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Cupertino, CA, United States

Alvarado M.,Monte Vista High School | Maskiewicz A.C.,Point Loma Nazarene University
American Biology Teacher | Year: 2011

Teachers know that educational experiences extend far beyond the classroom. With a wide variety of science-related programs on television, there is a need for more research into how these programs can he utilized in a classroom setting. In this mixed-methods study, we asked the question: Can student understanding of human physiology he improved through the use of multimedia resources, specifically through the use of popular television? Episodes of Fox's popular medical drama "House, M.D." were incorporated into high school biology curricula during instructional units on two body systems: the nervous system and the immune system. Through the use of integrated media and classroom discussions, students were exposed to the social aspect of learning as they worked together to analyze what they viewed on TV. This study was conducted over a traditional school year in a general biology class at a lower-socioeconomic urban high school. © 2011 by National Association of Biology Teachers. All rights reserved.

Cunha G.R.,University of California at San Francisco | Cunha G.R.,Monash University | Risbridger G.,Monash University | Wang H.,Monash University | And 16 more authors.
Differentiation | Year: 2014

This review/research paper summarizes data on development of the external genitalia of the spotted hyena, a fascinating mammal noted for extreme masculinization of the female external genitalia. The female spotted hyena is the only extant mammal that mates and gives birth through a pendulous penis-like clitoris. Our studies indicate that early formation of the phallus in both males and females is independent of androgens; indeed the phallus forms before the fetal testes or ovaries are capable of synthesizing androgens. Likewise, pre- and postnatal growth in length of the penis and clitoris is minimally affected by "androgen status". Nonetheless, several internal morphologies, as well as external surface features of the phallus, are androgen-dependent and thus account for dimorphism between the penis and clitoris. Finally, estrogens play a critical role in penile and clitoral development, specifying the position of the urethral orifice, determining elasticity of the urethral meatus, and facilitating epithelial-epithelial fusion events required for proper formation of the distal urethra/urogenital sinus and prepuce. Accordingly, prenatal inhibition of estrogen synthesis via administration of letrozole (an aromatase inhibitor) leads to malformations of the glans as well as the prepuce (hypospadias). The effects of prenatal androgens, anti-androgens and impaired estrogen synthesis correlated with the tissue expression of androgen and estrogen receptors. © 2014 International Society of Differentiation.

Rodriguez Jr. E.,University of California at San Francisco | Weiss D.A.,University of California at San Francisco | Yang J.H.,University of California at Davis | Menshenina J.,University of California at San Francisco | And 7 more authors.
Biology of Reproduction | Year: 2011

The adult mouse penis represents the end point of masculine sex differentiation of the embryonic genital tubercle and contains bone, cartilage, the urethra, erectile bodies, several types of epithelium, and many individual cell types arrayed into specific anatomical structures. Using contemporary high-resolution imaging techniques, we sought to provide new insights to the current description of adult mouse penile morphology to enable understanding of penile abnormalities, including hypospadias. Examination of serial transverse and longitudinal sections, scanning electron microscopy, and three-dimensional (3D) reconstruction provided a new appreciation of the individual structures in the adult mouse penis and their 3D interrelationships. In so doing, we discovered novel paired erectile bodies, the male urogenital mating protuberance (MUMP), and more accurately described the urethral meatus. These morphological observations were quantified by morphometric analysis and now provide accurate morphological end points of sex differentiation of mouse penis that will be the foundation of future studies to identify normal and abnormal penile development. © 2011 by the Society for the Study of Reproduction, Inc.

Weiss D.A.,University of California at San Francisco | Rodriguez E.,University of California at San Francisco | Cunha T.,University of California at San Francisco | Menshenina J.,University of California at San Francisco | And 5 more authors.
Molecular and Cellular Endocrinology | Year: 2012

Adult external genitalia (ExG) are the endpoints of normal sex differentiation. Detailed morphometric analysis and comparison of adult mouse ExG has revealed 10 homologous features distinguishing the penis and clitoris that define masculine vs. feminine sex differentiation. These features have enabled the construction of a simple metric to evaluate various intersex conditions in mutant or hormonally manipulated mice. This review focuses on the morphology of the adult mouse penis and clitoris through detailed analysis of histologic sections, scanning electron microscopy, and three-dimensional reconstruction. We also present previous results from evaluation of "non-traditional" mammals, such as the spotted hyena and wallaby to demonstrate the complex process of sex differentiation that involves not only androgen-dependent processes, but also estrogen-dependent and hormone-independent mechanisms. © 2011 Elsevier Ireland Ltd.

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