Factors affecting the production of potential transgenic pigs by DNA microinjection; a six-year retrospective study

J Jura,R Słomski,B Gajda,D Lipiński,Z Smorąg

doi:10.22358/jafs/66820/2007

Abstract

Transgenesis is a complex process. Among the most important factors affecting the production of potential transgenic pigs using standard DNA microinjection into zygote pronuclei are the type of promoter used to express the gene construct and the method of zygote transfer used for transformation. The transformation of zygotes using different gene constructs showed that the promoter type infl uenced the developmental capability of the transformed zygotes, and this affected the percentage of born piglets. The transfer of transformed zygotes into a single oviduct resulted in a higher percentage of potential transgenic piglets born, this fi gure was almost doubled compared with transfer into both oviducts. Recently, research into the production of transgenic pigs has shown that factors connected with reproduction physiology and embryological factors such as the number of zygotes transferred after transformation and the season of the year have a signifi cant infl uence but are not critical to the effi ciency of production of transgenic pigs. The best results were obtained when less than 20 transformed zygotes per recipient were transplanted and the autumn season is the time when the environmental factors are optimal for production of potential transgenic pigs.

Highlights

The production of transgenic animals is a complex process
This paper presents data obtained over six years of research into the production of transgenic pigs using standard DNA microinjection techniques and is focused on analysis of embryological and physiological factors which influence efficiency of transgenesis in pigs
The transformation of zygotes using different gene constructs showed that the promoter type influenced the developmental capability of the transformed zygotes, and this affected the percentage of born piglets

Summary

Introduction

The production of transgenic animals is a complex process. Despite the development of increasingly sophisticated technologies, the efficiency of the process remains disproportionately low compared to labour inputs and costs. Transgenic efficiency using standard DNA microinjection, which is still the leading technique in this species, does not exceed 2% in terms of the number of zygotes subjected to microinjection (Jura and Jurkiewicz, 2006). Cloning techniques using transfected somatic cells or their nuclei to produce transgenic animals are even less efficient. The inefficiency of the cloning process is due to the complexity and limitations of the cloning procedure, which have been well documented in the previous literature (Jura and Jurkiewicz, 2006)

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Discussion

Conclusion