Life Sciences Commons^™

Natural Selection On Protein Polymorphism In The Rodent Genus Peromyscus: Evidence From Interlocus Contrasts, Jay F. Storz, Michael W. Nachman

Jay F. Storz Publications

The effects of natural selection are generally locus-specific, whereas migration, drift, and inbreeding are expected to have relatively uniform effects across the entire genome. This suggests that multilocus surveys of multiple populations can be used to distinguish selection from demographic effects. The purpose of this study was to test for evidence of selection on protein polymorphism in natural populations of mice in the genus Peromyscus. We analyzed published data from geographic surveys of allozyme variation and used a coalescent- based simulation model to identify specific loci that deviated from neutral expectations. Observed F_ST values generally exhibited a remarkably …

A Bt Transgene Reduces Herbivory And Enhances Fecundity In Wild Sunflowers, A. A. Snow, Diana Pilson, L. H. Rieseberg, M. J. Paulsen, N. Pleskac, M. R. Reagon, D. E. Wolf, S. M. Selbo

Diana Pilson Publications

Gene flow from transgenic crops can introduce novel traits into related species, but the ecological importance of this process is unknown. Here, we report the first empirical evidence that wild plants can benefit from a bacterial transgene under uncaged, natural conditions. Cultivated sunflower (Helianthus annuus) is known to hybridize frequently with wild sunflower (H. annuus) in the western and midwestern United States. We studied a crop-developed Bacillus thuringiensis (Bt) transgene, cry1Ac, in backcrossed wild sunflower populations. Lepidopteran damage on transgenic plants was strongly reduced relative to control plants at our two study sites, while damage …

Life Span Extension Of Drosophila Melanogaster: Genetic And Population Studies, Lawrence G. Harshman

Lawrence G. Harshman Publications

During the past two decades, genetic studies of model organisms have been the most important tool underlying advances in understanding the biological basis of aging and longevity. Drosophila melanogaster, the geneticist's "fruit fly," is a model organism because it has been the focus of genetic studies for more than 90 years. This review argues that studies on D. melanogaster will make an especially important contribution to the field of aging and longevity at the intersection of research on genetics, complex traits, and fly populations.

Five approaches have been used to study the genetics of longevity of D. melanogaster: …

Estrogen Receptor-Α Populations Change With Age In Commercial Laying Hens, K.K. Hansen, R.J. Kittok, G. Sarath, C.F. Toombs, N. Caceres, M.M. Beck

Department of Animal Science: Faculty Publications

Older hens in production lay larger but fewer eggs than younger birds, and the incidence of soft and broken shells is greater in older hens than younger. These changes are attributable at least in part to changing hormone profiles and diminished ability of the hen to transport calcium at the duodenum. In further exploration of this relationship, a study was conducted with three ages of Hy-Line W-36 birds: prelay pullets (PL; 19 wk, 0% production), peak-production hens (PP; 29 wk, ∼93% production), and late-stage hens (LS; 71 wk, ∼80% production). Hens from the PP and LS groups were palpated for …

Codon Usage, Estuko N. Moriyama

Papers in Genetics

The genetic codes have degeneracy; that is, most amino acids (18 out of 20 in the universal genetic code) are encoded by more than one codon. Codons encoding the same amino acid are called synonymous codons. Both in prokaryotic and eukaryotic genes, the synonymous codons are not used with equal frequencies.

Growth And Carcass Characteristics In Wether Lambs Of A Crossbred Dam Line, A. M. Van Heelsum, R. M. Lewis, M. H. Davies, W. Haresign

Department of Animal Science: Faculty Publications

While crossing of specialized sire and dam breeds can be biologically efficient overall, a by-product is produced in the form of (crossbred) males of the dam line that are unwanted for breeding. In the UK sheep indusiru, most commercial females are first crosses between males of 'longwool' crossing sire breeds, predominantly the Biuefaced Leicester, and females of hill breeds. Genetic improvement of carcass quality in longwool breeds would benefit the surplus F₁males as well asfilter through to tile terminal sire cross lambs produced by the F₁ewes. As afirst step, this paper aims to describe thegrowth and …

The Ability Of The N-Alkane Technique To Estimate Intake And Diet Choice Of Sheep, R. M. Lewis, A. M. Magadlela, N. S. Jessop, G. C. Emmans

Department of Animal Science: Faculty Publications

This study assessed the efficacy of the n-alkane technique to estimate intake and diet composition in animals given single foods or a choice of two. In thefirst experiment intakes of pelleted ryegrassand lucerne, given eitheralone or as a choice, were measured in lambshoused indoors in individual pens. Each of the three feeding treatments was given to 12 lambs at two degrees of maturity (0.30 and 0·45 of estimated mature sizes). The 12 lambs were constituted as three replicates of the two sexes of each of two breeds. The measured intakes werecompared with those estimated using the n-alkanes C31 andC33, found …

Animal Anti-Apoptotic Genes Ameliorate The Loss Of Turgor In Water-Stressed Transgenic Tobacco, Tala Awada, D. D. Dunigan, M. B. Dickman

Nebraska Center for Virology: Faculty Publications

Nicotiana tabacum L. ‘Glurk’ plants were transformed with antiapoptotic animal genes [chicken Bcl-xl; nematode CED-9; chicken Bcl-xl(GA) a mutant of Bcl-xl; and a 3’ non-coding region of human Bcl-2, referred to as 161-1]. Our objectives were to determine whether plant transformation with anti-apoptotic genes ameliorates drought tolerance in tobacco plants by subjecting the plants to a dry-down period. The non-transformed Glurk and the transgenic Glurk harboring G115, which expresses β-glucuronidase, served as controls. Transformation of tobacco plants with animal anti-apoptotic genes significantly impacted the rates of photosynthesis (A) and stomatal conductance (g_s), but not to the same extent …

Identification Of Novel Domains Within Sox-2 And Sox-11 Involved In Autoinhibition Of Dna Binding And Partnership Specificity, Matthew S. Wiebe, Tamara K. Nowling, Angie Rizzino

Nebraska Center for Virology: Faculty Publications

Sox transcription factors play key regulatory roles throughout development, binding DNA through a consensus (A/T)(A/T)CAA(A/T)G sequence. Although many different Sox proteins bind to this se-quence, it has been observed that gene regulatory elements are commonly responsive to only a small subset of the entire family, implying that regulatory mechanisms exist to permit selective DNA bind-ing and/or transactivation by Sox family members. To identify and explore the mechanisms modu-lating gene activation by Sox proteins further, we compared the function of Sox-2 and Sox-11. This led to the discovery that Sox proteins are regulated differentially at multiple levels, including trans-activation, protein partnerships …

Structural Analyses Of Phycodnaviridae And Iridoviridae, Alan A. Simpson, Narayanasamy Nandhagopal, James L. Van Etten, Michael G. Rossmann

Nebraska Center for Virology: Faculty Publications

The Phycodnaviridae, Iridoviridae and related viruses, with diameters of 1500±2000 A Ê , are formed from large trigonal arrays of hexagonally close-packed capsomers forming the faces of icosahedra [Yan et al. (2000), Nature Struct. Biol. 7, 101-103; Nandhagopal et al. (2002), Proc. Natl Acad. Sci. USA, 99, 14758-14763]. Caspar and Klug predicted that such structures could be assembled from hexameric capsomers [Caspar & Klug (1962), Cold Spring Harbor. Symp. Quant. Biol. 27, 1-24], as was subsequently found in numerous icosahedral viruses. During the course of evolution, some viruses, including the virus families …

Functional Implications In Apoptosis By Interferon Inducible Gene Product 1-8d, The Binding Protein To Adenovirus Preterminal Protein, Insil Joung, Peter C. Angeletti, Jeffrey A. Engler

Nebraska Center for Virology: Faculty Publications

Adenovirus (Ad) precursor to the terminal protein (pTP) plays an essential roles in the viral DNA

replication. Ad pTP serves as a primer for the synthesis of a new DNA strand during the initiation

step of replication. In addition, Ad pTP forms organized spherical replication foci on the nuclear

matrix (NM) and anchors the viral genome to the NM. Here we identified the interferon inducible

gene product 1-8D (Inid) as a pTP binding protein by using a two-hybrid screen of a HeLa cDNA

library. Of the clones obtained in this assay, nine were identical to the Inid, a 13-kDa polypeptide …