Multigenerational impacts of poor maternal nutrition on mitochondrial cardiolipin content and muscle fiber cross-sectional area in sheep

Poor maternal nutrition during gestation leads to altered muscle development and growth pre- and post-natally, which may be associated with a reduced ability to generate ATP through mitochondrial oxidative phosphorylation (OXPHOS). Cardiolipin is a phospholipid found within the inner mitochondrial membrane required for membrane integrity and respiratory supercomplex structure. Disruptions in the cardiolipin concentration can lead to mitochondrial dysfunction, limiting OXPHOS, which may limit muscle growth. We previously found that offspring of restricted-fed dams had fewer, but larger, muscle fibers in the longissimus muscle (LM) than offspring of over- and control-fed sheep. Further, the muscle fiber cross-sectional area (CSA) of the semitendinosus (STN) was smaller in offspring of restricted- and over-fed dams compared with control offspring. Moreover, these impacts may be transmitted to a second generation of offspring. However, it is unknown how poor maternal nutrition impacts cardiolipin content in multiple generations of offspring. We hypothesized that poor maternal nutrition during gestation would decrease muscle fiber CSA and increase intramuscular adiposity in F2 offspring, and decrease cardiolipin content in F1 and F2 offspring of poorly nourished dams. To test this hypothesis, pregnant sheep (F0; n = 46) were fed 100% (CON), 60% (RES), or 140% (OVER) of nutrient requirements (NRC, 2007) for gestating sheep. The resulting offspring (n = 37; F1 generation; identified as F1-CON, F1-RES, F1-OVER corresponding to F0 diet) were maintained on a control diet. At 16 to 19 months of age, F1 ewes were bred to generate F2 offspring (F2-CON, F2-RES, F2-OVER). Male offspring from each generation were necropsied at 285 ± 0.93 days of age, and portions of the LM and STN were collected for analysis. Muscle fiber CSA was visualized using wheat germ agglutinin. Intramuscular adiposity was visualized using BODIPY fluorescent staining. ImageJ was used to quantify muscle fiber CSA and BODIPY staining. Cardiolipin content was determined in the LM using a fluorometric assay. Data were analyzed using Proc MIXED in SAS with significance set at P < 0.05. Poor maternal nutrition did not alter LM CSA (P = 0.15) or intramuscular adiposity (P = 0.37) in the F2 generation. Additionally, there were no differences in the muscle fiber CSA (P = 0.22) or intramuscular adiposity in the STN (P = 0.35). We did not detect a difference in cardiolipin content between the CON, RES, and OVER offspring in the F1 (P = 0.77) or the F2 (P = 0.79) generations. In summary, poor maternal gestational nutrition did not alter muscle fiber CSA in F2 generation or mitochondrial cardiolipin content in multiple generations of offspring. Future work includes evaluating additional phospholipids and genes responsible for mitochondrial respiration in muscle development. This work was supported by the American Physiological Society’s Summer Undergraduate Research Fellowship and the USDA (2019-67015-29736 to SAR). This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.