Table 1.

Breakpoint sequence motif frequencies in three classes of sequence in six Muller elements in D. pseudoobscura



Breakpoints

Noncoding

Coding
Muller element
na
(% ± SD)b
n
(% ± SD)
χ2
n
(% ± SD)
χ2
A 210 33.8 ± 3.3 1698 15.3 ± 0.9 45.5c 1851 0.8 ± 0.2 513.6c
B 135 43.0 ± 4.3 2031 12.9 ± 0.7 90.3c 2124 0.8 ± 0.2 703.0c
C 205 39.0 ± 3.4 2082 11.4 ± 0.7 119.4c 2276 0.7 ± 0.2 733.4c
D 141 42.6 ± 4.2 2068 14.3 ± 0.8 78.3c 2159 0.6 ± 0.2 758.0c
E 223 38.1 ± 3.3 2636 10.3 ± 0.6 146.1c 2923 0.4 ± 0.1 985.8c
F
7
57.1 ± 18.7
76
44.7 ± 5.7
0.4
63
17.5 ± 4.8
5.9c

a The total number of sequences within each category

b The percentage of sequences within each category that matched the conserved sequence motif ± standard deviation. The three categories are breakpoints, sequences at the boundary of two conserved linkage groups; noncoding, sequences that are not breakpoints or coding; and coding, sequences of protein-coding genes including introns

c Probability of the χ2 value for the heterogeneity test with one degree of freedom is ≤0.05 after applying a Bonferroni correction for multiple comparisons (Rice 1989). A χ2 heterogeneity test is used to determine if the frequency of the breakpoint motif is significantly different between either the noncoding or coding regions