Biology Reference
In-Depth Information
TABLE 18.1
Mating Experiments to Detect CI Caused by the Respective Three Wolbachia Strains
Infection State
Eggs
Wolbachia
Type
Examined for CI
Hatch
Rate
Pairs
a
Total
Hatched
SD
wBruCon
CA
A
19
556
0
0.000
0.000
A
CA
13
243
224
0.922
0.076
CA
CA
15
359
322
0.897
0.076
A
A
18
532
495
0.930
0.058
wBruOri
COA
CA
16
335
206
0.615
0.213
CA
COA
15
436
352
0.807
0.263
COA
COA
20
587
534
0.910
0.115
CA
CA
15
359
322
0.897
0.076
wBruAus
COA
CO
21
477
402
0.843
0.108
CO
COA
11
258
221
0.857
0.266
COA
COA
20
587
534
0.910
0.115
CO
CO
33
861
640
0.743
0.183
a
Matings were conducted using a COA strain, three CO strains, seven CA strains, and an A strain. Bold type indicates
crosses expected to be incompatible. SD = standard deviation.
showed complete
incompatibility. The difference in hatch rate was unequivocal (Mann-Whitney
U
-test,
p
< 0.001).
In crosses between COA and CA strains, CA
between CA and A strains, A
CA
was compatible, whereas CA
A
COA
showed a normal hatch rate, whereas
COA
was partially incompatible. The difference in hatch rate was statistically signiÝcant
(Mann-Whitney
U
-test,
p
< 0.05). In crosses between COA and CO strains, no signiÝcant difference
in hatch rate was observed between COA
CA
(Mann-Whitney
U
-test,
p
> 0.05). These results indicated that in the same host insect, wBruCon caused complete CI,
wBruOri induced moderate CI, and wBruAus showed no CI or very weak CI at an undetectable level.
CO
and CO
COA
QUANTIFICATION OF
WOLBACHIA
DENSITY IN HOST INSECT
Using a quantitative PCR technique, densities of wBruCon, wBruOri, and wBruAus in adult insects
of
C. chinensis
were quantiÝed in terms of
wsp
gene copies per dry body weight
(Figure 18.5).
Among the three
Wolbachia
strains, wBruAus exhibited remarkably lower density (around 10
7
wsp
copies/mg) than wBruCon and wBruOri (around 10
8
wsp
copies/mg). This pattern Ð lower density
of wBruAus in comparison with wBruCon and wBruOri Ð was consistently found in samples
from different local populations in Japan (data not shown). These results suggested that in the same
host body, the densities of the respective three
Wolbachia
strains might be controlled to be at
different levels.
POPULATION DYNAMICS OF
WOLBACHIA
THROUGH
HOST DEVELOPMENT
Population dynamics of wBruCon, wBruOri, and wBruAus were monitored throughout the devel-
opment of
C. chinensis
using quantitative PCR
(
Figure 18.6)
.
The populations of the three
Wolbachia
strains consistently increased as development of the host proceeded, although they exhibited
different population-growth patterns. In early eggs, wBruOri was the most abundant (around 4
10
5
wsp
copies equivalent per insect), wBruCon was intermediate in amount (around 4 10
4
wsp
copies equivalent per insect), and wBruAus was the least abundant (around 1 10
2
wsp
copies
