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As students apply their knowledge of scientific concepts and of science as a method of inquiry, learning becomes relevant. This laboratory exercise is designed to foster students' understanding of the genetics of quantitative traits and of the nature of science as a method of inquiry by engaging them in a real-world business scenario. During the investigation, students explore the question of whether the patent rights of a commercial producer of sunflower seeds have been infringed upon by a rival company. Students work as a research team to explore the question, making observations, collecting and analyzing data utilizing statistical tools, and ultimately drawing conclusions regarding possible patent violations. Student-evaluations of the exercise indicate that they perceive that the activity fostered their understanding of genetic principles and of important aspects of scientific inquiry and made the content relevant by linking it to real-world issues. (Contains 3 tables.)

Several hands-on and wet laboratory activities have been proposed to model the genetic concepts of genotypes and phenotypes and their relationship. The exercise presented in this article is a novel, time effective, student-centered, role-playing activity in which students learn about the intricate connection between genotype and phenotype by exploring the fundamental effect of mutation on protein function beginning with a very real and human phenotype, albinism. This exercise is based on a long established role-playing model of enzyme kinetics by allowing students to act out the role of enzyme (Oreo-ase). However, in this model exercise, instead of learning only about the enzyme, students learn about the genes and mutations, bringing this model to its full genetic extension. This exercise can be adapted easily to students of various grade levels. (Contains 7 figures.)

Abstract: Lactoferrin (LTF) is a multifunctional iron-binding protein that is also capable of binding other divalent metal cations, especially [Zn.sup.2+]. Recent investigations indicate that lactoferrin levels are elevated in many [...]

The influence of transacting factors in mu gene regulation is investigated. The polyadenylation factor CstF-64 is shown to be specifically up-regulated during B cell differentiation. Overexpression of the factor in a B cell line raises intact CstF concentration and reproduces the shift in IgM pre-mRNA processing that occurs during differentiation. A detailed model for regulating the mum-to-mus mRNA switch is also proposed.

ABSTRACT -- Borrelia burgdorferi is the causative agent of Lyme disease and is transmitted by the black-legged tick, Ixodes scapularis. Clinical diagnosis of Lyme disease is often made on the [...]

Abstract: Zinc metallopeptidases are ubiquitous enzymes with diverse cellular functions that can be found in most organisms. Leukotriene A4 hydrolase (LTA4H; E.C. 3.3.2.6) is an unusual zinc metallopeptidase of the M1 family that also possesses an epoxide hydrolase activity; however, the role of its peptidase activity remains unknown. To further characterize the peptidase activity of LTA4H and other closely related metallopeptidases, a multiple sequence alignment and predicted structure were used to target three amino acid residues of yeast LTA4H for mutagenesis: Asn362, Trp365, and Asp399. Although mutating Trp365 and Asp399 had little effect on catalysis, altering Asn362 had varying effects on catalysis, depending on the replacement residue. Mutation of Asn362 to glutamine (N362Q) caused minor catalytic defects, while mutation to leucine (N362L) or glutamate (N362E) caused large reductions in activity. Both N362L and N362E also exhibited an altered pH dependence of catalysis, reduced chloride activation, and reduced zinc affinity and content, indicating that Asn362 may interact with the nearby zinc coordinating residue His344, and possibly with Glu363 as well, to polarize and/or orient these residues. [ABSTRACT FROM AUTHOR]

The Chlorarachniophyceae are unicellular eukaryotic algae characterized by an amoeboid morphology that may be the result of secondary endosymbiosis of a green alga by a nonphotosynthetic amoeba or amoeboflagellate. Whereas much is known about the phylogeny of chlorarachniophytes, little is known about their physiology, particularly that of their lipids. In an initial effort to characterize the lipids of this algal class, four organisms from three genera were examined for their fatty acid and sterol composition. Fatty acids from lipid fractions containing chloroplast-associated glycolipids, storage triglycerides, and cytoplasmic membrane-associated polar lipids were characterized. Glycolipid-associated fatty acids were of limited composition, principally eicosapentaenoic acid [20:5(n-3)] and hexadecanoic acid (16:0). Triglyceride-associated fatty acids, although minor, were found to be similar in composition. The polar lipid fraction was dominated by lipids that did not contain phosphorus and had a more variable fatty acid composition with 16:0 and docosapentaenoic acid [22:5(n-3)] dominant along with a number of minor C18 and C20 fatty acids. Crinosterol and one of the epimeric pair poriferasterol/stigmasterol were the sole sterols. Several genes required for synthesis of these sterols were computationally identified inBigelowiella natansMoestrup. One sterol biosynthesis gene showed the greatest similarity toSMT1of the green alga,Chlamydomonas reinhardtii. However, homologues to other species, mostly green plant species, were also found. Further, the method used for identification suggested that the sequences were transferred to a genetic compartment other than the likely original location, the nucleomorph nucleus. [ABSTRACT FROM AUTHOR]

As students apply their knowledge of scientific concepts and of science as a method of inquiry, learning becomes relevant. This laboratory exercise is designed to foster students' understanding of the genetics of quantitative traits and of the nature of science as a method of inquiry by engaging them in a real-world business scenario. During the investigation, students explore the question of whether the patent rights of a commercial producer of sunflower seeds have been infringed upon by a rival company. Students work as a research team to explore the question, making observations, collecting and analyzing data utilizing statistical tools, and ultimately drawing conclusions regarding possible patent violations. Student-evaluations of the exercise indicate that they perceive that the activity fostered their understanding of genetic principles and of important aspects of scientific inquiry and made the content relevant by linking it to real-world issues. [ABSTRACT FROM AUTHOR]

Abstract: Saccharomyces cerevisiae leukotriene A4 hydrolase (LTA4H) is a bifunctional aminopeptidase/epoxide hydrolase and a member of the M1 family of metallopeptidases. In order to obtain a more thorough understanding of the aminopeptidase activity of the enzyme, two conserved tyrosine residues, Tyr244 and Tyr456, were altered to phenylalanine and the mutant proteins characterized by determining K M and k cat for various amino acid β-naphthylamide substrates. While mutation of Tyr456 exhibited minimal effect on catalysis, mutation of Tyr244 caused an overall 25–100-fold reduction in catalytic activity for all substrates tested. Furthermore, LTA4H Y244F exhibited a 40-fold decrease in affinity for RB-3014, a transition state analog inhibitor, implicating Tyr244 in transition state stabilization. [Copyright &y& Elsevier]