Annual Report 2006

Fig. 2
p/+ and +/+ tagged by RFLP
linkage analysis and mapping that were very
efficient for the organisms without crossing
over in one sex were developed. Scanning
linkage analysis (SLA) is the method for linkage
analysis using the same backcross segregants
to know where genes are linked. BCMAP is the
mapping method for the same individuals of the
backcross segregants. These methods were
introduced for making the molecular genetic
map of EST-cDNA clones in the silkworm,
. The newly developed ESTcDNA
clones were examined by Southern blot
hybridization to clarify whether those showed
effective RFLP or not. The clones showing
effective RFLP were used for SLA and
BCMAP. Finally new 70 clones were added to
the map this year.
The markers on the map and the methods
were introduced to analyze many kinds of
characters like resistant genes against BTtoxin,
polyphagous gene and etc. The molecular
markers on the map was also used to make
homozygote of p and +p genes on the second
chromosome. As shown on Fig. 1, p/+ and +/+
were identified by using very closely linked
RFLP marker.
Induction of cell-differentiation
of insect cultured cell by drags,
and its application
Characterization of new insect cultured
cell lines was analyzed. BmN4 cells that was
derived from ovary tissues was induced
strongly to fat cells by treatment of the three
complex drags, Insulin, Dexamethason and
IBMX. Particularly, Dexamethason promoted
to accumulate the fat in the cells. We analyzed
the gene related to form the fat. The gene was
designated to the BmFABP1. This genes
promoter region was analyzed in detail. We
discovered the suppression-region of
expression of the gene. By a method of gel sift
assay, we clarified the existence of protein that
combined to origo DNA that contained the
partial sequences of the BmFABP1 gene in the
extracts of BmN4 cells. We established the
insect cell culture system of Baculovirus gene
expression by using serum-free
cultured cell line, NIAS-Bm-Ke1. To produce a
high amount of the gene product of luciferase,
heat-treated serum has to be
contained in culture medium (see p12, Figs. 1
and 2; p13, Fig. 3). As an experimental system,
clone cell lines from cell line
(NISES-BoMo-Cam1) was selected.
Utilization of transposon for the
construction of transgenic insects
and application for the analysis
of insect genes
The technologies that developed a
transgenic insect for these five years has been
joined and the standard methods for making
the transgenic silkworm, including the injection
method for the preblastodermal embryos,
marker genes for the screening of the transgenic
silkworm and non-diapausing strains for the
injection, have been authorized. The method
development has been shown to be very useful
and gave very high efficiency of transformation