Cellularity changes in developing red and white fish muscle at different temperatures: simulating natural environmental conditions for a temperate freshwater cyprinid
Walter Stoiber1,*,
John R. Haslett1,
Ralf Wenk1,
Peter Steinbacher1,
Hans-Peter Gollmann2 and
Alexandra M. Sänger1
1 University of Salzburg, Department of Vascular and Performance Biology,
Institute of Zoology, Hellbrunnerstrasse 34, A-5020 Salzburg,
Austria
2 Institute for Water Ecology, Fisheries and Lake Research, Scharfling 18,
A-5310 Mondsee, Austria
View larger version (165K):
[in a new window]
|
Fig. 1. Fibre typing and tracing of muscle fibre outlines in cross sections. (A)
40-somite (stage-1) embryo of the warm regime immunoreacted with the F59
antibody. The superficial monolayer of red fibres (RF) stains more intensively
than the bulk of white fibres (WF) underneath. Scale bar, 100 µm. (B)
Stage-5 larva of the cold regime. Detail of an epaxial quadrant with fibre
contours and myofibrils as visualized by PAMS. Myofibrils form garland-like
patterns in red fibres (RF) but radial patterns in white fibres (WF). Scale
bar, 25 µm. (C,D) Discrimination between fibre types in the horizontal
septum area. (C) Stage-6 larva (warm regime). Histochemical staining for
myofibrillar ATPase after preincubation at pH 10.2 leaves white fibres (WF)
active while red fibres (RF) are inactivated. Scale bar, 50 µm. (D) Swim-up
larva (stage 3, cold regime). Immunostaining with the S58 antibody
highlights the red fibres (RF) monolayer, white fibres (WF) are unreactive.
Scale bar, 25 µm. spc, spinal cord; nc notochord; ms, myoseptum; hs,
horizontal septum; ln, lateral line nerve; ep, epidermis.
|
|
View larger version (176K):
[in a new window]
|
Fig. 2. Myogenic cells provide the basis of hyperplastic growth. All images are
from cross sections. (A) Low magnification electron micrograph of a 40-somite
embryo (stage 1, warm regime). Undifferentiated cells assumed to be myogenic
are clustered within the mesenchyme (mes) next to the dorsal apex of the
myotome and attach to the myotome's surface (arrows). Scale bar, 10 µm. (B)
Electron micrograph of two myosatellite cells (SC) inserting between white
fibres (WF) of a larva at first feeding (stage 4, warm regime). Scale bar, 2
µm. (C,D) Presumptive myosatellite cells and activated myosatellite cells
within epaxial muscle of stage-5 larvae (warm regime), as labelled by anti
m-met (C) and anti MyoD (D), respectively (arrows). Scale bars, 50 µm. spc,
spinal cord; nc, notochord; ne, nerve; ep, epidermis; WF, white fibres; RF,
red fibres.
|
|
View larger version (21K):
[in a new window]
|
Fig. 3. Scatter plot with regression lines demonstrating the correlation of red
muscle relative proportions (white-to-red ratio, w/r) with fish size as given
by total muscle cross sectional area (c.s.a) in Danube bleak (Cc)
reared under constant (thin black line) and changing (rising) thermal
conditions (thick red and blue lines). Also shown, for comparison, are data
for two further cyprinid species (roach, Rr; pearlfish, Rf)
reared at various constant temperatures. Equations for Danube bleak:
Cc 20 °C: y=2.824x+13.284
(r2=0.894, P<0.001); Cc 18-20 °C:
y=1.6178x+8.9764 (r2=0.686,
P<0.001); Cc 12-16 °C:
y=1.6032x+8.7289 (r2=0.794,
P<0.001).
|
|
View larger version (20K):
[in a new window]
|
Fig. 4. Scatter plot showing the correlation of mean red (RF) and white fibre (WF)
sizes with fish size as given by total muscle cross sectional area (c.s.a.)
for Danube bleak reared under the two rising temperature regimes, 12-16 °C
and 18-20 °C. Logarithmic regressions were calculated for red and white
fibre data of each temperature regime: thick lines, red fibres; thin lines,
white fibres; blue lines, cold regime; red lines, warm regime.
|
|
View larger version (22K):
[in a new window]
|
Fig. 5. Frequency distributions of fibre sizes (cross-sectional areas) from white
muscle of Danube bleak from the two temperature regimes. Data are grouped in
20 µm2 size classes; histograms give mean fibre numbers per
class for one epaxial quadrant per fish (N=6 for each stage and
temperature).
|
|
View larger version (19K):
[in a new window]
|
Fig. 6. Frequency distributions of fibre sizes (cross-sectional areas) from red
muscle of Danube bleak from the two temperature regimes. Data are grouped in
20 µm2 classes; histograms give mean fibre numbers per class for
one epaxial quadrant per fish (N=6 for each stage and
temperature).
|
|
View larger version (21K):
[in a new window]
|
Fig. 7. Hypertrophy of `first wave' somitic red fibres in Danube bleak
(Cc) reared at rising temperatures (12-16°C versus
18-20°C) and pearlfish (Rf) reared at constant temperatures
(12°C versus 16°C). Size (cross-sectional area) means of
defined numbers of largest fibres per epaxial quadrant (Cc: N=25,
Rf: N=40; for rationale see Materials and methods, Data
analysis) within developmental stages as defined in
Table 1 (40som, 40 somite
embryo; hatch, newly hatched free embryo; swup, free embryo at onset of free
swimming; feed, larva after first uptake of exogeneous food; larv1,
Cc larvae of stage 5, Rf larvae at 11 mm body length; larv2,
Cc larvae of stage 6, Rflarvae at 12.5 mm body length).
Values are means ± 1 S.D.
|
|
View larger version (21K):
[in a new window]
|
Fig. 8. Hypertrophy of `first wave' somitic white fibres in Danube bleak
(Cc) reared at rising temperatures and pearlfish (Rf) reared
at constant temperatures. Size (cross-sectional area) means of defined numbers
of largest fibres per epaxial quadrant (Cc, N=70; Rf, N=80)
within developmental stages as defined in
Table 1 (stage terminology and
other explanations as in Fig.
7). Values are means ± 1 S.D.
|
|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati 
Twitter What's this?
© The Company of Biologists Ltd 2002
