Oviductal Retention of Embryos in Female Mice Lacking Estrogen Receptor α in the Isthmus and the Uterus

Abstract

Estrogen receptor α (ESR1; encoded by Esr1) is a crucial nuclear transcription factor for female reproduction and is expressed throughout the female reproductive tract. To assess the function of ESR1 in reproductive tissues without confounding effects from a potential developmental defect arising from global deletion of ESR1, we generated a mouse model in which Esr1 was specifically ablated during postnatal development. To accomplish this, a progesterone receptor Cre line (PgrCre) was bred with Esr1f/f mice to create conditional knockout of Esr1 in reproductive tissues (called PgrCreEsr1KO mice) beginning around 6 days after birth. In the PgrCreEsr1KO oviduct, ESR1 was most efficiently ablated in the isthmic region. We found that at 3.5 days post coitus (dpc), embryos were retrieved from the uterus in control littermates while all embryos were retained in the PgrCreEsr1KO oviduct. Additionally, serum progesterone (P4) levels were significantly lower in PgrCreEsr1KO compared to controls at 3.5 dpc. This finding suggests that expression of ESR1 in the isthmus and normal P4 levels allow for successful embryo transport from the oviduct to the uterus. Therefore, alterations in oviductal isthmus ESR1 signaling and circulating P4 levels could be related to female infertility conditions such as tubal pregnancy.

The autophagy protein, ATG14 safeguards against unscheduled pyroptosis activation to enable embryo transport during early pregnancy

“…The retention of preimplantation embryos in the oviduct established as a significant contributor to implantation failures, presenting challenges to the overall reproductive health of women [4][5][6]. Embryo transport in the oviduct is known to be controlled primarily by two major physiological responses: ciliary activity and muscle contractility.…”

“…Any perturbations in these early pregnancy events can lead to adverse ripple effects that can compromise pregnancy outcomes. Previous studies have reported that impaired oviductal transport of embryos can lead to pregnancy failure and cause infertility in mice [3][4][5][6]. However, the underlying mechanism is not yet completely understood.…”

Oviduct Transcriptomic Reveals the Regulation of mRNAs and lncRNAs Related to Goat Prolificacy in the Luteal Phase

“…Zhang et al emphasized that the different levels of GnRH were among the reasons for the different number of lambs [ 44 ]. During the estrous cycle, estrogen and progesterone affect the morphological and functional responses of the oviduct, which are critical for female fertility [ 39 , 45 ]. In the present study, most DEGs in the LL and LH comparison groups were significantly enriched in pathways, including GnRH, thyroid hormone, prolactin signaling pathway, dopaminergic synapse, insulin secretion, melanogenesis, and progesterone-mediated oocyte maturation.…”

Oviductal Telocytes in Patients with Uterine Myoma

“…All mentioned processes are controlled by sex hormones, nerves, growth factors, and other paracrine signals [11]. Sufficient expression of estrogen receptor alpha in the isthmus of the oviduct and normal progesterone levels allow for the successful transport of the embryo from the Fallopian tube to the uterus [12].…”