Biology Commons^™

Callose (Β-1,3 Glucan) Is Essential For Arabidopsis Pollen Wall Patterning, But Not Tube Growth, Rob Swanson

Biology Faculty Publications

Background: Callose (β-1,3 glucan) separates developing pollen grains, preventing their underlying walls (exine) from fusing. The pollen tubes that transport sperm to female gametes also contain callose, both in their walls as well as in the plugs that segment growing tubes. Mutations in CalS5, one of several Arabidopsis β-1,3 glucan synthases, were previously shown to disrupt callose formation around developing microspores, causing aberrations in exine patterning, degeneration of developing microspores, and pollen sterility. Results: Here, we describe three additional cals5 alleles that similarly alter exine patterns, but instead produce fertile pollen. Moreover, one of these alleles (cals5-3) resulted in the …

Redescripción De La Morfología Larval Externa De Dos Especies Del Grupo De Leptodactylus Fuscus (Anura, Leptodactylidae), José A. Langone, Rafael O. De Sá

Biology Faculty Publications

Re-description of the larval external morphology of two species of the Leptodactylus fuscus group (Anura, Leptodactylidae). The larvae of Leptodactylus gracilis (D’Orbigny y Bibron, 1840) and L. mystacinus Bumeister, 1861 are re-described and compared with previous descriptions noting intraspecific variation in oral disc characteristics (arrangement of papillae and rows of cornified teeth). The external morphological analysis of larvae of the Leptodactylus fuscus group suggest that the lack of comparable descriptions among species, as well as the lack of analyses of their intraspecific variation, limits the use of larval characteristics for diagnostic purposes.

A Phylogenetic Analysis Of Vanzolinius Heyer, 1974 (Amphibia, Anura, Leptodactylidae): Taxonomic And Life History Implications, Rafael O. De Sá, W. Ronald Heyer, Arley Camargo

Biology Faculty Publications

The validity of the monotypic leptodactylid frog genus Vanzolinius Heyer, 1974 has been questioned recently. We explore the relationship of Vanzolinius discodactylus within the cluster of closely related genera Adenomera, Leptodacylus, and Lithodytes with both morphological and molecular data sets. Morphological and combined morphological and molecular data were analyzed using maximum parsimony; molecular data sets were analyzed with maximum likelihood methods. The resultant relationships are unambiguous in Vanzolinius being imbedded within Leptodactylus. In order to maintain Leptodactylus as a monophyletic genus, Vanzolinius is placed in the synonymy of Leptodactylus Fitzinger, 1826. The implications of relationships analyzed in …

Atypical Pkciota Contributes To Poor Prognosis Through Loss Of Apical-Basal Polarity And Cyclin E Overexpression In Ovarian Cancer, Astrid M. Eder, Xiaomei Sui, Daniel G. Rosen, Laura K. Nolden, Kwai Wa Cheng, John P. Lahad, Madhuri Kango-Singh, Karen H. Lu, Carla L. Warneke, Edward N. Atkinson, Isabelle Bedrosian, Khandan Keyomarsi, Wen-Lin Kuo, Joe W. Gray, Jerry C. P. Yin, Jinsong Liu, Georg Halder, Gordon B. Mills

Biology Faculty Publications

We show that atypical PKCι, which plays a critical role in the establishment and maintenance of epithelial cell polarity, is genomically amplified and overexpressed in serous epithelial ovarian cancers. Furthermore, PKCι protein is markedly increased or mislocalized in all serous ovarian cancers. An increased PKCι DNA copy number is associated with decreased progression-free survival in serous epithelial ovarian cancers. In a Drosophila in vivo epithelial tissue model, overexpression of persistently active atypical PKC results in defects in apical-basal polarity, increased Cyclin E protein expression, and increased proliferation. Similar to the Drosophila model, increased PKCι proteins levels are associated with …

"Sibling Species, Advertisement Calls, And Reproductive Isolation In Frogs Of The Leptodactylus Pentadactylus Species Cluster (Amphibia, Leptodactylidae), W. Ronald Heyer, Rafael O. De Sá, A. Rettig

Biology Faculty Publications

A recent re-evaluation of morphological and advertisement call variation in the large species of frogs of the Leptodactylus pentadactylus cluster discovered more examples of sibling species as defined by Ernst Mayr in his influential book Animal Species and Evolution. All previously documented instances of sibling species in frogs demonstrated advertisement call differentiation consistent with the calls serving as pre-mating isolating mechanisms. However, we find one instance of two species with nondistinguishable adult morphologies as well as nondistinguishable advertisement calls. Presumably, the new instances of sibling species reflect retention of ancestral adult morphologies and advertisement calls. Larval and habitat differentiation appear …

Group 13 Hox Proteins Interact With The Mh2 Domain Of R-Smads And Modulate Smad Transcriptional Activation Functions Independent Of Hox Dna Binding Capability, Thomas M. Williams, Melissa E. Williams, Joanne H. Heaton, Thomas D. Gelehrter, Jeffrey W. Innis

Biology Faculty Publications

Interactions with co-factors provide a means by which HOX proteins exert specificity. To identify candidate protein interactors of HOXA13, we created and screened an E11.5–E12.5, distal limb bud yeast two-hybrid prey library. Among the interactors, we isolated the BMP-signaling effector Smad5, which interacted with the paralogous HOXD13 but not with HOXA11 or HOXA9, revealing unique interaction capabilities of the AbdB-like HOX proteins. Using deletion mutants, we determined that the MH2 domain of Smad5 is necessary for HOXA13 interaction.

This is the first report demonstrating an interaction between HOX proteins and the MH2 domain of Smad proteins. HOXA13 and HOXD13 …

First Confirmed Breeding Of The Rock Wren In Minnesota, Philip C. Chu

Biology Faculty Publications

No abstract provided.

The Biology Of Canadian Weeds. 131. Polygonum Aviculare L., Mihai Costea, François J. Tardif

Biology Faculty Publications

A review and assessment of biological information as well as personal data are provided for Polygonum aviculare in Canada. The species has been revised taxonomically and the six subspecies that occur in Canada are presented. Three of the subspecies, P. aviculare subsp. aviculare, P. aviculare subsp. neglectum and P. aviculare subsp. depressum are weeds introduced to Canada from Europe. A fourth subspecies, P. aviculare subsp. buxiforme is apparently native to North America. The geographical distribution of the latter four subspecies is very wide. Plants exhibit a high phenotypic plasticity and genetic variability, and they easily adapt to a multitude …

Investigations Of Migratory Bull Trout (Salvelinus Confluentus) In Relation To Fish Passage At Albeni Falls Dam, Allan T. Scholz, Holly J. Mclellan, David R. Geist, Richard S. Brown, United States Department Of The Army Corps Of Engineers, Seattle District, Eastern Washington University

Biology Faculty Publications

Final report prepared for the United States Department of the Army Corps of Engineers, Seattle District. Contract No. DACW68-02-D-001

Two Purified Domains Of Telomerase Reverse Transcriptase Reconstitute Sequence-Specific Interactions With Rna, C. M. O'Connor, Cary K. Lai, Kathleen Collins

Biology Faculty Publications

Telomerase reverse transcriptase (TERT) and telomerase RNA (TER) function together to create a uniquely specialized polymerase. Here we have described for the first time domains of bacterially expressed Tetrahymena TERT that interacted directly with TER in the absence of assembly chaperones. We used quantitative binding assays to define TER sequence requirements for recognition by the high affinity RNA binding domain and an independent N-terminal RNA interaction domain. The TERT RNA binding domain and N-terminal RNA interaction domain had distinct, nonoverlapping requirements for TER sequence and structure that together accounted for all of the sites of TER contact inferred for full-length …

Intra-Guild Compensation Regulatesspecies Richness In Desert Rodents, J. Goheen, Ethan P. White, S.K. Morgan Ernest, J. H. Brown

Biology Faculty Publications

Evidence from numerous studies suggests that species richness is an emergent property of local communities. The maintenance of species richness, despite changes in species composition and environmental conditions, requires compensatory colonization and extinction events with species coming from a regional pool. Using long-term data from a rodent community in the Chihuahuan Desert, we use randomization methods to test the null hypothesis that changes in species richness occur randomly. We find that the dynamics of species richness differ significantly from a random process, and that these nonrandom dynamics occur largely within the most speciose guild. Finally, we propose a general framework …

Evidence For A General Species Time Arearelationship, P. B. Adler, Ethan P. White, W. K. Lauenroth, D. M. Kaufman, A. Rassweiler, J. A. Rusak

Biology Faculty Publications

The species-area relationship (SAR) plays a central role in biodiversity research, and recent work has increased awareness of its temporal analog, the species-time relationship (STR). Here we provide evidence for a general species-time-area-relationship (STAR), in which species number is a function of the area and time span of sampling, as well as their interaction. For eight assemblages ranging from lake zooplankton to desert rodents, this model outperformed a sampling-based model and two simpler models in which area and time had independent effects. In every case the interaction term was negative, meaning that rates of species accumulation in space decreased with …

The Flood Pulse In A Semi-Arid Riparian Forest:Metabolic And Biogeochemical Responses To Inter-Flood Interval, H. M. Valett, Michelle A. Baker, J. A. Morrice, C. S. Crawford, M. C. Molles, C. N. Dahm, D. L. Moyer, J. R. Thibault

Biology Faculty Publications

Flood pulse inundation of riparian forests alters rates of nutrient retention and organic matter processing in the aquatic ecosystems formed in the forest interior. Along the Middle Rio Grande (New Mexico, USA), impoundment and levee construction have created riparian forests that differ in their inter-flood intervals (IFIs) because some floodplains are still regularly inundated by the flood pulse (i.e., connected), while other floodplains remain isolated from flooding (i.e., disconnected). This research investigates how ecosystem responses to the flood pulse relate to forest IFI by quantifying nutrient and organic matter dynamics in the Rio Grande floodplain during three years of experimental …

North American Watersnakes: A Natural History, Alan H. Savitzky

Biology Faculty Publications

No abstract provided.

Body Size, Energy Use, And Community Structure Of Small Mammals, S.K. Morgan Ernest

Biology Faculty Publications

Body size has long been hypothesized to play a major role in community structure and dynamics. Two general hypotheses exist for how resources are distributed among body sizes: (1) resources are equally available and uniformly utilized across body sizes and (2) resources are differentially available to organisms of different body sizes, resulting in a nonuniform or modal distribution. It has also been predicted that the distri-bution of body sizes of species in a community should reflect the underlying availability of resources, with the emergence of aggregations of species around specific body sizes. I examined the relationship between energy utilization, body …

2005 Virginia Wildflower Of The Year: Bloodroot, Sanguinaria Canadensis, W. John Hayden

Biology Faculty Publications

Bloodroot is an herbaceous perennial that grows from a persistent, branched underground stem or rhizome. Early each spring, while the forest canopy is still bare, each well-developed rhizome tip produces one leaf and one flower stalk. The leaf is kidney-shaped in its overall outline, but it is also divided into a pattern of rounded lobes and sinuses, rendering a complex overall shape. At flowering time, bloodroot leaves form a loose vertically-oriented collar around the flower stalk with the bluish-green lower leaf surface forming the outside of the collar; as the season progresses, the leaves open flat and expand to their …

Common Names For The Frog Genus Leptodactylus (Amphibia, Anura, Leptodactylidae), Ulisses Caramaschi, Rafael O. De Sá, W. Ronald Heyer

Biology Faculty Publications

Most species of the frog genus Leptodactylus lack common names. Common names are those names used by different human cultures and societies for the species of animals and plants where humans and biota reside together. Often times common names are lacking for Neotropical frogs or are broad in scope. For example, indigenous people may have a single name for frogs that occur on the ground and another name for frogs that occur in shrubs and trees, even though there are many species of ground frogs called by the same name as well as for the tree frogs. Sometimes colonists have …

Are Leptodactylus Didymus And L. Mystaceus Phylogenetically Sibling Species (Amphibia, Anura, Leptodactylidae)?, Rafael O. De Sá, W. R. Heyer, Arley Camargo

Biology Faculty Publications

The Leptodactylus fuscus species group consists of 25 currently recognized species; within this species group and distributed throughout the Amazon Basin, Atlantic Forests, Gran Chaco, and cerrados is the L. mystaceus species complex. This species complex consists of L. didymus, L. elenae, L. mystaceus, L. notoaktites, and L. spixi. Adult morphologies have been used to distinguish these species from each other except for L. didymus and L. mystaceus (Heyer, 1978; Heyer et al., 1996). Leptodactylus didymus and L. mystaceus are morphologically indistinguishable; the species are recognizable only by the characteristics of their advertisement calls: non-pulsed in L. didymus and pulsed …

Plant Composition Of Mixed-Grass Prairie Of Cedar Point Biological Research Station, Keith County, Nebraska, David A. Mckenzie

Biology Faculty Publications

This study involved a vegetation analysis of 15 permanent plots established on the short-grass and mixed grass prairie slopes at the Cedar Point Biological Station in Keith County, Nebraska. Ninety-nine species were found in the plots, including members of 75 genera and 31 families. Twenty-one were graminoids, 71 were forbs or succulents, 6 were shrubs and one was a tree. Bouteloua gracilis (19 % cover) and Carex filifolia (15 % cover) were the dominant graminoids at the site, while Yucca glauca (1% cover) and Artemisia frigida (1% cover) were the most frequent forbs. Comparisons of species richness by slope categories …

Controls On Nitrogen Cycling In Terrestrial Ecosystems: A Synthetic Analysis Of Literature Data, M. S. Booth, E. Rastetter, John M. Stark

Biology Faculty Publications

Isotope pool dilution studies are increasingly reported in the soils and ecology literature as a means of measuring gross rates of nitrogen (N) mineralization, nitrification, and inorganic N assimilation in soils. We assembled data on soil characteristics and gross rates from 100 studies conducted in forest, shrubland, grassland, and agricultural systems to answer the following questions: What factors appear to be the major drivers for production and consumption of inorganic N as measured by isotope dilution studies? Do rates or the relationships between drivers and rates differ among ecosystem types? Across a wide range of ecosystems, gross N mineralization is …

Common Names For The Frog Genus Leptodactylus (Amphibia, Anura, Leptodactylidae), Ulisses Caramaschi, Rafael O. De Sá, W. Ronald Heyer

Biology Faculty Publications

Most species of the frog genus Leptodactylus lack common names. Common names are those names used by different human cultures and societies for the species of animals and plants where humans and biota reside together. Often times common names are lacking for Neotropical frogs or are broad in scope. For example, indigenous people may have a single name for frogs that occur on the ground and another name for frogs that occur in shrubs and trees, even though there are many species of ground frogs called by the same name as well as for the tree frogs. Sometimes colonists have …

Invertebrate Diversity In Taylor Valley Soils And Sediments, Amy M. Treonis, Diana H. Wall, Ross A. Virginia

Biology Faculty Publications

Explaining how ecosystems function across variable landscapes will require knowledge of biodiversity patterns. In particular, biodiversity studies of soils and sediments will help in understanding the linkages between ecosystem processes in both of these habitats (Freckman et al. 1997). Soils and sediments are domains for ecosystem processes such as decomposition and trace gas exchange. There are few studies, however, that have compared abundance and diversity of organisms in adjacent soils and sediments (Freckman et al. 1997). The goal of this study was to increase understanding of how the biotic communities involved in ecosystem processes are organized within an important feature …

Are Leptodactylus Didymus And L. Mystaceus Phylogenetically Sibling Species (Amphibia, Anura, Leptodactylidae)?, Rafael O. De Sá, W. R. Heyer, A. Camargo

Biology Faculty Publications

The Leptodactylus fuscus species group consists of 25 currently recognized species; within this species group and distributed throughout the Amazon Basin, Atlantic Forests, Gran Chaco, and cerrados is the L. mystaceus species complex. This species complex consists of L. didymus, L. elenae, L. mystaceus, L. notoaktites, and L. spixi. Adult morphologies have been used to distinguish these species from each other except for L. didymus and L. mystaceus (Heyer, 1978; Heyer et al., 1996). Leptodactylus didymus and L. mystaceus are morphologically indistinguishable; the species are recognizable only by the characteristics of their advertisement calls: non-pulsed in L. didymus and pulsed …

On The Enigmatic Distribution Of The Honduran Endemic Leptodactylus Silvanimbus (Amphibia: Anura: Lep Todactylidae), W. Ronald Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Most species of the frog genus Leptodactylus occur in South America, and all authors who have treated the zoogeography of the genus have concluded that it originated somewhere in South America (e.g., Savage 1982). Savage (1982,518) summarized the historical herpetofaunal units of the Neotropics as follows: "All evidence points to an ancient contiguity and essential similarity of a generalized tropical herpetofauna that ranged over tropical North, Middle, and most of South America in Cretaceous-Paleocene times. Descendents of this fauna are represented today by the South and Middle American tracks (Elements). To the north of this fauna ranged a subtropical-temperate Laurasian …

The Challenge Of Environmental Protection, Jennifer Mattei

Biology Faculty Publications

Connecticut is in the midst of a demographic transition to a period of lower population growth. These demographic changes will help check the pressures exerted on the state's natural resources by population growth. Water, air, soil, energy sources, food, fisheries, forests, and biodiversity are common pool resources upon which we depend in ways that transcend political boundaries. Those governing Connecticut should help turn the state into a model of how to manage natural resources by halting forest fragmentation, reducing pollution, and promoting environmental science education.

Phylogenetic Relationships Of African Microhylid Frogs Inferred From Dna Sequences Of Mitochondrial 12s And 16s Rrna Genes, Simon P. Loader, David J. Gower, Kim M. Howell, Nike Doggart, Mark-Oliver Rödel, Barry T. Clarke, Rafael O. De Sá, Bernard L. Cohen, Mark Wilkinson

Biology Faculty Publications

The phylogenetic relationships of microhylid frogs are poorly understood. The first molecular phylogeny for continental African microhylids is presented, including representatives of all subfamilies, six of the eight genera, and the enigmatic hemisotid Hemisus. Mitochondrial 12S and 16S rRNA sequence data were analysed using parsimony, likelihood and Bayesian methods. Analyses of the data are consistent with the monophyly of all sampled subfamilies and genera. Hemisus does not nest within either brevicipitines or non-brevicipitines. It is possibly the sister group to brevicipitines, in which case brevicipitines might not be microhylids. Phrynomantis and Hoplophryne potentially group with non-African, non-brevicipitine microhylids, in …

Monitoring Heart Rate In Drosophila Larvae By Various Approaches, Sameera Dasari, Robin L. Cooper

Biology Faculty Publications

No abstract provided.

Monitoring Carbon Dioxide Production By Drosophila Larvae, Robin L. Cooper, D. Nicholas Mcletchie

Biology Faculty Publications

No abstract provided.

Monitoring Activity Of Drosophila Larvae: Impedance & Video Microscopy Measures, Ann Simone Cooper, Robin L. Cooper

Biology Faculty Publications

No abstract provided.

Planting Date Effects On The Germinability And Seedling Vigor Of Abutilon Theophrasti Seeds, R E. Nurse, A Ditommaso, Ricardo A. Ramirez

Biology Faculty Publications

Abutilon theophrasti (Malvaceae) is a troublesome annual weed in many maize and soybean cropping systems of Canada and the United States. Seeds of A. theophrasti exhibit physical dormancy. Differences in the growing environment of parent plants may influence the germinability of seeds and vigour of seedlings produced by this species because of variation in resource allocation to seed development. Thus, the germinability of seeds and subsequent seedling vigour were examined for A. theophrasti plants grown in monoculture at a density of 4.2 plants m -2 under varying natural photoperiods in central New York State. Treatments were established by transplanting A. …