|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 1. Photomicrographs and primary data sets for protein synthesis and
respiration rate measurements of 13-day-old fed larvae of Lytechinus
pictus. (A) Photomicrograph of 13-day-old unfed and (B) fed larvae. Scale
bars, 200 µm. (C) Linear increase of [14C]alanine incorporation
into the protein pool (TCA-insoluble fraction) of 13-day-old fed larvae of
L. pictus: y=41.4(±2.71)x-68.4
(r2=0.98; P<0.001). Rates of
[14C]alanine incorporation were converted to absolute rates of
protein synthesis (ng protein individual-1 h-1) using
the change in the specific activity of [14C]alanine in the
precursor free amino acid pool (Fig. 1E), the mole-percent of alanine in
protein (7.8%; Table 1) and the
mole-percent corrected molecular mass for amino acids in protein (129.4 g
mole-1; Table 1).
(D) Chromatogram of extracted free amino acid pool from 13-day-old larvae of
L. pictus separated using high performance liquid chromotagraphy
(HPLC). D, aspartate; E, glutamate; N, asparagine; S, serine; H, histidine; G,
glycine; R, arginine. Alanine was the [14C]amino acid tracer used
to determine rates of protein synthesis. (E) Specific activity of
[14C]alanine in the free amino acid pool during protein synthesis
experiments with 13-day-old larvae of L. pictus. Specific activity
was measured at the specified sampling intervals by quantifying the moles of
total alanine with HPLC (as in Fig. 1D). [14C]alanine was measured
by liquid scintillation counting of the radioactivity associated with the
alanine peak fraction. Increase of specific activity was described by the
linear equation: y=39.2(±3.85)x+279.9
(r2=0.96; P<0.001 for ANOVA of regression
slope). (F) Respiration rate of 13-day-old fed larvae of L. pictus.
Each data point represents a different respiration chamber. Respiration rate
was calculated by determining the slope of total oxygen consumption in each
respiration chamber for the known number of larvae in that chamber:
y=109.5(±8.4)x+1254 (r2=0.97;
P<0.0001), where the slope of 109.5 has units of pmol
O2 larva-1 h-1.
|
