DHA-restricted mothers produce offspring with a series of morphological phenotypes, and phenotype severity is related to offspring DHA and ARA status. A: Example 4 dpf larvae from each experimental group. The elovl2-DEF larva shown here is representative of the more severe morphological phenotype observed. This severe phenotype was characterized by the 4 abnormal features labeled in this panel. For both DEF groups, a series of phenotypes was observed between and within clutches, with some offspring exhibiting 1 to 3 of these features. For example, the WT-DEF larva in this panel has 3 of the 4 features (no pericardial edema). B: Proportion of offspring per clutch with or without severe morphological abnormalities at 4 dpf, expressed as a mean percentage ± SEM (n = 9–13 clutches/group, with n = 998–1638 larvae evaluated/group). Larvae were binned into the “severe” phenotype category if they exhibited ≥3 of the following abnormal features: small eyes, curved axis, uninflated swim bladder, and pericardial edema. The severe phenotype was most often observed in elovl2-DEF offspring (12% per clutch), followed by WT-DEF (4%) and WT-SUFF (0%). The elovl2-DEF “severe” defects bar (purple) is magnified to show that offspring genotype does not explain the phenotype; the proportions of elovl2 +/+ (29%) +/− (47%) and −/− (24%) larvae with severe defects follow the predicted 1:2:1 Mendelian ratios. Percentages were calculated from n = 130 genotyped larvae collected at 4 dpf, generated from 7 elovl2-DEF clutches. C: Offspring with severe phenotypes (≥3 abnormal features) have lower DHA and ARA status than their morphologically normal siblings. Dots represent individually analyzed larvae, generated from DEF-fed mothers for 20–42 weeks (n = 6–12 larvae/group). Two-tailed unpaired Student’s t-tests or Mann-Whitney tests were used when appropriate.
|
