Skip to main content

Table 2 Test for positive selection and identification of positively selected sites

From: Selection, diversity and evolutionary patterns of the MHC class II DAB in free-ranging Neotropical marsupials

Species

Substitution rate

ω = d N /d S

Model [100]

2(Lb-La)

P

Positively selected sites

 

d N

d S

    

26

37

57

60

70

71

74

77

86

G. microtarsus

0.159

0.178

0.893

M1 – M2a

63.46

<0.001

x

x

x

x

x

x

x

x

x

 

(± 0.028)

(± 0.039)

n.s.

M7 – M8

56.01

<0.001

x

x

x

x

x

x

x

x

x

    

Dist. to human ABS

  

2

0

1

0

0

0

0

1

0

M. incanus

0.143

0.183

0.781

M1 – M2a

13.32

<0.005

 

x

   

x

   
 

(± 0.026)

(± 0.047)

n.s.

M7 – M8

11.50

<0.005

    

x

x

   
    

Dist. to human ABS

   

0

  

0

0

   
  1. The rates of non-synonymous (d N ) and synonymous (d S ) substitutions were calculated for the entire sequence. In the analyses of positively selected sites, twice the difference in likelihood 2(Lb-La) between the models was compared with a Ï„2-distribution (df = 2) to assess significance [100]. x represents sites under positive selection identified at the >95% confidence level. Sites in bold are antigen binding sites (ABS) according to the human DR1 molecule [37], distance (dist.) to human ABS corresponds to the amino acid distance between identified site and the nearest human ABS.