Fiber-type-specific measures: fiber cross-sectional area (CSA) and fiber count.
FIBER_TYPESAn object of class data.frame with 672 rows and 10 columns:
character; randomly generated 8-digit identifier used in linkage to phenotypic data. All samples from the same animal have the same PID.
character; unique ID used for each rat at the Iowa PASS.
factor; the sex of the rat with levels "Female" and "Male".
factor; exercise training group. Either "SED" (sedentary) or the number of weeks of training ("1W", "2W", "4W", "8W").
factor; the age of the rat at the beginning of the training protocol. Levels: "6M" (Adult) and "18M" (Aged).
factor; the muscle that was sampled with levels "LG" (lateral gastrocnemius), "MG" (medial gastrocnemius), "PL" (plantaris), and "SOL" (soleus).
factor; the muscle fiber type with levels "I", "IIa", "IIx", and "IIb".
numeric; muscle fiber cross-sectional area (\(\mu m^2\)).
integer; number of muscle fibers by fiber type.
integer; total number of muscle fibers across fiber types.
print.data.frame(head(FIBER_TYPES))
#> pid iowa_id sex group age muscle type fiber_area fiber_count
#> 1 10043799 06F8T3 Female SED 6M LG I 1225.5501 673
#> 2 10043799 06F8T3 Female SED 6M LG IIa 894.3318 613
#> 3 10043799 06F8T3 Female SED 6M LG IIx 1605.6061 2165
#> 4 10043799 06F8T3 Female SED 6M LG IIb 2586.3476 4905
#> 5 10043799 06F8T3 Female SED 6M MG I 1087.2770 769
#> 6 10043799 06F8T3 Female SED 6M MG IIa 868.7957 573
#> total_fiber_count
#> 1 8356
#> 2 8356
#> 3 8356
#> 4 8356
#> 5 5461
#> 6 5461