A low cost multi-level sampling device for synchronous aseptic collection of environmental water samples.

We describe a simple device for the aseptic collection of environmental water samples at high spatial resolution to depths of 50m. To demonstrate the utility of this technique we present geochemical and archaeal community data from samples collected throughout the water column of a stratified lake.

Resources and strategies to integrate the study of ethical, legal, and social implications of genetics into the undergraduate curriculum.

Gene therapy, genetically modified organisms, and the privacy of an individual's genetic information are just a few of the developments emerging from recent advances in molecular genetics that are controversial. Oversight and regulation of emerging technologies are the responsibility of both experts and the general public who both need to understand the science and the societal impact of its use. The study of ethical, legal, and social implications (ELSI) of advances in genetics provides a very powerful pedagogical tool to accomplish two goals. These are, first of all, to interest nonscientists in genetics and engage them in learning the science behind the ELSI developments they are considering, and secondly, to broaden the perspective of science students to consider the history and social consequences of the science they are studying. The resources and strategies presented in this chapter for teaching ELSI issues that arise in modern genetics are designed to aid in accomplishing these goals throughout the undergraduate curriculum. This chapter provides (1) a set of nine ELSI topic modules that can be incorporated into courses for both majors (from introductory to graduate level) and nonmajors and (2) examples of course pedagogy for specific classes.

Amino acid transport through the Saccharomyces cerevisiae Gap1 permease is controlled by the Ras/cAMP pathway.

The general amino acid permease (Gap1p) of Saccharomyces cerevisiae is a broad range, low affinity permease that imports amino acids in cells growing on poor nitrogen sources. This permease also signals the presence of amino acids through the fermentable growth medium pathway allowing the cell to respond to new sources of nitrogen in the surrounding medium. Yeast with an activated Ras2/cAMP pathway show many phenotypes indicative of altered nitrogen uptake and metabolism; sensitivity to nitrogen starvation, low amino acid pools. We have shown that Gap1p activity is lowered in cells with an activated RAS2(val19) allele or elevated cAMP levels whereas cells with inactive ras2 allele lose ammonia repression of Gap1p-mediated transport. This regulation is through a post-transcriptional mechanism; transcription of GAP1 is not affected by cAMP level. A mechanism by which the Ras2/cAMP/PKA pathway controls the ubiquitin-dependent degradation of Gap1p is most consistent with the data.

Instructors' practices in and attitudes toward teaching ethics in the genetics classroom.

There is strong consensus among educators that training in the ethical and social consequences of science is necessary for the development of students into the science professionals and well-rounded citizens needed in the future. However, this part of the curriculum is not a major focus of most science departments and it is not clear if, or how, students receive this training. To determine the current status of bioethics education of undergraduate biology students in the United States, we surveyed instructors of introductory genetics. We found that there was support for more ethics education both in the general curriculum and in the genetics classroom than is currently being given. Most instructors devote <5% of class time to ethical and social issues in their genetics courses. The majority feels that this is inadequate treatment of these topics and most cited lack of time as a major reason they were unable to give more attention to bioethics. We believe biology departments should take the responsibility to ensure that their students are receiving a balanced education. Undergraduate students should be adequately trained in ethics either within their science courses or in a specialized course elsewhere in the curriculum.

Yeast Agp2p and Agp3p function as amino acid permeases in poor nutrient conditions.

The gene AGP2 and the ORF YFL055w (here named AGP3) are classified as members of the yeast amino acid permease gene family. Analysis of the growth of multiply-mutant strains in which these genes are disrupted shows that both encode permeases capable of supplying branched chain, and other, amino acids as nitrogen source. Both Agp2p and Agp3p are low affinity permeases for leucine (Kmapp 0.2-0.5 mM) and are expressed at lower levels than other permeases on all media tested. Thus, it appears that these two permeases can function as low affinity, relatively non-specific, permeases with redundant functions in the cell. Transcription of AGP2 and AGP3 is very low but is increased in cells lacking other functional general amino acid permeases (Gap1p or Agp1p). These results suggest Agp2p and Agp3p function in amino acid transport when nitrogen sources are limiting and/or other permeases are inactive.