Theses and Dissertations at Montana State University (MSU)
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/733
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Item Maternal injectable mineral during early gestation impacts placental function and calf performance(Montana State University - Bozeman, College of Agriculture, 2022) Ogg, Makayla Anne; Chairperson, Graduate Committee: Sarah R. McCoskiLimited research has evaluated the effects of maternal mineral supplementation during early gestation on placental function and progeny growth. For this study, Angus and SimAngus cows (n = 52) were bred via artificial insemination. At day (d) 60 of gestation, cows were assigned to one of two treatment groups; an injectable group (INJ, n = 26) receiving a single subcutaneous mineral injection and a control group (CON; n = 26). A subset of cows (CON n = 10; INJ n = 6) were selected for liver biopsy at d60 and 209 + or - 1 of gestation. At d139.5 + or - 0.5 and 209 + or - 1 of gestation, uterine artery measurements were collected using Color Doppler ultrasonography. Placentas, liver tissue, and blood samples were collected from the first 11 cows from the subset group that calved (n = 11; CON, n = 5; INJ, n = 6). Analysis revealed a TRT*d interaction at d139.5 + or - 0.5 for circulating Co concentrations which were greater in INJ (P = 0.05) compared to CON cows. Circulating Zn concentrations tended to be decreased at d209 + or - 1 (P = 0.06) in INJ cows compared to the CON cows. Circulating Cu tended to be increased (P-value = 0.09) and Mn was decreased (P = 0.04) in INJ cows throughout the study. A TRT*d interaction was observed at d139.5 + or - 0.5 for non-gravid uterine artery area, diameter, and circumference to be increased in the INJ cows (P = 0.004, 0.006, and 0.006, respectively). Additionally, pulsatility index of the gravid uterine artery tended to be increased (P = 0.09) in the INJ cows. Hepatic Fe concentrations were decreased in the INJ cows (P = 0.01) at d209 + or - 1. Blood and liver samples were collected from calves (CON n = 24; INJ n = 26). INJ calves had greater liver Se concentrations (P = 0.001), lower Fe concentrations (P=0.04), and tended to have increased liver concentrations of Zn (P = 0.09) and Mn (P = 0.08) compared to CON calves. Finally, INJ calves tended to have elevated levels of serum Se (P = 0.09) compared to CON calves. These results suggest that injectable mineral administration during early gestation altered placental function and calf performance.Item Mid-and late-gestation lethality in mice lacking the N terminus of TATA-binding protein(Montana State University - Bozeman, College of Agriculture, 2004) Hobbs, Nicole Kay; Chairperson, Graduate Committee: Edward E. Schmidt.TATA-binding protein (TBP) is a transcription factor comprised of a 180 amino acid core that is shared by all eukaryotes. TBP also has an N-terminal region that, in vertebrates, is highly conserved. We have generated mice bearing a mutant tbp allele, tbp deltaN, that lacks 111 of the 135 amino acids of the vertebrate-specific N terminus. Most homozygous mutants, tbp deltaN/deltaN, die at midgestation from an apparent defect in their placentas. tbp deltaN/deltaN fetuses were rescued at this midgestational crisis if supplied with a wild-type tetraploid placenta. tbp deltaN/deltaN fetuses also survived in immune-normal mothers when fetal/placental beta 2m expression was genetically disrupted. When reared in immunocompromised mothers, tbp deltaN/deltaN fetuses also survived midgestation. These results suggest the N terminus of TBP functions in beta 2M-dependent processes and within the placenta to favor immunotolerance during pregnancy at midgestion. Beyond midgestation, tbp deltaN/deltaN fetuses that survive in immunocompromised mothers were found to be runted at the perinatal period and died shortly after birth. These latter results suggest that the N terminus of TBP also functions in non-immune processes required for normal birth weight and successful pregnancy.