Nuclear Progestin Receptor-mediated Linkage of Blood Coagulation and Ovulation.

Ovulation is a dramatic remodeling process that includes rupture of blood capillaries and clotting, but coagulation is not thought to directly regulate this process. Herein, we report remarkable increases of coagulation factors V (f5, ~3145-fold) and tissue factor (f3a, ~120-fold) in zebrafish ovarian follicle cells during ovulation. This increase was mediated through the nuclear progestin receptor (Pgr), which is essential for ovulation in zebrafish, and was totally abolished in ovarian follicular cells from pgr-/- mutants.

Impaired oocyte maturation and ovulation in membrane progestin receptor (mPR) knockouts in zebrafish.

Accumulating evidence suggest that membrane progestin receptor α (mPRα) is the membrane receptor mediating nongenomic progestin signaling that induces oocyte maturation in teleost. However, the involvement of other members of mPR family in oocyte maturation is still unclear. In this study, we found impaired oocyte maturation in zebrafish lacking mPRα1, mPRα2, mPRβ, or mPRγ2.

Upregulation of adamts9 by gonadotropin in preovulatory follicles of zebrafish.

Previously we had identified adamts9 as a downstream target of Pgr, which is essential for ovulation in zebrafish. The primary goal of this study is to determine whether human chorionic gonadotropin (hCG, LH analog) also regulate adamts9 expression prior to ovulation. The expression of adamts9 was induced by hCG in a dose and time dependent manner in zebrafish preovulatory follicles in vitro.

Paralogues From the Expanded Tlr11 Gene Family in Mudskipper () Are Under Positive Selection and Respond Differently to LPS/Poly(I:C) Challenge.

Toll-like receptors (TLRs) are major molecular pattern recognition receptors, which are essential for triggering a series of innate immune responses against invading pathogens by recognizing their evolutionary conserved molecular patterns. The mudskipper, is exceptional among fishes due to its amphibious lifestyle and adaptation to living on mudflats. The whole-genome sequencing of has revealed that this species possesses an expansion of Tlr11 family [12 Tlr11 family genes (one , 4 , and 7 )] that we focused on in the present study.

Progestin and Nuclear Progestin Receptor Are Essential for Upregulation of Metalloproteinase in Zebrafish Preovulatory Follicles.

Ovulation requires proteinases to promote the rupture of ovarian follicles. However, the identity of these proteinases remains unclear. In our previous studies using RNA-seq analysis of differential expressed genes, we found significant down-regulation of five metalloproteinases: (a disintegrin and metalloproteinase domain 8b), (a disintegrin and metalloproteinase with thrombospondin motif 8a), (matrix metalloproteinase 2), and in the nuclear progestin receptor knockout ( ) zebrafish that have failed to ovulate.

Involvement of Membrane Progestin Receptor Beta (mPRβ/Paqr8) in Sex Pheromone Progestin-Induced Expression of Luteinizing Hormone in the Pituitary of Male Chinese Black Sleeper ().

Our previous studies showed that 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) acted as a sex pheromone to induce reproductive success in Chinese black sleeper (), but its functional mechanism remains unclear. In the present study, we cloned the cDNAs of the gonadotropin subunits (αβ, and β), and found that, in exposure to 5 nM DHP, transcript levels of β significantly increased in the pituitary at 6 h post exposure; plasma 11-KT levels increased at 24 h post exposure in mature male fish. In contrast, DHP exposure failed to increase the transcript levels of β in the pituitary of immature male fish, suggesting that the responsiveness to DHP depends on reproductive status.

Transcriptomic signatures for ovulation in vertebrates.

The central roles of luteinizing hormone (LH), progestin and their receptors for initiating ovulation have been well established. However, signaling pathways and downstream targets such as proteases that are essential for the rupture of follicular cells are still unclear. Recently, we found anovulation in nuclear progestin receptor (Pgr) knockout (Pgr-KO) zebrafish, which offers a new model for examining genes and pathways that are important for ovulation and fertility.

Cloning and olfactory expression of progestin receptors in the Chinese black sleeper Bostrichthys sinensis.

Our previous studies suggested that 17α,20β-dihydroxy-4-pregnen-3-one (DHP), an oocyte maturation inducing progestin, also acts as a sex pheromone in Chinese black sleeper Bostrichthys sinensis, a fish species that inhabits intertidal zones and mates and spawns inside a muddy burrow. The electro-olfactogram response to DHP increased during the breeding season. In the present study, we cloned the cDNAs of the nine progestin receptors (pgr, paqr5, 6, 7(a, b), 8, 9, pgrmc1, 2) from B.