Misawa et al.: Population structure of Okame/ei keno/ei 
27 
Table 1 
Genetic diversity indices calculated from mtCR 597 base pairs from 6 regional populations within 
Okamejei kenojei. n=number of individuals sampled; H=number of haplotypes; /i=haplotype diver¬ 
sity; 7r=nucleotide diversity. Range is followed by mean ±standard deviation. 
Population 
Area 
n 
H 
h 
71 
EC 
East China Sea 
31 
5 
0.6989 ±0.0498 
0.0016 
±0.0013 
YS 
Yellow Sea 
10 
3 
0.5111 ±0.1643 
0.0011 
±0.0011 
SJ 
Sea of Japan 
74 
7 
0.5050 ±0.0654 
0.0011 
±0.0010 
EK 
East coast of Kyushu Is. 
1 
1 
0 
0 
OS 
Osaka Bay 
24 
2 
0.0833 ±0.0749 
0.0001 
±0.0003 
NP 
Pacific coast of northern Japan 
54 
2 
0.2013 ±0.0667 
0.0003 
±0.0005 
Total 
194 
14 
0.8191 ±0.0137 
0.0036 
±0.0022 
Table 2 
Pairwise F ST (below diagonal) and associated signifi¬ 
cance (above diagonal) of mtCR 597 base pairs from 5 
regional populations (except EK) of Okamejei kenojei. 
+=significant at P<0.001 level (after Bonferroni correc¬ 
tion). Population abbreviations are given in Table 1. 
EC 
YS 
SJ 
OS 
NP 
EC 
+ 
+ 
+ 
+ 
YS 
0.372 
+ 
+ 
+ 
SJ 
0.416 
0.493 
+ 
+ 
OS 
0.584 
0.778 
0.634 
+ 
NP 
0.592 
0.727 
0.631 
0.838 
populations, except for EK, the number of haplotypes 
ranged from 2 to 7, and haplotype (. h ) and nucleotide 
(7t) diversity ranged from 0.0833 to 0.6989 and from 
0.0001 to 0.0016, respectively (Table 1). Genetic diver¬ 
sity indices were highest in the EC population, and 
lowest in the OS population. 
Among a total of 14 haplotypes, 11 haplotypes were 
unique to a regional population (i.e., were private hap¬ 
lotypes), and 5 singletons seen in only one individual 
(having an unshared haplotype) (Fig. 2). Three hap¬ 
lotypes (Okl-3) were shared among different regional 
populations and placed in central positions in the net¬ 
work; one among EC, YS, SJ and NP populations (Okl), 
another among EC, YS and SJ (Ok2), and the others 
between EC and SJ (Ok3). Although most of the haplo¬ 
types differed from each other by single substitutions, 
two unique haplotypes found in the OS population (Okl3 
and 14) were characterized by 2 and 3 substitutions, 
respectively. The frequency of private haplotypes was 
high, which accounted for 45% (88/194) of all observa¬ 
tions (EC=55%, 17/31; YS=10%, 1/10; SJ: 23%, 17/74; 
EK=100%, 1/1; OS=100%, 24/24; NP=52%, 28/54). 
The pairwise F ST values among the five regional 
Figure 2 
Haplotype network constructed from the mtCR 
(597 bp) variations of Okamejei kenojei from 6 
regional populations. Each circle represents a 
single haplotype. Circle size represents number 
of individuals. Each bar represents one sub¬ 
stitution. Numerals indicate haplotype codes. 
EC=East China Sea; YS=Yellow Sea; SJ=Sea of 
Japan; EK=East coast of Kyushu Is.; OS=Osaka 
Bay; NP=Pacific coast of northern Japan. 
populations (except that of EK) ranged from 0.372 to 
0.838, and were statistically significant after Bonfer¬ 
roni corrections in all cases (P<0.001) (Table 2). The 
F st values between OS or NP and the other popula¬ 
tions were especially high (OS: 0.584-0.838; NP: 
0.592-0.838). 
