Ionotropic Glutamate Receptor AMPA 1 Is Associated with Ovulation Rate

Ionotropic glutamate receptors mediate most excitatory neurotransmission in the central nervous system by opening ion channels upon the binding of glutamate. Despite the essential roles of glutamate in the control of reproduction and anterior pituitary hormone secretion, there is a limited understanding of how glutamate receptors control ovulation. Here we reveal the function of the ionotropic glutamate receptor AMPA-1 (GRIA1) in ovulation. Based on a genome-wide association study in Bos taurus, we found that ovulation rate is influenced by a variation in the N-terminal leucine/isoleucine/valine-binding protein (LIVBP) domain of GRIA1, in which serine is replaced by asparagine. GRIA1Asn has a weaker affinity to glutamate than GRIA1Ser, both in Xenopus oocytes and in the membrane fraction of bovine brain. This single amino acid substitution leads to the decreased release of gonadotropin-releasing hormone (GnRH) in immortalized hypothalamic GT1-7 cells. Cows with GRIA1Asn have a slower luteinizing hormone (LH) surge than cows with GRIA1Ser. In addition, cows with GRIA1Asn possess fewer immature ovarian follicles before superovulation and have a lower response to hormone treatment than cows with GRIA1Ser. Our work identified that GRIA1 is a critical mediator of ovulation and that GRIA1 might be a useful target for reproductive therapy

A Study on the Correlation of Structure and Fluidity of Three Asian Coal Ashes and Slags

Correlations among structures and flow properties of three typical Asian coal ashes and their slags were carefully examined using multi-nuclear solid-state NMR and self-manufactured viscometer. The amorphous structures of slags were successfully quantified through the NMR measurement. The Si structure of slag D which showed highest viscosity among three slags was mainly Q^4 structures with a high degree of polymerization. Slag M which contained high Fe content showed similar Si structure to that of slag D. Alkaline-earth ions of Ca^<2+> and Mg^<2+> in slag A successfully segmented the framework to form the primary Q^2 structures, which resulted in the lowest viscosity of slag A