
Number of orthologous pairs


Chromosome arm*

Tested^{†}

Harboring microinversions^{‡}

Harboring intragenic indels^{‡}


X

880

24 (0.111)

12 (0.889)

2L

997

34 (0.003)

19 (0.294)

2R

1,120

7 (<0.001)

15 (0.805)

3L

1,177

21 (0.752)

22 (0.279)

3R

1,560

26 (0.464)

18 (0.297)

All 5 major arms

5,734

112

86

 *The chromosome arms are given the D. melanogaster designations, X, 2L, 2R, 3L, and 3R. These arms are known to be orthologous to D. pseudoobscura arms, XL, 4, 3, XR, and 2, respectively [58]. ^{†}The number of conserved orthologs residing on each arm. ^{‡}Values in parentheses are P values from a twosided Binomial test of whether the number of eventharboring orthologs per arm differs from expectation. For each test, the number of trials equals the number of conserved orthologs per arm, the number of successes equals the number of eventharboring genes per arm, and the probability of success is equal to the total number of eventharboring genes detected divided by the total number of conserved orthologs tested (5,738).