SSCP analysis in the D-loop region of porcine mitochondrial DNA as confirmed by sequence diversity

l-Arginine supplementation of gilts during early gestation modulates energy sensitive pathways in pig conceptuses

Dietary l-arginine (ARG) supplementation has been studied as a nutritional strategy to improve reproductive performance of pregnant sows, since arginine is a conditionally essential amino acid. However, reports addressing the molecular mechanisms that mediate supplementation effects on embryos and fetuses development are still scarce. Therefore, we aimed to evaluate the effects of 1.0% ARG supplementation of commercial pregnant gilts on genes and proteins from energy metabolism and antioxidant defense pathways in embryos and fetuses. We also analyzed the global transcriptome profile of 25- and 35-day-old conceptuses. At Day 25, we observed a lower abundance of phospho-AMP-activated protein kinase (phospho-AMPK) protein and downregulation of oxidative phosphorylation system genes in ARG embryos. On the other hand, ARG fetuses showed greater expression of MLST8 and lower expression of MTOR genes, in addition to lower abundance of phospho-AMPK and phospho-mammalian target of rapamycin (phospho-mTOR) proteins. Transcriptome analysis at Day 35 did not present differentially expressed genes. For the antioxidant defense pathway, no differences were found between CON and ARG conceptuses, only trends. In general, supplementation of gilts with 1.0% ARG during early gestation affects energy sensitive pathways in 25- and 35-day conceptuses; however, no effects of supplementation were found on the antioxidative defense pathway in 25-day embryos.

Mitochondrial DNA Polymorphism and Determination of Effects on Reproductive Trait in Pigs

The purposes of this study were to investigate single strand conformation polymorphisms (SSCP) in the D-loop region of pig mitochondrial DNA (mtDNA) and to determinate their association with the reproductive traits of meishan pigs. A total of four types of band patterns, designed SSCP band pattern A, B, C and D, were identified. A type of SSCP band pattern was present in all European-American breeds, but not in East Asian breeds. This result showed the diversified sequence in the D-loop region between European-American and East Asian populations. Two types of band patterns, B and C, were found in Meishan pigs. The average body weight at day 21 of piglets from B type dams was significantly heavier than the body weight of C type (p < 0.05). We also tested whether the SSCP patterns would be suitable for paternity testing in a family group and found that bands of all the offspring were derived from their maternal parent. Therefore, we conclude that SSCP may be a marker for identification of maternal ancestors.