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Targeting gene expression to the wool follicle in transgenic sheep
S Damak1, N P Jay, G K Barrell
1Centre for Molecular Biology, Lincoln University, Canterbury, New Zealand.
Bio/Technology (Nature Publishing Company)
|February 1, 1996
Summary
Researchers created transgenic sheep to study gene overexpression in wool follicles. The mouse ultrahigh-sulfur keratin promoter successfully directed gene expression to the wool follicle, showing potential for improving wool production.
Area of Science:
- Animal biotechnology
- Molecular genetics
- Agricultural science
Background:
- Overexpressing foreign genes in livestock can enhance desirable traits.
- Wool follicle gene expression is key to wool production and quality.
Purpose of the Study:
- To assess the feasibility of using a mouse ultrahigh-sulfur keratin promoter for foreign gene overexpression in sheep wool follicles.
- To evaluate the heritability and tissue-specific expression of a transgene in sheep.
Main Methods:
- Pronuclear microinjection of a DNA construct (mouse keratin promoter linked to chloramphenicol acetyl transferase gene) into sheep zygotes.
- Mating of transgenic rams to assess Mendelian inheritance of the transgene.
- Analysis of transgene expression in various tissues using biochemical assays and in situ hybridization.
Main Results:
- Four out of 31 lambs born were transgenic, with an overall efficiency of 1.1%.
- The transgene was transmitted to offspring in Mendelian fashion.
- Chloramphenicol acetyl transferase (CAT) expression was detected in the skin of transgenic sheep, specifically within the wool follicle's keratogenous zone.
- Expression levels in skin correlated with wool growth rates, influenced by diet and season.
Conclusions:
- The mouse ultrahigh-sulfur keratin promoter is effective for directing gene expression within the wool follicle.
- This approach holds promise for genetically modifying sheep to enhance wool production and properties.
- The promoter's specificity and responsiveness to physiological changes make it a valuable tool for wool follicle research.
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