Hi,all

Does anyone meet this question.

Blastn Error：

Error ：m=0, E-value = e-141，Gaps=3, However when m=8，E-value is 2e-141, Gaps=2

Tool：Blast

The version number：blast-2.2.26 /blastn

Parameter：default

Query ：DNA sequence, 1477 bp, test.fa

Database: Rv0002, 1209 bp, Rv0002.fa

Output:

m=0

Score = 490 bits (247), Expect = e-141

Identities = 263/266 (98%), Gaps = 3/266 (1%)

Strand = Plus / Plus

m=8

test Rv0002 98.87 266 0 2 944 1206 178 443 2e-141 490

Thanks very much!