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Imaginal disc morphogenesis during metamorphosis in Drosophilaprovides an ideal system for studying the hormonal control of morphogenesis. During metamorphosis, ecdysone signaling initiates a gene regulatory network.....Imaginal disc morphogenesis during metamorphosis in Drosophila melanogasterprovides an excellent model to uncover molecular mechanisms by which hormonal signals effect physical changes during development. The broad(br) Z2isoform encodes a transcription factor required for disc morphogenesis in response to 20-hydroxyecdysone, yet how it accomplishes this remains largely unknown. Here, we use functional studies of amorphic br5mutants and a transcriptional target approach to identify processes driven by brand its regulatory targets in leg imaginal discs. br5mutants fail to properly remodel their basal extracellular matrix (ECM) between 4 and 7 hr after puparium formation. Additionally, br5mutant discs do not undergo the cell shape changes necessary for leg elongation and fail to elongate normally when exposed to the protease trypsin. RNA-sequencing of wild-type and br5mutant leg discs identified 717 genes differentially regulated by br, including a large number of genes involved in glycolysis, and genes that encode proteins that interact with the ECM. RNA interference-based functional studies reveal that several of these genes are required for adult leg formation, particularly those involved in remodeling the ECM. Additionally, brZ2expression is abruptly shut down at the onset of metamorphosis, and expressing it beyond this time results in failure of leg development during the late prepupal and pupal stages. Taken together, our results suggest that brZ2is required to drive ECM remodeling, change cell shape, and maintain metabolic activity through the midprepupal stage, but must be switched off to allow expression of pupation genes.

Rodent models have been invaluable for biomedical research. Preclinical investigations with rodents allow researchers to investigate diseases by using study designs that are not suitable for human subjects. The primary criticism of preclinical animal models is that results are not always translatable to humans. Some of this lack of translation is due to inherent differences between species. However, rodent models have been refined over time, and translatability to humans has improved. Transgenic animals have greatly aided our understanding of interactions between genes and disease and have narrowed the translation gap between humans and model animals. Despite the technological innovations of animal models through advances in genetics, relatively little attention has been given to animal diets. Namely, developing diets that replicate what humans eat will help make animal models more relevant to human populations. This review focuses on commonly used rodent diets that are used to emulate the Western dietary pattern in preclinical studies of obesity and type 2 diabetes, nonalcoholic liver disease, maternal nutrition, and colorectal cancer.

Traditionally, mouse humanization studies have used human fecal transfer to germ-free animals. This practice requires gnotobiotic facilities and is restricted to gnotobiotic mouse lines, which limits humanized mouse research. We have developed a generalizable method to humanize non germ-free mice using antibiotic treatment and human fecal transfer. The method involves depleting resident intestinal microbiota with broad-spectrum antibiotics, introducing human microbiota from frozen fecal samples by weekly gavage, and maintaining mice in HEPA-filtered microisolator cages. Pyrosequencing cecal microbiota 16S rRNA genes showed that recipient mice adopt a humanized microbiota profile analogous to their human donors, and distinct from mice treated with only antibiotics (no fecal transfer) or untreated control mice. In the humanized mice, 75% of the sequence mass was observed in their respective human donor and conversely, 68% of the donor sequence mass was recovered in the recipient mice. Principal component analyses of GC- and HPLC-separated cecal metabolites were performed to determine effects of transplanted microbiota on the metabolome. Cecal metabolite profiles of mice treated with only antibiotics (no fecal transfer) and control mice were dissimilar from each other and from humanized mice. Metabolite profiles for mice humanized from different donor samples clustered near each other, yet were sufficiently distinct that separate clusters were apparent for each donor. Also, cecal concentrations of 57 metabolites were significantly different between humanization treatments. These data demonstrate that our protocol can be used to humanize non germ-free mice and is sufficiently robust to generate metabolomic differences between mice humanized from different human donors.

A method was developed to isolate mono- and disaccharide-free oligosaccharides from human and bovine milk using a combination of enzymatic digestion of lactose and solid-phase extraction. In the initial trial, 2.5 g of oligosaccharides were isolated from one liter of human milk. In subsequent trials this was increased to over 5 g of oligosaccharides per liter. Compared to filtration-based extraction methods, this procedure allows for further isolation of oligosaccharide fractions via modulation of the column rinsing solvent. Neutral monosaccharide composition of the oligosaccharide polymers was investigated using gas chromatographic analysis of the monosaccharides as alditol acetate derivatives. Results indicate oligosaccharides are approximately made up of 24% fucose, 41% galactose, 22% glucose and 13% glucosamine. Isolated bovine and human milk oligosaccharides were compared to lactose as fermentation substrates for Bifidobacterium longum biovar infantis. Lactose fermentation yielded the greatest production of biomass followed by bovine and human milk oligosaccharides.

Milk is the only biomaterial that evolved under the Darwinian selective pressure to nourish growing mammals. The purpose of this article is to review the scientific research that is using new techniques of integrating biological sequence, structure and function, to understand the innovative biology underlying the products of that evolutionary pressure. As it emerges that milk is actively communicating between the maternal mammary epithelia and the infant's gastrointestinal system, actively directing and educating the immune, metabolic and microflora systems within the infant, enhancing nutrient absorption and delivery, and conferring multiple means of protection, nutritionists are gaining a host of new molecular targets towards which to build scientific strategies for future foods and clinical applications. As new components and functions are being discovered in milk by using traditional methods and modern genomic tools, the complexities of demonstrating in vivo, and particularly in humans, the functional mechanisms behind milk's newly observed physiological benefits are becoming the next challenge of this rapidly growing field.

Several esterases from barley and malt have been separated on polyacrylamide gels. The slowest moving bands appear to represent a single enzyme displaying a spread of migration owing to differences in surface charge. During malting, this enzyme, which is located in the starchy endosperm, shifts to a more migratory form. Two other main esterase groups are identified through gel electrophoresis, notably a highly anionic, highly labile enzyme, MW 62,000, located in the aleurone. The slowest and fastest moving bands have been partially purified using salt fractionation and ion-exchange chromatography. The former, MW 47,000, has strong capability for hydrolyzing acetylxylan and it is speculated that its role in the starchy endosperm is as part of the enzyme system that hydrolyzes the cell walls.

Reports on the passage of the Economic Growth and Tax Relief Reconciliation Act of 2001 in the U.S. Increase in the deductible contribution limit for 50-year old individuals; Tax benefits for education costs; Elimination of the phase-out of the personal exemption for upper-income taxpayers.

Bacteriophage T4 provides a simple model system in which to examine the mechanism of action of antitumor agents that have been proposed to attack type II DNA topoisomerases. Prior results demonstrated that T4 type II DNA topoisomerase is the target of antitumor agent 4'-(9-acridinylamino)methanesulfon-m-anisidide (m-AMSA) in phage-infected Escherichia coli: a point mutation in topoisomerase structural gene 39 was shown to confer both m-AMSA-resistant phage growth and m-AMSA-insensitive topoisomerase activity. We report here that a point mutation in T4 topoisomerase structural gene 52 can also independently render both phage growth and topoisomerase activity resistant to m-AMSA. The DNA relaxation and DNA cleavage activities of this newly isolated mutant topoisomerase were significantly insensitive to m-AMSA. The drug-resistance mutation in gene 52, as well as that in gene 39, alters the DNA cleavage site specificity of wild-type T4 topoisomerase. This fording is consistent with a mechanism of drug action in which both topoisomerase and DNA participate in formation of the drug-binding site.

Although extensively studied biochemically, members of the Protein 4.1 superfamily have not been as well characterized genetically. Studies of coracle, a DrosophilaProtein 4.1 homologue, provide an opportunity to examine the genetic functions of this gene family. coraclewas originally identified as a dominant suppressor ofEgfrElp, a hypermorphic form of theDrosophila Epidermal growth factor receptor gene. In this article, we present a phenotypic analysis ofcoracle, one of the first for a member of the Protein 4.1 superfamily. Screens for new coraclealleles confirm the null coraclephenotype of embryonic lethality and failure in dorsal closure, and they identify additional defects in the embryonic epidermis and salivary glands. Hypomorphiccoraclealleles reveal functions in many imaginal tissues. Analysis of coraclemutant cells indicates that Coracle is a necessary structural component of the septate junction required for the maintenance of the transepithelial barrier but is not necessary for apical–basal polarity, epithelial integrity, or cytoskeletal integrity. In addition, coraclephenotypes suggest a specific role in cell signaling events. Finally, complementation analysis provides information regarding the functional organization of Coracle and possibly other Protein 4.1 superfamily members. These studies provide insights into a range of in vivo functions for coraclein developing embryos and adults.

A conical mirror offers a means of magnifying the image of an object on an opaque screen, so that it may be viewed from a position directly in front of the screen, and the projecting distance necessary to produce the magnification is much less than that required by present methods. An experiment shows that the conical mirror gives high resolution when used in a specific projecting system. It may provide a convenient means with which to obtain high magnification for many optical systems. The magnification is shown by theory and experiment to be equal to the secant of the conical mirror angle.

The term “political modernization” is of late encountered with increasing frequency in the literature of political science. Its antecedents are somewhat diffuse. In the most general sense, it seems to represent a specialized adaptation of scholars' long-standing concern with the question of whether the process of social change is determinate or variable, random or patterned, continuous or episodic, cyclic or evolutionary. Within this tradition “political modernization” is a concept opposed in tendency to the relativistic character of much modern scholarship in the field of politics. It would seem to be oriented more in the direction of a patterned and evolutionary—although not necessarily determinate or value-laden—interpretation of social change.