Flies expressing Mef2GD5039 in the fat body under the control of Scer\GAL4c564 exhibit a significant reduction in survival time after a high-dose M. marinum infection compared to controls. A similar response in seen following infection with Listeria monocytogenes, Enterobacter cloacae or Candida albicans. There is no visible reduction in fat body size in these mutants. Bacterial numbers are increased in animals infected with E. cloacae or M. marinum.
Flies expressing Mef2GD5039 under the control of Scer\GAL4c564 are almost entirely devoid of triglyceride and glycogen, but have normal levels of free glucose and trehalose.
Flies expressing Mef2GD5039 under the control of Scer\GAL4c564 die more rapidly than wild-type flies when starved. However, they are not generally stress sensitive, exhibiting normal survival under either hyperpoxia or heat stress.
Animals expressing Mef2GD5039 under the control of Scer\GAL41151 develop normally but remain in their pupal cases and eventually die, unable to eclose. The animals lack essentially all major somatic muscles in their bodies. Cardiac and visceral muscles are unaffected.
In developing pupae expressing Mef2GD5039 under the control of Scer\GAL41151 the development of the indirect flight muscles is severely affected due to a lack of myoblast fusion to form myofibre syncytia. The larval oblique muscles which form the templates for the dorsal longitudinal muscles do not undergo splitting at 24 hours after puparium formation (APF), in contrast to wild type. These templates are smaller than normal in the mutant pupae, whereas the layer of swarming myoblasts surrounding them is significantly thicker than normal. Groups of myoblasts are seen at the putative sites of dorso-ventral muscle formation in the mutant pupae, but they are never accompanied by a fusion core. Fused myofibres are not seen in the thorax of mutant animals at 30 hours APF, but instead large numbers of unfused myoblasts are apparent. At 48 hours APF there is still a lack of fused myotubes, but the number of unfused myoblasts is significantly decreased (they are detected only as small groups of loosely aggregated cells).
The dorsal longitudinal muscles often collapse to the back of the thorax by 48 hours after puparium formation in animals expressing Mef2GD5039 under the control of Scer\GAL4Act88F.PB. The dorso-ventral muscles (DVMs) develop normal looking myofibrils by the end of the pupal stage, although they are somewhat wavy in their organisation. The morphology of the DVM myofibrils is worsened if the animals also carry either Mef2P544 or Mef2dsRNA.IR2.Scer\UAS.
Expression of Mef2GD5039 under the control of Scer\GAL4Act79B.PB results in moderate but persistent changes in morphology in the tergal depressor of the trochanter muscle, including the presence of a central cavity within the myofibre rosette, mis-localised and aggregated nuclei and a reduction in overall muscle size.
Embryos expressing Mef2GD5039 under the control of Scer\GAL4Mef2.PR show muscle extension and attachment defects. Larvae show a significant reduction in the number of body wall contractions per minute compared to controls.
Expression of Mef2GD5039 under the control of Scer\GAL4P0.5.Pdf (in the presence of Dcr-2Scer\UAS.cDa to increase RNAi efficiency) causes long locomotor activity rhythms, with a period of 25.0 +/- 0.4 hours. These rhythms have a much lower power than in control flies (32.6 compared to 80.7).
Expression of Mef2GD5039 under the control of Scer\GAL4tim.Scer\UAS (in the presence of Dcr-2Scer\UAS.cDa to increase RNAi efficiency) results in 70% of the flies becoming progressively arrhythmic over a 12 day period.
Adult LN[[v]] neurons are present and project normally when Mef2GD5039 is expressed under the control of Scer\GAL4tim.Scer\UAS.
Adults expressing Mef2GD5039 under the control of Scer\GAL4elav.PLu (in the presence of Dcr-2Scer\UAS.cDa to increase the efficiency of RNAi) do not show a significant defect in avoidance of noxious temperature (46[o]C) compared to control flies.
Depending on the insertion line used, expression under the control of Scer\GAL4Mef2.PR can result in early pupal lethality or late larval lethality.
Expression under the control of Scer\GAL4pnr-MD237 results in bristle morphology defects on the notum in 0% or 20-30% of the Scer\GAL4pnr-MD237 expression domain, depending on the insertion line used.
Expression under the control of Scer\GAL4pnr-MD237 results in the absence of 60-70% or 80-90% of the Scer\GAL4pnr-MD237-expressing area of the notum, depending on the insertion line used.
Expression of Mef2GD5039 under the control of Scer\GAL4elav.PLu leads to a variable phenotype depending on the insertion, with flies showing variable levels of lethality and some flies showing abnormal wing posture. Scer\GAL4elav.PLu>Mef2GD5039 flies also show flight defects.