Impact of exogenous adrenocorticotropic hormone on gelatinase expression and steroidogenesis in the newly formed corpus luteum in sows

Gelatinase MMP Expression Is Correlated with Muscle Fiber Growth in Maiwa Yak Gluteus Maximus

Yak (Bos grunniens) is the only large mammal species in the Qinghai-Tibet Plateau. The most of the studies in yak remain confined for the main contributor of meat, which requires a good understanding of muscle growth. Matrix metalloproteinases-2 (MMP-2) and MMP-9 are widely expressed in mammal tissues they mainly degrade collagen in the extracellular matrix for muscle development. However, the influence of MMPs on yak muscle remains unclear. Hence, we assessed the expression of MMP-2, MMP-9, and related factors with ages in Maiwa yak for study the correlation between MMPs expression and yak muscle growth. The mRNA expression of MMP-2, MMP-9, MMP-14, and collagen III increased with age, except collagen I by quantitative real-time PCR. Moreover, muscle fiber diameter increased with age, whereas the density decreased, which showed that fiber grew thicker with age using hematoxylin-eosin staining. Interestingly, MMP and collagen expression significantly decreased with age using western blotting. Pearson correlation method showed that both mRNA and protein expression of MMP-14 and collagen were strongly correlated with muscle fiber growth, but MMP-2 protein and MMP-9 mRNA expression were moderately correlated with muscle fiber growth. Overall, the expression of MMPs and collagen significantly changed with age, which means that MMPs and their function related genes could correlate with Maiwa yak muscle fiber growth.

Placental Malfunction, Fetal Survival and Development Caused by Sow Metabolic Disorder: The Impact of Maternal Oxidative Stress

The energy and metabolic state of sows will alter considerably over different phases of gestation. Maternal metabolism increases dramatically, particularly in late pregnancy. This is accompanied by the development of an increase in oxidative stress, which has a considerable negative effect on the maternal and the placenta. As the only link between the maternal and the fetus, the placenta is critical for the maternal to deliver nutrients to the fetus and for the fetus' survival and development. This review aimed to clarify the changes in energy and metabolism in sows during different pregnancy periods, as well as the impact of maternal oxidative stress on the placenta, which affects the fetus' survival and development.

Housing Conditions and a Challenge with Lipopolysaccharide on the Day of Estrus Can Influence Gene Expression of the Corpus Luteum in Gilts

The corpus luteum (CL) is a temporary endocrine gland that plays a decisive role in the reproductive physiology of gilts. Recently, it has been suggested that exogenous factors may compromise the normal functioning of the CL. In the present study, we aimed to understand to what extent an acute and systemic challenge with lipopolysaccharide (LPS) on the day of estrus could compromise gene expression of gilts’ CLs housed in different welfare conditions. For this, we housed 42 gilts in three different housing systems: crates, indoor group pens, and outdoor housing. Then, we challenged six females from each group with LPS and eight with saline (SAL) on the day of estrus. After slaughtering the gilts on the fifth day after the challenge, ovaries were collected for gene expression analysis by RT-qPCR. Housing system and LPS challenge did not have a significant interaction for any genes evaluated; thus, their effects were studied separately. We identified significant (p < 0.05) downregulation of the angiogenic genes VEGF and FTL1 among LPS-challenged animals. Meanwhile, we also observed upregulation of HSD3B1 gene among LPS-challenged animals. We found that STAR and LHCGR genes were differentially expressed depending on the housing system, which indicates that the environment may affect adaptation capabilities. Our results indicate that an acute health challenge on the estrus day alters CL gene expression; however, the role of the housing system remains uncertain.