Production of a transgenic piglet by a sperm injection technique in which no chemical or physical treatments were used for oocytes or sperm.
As a method of producing transgenic animals, spermatozoa have been used to fertilize mammalian oocytes through natural copulation, artificial insemination (AI), and in vitro fertilization (IVF). Our objective was to produce live piglets expressing the enhanced green fluorescent protein (eGFP) by the modified ICSI procedure based on Yong et al. (2003) (Hum. Reprod. 18:2390) where this procedure resulted in an improvement in development in vitro as compared to conventional ICSI and IVF. After injecting frozen-thawed sperm, recovered from the descendant of a transgenic boar derived by oocyte transduction, into in vitro matured oocytes the injected oocytes were surgically transferred into the oviduct of six surrogate gilts. Two gilts (33%) became pregnant. One gave birth to a healthy male piglet. Expression of the eGFP was easily observed in the nose and hooves by direct epifluorescent examination in the newborn piglet. These results show the production of the first viable transgenic piglet by in vitro maturation and our new sperm injection method.
Division of Animal Science, University of Missouri-Columbia, Columbia, Missouri 65211, USA.
Hwan Yul
HY
Yong
Yanhong
Y
Hao
Liangxue
L
Lai
Rongfeng
R
Li
Clifton N
CN
Murphy
August
A
Rieke
David
D
Wax
Melissa
M
Samuel
Randall S
RS
Prather
D000818:Animals; D030801:Animals, Genetically Modified; D005260:Female; D005307:Fertilization in Vitro; D007315:Insemination, Artificial; D008297:Male; D009865:Oocytes; D011247:Pregnancy; D013094:Spermatozoa; D013552:Swine; D014161:Transduction, Genetic