APPLIED AND ENVIRONMENTAL MICROBIOLOGY

Oct. 2005, p. 6126-6133

報告者：簡鈺晴

有毒藻之藻華現象 - Microcystis aeruginosa

研究 此藻種之多樣性形體差異基因差異（在同一族群或不同族群間）

為何從基因的角度無法由形體辨識是否產毒

實驗設計

（ BG-11, n=3)

（ WC, n=2)

數據分析

G-test, although it is also sometimes called a log-likelihood test or a likelihood ratio test.

With sample sizes between 50 and 1000, it generally doesn't make much difference which test you use, so you shouldn't criticize someone for using the chi-square or G-test

The G-test of independence is used for two nominal variables, not one.

)]/ln([2 EOOG

結果 Survival rate

Range: 0-30%Mean ± SD , 7.4

±2.1% Relationship

湖泊總磷與高營養培養基之存活率中度相關

培養基的影響（ G = 38.7, df=4,

p<0.001)

Slope= 0.943r2=0.407p=0.014n=14

實驗

PCR result of HIP primers

序列　　　　　　差異處Seq 1: AATTAATTCG 　→ＡＴＴSeq 2: AACCAATTCG 　→ＡＣＣSeq 3: AGTTAATTCG 　→ＧＴＴ

Seq 1 和 Seq 2 間差了兩個鹼基， Seq 1 和 Seq 3卻只差一個鹼基。然而三條序列在 Wright’s F 的觀點下都被視為不同的 alleles 。

Microcystis aeruginosa Population Colony Strain

10 colonies 3 stranis

8 colonies 8 stranis 7 colonies 1 stranis

http://www.docstoc.com/docs/2370106/Analysis-of-Molecular-Variance-(AMOVA)

Level of

variation

df Sum of squares Mean

squares

Variance

Among

haplotypes within

demes

n– d SS(WD) =

Among demes

within groups d – G

SS(AD) =

– SS(WD)

Among groups

within population G – 1

SS(AG) =

SS(T) –

Total n – 1

SS(T) =

Level of population hierarchy F-statistic

Among demes within group

Among groups within population

Among demes within population

Level of population hierarchy -statistic

Among demes within group

Among groups within population

Among demes within population

基因型（％） Percent distinct genotypes

=

Range: 42-100%Mean ± SD , 78 ±7.8%

no. of distinct

genotypes

no. of isolates

analyzed

AMOVA用來評估湖泊藻族群內與藻族群間單體的差異

p value of Φsc

結果 AMOVA

各湖泊藻種基因之變異41% 基因變異解釋湖泊間藻基因之不同59% 基因變異解釋湖泊內藻基因之不同

Paper Course Note

G-test χ2 觀察值 , 平均值之比較

AMOVA ANOVA單因子變異數分析

F-test(or F-statistics)

Φ-statistics

檢定變異數

E

EO 22 )(

)]/ln([2 EOOG

1.表 (p value of Φsc) 是否應該對角對稱

2.比較表

Q & A section

the phi coefficient φ or rφ is a measure of association for two binary variables.