First Advisor

Burns, Patrick

Date Created

8-2019

Embargo Date

8-2019

Abstract

The corpus luteum is a transient endocrine gland that develops from the remnants of the ovulatory follicle and secretes the steroid hormone progesterone. Progesterone is essential in the establishment and maintenance of pregnancy in all mammalian species. In the non-pregnant bovine, uterine prostaglandin F2α is secreted in a series of pulses between days 15 and 17 after ovulation, allowing the corpus luteum to undergo functional and structural regression and an opportunity for mating. During early pregnancy, trophoblastic cells of the developing embryonic placenta secrete interferon-tau, which attenuates uterine prostaglandin F2α secretion allowing for maintenance of the corpus luteum during the period referred to as maternal recognition of pregnancy. Inadequate secretion of interferon-tau or a delayed signal from trophoblastic cells can lead to luteal regression and loss of the pregnancy. Thus, altering luteal responsiveness to prostaglandin F2α during maternal recognition of pregnancy may prevent early embryo loss. Inclusion of omega-3 fatty acids into the diet may be a novel approach to regulate luteal function during early pregnancy. Supplementation with omega-3 fatty acids in the diet has been shown to incorporate into luteal tissue, resulting in altered membrane ultrastructure and mobility of the prostaglandin FP receptor. However, the effects of omega-3 fatty acids on luteal sensitivity to prostaglandin F2α is lacking. It was hypothesized that omega-3 fatty acid supplementation from fish meal may have a luteoprotective effect on the expression of immediate early genes (NR4A1 and FOS), key luteotropic (STARD1, CYP11A1, 3βHSD, and LDLR), luteolytic (PGHS2 and PTGFR), and apoptotic genes (BAX, BCL-2, and CAS3) that regulate luteal ability to produce progesterone and the longevity of the gland. Administration of prostaglandin F2α resulted in downregulation of luteotropic genes and PTGFR, upregulation of immediate early genes and no change in apoptotic genes and PGHS2 regardless of luteal function. Supplementation with fish meal resulted in a decrease in BAX expression as compared to corn gluten meal supplementation. Outcomes from proposed studies bridge our current gap in knowledge regarding the influence of dietary supplementation of omega-3 fatty acids on luteal function and gene expression in response to prostaglandin F2α. The dietary supplementation of omega-3 fatty acids may be a strategy to improve reproductive performance in breeding females

Extent

99 pages

Local Identifiers

CedilloThesis2019

Rights Statement

Copyright is held by the author

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