Washington State University

About: Washington State University is a education organization based out in Pullman, Washington, United States. It is known for research contribution in the topics: Population & Gene. The organization has 26947 authors who have published 57736 publications receiving 2341509 citations. The organization is also known as: WSU & Wazzu.

DMRT1 prevents female reprogramming in the postnatal mammalian testis

Abstract: Sex in mammals is determined in the fetal gonad by the presence or absence of the Y chromosome gene Sry, which controls whether bipotential precursor cells differentiate into testicular Sertoli cells or ovarian granulosa cells. This pivotal decision in a single gonadal cell type ultimately controls sexual differentiation throughout the body. Sex determination can be viewed as a battle for primacy in the fetal gonad between a male regulatory gene network in which Sry activates Sox9 and a female network involving WNT/β-catenin signalling. In females the primary sex-determining decision is not final: loss of the FOXL2 transcription factor in adult granulosa cells can reprogram granulosa cells into Sertoli cells. Here we show that sexual fate is also surprisingly labile in the testis: loss of the DMRT1 transcription factor in mouse Sertoli cells, even in adults, activates Foxl2 and reprograms Sertoli cells into granulosa cells. In this environment, theca cells form, oestrogen is produced and germ cells appear feminized. Thus Dmrt1 is essential to maintain mammalian testis determination, and competing regulatory networks maintain gonadal sex long after the fetal choice between male and female. Dmrt1 and Foxl2 are conserved throughout vertebrates and Dmrt1-related sexual regulators are conserved throughout metazoans. Antagonism between Dmrt1 and Foxl2 for control of gonadal sex may therefore extend beyond mammals. Reprogramming due to loss of Dmrt1 also may help explain the aetiology of human syndromes linked to DMRT1, including disorders of sexual differentiation and testicular cancer.

LPA3-mediated lysophosphatidic acid signalling in embryo implantation and spacing.

Abstract: The molecular mechanisms affecting female reproduction, particularly therapeutically tractable ones, are incompletely understood. So the identification of a new signalling mechanism affecting fertility via embryo implantation could be important. The compound involved is lysophosphatidic acid (LPA), acting through a G protein-coupled receptor. Targeted deletion of the receptor, called LPA3, produces mice that display delayed implantation, altered implantation spacing, hypertrophic placentas and embryonic death. G protein-coupled receptors are among the most common targets of drug action, raising the possibility of developing new medicines for the treatment of infertility by targeting the LPA3 receptor. Every successful pregnancy requires proper embryo implantation. Low implantation rate is a major problem during infertility treatments using assisted reproductive technologies1. Here we report a newly discovered molecular influence on implantation through the lysophosphatidic acid (LPA) receptor LPA3 (refs 2–4). Targeted deletion of LPA3 in mice resulted in significantly reduced litter size, which could be attributed to delayed implantation and altered embryo spacing. These two events led to delayed embryonic development, hypertrophic placentas shared by multiple embryos and embryonic death. An enzyme demonstrated to influence implantation, cyclooxygenase 2 (COX2) (ref. 5), was downregulated in LPA3-deficient uteri during pre-implantation. Downregulation of COX2 led to reduced levels of prostaglandins E2 and I2 (PGE2 and PGI2), which are critical for implantation1. Exogenous administration of PGE2 or carbaprostacyclin (a stable analogue of PGI2) into LPA3-deficient female mice rescued delayed implantation but did not rescue defects in embryo spacing. These data identify LPA3 receptor-mediated signalling as having an influence on implantation, and further indicate linkage between LPA signalling and prostaglandin biosynthesis.

The isotopic composition of Yb and the precise and accurate determination of Lu concentrations and Lu/Hf ratios by isotope dilution using MC-ICPMS

Abstract: [1] We report Yb isotopic data for the purpose of accurately correcting measurements of Lu and Lu/Hf ratios during Multicollector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS) analysis. The Yb isotopic ratios agree with recent results of Chu et al. [2002] and Amelin and Davis [2004], when corrected for mass fractionation to the same reference values. Protocols for Lu measurement involving simultaneous subtraction of Yb interference and application of a fractionation correction based on Yb are described. It is shown that Lu concentrations and Lu/Hf ratios determined by MC-ICPMS using this methodology are more precise and potentially more accurate than results based on analysis of Lu by Thermal Ionization Mass Spectrometry (TIMS). A number of MC-ICPMS Lu-Hf isotopic analyses of standard rocks and other geological samples, previously analyzed by TIMS, are presented. These document reproducibility of Lu/Hf within 0.2%, where most discrepancies can be assigned to the unknown Lu mass fractionation during TIMS analysis.

Beyond the looking-glass self: social structure and efficacy-based self-esteem.

Abstract: The "looking-glass self" has been the dominant metaphor within sociology for the development of self-conception and has contributed to an overly passive and oversocialized view of human beings. The major theme in this paper is that our self-conceptions are also based upon our actions in the world, especially efficacious actions. The notions of human agency and self-creativity, which have been a hallmark of the symbolic interactionist tradition at the philosophical level, can be brought into our studies of self-concept through the concept of self-efficacy. Efficacy-based self-esteem not only places greater emphasis upon "self-determination" in the process of self-concept formation, but also underscores the reciprocity between self and social structure. Several aspects of social structure are examined as they affect the development of efficacy-based self-conception.

What signal are you sending? how website quality influences perceptions of product quality and purchase intentions

Abstract: An electronic commerce marketing channel is fully mediated by information technology, stripping away much of a product's physical informational cues, and creating information asymmetries (i.e., limited information). These asymmetries may impede consumers' ability to effectively assess certain types of products, thus creating challenges for online sellers. Signaling theory provides a framework for understanding how extrinsic cues ᾢ signals ᾢ can be used by sellers to convey product quality information to consumers, reducing uncertainty and facilitating a purchase or exchange. This research proposes a model to investigate website quality as a potential signal of product quality and consider the moderating effects of product information asymmetries and signal credibility. Three experiments are reported that examine the efficacy of signaling theory as a basis for predicting online consumer behavior with an experience good. The results indicate that website quality influences consumers' perceptions of product quality, which subsequently affects online purchase intentions. Additionally, website quality was found to have a greater influence on perceived product quality when consumers had higher information asymmetries. Likewise, signal credibility was found to strengthen the relationship between website quality and product quality perceptions for a high quality website. Implications for future research and website design are examined.