495399809525900

Cited by 16 publications

(3 citation statements)

References 12 publications

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“…Recent findings from our IGF-1 transgenic sheep also support the less important role of systemic IGF-1 to wool growth. Plasma IGF-1 levels are similar between the UHS-KER-IGF-1 transgenic sheep and nontransgenic half-sibs while increased wool production was found in transgenics (Su et al, 1998). Further studies in our UHS-KER-IGF-1 transgenic mice would require to measure the circulating level of IGF-1 and to determine its involvement on vibrissa growth.…”

Section: Discussionmentioning

confidence: 83%

Increased Vibrissa Growth in Transgenic Mice Expressing Insulin-like Growth Factor 1

Hickford

Hill

et al. 1999

Journal of Investigative Dermatology

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Insulin-like growth factor 1 (IGF-1) mediates many of the actions of growth hormone. Overexpression of IGF-1 has been reported to have endocrine and paracrine/autocrine effects on somatic growth in transgenic mice. To study the paracrine/autocrine effects of IGF-1 in hair follicles, transgenic mice were produced by pronuclear microinjection of a construct containing a mouse ultra-high sulfur keratin (UHS-KER) promoter linked to an ovine IGF-1 cDNA. This UHS-KER promoter has previously been shown to direct expression of a reporter gene to the hair follicles of transgenic mice. Four transgenic mouse lines were established as a result of microinjection of 435 embryos. Transgene expression was found in skin at day 8 and day 15 of age in three of the lines. Progeny tests were carried out by mating two of the transgenic expressing males to nontransgenic females. Mice from one line were all nonexpressors while four of the 12 mice from the other showed integration of the transgene and three expressed transgene IGF-1 mRNA in the skin. Vibrissa growth at 11-21 d of age was significantly greater in transgenic expressors than in their nontransgenic littermates. Specifically, the increase in vibrissa length for transgenics at days 11-16 (20.5%) is approximately 2-fold compared with days 16-21 (11.9%). These results demonstrate that local overexpression of IGF-1 in transgenic mice is capable of stimulating vibrissa growth during the first neonatal hair cycle.

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Section: Discussionmentioning

confidence: 83%

Increased Vibrissa Growth in Transgenic Mice Expressing Insulin-like Growth Factor 1

Hickford

Hill

et al. 1999

Journal of Investigative Dermatology

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“…Sheep expressing the IGF1 gene were evaluated for changes in wool growth but contrary to earlier results (101) there was no gain in wool production (102). Similarly, transgenic sheep expressing an extra copy of ovine growth hormone (GH) regulated by a metallothionine promoter have been extensively evaluated for the effect on production including wool (103).…”

Section: Altering Wool Structure and Wool Growth By Sheep Transgenesismentioning

confidence: 99%

Biology of the wool follicle: an excursion into a unique tissue interaction system waiting to be re‐discovered

Rogers

2006

Experimental Dermatology

129

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: Wool fibres are hairs and the term ‘wool’ is usually restricted to describe the fine curly hairs that constitute the fleece produced by sheep. In a broader sense, it can be used to describe the fleeces produced by related species such as goat or yak. Research into the biology of wool growth and the structure of the wool fibre has been driven by the demands of the wool industry to improve both the efficiency of growing wool and the quality of the product. Well beyond this very applied perspective however, the wool follicle is a unique basic research model for the life sciences in general. These unique features include, to name just a few selected examples, accessibility for studying the molecular controls involved in branching of secondary epithelial‐mesenchymal structures, the photoperiod‐dependence of regenerating tissue interaction systems, the origin of fibre curliness and follicle wave pattern formation, and the effect of alterations in nutrient supply on epithelial growth and fibre structure. In this review, investigation of growth processes in the formation of the wool fibre is broadly surveyed. The relevance and potential for practical outcomes through characterization of wool follicle genes are discussed and particular features of the wool follicle contributing to our knowledge of the biology of hair growth are highlighted. The practical potential of gene discovery in wool research is the provision of molecular markers for selective breeding and for altering wool growth and wool structure by other biological pathways such as sheep transgenesis that could lead to novel wool properties. In this background, the current review attempts to revive general interest in the fascinating biology of the wool follicle which is not only of profound economic and practical importance but offers an exquisite, highly instructive research model for addressing key questions of modern biology.

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“…The IGF-1 pigs did not experience these same problems but rather experienced a decrease in body fat and increase in lean tissue, and they are still being studied for potential food animal use (26). IGF-1 transgenic sheep were also produced to increase wool growth rate and yield, for increased productivity with the same resource input, and for the potential to impact sustainability; however, increased wool yield diminished between the first and second generations (27,28). Similarly, cattle expressing shRNA to knock down myostatin were produced to increase muscling and therefore carcass yield (19).…”

Section: Agriculture Use Food Animalsmentioning

confidence: 99%

Genetically Engineered Livestock: Ethical Use for Food and Medical Models

Garas¹,

Murray

Maga³

2015

Annu. Rev. Anim. Biosci.

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Recent advances in the production of genetically engineered (GE) livestock have resulted in a variety of new transgenic animals with desirable production and composition changes. GE animals have been generated to improve growth efficiency, food composition, and disease resistance in domesticated livestock species. GE animals are also used to produce pharmaceuticals and as medical models for human diseases. The potential use of these food animals for human consumption has prompted an intense debate about food safety and animal welfare concerns with the GE approach. Additionally, public perception and ethical concerns about their use have caused delays in establishing a clear and efficient regulatory approval process. Ethically, there are far-reaching implications of not using genetically engineered livestock, at a detriment to both producers and consumers, as use of this technology can improve both human and animal health and welfare.

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Wool production in transgenic sheep: Results from first‐generation adults and second‐generation lambs

Cited by 16 publications

References 12 publications

Increased Vibrissa Growth in Transgenic Mice Expressing Insulin-like Growth Factor 1

Increased Vibrissa Growth in Transgenic Mice Expressing Insulin-like Growth Factor 1

Biology of the wool follicle: an excursion into a unique tissue interaction system waiting to be re‐discovered

Genetically Engineered Livestock: Ethical Use for Food and Medical Models

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