For more than two decades, the intracytoplasmic sperm injection (ICSI) technique has been used as a valuable tool to provide opportunities for studying fertilization, treating human infertility, and producing transgenic animals. Not only in facilitating fertilization but also in propagating mammalian species, ICSI has enhanced the potential of assisted reproductive technologies in human. Polyspermic fertilization has been one of major problems in pig reproduction, but the ICSI helped to solve the problem, and used widely to generate transgenic piglets. Although the ICSI technique is considered to be a very useful tool in assisted reproductive technologies, including generation of transgenic animals, there are some disadvantages using the technique. In this review, we describe the ICSI technique and its application in animal production and human infertility, and discuss advantage and disadvantage of the technique in mammals.

ABSTRACT   
INTRODUCTION   
WHAT IS ICSI? WHY TO DO THAT?   
ICSI IN ANIMALS   
ICSI in Human   
DISADVANTAGE OF ICSI    
Low Efficiency    
Safety   
CONCLUSION   
REFERENCES

• Xiao Xia Li(Department of Animal Science and Biotechnology, College of Agriculture Life Science, Chungnam National University)
• Kyung Bon Lee(Department of Animal Science and Biotechnology, College of Agriculture Life Science, Chungnam National University)
• Ji Hye Lee(Department of Animal Science and Biotechnology, College of Agriculture Life Science, Chungnam National University)
• Keun Jung Kim(Department of Animal Science and Biotechnology, College of Agriculture Life Science, Chungnam National University)
• Kang Sun Park(Department of Animal Science and Biotechnology, College of Agriculture Life Science, Chungnam National University)
• Min Kyu Kim(Department of Animal Science and Biotechnology, College of Agriculture Life Science, Chungnam National University) Corresponding author