Introduction of Foreign Genes into Silkworm Eggs by Electroporation and Its Application in Transgenic Vector Test

Xiu-Yang GUO#, Liang
DONG#, Sheng-Peng WANG, Ting-Qing GUO, Jian-Yang WANG, and Chang-De LU*
( Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological
Sciences, the Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031,
China )

Abstract Electroporation
as a methodology to introduce foreign genes into silkworm eggs was systematically
analyzed. The foreign gene in both the newly hatched and 3rd instar larva DNA
can be detected by PCR. The amount of foreign gene in 3rd instar larva DNA was
about 1/1000 of that in newly hatched larva DNA. The ratio of foreign gene entering
into silkworm eggs was voltage dependent and showed significant difference between
the tested silkworm strains. When the piggyBac transposon system was
applied, the effect of nuclear localization signal (NLS) peptide and the
in vitro transcribed transposase mRNA on the transposition rate has been
measured. Results showed that the in vitro transcribed transposase mRNA
facilitated transposition to take place earlier and NLS could result in higher
transposition probability and earlier transposition as well. When linearized
vectors containing varied length of flanking homologous sequences around a reporter
gene were introduced into silkworm eggs by electroporation, the one with 2.6
kb total arm length gave higher G1 positive ratio than that with total arm length
of 1.5 kb and 800 bp.

Key words silkworm eggs;
gene introduction; electroporation; transposon; homologous sequences

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Received: March 5, 2004 Accepted:
March 25, 2004
This work was supported by the grants from the Natural Science Foundation
of China (No. 30370326) and the Science and Technology Committee of Shanghai
(No. 024319209).
#These authors contributed equally to this work
*Corresponding author: Tel,86-21-54921234; Fax, 86-21-54921011; Email,[email protected]