Notes

1. It is also possible to use other types of medium, especially mashed potato—in this case, use 1.0 g of mashed potato, and 5 mL of the test solution.

2. In balancer heterozygous flies, induced LOH leads to only single mwh spots, reflecting predominantly point mutation and chromosome aberration, because the products of mitotic recombination involving the TM3 chromosome and its structurally normal homologs are probably inviable (58). Note that because the TM3 balancer chromosome carries fr+, only mwh clones are observed.

3. Large clones mostly show an elongated shape and usually extend parallel to the longitudinal axis of the wing.

4. Marked clones on the wing blade appear in general as contiguous, noninterrupted spots.

5. In some cases, the spots are split into two or more cell groups of different size arranged along the axis of the main growth direction. In this case, those separated by three or more wild-type cell rows are scored as separate spots.

6. Heterogeneity tests are two-sided (e.g., comparisons among controls or among repetitions or between sexes).

7. Testing against both the null hypothesis and the alternative hypothesis allows four possible diagnoses:

a. If H0 is accepted and HA rejected: negative.

b. If H0 and HA are accepted: inconclusive.

c. If H0 is rejected and HA accepted: positive.

d. If H0 and HA are rejected: weak positive.

8. Aggregated data pooled over individuals, sex and experiments may show overdispersion; that is, there may be more variability in the data than theoretically expected. The statistical comparison of pooled control and treatment totals may then be too liberal because false-positive results (as well as of false-negative ones in decision procedures) are more likely to occur. Hence, such testing would increase the overall chance for conflicting diagnoses in critical situations (56).

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