Biology Commons^™

Chemical Inhibition Of Caax Protease Activity Disrupts Yeast Ras Localization, Surya P. Mandahar, Emily R. Hildebrandt, William H. Jacobsen, George M. Santangelo, Walter K. Schmidt

Faculty Publications

Proteins possessing a C-terminal CaaX motif, such as the Ras GTPases, undergo extensive post-translational modification that includes attachment of an isoprenoid lipid, proteolytic processing and carboxylmethylation. Inhibition of the enzymes involved in these processes is considered a cancer-therapeutic strategy. We previously identified nine in vitro inhibitors of the yeast CaaX protease Rce1p in a chemical library screen (Manandhar et al., 2007). Here, we demonstrate that these agents disrupt the normal plasma membrane distribution of yeast GFP-Ras reporters in a manner that pharmacologically phenocopies effects observed upon genetic loss of CaaX protease function. Consistent with Rce1p being the in vivo target …

Genomic Organization And Molecular Phylogenies Of The Beta (Β) Keratin Multigene Family In The Chicken (Gallus Gallus) And Zebra Finch (Taeniopygia Guttata): Implications For Feather Evolution, Matthew J. Greenwold, Roger H. Sawyer

Faculty Publications

Background: The epidermal appendages of reptiles and birds are constructed of beta (β) keratins. The molecularphylogeny of these keratins is important to understanding the evolutionary origin of these appendages, especially feathers. Knowing that the crocodilian β-keratin genes are closely related to those of birds, the published genomes ofthe chicken and zebra finch provide an opportunity not only to compare the genomic organization of their β- keratins,but to study their molecular evolution in archosaurians.

Results: The subfamilies (claw, feather, feather-like, and scale) of β-keratin genes are clustered in the same 5' to 3' orderon microchromosome 25 in chicken and zebra finch, …

Development Of A ‘Universal’ Rubric For Assessing Undergraduates’ Scientific Reasoning Skills Using Scientific Writing, Briana Eileen Timmerman, Denise Strickland, Robert L. Johnson, John R. Payne

Faculty Publications

We developed a rubric for measuring students’ ability to reason and write scientifically. The Rubric for Science Writing (Rubric) was tested in a variety of undergraduate biology laboratory courses (total n = 142 laboratory reports) using science graduate students (teaching assistants) as raters. Generalisability analysis indicates that the Rubric provides a reliable measure of students’ abilities (g = 0.85) in these conditions. Comparison of student performance in various biology classes indicated that some scientific skills are more challenging for students to develop than others and identified a number of previously unappreciated gaps in the curriculum. Our findings suggest that use …

Role Of Casein Kinase 1 In The Glucose Sensor-Mediated Signaling Pathway In Yeast, Satish Pasula, Samujjwal Chakraborty, Jae H. Choi, Jeong-Ho Kim

Faculty Publications

Background

In yeast, glucose-dependent degradation of the Mth1 protein, a corepressor of the glucose transporter gene (HXT) repressor Rgt1, is a crucial event enabling expression of several HXT. This event occurs through a signaling pathway that involves the Rgt2 and Snf3 glucose sensors and yeast casein kinase 1 and 2 (Yck1/2). In this study, we examined whether the glucose sensors directly couple with Yck1/2 to convert glucose binding into an intracellular signal that leads to the degradation of Mth1.

Results

High levels of glucose induce degradation of Mth1 through the Rgt2/Snf3 glucose signaling pathway. Fluorescence microscopy analysis …

The Role Of Adaptive Trans-Generational Plasticity In Biological Invasions Of Plants, Andrew R. Dyer, Cynthia S. Brown, Erin K. Espeland, John K. Mckay, Harald Meimberg, Kevin J. Rice

Faculty Publications

High-impact biological invasions often involve establishment and spread in disturbed, high-resource patches followed by establishment and spread in biotically or abiotically stressful areas. Evolutionary change may be required for the second phase of invasion (establishment and spread in stressful areas) to occur. When species have low genetic diversity and short selection history, within-generation phenotypic plasticity is often cited as the mechanism through which spread across multiple habitat types can occur. We show that trans-generational plasticity (TGP) can result in pre-adapted progeny that exhibit traits associated with increased fitness both in high-resource patches and in stressful conditions. In the invasive sedge, …

Organismal Climatology: Analyzing Environmental Variability At Scales Relevant To Physiological Stress, Brian Helmuth, Bernardo R. Broitman, Lauren Yamane, Sarah E. Gilman, Katharine Mach, K. A.S. Mislan, Mark W. Denny

Faculty Publications

Predicting when, where and with what magnitude climate change is likely to affect the fitness, abundance and distribution of organisms and the functioning of ecosystems has emerged as a high priority for scientists and resource managers. However, even in cases where we have detailed knowledge of current species’ range boundaries, we often do not understand what, if any, aspects of weather and climate act to set these limits. This shortcoming significantly curtails our capacity to predict potential future range shifts in response to climate change, especially since the factors that set range boundaries under those novel conditions may be different …

Latitudinal Differences In The Hibernation Characteristics Of Woodchucks (Marmota Monax), Stam M. Zervanos, Christine R. Maher Phd, Jerry A. Waldvogel, Gregory L. Florant

Faculty Publications

There is little information on the phenotypic flexibility of hibernation characteristics within species. To address this issue, we observed differences in hibernation characteristics of three free-ranging populations of woodchucks (Marmota monax) distributed along a latitudinal gradient from Maine to South Carolina. Data from free-ranging animals exhibited a direct relationship between latitude and length of the hibernation season. As expected, woodchucks in the northern latitudes hibernated longer than those in the southern latitudes. Also, the length of interbout arousals decreased with increase in latitude, whereas the length of torpor bouts and the number of arousals increased. Thus, we observed phenotypic plasticity …

Methane Emission From A Tropical Wetland In Ka'au Crater, O'Ahu, Hawai'i, Maxime Grand, Eric Gaidos

Faculty Publications

Natural tropical wetlands constitute an important but still poorly studied source of atmospheric methane, a powerful greenhouse gas. We measured net methane emission, soil profiles of methane generation and oxidation, and related environmental parameters in a tropical wetland occupying the Ka'au extinct volcanic crater on the Hawaiian island of O'ahu. The wetland has a fluctuating water table with dynamics that can be reproduced using precipitation data and a simple model. Median net methane flux was 117 mg m-2 day-1 and is consistent with measurements at other tropical sites. Net methane flux in the Commelina diffusa—dominated vegetation pattern (honohono) was significantly …

Batrachochytrium Dendrobatidis Detected In Amphibians From National Forests In Eastern Texas, Usa, Daniel Saenz, Brendan T. Kavanagh, Matthew Kwiatkowski

Faculty Publications

The amphibian disease chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd, Longcore et al. 1999), is well known as a major threat to amphibians resulting in mass die-offs and population declines throughout the world (Berger et al. 1998; Blaustein and Keisecker 2002; Daszak et al. 2003; McCallum 2005; Rachowicz et al. 2006). Batrachochytrium dendrobatidis has been detected on amphibians from sites across North America (Ouellet et al. 2005; Woodhams et al. 2008) and appears to be most prevalent in the western and the northeastern United States (Longcore et al. 2007; Schlaepfer et al. 2007). Whereas infected anurans also have …

Development And Characterization Of 16 Microsatellite Markers For The Louisiana Pine Snake, Pituophis Ruthveni, And Two Congeners Of Conservation Concern, Matthew Kwiatkowski, Christopher M. Somers, Ray G. Poulin, D. Craig Rudolph, Jessica Martino, Tracey D. Tuberville, Cris Hagen, Stacey L. Lance

Faculty Publications

We isolated and characterized 16 microsatellite loci from the Louisiana pine snake, Pituophis ruthveni. Loci were screened in 24 individuals from locations throughout its distribution in Louisiana and Texas. The number of alleles per locus ranged from 4 to 12, observed heterozygosity ranged from 0.200 to 0.875, and the probability of identity ranged from 0.043 to 0.298. We examined cross-species amplification at these loci in P. catenifer (bullsnakes and gopher snakes) and P. melanoleucus (pine snakes). These new markers provide tools for examining the conservation genetics of this species complex. Louisiana pine snakes face numerous threats: population densities are extremely …

Occurrence Of Anisophylly And Anisoclady Within The Amaranthaceae [Abstract], Donald B. Pratt, Lynn G. Clark

Faculty Publications

No abstract provided.

Substrate And Cover Object Choice By The Red-Backed Salamander (Plethodon Cinereus), J. P. Iverson, Geoffrey R. Smith

Faculty Publications

No abstract provided.

Evolution Of An Mhc Class La Gene Fragment In Four North American Morone Species, J. X. Liu, Bert Ely

Faculty Publications

A nucleotide sequence analysis of a fragment of a Morone MHC class Ia gene detected high levels of polymorphism in striped bass Morone saxatilis, white perch Morone americana and yellow bass Morone mississippiensis. Extremely low levels of MHC diversity, however, were detected in white bass Morone chrysops, suggesting the possibility of a severe population bottleneck for this species.

Distribution Of Tadpoles Of Ollotis Occidentalis (Amphibia: Anura: Bufonidae) Along The Rio Salado, Puebla, Mexico, G. A. Woolrich-Pina, Geoffrey R. Smith, L. Oliver-Lopez, M. Barbosa Morales, J. A. Lemos-Espinal

Faculty Publications

No abstract provided.

Evaluation Of The Rate Of Artificial Coverboard Use By The Salamander, Plethodon Cinereus, In The Vicinity Of Natural Cover Objects, K. Ciul, L. Simpson, Geoffrey R. Smith, Jessica E. Rettig

Faculty Publications

No abstract provided.

Environmental Dna Sequencing Primers For Eutardigrades And Bdelloid Rotifers, Byron J. Adams, Jeremy Whiting, Elizabeth K. Costello, Kristen R. Freeman, Andrew P. Martin, Michael S. Robeson, Steve K. Schmidt

Faculty Publications

Background: The time it takes to isolate individuals from environmental samples and then extract DNA from each individual is one of the problems with generating molecular data from meiofauna such as eutardigrades and bdelloid rotifers. The lack of consistent morphological information and the extreme abundance of these classes makes morphological identification of rare, or even common cryptic taxa a large and unwieldy task. This limits the ability to perform large-scale surveys of the diversity of these organisms. Here we demonstrate a culture-independent molecular survey approach that enables the generation of large amounts of eutardigrade and bdelloid rotifer sequence data directly …

An Intertidal Sea Star Adjusts Thermal Inertia To Avoid Extreme Body Temperatures, Sylvain Pincebourde, Eric Sanford, Brian Helmuth

Faculty Publications

The body temperature of ectotherms is influenced by the interaction of abiotic conditions, morphology, and behavior. Although organisms living in different thermal habitats may exhibit morphological plasticity or move from unfavorable locations, there are few examples of animals adjusting their thermal properties in response to short-term changes in local conditions. Here, we show that the intertidal sea star Pisaster ochraceus modulates its thermal inertia in response to prior thermal exposure. After exposure to high body temperature at low tide, sea stars increase the amount of colder than-air fluid in their coelomic cavity when submerged during high tide, resulting in a …

Complex Evolution Of A Highly-Conserved Microsatellite Locus In Several Fish Species, J.-X. Liu, Bert Ely

Faculty Publications

The evolutionary dynamics of a highly conserved microsatellite locus (Dla 11) were studied in several fish species. The data indicated that multiple types of compound microsatellites arose through point mutations that were sometimes followed by expansion of the derived motif. Furthermore, extensive length variation was detected among species in the regions immediately flanking the repeat region.

Sibship Reconstruction Demonstrates The Extremely Low Effective Population Size Of Striped Bass Morone Saxatilis In The Santee-Cooper System, South Carolina, Usa, Jin-Xian Liu, Bert Ely

Faculty Publications

For organisms with great fecundity and high mortality in early life stages, such as shellfish or fishes, the need to match reproductive activity with environmental conditions conducive to spawning, fertilization, larval development and recruitment may result in extreme variance in reproductive success among individuals. The main objective of this study was to investigate evidence of large variance in the reproductive success of the striped bass Morone saxatilis in the Santee-Cooper system, South Carolina, USA. Seven microsatellite loci were analysed in 603 recruits representing three yearly cohorts from 1992 to 1994, and a group analysis was performed to identify full-sib families. …

Differential Mortality Drives Life-History Evolution And Population Dynamics In The Fish Brachyrhaphis Rhabdophora, Jerald B. Johnson, J. Jaime Zuniga-Vega

Faculty Publications

Life-history theory predicts that populations experiencing different levels of extrinsic mortality will evolve divergent reproductive strategies. Previous work in the live bearing fish Brachyrhaphis rhabdophora shows that individuals from populations that occur with piscivorous fish mature earlier and at smaller sizes and have more and smaller offspring than fish from populations without predators. However, until now, there have been no data to demonstrate that differences in mortality rates actually exist between predator and predator free sites. Here we present the results of a serial mark-recapture field study designed to estimate mortality rates in natural populations of B. rhabodophora from Costa …

Aintegumenta And Aintegumenta-Like6 Act Redundantly To Regulate Arabidopsis Floral Growth And Patterning, Beth A. Krizek

Faculty Publications

An Arabidopsis (Arabidopsis thaliana) flower consists of four types of organs arranged in a stereotypical pattern. This complex floral structure is elaborated from a small number of floral meristem cells partitioned from the shoot apical meristem during reproductive development. The positioning of floral primordia within the periphery of the shoot apical meristem depends on transport of the phytohormone auxin with floral anlagen arising at sites of auxin maxima. An early marker of lateral organ fate is the AP2/ERF-type transcription factor AINTEGUMENTA (ANT), which has been proposed to act downstream of auxin in organogenic growth. Here, I show that …

My Two Boots ... A Walk Through The Wetlands. An Annual Outing For 700 Middle School Students, Julie Cwikla, Mark Lasalle, Sybil Wilner

Faculty Publications

No abstract provided.

Transcriptomic Analysis Of The Entomopathogenic Nematode Heterorhabditis Bacteriophora Tto1, Byron J. Adams, Xiaodong Bai, Todd A. Ciche, Sandra Clifton, Randy Gaugler, Parwinder S. Grewal, Saskia A. Hogenhout, John Spieth, Paul W. Sternberg, Richard K. Wilson

Faculty Publications

Background: The entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium, Photorhabdus luminescens, are important biological control agents of insect pests. This nematode-bacterium-insect association represents an emerging tripartite model for research on mutualistic and parasitic symbioses. Elucidation of mechanisms underlying these biological processes may serve as a foundation for improving the biological control potential of the nematode-bacterium complex. This large-scale expressed sequence tag (EST) analysis effort enables gene discovery and development of microsatellite markers. These ESTs will also aid in the annotation of the upcoming complete genome sequence of H. bacteriophora. Results: A total of 31,485 high quality ESTs were generated …

Faculty Should Consider Peer Review As A Means Of Improving Students' Scientific Reasoning Skill, Briana Eileen Timmerman, Denise Strickland

Faculty Publications

The following article provides highlights of a larger body of work on the impact of peer review on undergraduate biology students’ scientific reasoning, scientific writing and attitudes. Results suggest that undergraduates, even freshman can be effective peer reviewers and that peer review improves scientific writing, content knowledge, and scientific reasoning skills. Students report peer review to be a beneficial experience both within the course and in terms of helping them to develop as aspiring scientists. Science faculty are therefore encouraged to consider incorporating peer review as a regular part of instruction.

From Cells To Coastlines: How Can We Use Physiology To Forecast The Impacts Of Climate Change?, Brian Helmuth

Faculty Publications

The interdisciplinary fields of conservation physiology, macrophysiology, and mechanistic ecological forecasting have recently emerged as means of integrating detailed physiological responses to the broader questions of ecological and evolutionary responses to global climate change. Bridging the gap between large-scale records of weather and climate (as measured by remote sensing platforms, buoys and ground-based weather stations) and the physical world as experienced by organisms (niche-level measurements) requires a mechanistic understanding of how ‘environmental signals’ (parameters such as air, surface and water temperature, food availability, water flow) are translated into signals at the scale of the organism or cell (e.g. body temperature, …

Desiccation Survival In An Antarctic Nematode: Molecular Analysis Using Expressed Sequenced Tags, Byron J. Adams, Bishwo N. Adhikari, Diana H. Wall

Faculty Publications

Background: Nematodes are the dominant soil animals in Antarctic Dry Valleys and are capable of surviving desiccation and freezing in an anhydrobiotic state. Genes induced by desiccation stress have been successfully enumerated in nematodes; however we have little knowledge of gene regulation by Antarctic nematodes which can survive multiple environmental stresses. To address this problem we investigated the genetic responses of a nematode species, Plectus murrayi, that is capable of tolerating Antarctic environmental extremes, in particular desiccation and freezing. In this study, we provide the first insight into the desiccation induced transcriptome of an Antarctic nematode through cDNA library construction …

Effects Of Light And Group Size On The Activity Of Wood Frog Tadpoles (Rana Sylvatica) And Their Response To A Shadow Stimulus, K. V. Mcclure, J. W. Mora, Geoffrey R. Smith

Faculty Publications

No abstract provided.

A Primitive Aphidiine Wasp In Albian Amber From Spain And A Northern Hemisphere Origin For The Subfamily (Hymenoptera: Braconidae: Aphidiinae), Jaime Ortega-Blanco, Daniel J. Bennett, Xavier Delclòs, Michael S. Engel

Faculty Publications

A description of a new genus and species of braconid, Archephedrus stolamissus, from Early Cretaceous (Albian) amber from Moraza-Peñacerrada I (Spain) is here provided. This is the first fossil Aphidiinae described in Cretaceous amber. The fossil has some typical characters of the subfamily but possesses a unique assemblage of characters among aphidiines, such as a fairly robust abdomen, with a more pronounced articulation between the first and second, instead of the second and third, metasomal segments, as well as several wing venational traits. The distribution of this and other aphidiine fossils, as well as their putative phylogenetic placement as …

A Remarkable Tiphiiform Wasp In Mid-Cretaceous Amber From Myanmar (Hymenoptera: Tiphiidae), Michael S. Engel, Jaime Ortega-Blanco, Daniel J. Bennett

Faculty Publications

The first tiphiid wasp (Aculeata: Euaculeata: Vespoidea: Tiphiiformes) in Cretaceous amber is described and figured. Thanatotiphia nyx, new genus and species, is represented by a male entombed in mid-Cretaceous (latest Albian) amber from Myanmar. Thanatotiphia possesses remarkable apomorphies in wing venation, lacks key traits of modern subfamilies, and is thus classified in a new subfamily, Thanatotiphiinae. The fossil is further shown to be nested well within the family, indicating that major lineages of Tiphiidae diverged by the mid-Cretaceous. The new taxon is compared with modern tiphiid subfamilies and the sparse fossil history of the family briefly overviewed.

Demographics Of A Geographically-Isolated Population Of Threatened Salamander (Caudata: Ambystomatidae) In Central Illinois, Stephen J. Mullin, Sarabeth Klueh

Faculty Publications

Amphibian populations that use small isolated wetlands are often small in size, susceptible to stochastic extinction processes, and have little to no contact with other populations. One can ascertain the persistence of such populations only by obtaining data that allow the prediction of future changes in population’s size, and propensity to achieve a sustainable number of individuals. The number of metamorphosing larvae leaving a pond predicts the viability of a salamander population, and thus, the number recruited into the terrestrial adult population. The Jefferson Salamander, Ambystoma jeffersonianum, is a listed threatened species in Illinois, occurring at fewer than 15 ponds …