Mef2⁶⁵/Mef2¹¹³ embryos exhibit a reduction in the number of dorsal longitudinal indirect flight muscles to three pairs due to defects in the template splitting process.

Mef2^25-42/Mef2⁶⁵ trans-heterozygotes exhibit major defects in their indirect flight muscles, based on reduced numbers and abnormal patterning of the dorsal longitudinal indirect flight muscles.

Mef2^26-6/Mef2⁶⁵ trans-heterozygotes exhibit major defects in their indirect flight muscles, based on reduced numbers and abnormal patterning of the dorsal longitudinal indirect flight muscles.

Mef2^25-34/Mef2⁶⁵ trans-heterozygotes exhibit a wild-type pattern and number of dorsal longitudinal indirect flight muscles.

Mef2⁶⁵/Mef2⁴²⁴ adults survive at 20-30% rate of sibling classes. Eggs laid by Mef2⁶⁵/+ show 92.3% wild type dorsal appendages, 6.2% reduced dorsal appendages and 1.5% broad dorsal appendages and normal egg length. Eggs laid by Mef2⁶⁵/Mef2⁴²⁴ females show 36.9% wild type dorsal appendages, 24.2% reduced dorsal appendages, 19.9% broad dorsal appendages and short egg length, 8.5% broad dorsal appendages and normal egg length, 6.9% abnormal dorsal appendages with short egg length and 3-6% cup-like eggs with no dorsal appendages and cup-like shape.

The three persistant larval oblique muscles per hemithorax of Mef2⁶⁵/Mef2¹¹³ animals escape from histolysis as in wild-type animals. Splitting of these muscles generally does not occur in Mef2⁶⁵/Mef2¹¹³ animals in contrast to wild-type, so that the number of dorsal longitudinal indirect flight muscles is reduced.

In homozygous mutant embryos, minor pattern deletions in the somatic muscles are evident. Specification of myoblasts is apparently normal. A low percentage of Mef2¹¹³/Mef2⁶⁵ progeny survive to adulthood. These survivors are flightless and their dorsal longitudinal muscles are reduced.