Table 2 Basic features of the S. strix introns. Characteristics of 21 introns found in 17 Streblomastix genes analysed. Size and base composition are shown. GC% mRNA shows base composition of the coding sequence (excluding introns).

1

57

0.29

0.46

2

88

0.38

3

57

0.3

1

60

0.25

0.49

1

46

0.11

0.37

2

66

0.09

1

122

0.16

0.35

1

63

0.22

0.47

2

66

0.18

3

91

0.15

1

100

0.36

0.38

1

229

0.21

0.44

1

105

0.22

0.37

2

168

0.15

1

56

0.27

0.41

2

58

0.2

1

64

0.27

0.44

2

61

0.31

3

102

0.23

4

54

0.3

5

69

0.22

85

0.23

0.42