Drosophila myosin mutants model the disparate severity of type 1 and type 2B distal arthrogryposis and indicate an enhanced actin affinity mechanism

Table 1 Flight and jump ability of DA1 (F437I) and DA2B (A234T) female transgenic flies

Line name (age)	Flight test, n	Up (%)	Horizontal (%)	Down (%)	Not at all (%)	Flight index ± SEM	Jump distance ± SEM
pwMhc2 (2 days)	122	48.4	29.5	22.1	0	4.54 ± 0.02	7.48 ± 0.20
F437I-3 (2 days)	106	0	0	0	100	0	2.27 ± 0.08
F437I-4 (2 days)	100	0	0	0	100	0	2.53 ± 0.13
A234T-2 (2 days)	50	0	0	0	100	0	0.25 ± 0.02
A234T-4 (2 days)	50	0	0	0	100	0	0.26 ± 0.01
pwMhc2/+ (2 days)	136	79.4	14	6.6	0	5.51 ± 0.04	7.82 ± 0.31
F437I-3/+ (2 days)	100	43.0	43.0	14.0	0	4.70 ± 0.07	6.33 ± 0.19
F437I-4/+ (2 days)	101	39.6	53.5	6.9	0	4.62 ± 0.04	6.63 ± 0.28
A234T-2/+ (2 days)	50	0	0	0	100	0	1.01 ± 0.04
A234T-4/+ (2 days)	53	0	0	0	100	0	1.19 ± 0.09
pwMhc2/+ (2 weeks)	126	46.8	34.1	19	0	4.83 ± 0.06	–
F437I-3/+ (2 weeks )	100	1	41	58	0	2.90 ± 0.04	–
F437I-4/+ (2 weeks)	127	3.9	52	44.1	0	3.30 ± 0.03	–

Flight and jump abilities for two independent lines expressing the F437I or A234T transgene are shown ± standard errors of the mean. Each homozygous transgene stock was in the Mhc¹⁰ IFM- and jump muscle myosin-null background [16]. Heterozygotes were generated by crossing these stocks to wild-type yw flies. Values are compared to pwMhc2 (wild-type myosin transgene) control for homozygotes or pwMhc2/+, for heterozygotes. For flight testing, cohorts of transgenic flies were assayed for the ability to fly up (U), horizontal (H), down (D), or not at all (N). Flight index and SEM were determined using the mean value of cohorts of ~ 15 flies each, using the following equation: 6U/T + 4H/T + 2D/T + 0N/T. T is the total number of flies tested in a cohort. All flight test values for mutants were significantly less than matched controls (P < 0.05). Jump distances were assessed 10 times for each fly, with the three longest distances averaged to yield the final value (> 20 flies/genotype). All jump test values for mutants were significantly less than matched controls (P < 0.01)

ISSN: 2044-5040