Gestational fish oil supplementation in a maternal high-fat diet reduces mitochondrial ultrastructural damage and increases fusion proteins in the soleus muscles of weanling rat offspring

[Display omitted] •Maternal high-fat (HF) diet damages soleus’ mitochondria of weanling offspring.•Gestational fish oil (FO) reduces maternal HF diet-induced mitochondrial damage.•FO increases mitochondrial fusion proteins in weanling offspring’s soleus muscle.•FO mitigates maternal HF-induced decreased mitochondrial dimensions. Perinatal maternal high-fat (HF) diet induces metabolic disorders in offspring associated with mitochondrial damage in their skeletal muscle. We hypothesized that gestational supplementation with fish oil (FO), rich in n-3 polyunsaturated fatty acids, may attenuate mitochondrial injury in the soleus muscle of male and female weanling HF offspring. Female rats received control or HF diet from 8 weeks premating throughout lactation. During gestation, part of HF dams received HF diet containing 3 % FO. Gestational FO mitigated HF-inducedsoleussarcomere misalignment and mitochondrial ultrastructural injuryin weanling offspring. FO increased mitochondrial complex proteins I and III in males and uncoupling protein-3 and PGC1α (biogenesis marker) in both sexes. FO enhanced fusion proteins mitofusin-2 (males) and OPA-1 (females) and mitochondrial size, suggesting increased mitochondrial fusion. Thus, gestational FO supplementation to maternal HF diet enhances biogenesis and mitochondrial fusionmarkers, improving mitochondria quality and potentially function in soleus muscle of weanling HF offspring.