Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 75

Full-Text Articles in Life Sciences

The First Hypogean Dipluran From Portugal: Description Of A New Species Of The Genus Litocampa (Diplura: Campodeidae), Ana Reboleira, Alberto Sendra, Fernando Gonçalves, Pedro Oromí Nov 2010

The First Hypogean Dipluran From Portugal: Description Of A New Species Of The Genus Litocampa (Diplura: Campodeidae), Ana Reboleira, Alberto Sendra, Fernando Gonçalves, Pedro Oromí

Ana Sofia P.S. Reboleira

A new species of subterranean Campodeid Dipluran of the genus Litocampa mendesi n. sp. is described. Despite the presence of this genus in Spain, this is the first record in Portugal, and it is also the first Portuguese species of hypogean Diplura. The new species combines unique characters absent in the European and American species of the genus. Litocampa mendesi n. sp. was collected only in one part of a cave of the Jurassic karstic massif of Algarve, the southwesternmost part of the Iberian Peninsula. The morphological features of this species show some adaptations to hypogean life but not a …


Science As A Human Right: Esa And The Aaas Science And Human Rights Coalition, Clifford S. Duke, George Middendorf, Jessica Wyndham Nov 2010

Science As A Human Right: Esa And The Aaas Science And Human Rights Coalition, Clifford S. Duke, George Middendorf, Jessica Wyndham

George Middendorf

No abstract provided.


Molecular Cloning And Characterization Of The Porcine Fto Promoter And Coding Regions.Pdf, Jinming Huang, Yunzhou Yang, Gang Liu, Jibin Zhang, Xinxing Dong, Ying Bai, Meiying Fang Nov 2010

Molecular Cloning And Characterization Of The Porcine Fto Promoter And Coding Regions.Pdf, Jinming Huang, Yunzhou Yang, Gang Liu, Jibin Zhang, Xinxing Dong, Ying Bai, Meiying Fang

Jibin Zhang

The fat mass and obesity associated gene (FTO) has been widely reported to be associated with fat mass or fat deposition in different species. In the present study, we cloned both promoter and codingregions of the gene in pigs with over 5 Kb of sequence for the former region and 1,596 bp for the latter region. Comparative analysis of the promoter region among 20 species including pig revealed four conserved regions that harbor transcriptional factors involved in adipose differentiation. Using a pooled DNA sequencing approach, we discovered 39 single nucleotide polymorphisms (SNPs) in the pig FTO gene and four of them were …


A Hypogean New Species Of Trechus Clairville, 1806 (Coleoptera, Carabidae) From Portugal And Considerations About The T. Fulvus Species Group, Ana Reboleira, Vicente Ortuño, Fernando Gonçalves, Pedro Oromí Oct 2010

A Hypogean New Species Of Trechus Clairville, 1806 (Coleoptera, Carabidae) From Portugal And Considerations About The T. Fulvus Species Group, Ana Reboleira, Vicente Ortuño, Fernando Gonçalves, Pedro Oromí

Ana Sofia P.S. Reboleira

A new hypogean ground beetle species, Trechus tatai n. sp. from the Montejunto karstic massif in Portugal is described. Morphological diagnostic characters of the imago are provided and the new species is included in the Trechus fulvus-group. Comments on the biogeography of hypogean carabid beetles in karstic areas of Portugal and an illustrated key to the males of the T. fulvus-group in the Iberian Peninsula are also included.


Invasive Honeysuckle Eradication Reduces Tick-Borne Disease Risk By Altering Host Dynamics, Brian F. Allan, Humberto P. Dutra, Lisa S. Goessling, Kirk Barnett, Jonathan M. Chase, Robert J. Marquis, Genevieve Pang, Gregory A. Storch, Robert E. Thach, John L. Orrock Oct 2010

Invasive Honeysuckle Eradication Reduces Tick-Borne Disease Risk By Altering Host Dynamics, Brian F. Allan, Humberto P. Dutra, Lisa S. Goessling, Kirk Barnett, Jonathan M. Chase, Robert J. Marquis, Genevieve Pang, Gregory A. Storch, Robert E. Thach, John L. Orrock

Robert Marquis

Despite the ubiquity of invasive organisms and their often deleterious effects on native flora and fauna, the consequences of biological invasions for human health and the ecological mechanisms through which they occur are rarely considered. Here we demonstrate that a widespread invasive shrub in North America, Amur honeysuckle (Lonicera maackii), increases human risk of exposure to ehrlichiosis, an emerging infectious disease caused by bacterial pathogens transmitted by the lone star tick (Amblyomma americanum). Using large-scale observational surveys in natural areas across the St. Louis, Missouri region, we found that white-tailed deer (Odocoileus virginianus), a preeminent tick host and pathogen reservoir, …


Genomic Variation And Adaptation In Africa: Implications For Human Evolutionary History And Disease, Michael C. Campbell Oct 2010

Genomic Variation And Adaptation In Africa: Implications For Human Evolutionary History And Disease, Michael C. Campbell

Michael C. Campbell

Africa contains the greatest levels of human genetic variation and is the source of the worldwide range expansion of all modern humans. However, relatively little is known about genomic variation in ethnically diverse African populations.


Laboratory Studies In Integrated Principles Of Zoology, Lee Kats, Cleveland Hickman, Susan Keen Oct 2010

Laboratory Studies In Integrated Principles Of Zoology, Lee Kats, Cleveland Hickman, Susan Keen

Lee Kats

The 15th Edition of Laboratory Studies in Integrated Principles of Zoology uses a comprehensive, phylogenetic approach in emphasizing basic biological principles, animal form and function, and evolutionary concepts. This introductory lab manual is ideal for a one- or two-semester course. The new edition expertly combines up-to-date coverage with the clear writing style and dissection guides that have distinguished this manual from edition to edition.


Long-Term Isolation Of A Highly Mobile Seabird On The Galapagos, Patricia Parker, Frank Hailer, E.A. Schreiber, Joshua M. Miller, Iris I. Levin, R. Terry Chesser, Robert C. Fleischer Sep 2010

Long-Term Isolation Of A Highly Mobile Seabird On The Galapagos, Patricia Parker, Frank Hailer, E.A. Schreiber, Joshua M. Miller, Iris I. Levin, R. Terry Chesser, Robert C. Fleischer

Patricia Parker

The Galapagos Islands are renowned for their high degree of endemism. Marine taxa inhabiting the archipelago might be expected to be an exception, because of their utilization of pelagic habitats—the dispersal barrier for terrestrial taxa—as foraging grounds. Magnificent frigatebirds (Fregata magnificens) have a highly vagile lifestyle and wide geographical distribution around the South and Central American coasts. Given the potentially high levels of gene flow among populations, the species provides a good test of the effectiveness of the Galapagos ecosystem in isolating populations of highly dispersive marine species. We studied patterns of genetic (mitochondrial DNA, microsatellites and nuclear introns) and …


Endothelial Cell Cortactin Phosphorylation By Src Contributes To Polymorphonuclear Leukocyte Transmigration In Vitro, L. Yang, Jennifer R. Kowalski, X. Zhan, S. M. Thomas, F. W. Luscinskas Sep 2010

Endothelial Cell Cortactin Phosphorylation By Src Contributes To Polymorphonuclear Leukocyte Transmigration In Vitro, L. Yang, Jennifer R. Kowalski, X. Zhan, S. M. Thomas, F. W. Luscinskas

Jennifer Kowalski

The underlying mechanisms that regulate leukocyte transendothelial migration through the vascular endothelium remain unclear. Cortactin is a substrate of Src tyrosine kinases and a regulator of cytoskeletal dynamics. Previous studies demonstrated a role for Src phosphorylation of cortactin in clustering of E-selectin and intercellular cell adhesion molecule-1 around adherent leukocytes. In the current study, we used an in vitro flow model to investigate the role of Src-induced cortactin phosphorylation in endothelium during polymorphonuclear leukocyte (PMN) transmigration through human umbilical vein endothelium (HUVEC) monolayers preactivated with tumor necrosis factor-{alpha}. Inhibition of Src in HUVEC using Src kinase inhibitors PP2 and SU6656 …


Cortactin Regulates Cell Migration Via Activation Of N-Wasp, Jennifer Kowalski, C. Egile, S. Gil, S. Snapper, R. Li, S. Thomas Sep 2010

Cortactin Regulates Cell Migration Via Activation Of N-Wasp, Jennifer Kowalski, C. Egile, S. Gil, S. Snapper, R. Li, S. Thomas

Jennifer Kowalski

Cortactin is an actin-associated scaffolding protein that regulates cell migration. Amplification of the human gene, EMS1, has been detected in breast, head and neck tumors, where it correlates with increased invasiveness. Cortactin can regulate actin dynamics directly via its N-terminal half, which can bind and activate the Arp2/3 complex. The C-terminal portion of cortactin, however, is thought to have limited function in its regulation of the actin polymerization machinery. In this report, we identify a role for the cortactin C-terminus in regulating cell migration and, more specifically, actin dynamics. Overexpression of either full-length cortactin or cortactin C-terminus is sufficient to …


Morphology Of Epithelial Cells Lining The Digestive Tract Of The Giant Keyhole Limpet, Megathura Crenulata (Mollusca; Vetigastropoda)., Gary Martin, Tracy Bessette, Alanna Martin, Christopher Oakes Aug 2010

Morphology Of Epithelial Cells Lining The Digestive Tract Of The Giant Keyhole Limpet, Megathura Crenulata (Mollusca; Vetigastropoda)., Gary Martin, Tracy Bessette, Alanna Martin, Christopher Oakes

Gary Martin

To understand the digestive functions in the giant keyhole limpet, it is important to know the types of cells present in each region of the gut and their roles in the secretion of digestive enzymes and absorption of nutrients. This study describes the morphology of cells lining the entire gut and identifies sites that may be secreting materials to aid digestion. Previous studies involving electron microscopy and enzyme analysis have focused on the salivary and digestive glands of several gastropods. Studies on the rest of the gut tract typically include only histological descriptions of the epithelia and although several types …


Recent Advances In The Climate Change Biology Literature: Describing The Whole Elephant, A. Townsend Peterson, Shaily Menon, Xingong Li Aug 2010

Recent Advances In The Climate Change Biology Literature: Describing The Whole Elephant, A. Townsend Peterson, Shaily Menon, Xingong Li

Shaily Menon

Climate change biology is seeing a wave of new contributions, which are reviewed herein. Contributions treat shifts in phenology and distribution, and both document past and forecast future effects. However, many of the current wave of contributions are observational and correlational, and few are experimental in nature, and too often a conceptual framework in which to contextualize the results is lacking. An additional gap is the lack of effective cross-linking among areas of research, for example, connection of sea-level rise and climate change implications for distributions of species, or evolutionary adaptation studies with distributional shift studies. Although numerous important contributions …


Potential Biases In Estimating The Rate Parameter Of Sigmoid Growth Functions, Robert Ricklefs, Suzanne H. Austin, Tara Rodden Robinson, W. Douglas Robinson Aug 2010

Potential Biases In Estimating The Rate Parameter Of Sigmoid Growth Functions, Robert Ricklefs, Suzanne H. Austin, Tara Rodden Robinson, W. Douglas Robinson

Robert Ricklefs

1. We compare biases in estimates of the rate constant of the logistic and Gompertz functions applied to avian growth using three methods of parameter estimation. The methods differ in how the asymptote is determined, and consist of either floating asymptotes estimated from the full data (floating A) or data truncated at 70% of the adult mass (70%A), or fixing the asymptote at the adult mass (fixed A).

2. First, using data for two passerine species exhibiting different growth patterns, we truncated mass measurements at different ages to explore how each method of growth rate estimation responded to simulated differences …


From Structure To Function: The Ecology Of Host-Associated Microbial Communities, Courtney Jaime Robinson, Brendan J M Bohannan, Vincent Bensan Young Jul 2010

From Structure To Function: The Ecology Of Host-Associated Microbial Communities, Courtney Jaime Robinson, Brendan J M Bohannan, Vincent Bensan Young

Courtney Robinson

In the past several years, we have witnessed an increased interest in understanding the structure and function of the indigenous microbiota that inhabits the human body. It is hoped that this will yield novel insight into the role of these complex microbial communities in human health and disease. What is less appreciated is that this recent activity owes a great deal to the pioneering efforts of microbial ecologists who have been studying communities in non-host-associated environments. Interactions between environmental microbiologists and human microbiota researchers have already contributed to advances in our understanding of the human microbiome. We review the work …


Effect Of Feathers As Nest Insulation On Incubation Behavior And Reproductive Performance Of Tree Swallows (Tachycineta Bicolor), Michael Lombardo, Ruth Bosman, Christine Faro, Stephen Houtteman, Timothy Kluisza Jul 2010

Effect Of Feathers As Nest Insulation On Incubation Behavior And Reproductive Performance Of Tree Swallows (Tachycineta Bicolor), Michael Lombardo, Ruth Bosman, Christine Faro, Stephen Houtteman, Timothy Kluisza

Michael P Lombardo

Many species of birds line their nests with feathers, presumably because of the insulative qualities of feathers and because feathers may act as a barrier between nest parasites and nestlings. In 1993, we experimentally examined the role of feathers as nest insulation on the incubation behavior, nestling growth, and reproductive performance of Tree Swallows (Tachycineta bicolor) nesting in boxes in western Michigan. There were no significant differences between the incubation rhythms of females with experimental nests (i.e. no feathers) and females with control nests (i.e. with feathers). Nestlings that were reared in control nests had significantly longer right tarsi and …


Repeated Sampling Affects Tree Swallow Semen Characteristics, Michael Lombardo, M.L. Green, P.A. Thorpe, M.R. Czarnowski, H.W. Power Jul 2010

Repeated Sampling Affects Tree Swallow Semen Characteristics, Michael Lombardo, M.L. Green, P.A. Thorpe, M.R. Czarnowski, H.W. Power

Michael P Lombardo

Male Tree Swallows (Tachycineta bicolor) face intense sperm competition because mated pairs copulate frequently, extra-pair copulations are common, and females store sperm. We examined the effects of repeated sampling on the characteristics of Tree Swallow semen by manually expressing semen from 15 males immediately after capture (T0) and then hourly for 4 h (T1-T4). The semen characteristics of individual males varied in response to repeated sampling. The total number of sperm cells we obtained from each male over the 4-h sampling period varied from 104-107. Semen samples lacking …


Communities Of Cloacal Bacteria In Tree Swallow Families, Michael Lombardo, Patrick Thorpe, R. Cichewicz, M. Henshaw, C. Millard, C. Steen, T. Zeller Jul 2010

Communities Of Cloacal Bacteria In Tree Swallow Families, Michael Lombardo, Patrick Thorpe, R. Cichewicz, M. Henshaw, C. Millard, C. Steen, T. Zeller

Michael P Lombardo

Our aim in this study was to survey the communities of bacteria found in the cloacae of adult and nestling Tree Swallows (Tachycineta bicolor), determine if there were familial patterns of prevalence, and determine if there were relationships between bacteria loads and nestling size when 12 days old and fledging success.


Left-Sided Directional Bias Of Cloacal Contacts During House Sparrow Copulations, Karen Nyland, Michael Lombardo, Patrick Thorpe Jul 2010

Left-Sided Directional Bias Of Cloacal Contacts During House Sparrow Copulations, Karen Nyland, Michael Lombardo, Patrick Thorpe

Michael P Lombardo

Most female birds have only a left ovary and associated oviduct. The entry to the oviduct is on the left side of the urodeum of the cloaca. This arrangement may favor males that mount females from the left during copulation if it results in sperm being placed closer to the opening of the oviduct. Therefore, we predicted a left-sided directional bias of cloacal contacts during House Sparrow (Passer domesticus) copulations. Cloacal contacts from the left outnumbered those from the right 74 to 25 (3:1) during 25 bouts of copulation at 11 House Sparrow nests. While this pattern suggests that a …


Homosexual Copulations By Male Tree Swallows, Michael P. Lombardo, Ruth M. Bosman, Christine A. Faro, Stephen G. Houtteman, Timothy S. Kluisza Jul 2010

Homosexual Copulations By Male Tree Swallows, Michael P. Lombardo, Ruth M. Bosman, Christine A. Faro, Stephen G. Houtteman, Timothy S. Kluisza

Michael P Lombardo

Homosexual courtship behavior in non-human animals is well known (Ford and Beach 1980) and occurs in a wide variety of taxa. However, homosexual copulations, especially between males, are less well known. In birds, males mounting other males have been observed in the colonially breeding Cattle Egret (Bubulcus ibis) (Fujioka and Yamagishi 1981) and Common Murre (Uria aalge) (Birkhead et al. 1985, Hatchwell 1988). Neither Fujioka and Yamagishi (1981) nor Birkhead et al. (1985) and Hatchwell (1988) reported whether cloacal contact occurred during their observations of male-male mountings. Here we describe homosexual copulations by male Tree Swallows …


Individual, Temporal, And Seasonal Variation In Sperm Concentration In Tree Swallows, Michael Lombardo, Armetris Forman, Matthew Czarnowski, Patrick Thorpe Jul 2010

Individual, Temporal, And Seasonal Variation In Sperm Concentration In Tree Swallows, Michael Lombardo, Armetris Forman, Matthew Czarnowski, Patrick Thorpe

Michael P Lombardo

We determined sperm concentrations in Tree Swallows (Tachycineta bicolor) by manually expressing semen samples from males during prelaying, egg-laying, incubation, and nestling periods. Sperm concentrations varied by orders of magnitude (0-109 sperm mL-1) among males. Sperm concentrations were highest during the incubation period and lowest during the prelaying period. None of the samples collected during the prelaying, egg-laying, and incubation periods were devoid of sperm. In contrast, 45% of samples collected during the nestling period lacked sperm. Sperm concentrations (1) did not vary over the course of the morning during prelaying, egg-laying, and incubation periods but significantly increased during the …


Access To Mutualistic Endosymbiotic Microbes: An Underappreciated Benefit Of Group Living, Michael Lombardo Jul 2010

Access To Mutualistic Endosymbiotic Microbes: An Underappreciated Benefit Of Group Living, Michael Lombardo

Michael P Lombardo

"The original publication is available at www.springerlink.com"

A central question in behavioral ecology has been why animals live in groups. Previous theories about the evolution of sociality focused on the potential benefits of decreased risk of predation, increased foraging or feeding efficiency, and mutual aid in defending resources and/or rearing offspring. This paper argues that access to mutualistic endosymbiotic microbes is an underappreciated benefit of group living and sets out to reinvigorate Troyer’s hypothesis that the need to obtain cellulolytic microbes from conspecifics influenced the evolution of social behavior in herbivores and to extend it to nonherbivores. This extension is …


Microbial Colonization Of The Cloacae Of Nestling Tree Swallows, Tamara Mills, Michael Lombardo, Patrick Thorpe Jul 2010

Microbial Colonization Of The Cloacae Of Nestling Tree Swallows, Tamara Mills, Michael Lombardo, Patrick Thorpe

Michael P Lombardo

Microbes have the potential to be important selective forces in many aspects of avian biology. Microbes can affect fitness as a result of either their pathogenic or beneficial effects on host health. Little is known about the chronology of microbial colonization of nestlings or the effects of microbes on fledgling condition. We set out to (1) characterize the time course of microbial colonization of the cloacae of nestling Tree Swallows (Tachycineta bicolor), (2) examine the relationship between cloacal microbes and fledgling condition, and (3) determine if nest mates had similar assemblages of cloacal microbes. We repeatedly measured nestlings and sampled …


Within-Pair Copulations: Are Female Tree Swallows Feathering Their Own Nests?, Michael Lombardo Jul 2010

Within-Pair Copulations: Are Female Tree Swallows Feathering Their Own Nests?, Michael Lombardo

Michael P Lombardo

A variety of hypotheses has been proposed to explain why socially monogamous birds copulate repeatedly with their mates when only a single copulation is necessary to fertilize an entire clutch (Birkhead and Møller 1992, Petrie 1992, Hunter et al. 1993). Petrie (1992) hypothesized that a female should copulate frequently with her mate so as to reduce her mate’s involvement in extrapair copulations. By reducing her mate’s involvement in extrapair copulations, a female may: (1) avoid the transmission of parasites and sexually transmitted diseases (Hamilton 1990); (2) may avoid sperm depletion by her mate; and (3) may monopolize her mate’s paternal …


On The Evolution Of Sexually Transmitted Diseases In Birds, Michael Lombardo Jul 2010

On The Evolution Of Sexually Transmitted Diseases In Birds, Michael Lombardo

Michael P Lombardo

"The definitive version is available at www.blackwell-synergy.com".

Sexually transmitted diseases (STDs) in animals are caused by pathogens that are transmitted during copulation. Birds have played an important role in the development of STD-centered theories of mating behavior. However, it is not known whether STDs exist in wild bird populations. While the avian cloaca with its dual functions of gamete transfer and excretion seemingly predisposes birds for the evolution of STDs, the life history patterns of most birds (i.e., seasonal breeders with relatively brief annual periods of sexual activity) suggest otherwise. The importance of STDs as selective forces that shape host …


Left-Sided Directional Bias Of Cloacal Contacts During Tree Swallow Copulations, Aaron Petersen, Michael Lombardo, Harry Power Jul 2010

Left-Sided Directional Bias Of Cloacal Contacts During Tree Swallow Copulations, Aaron Petersen, Michael Lombardo, Harry Power

Michael P Lombardo

Most female birds have only a left ovary and associated oviduct with entry to the oviduct on the left side of the urodeum of the cloaca. We hypothesized that male cloacal contacts during copulation would occur from the left side of females because this would put sperm closer to the entrance of the oviduct. We observed that cloacal contacts from the left outnumbered those from the right by a margin of 3:1 during tree swallow, Tachycineta bicolor, copulations at nestboxes in western Michigan in 1999. The directional bias of cloacal contacts may have an adaptive function.


The Beneficial Sexually Transmitted Microbe Hypothesis Of Avian Copulation, Michael Lombardo, Patrick Thorpe, Harry Power Jul 2010

The Beneficial Sexually Transmitted Microbe Hypothesis Of Avian Copulation, Michael Lombardo, Patrick Thorpe, Harry Power

Michael P Lombardo

Several hypotheses have been proposed to explain why female birds either copulate repeatedly with a single mate or copulate with multiple partners even though only a single copulation may be sufficient to fertilize an entire clutch. We hypothesize that females may directly benefit from high frequencies of copulation and multiple copulation partners if they receive a cloacal inoculation of beneficial sexually transmitted microbes (STMs) that can either protect them against future encounters with pathogens and/or serve as therapy against present infections. Experiments in domestic animal production, wildlife rehabilitation, and clinical medicine indicate that inoculations of beneficial microbes derived from the …


Elevated Levels Of Il-10 And G-Csf Associated With Asymptomatic Malaria In Pregnant Women, Winston A. Anderson Jun 2010

Elevated Levels Of Il-10 And G-Csf Associated With Asymptomatic Malaria In Pregnant Women, Winston A. Anderson

Winston Anderson

In sub-Saharan Africa, approximately 30 million pregnant women are at risk of contracting malaria annually. Nearly 36% of healthy pregnant women receiving routine antenatal care tested positive for Plasmodium falciparum HRP-II antigen in Ghana. We tested the hypothesis that asymptomatic HRP II positive pregnant women expressed a unique Th1 and Th2 phenotype that differs from healthy controls. Plasma from healthy (n = 15) and asymptomatic (n = 25) pregnant women were evaluated for 27 biomarkers (IL-1b, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12, IL-13, IL-15, IL- 17, Eotaxin, bFGF-2, G-CSF, GM-CSF, IFN-gamma, IP-10, MCP-1, MIP-1alpha, MIP-1beta, PDGF-bb, …


Rna Processing Of Nitrogenase Transcripts In The Cyanobacterium Anabaena Variabilis, Justin L. Ungerer, Brenda S. Pratte, Teresa Thiel Jun 2010

Rna Processing Of Nitrogenase Transcripts In The Cyanobacterium Anabaena Variabilis, Justin L. Ungerer, Brenda S. Pratte, Teresa Thiel

Teresa Thiel

Little is known about the regulation of nitrogenase genes in cyanobacteria. Transcription of the nifH1 and vnfH genes, encoding dinitrogenase reductases for the heterocyst-specific Mo-nitrogenase and the alternative V-nitrogenase, respectively, was studied by using a lacZ reporter. Despite evidence for a transcription start site just upstream of nifH1 and vnfH, promoter fragments that included these start sites did not drive the transcription of lacZ and, for nifH1, did not drive the expression of nifHDK1. Further analysis using larger regions upstream of nifH1 indicated that a promoter within nifU1 and a promoter upstream of nifB1 both contributed to expression of nifHDK1, …


Nonspecific Phospholipase C Npc4 Promotes Responses To Abscisic Acid And Tolerance To Hyperosmotic Stress In Arabidopsis, Xuemin Wang, Carlotta Peters, Maoyin Li, Rama Narasimhan, Mary Roth, Ruth Welti Jun 2010

Nonspecific Phospholipase C Npc4 Promotes Responses To Abscisic Acid And Tolerance To Hyperosmotic Stress In Arabidopsis, Xuemin Wang, Carlotta Peters, Maoyin Li, Rama Narasimhan, Mary Roth, Ruth Welti

Xuemin (Sam) Wang

Diacyglycerol (DAG) is an important class of cellular lipid messengers, but its function in plants remains elusive. Here, we show that knockout of the Arabidopsis thaliana nonspecific phospholipase C (NPC4) results in a decrease in DAG levels and compromises plant response to abscisic acid (ABA) and hyperosmotic stresses. NPC4 hydrolyzes various phospholipids in a calcium-independent manner, producing DAG and a phosphorylated head group. NPC4 knockout (KO) plants display decreased ABA sensitivity in seed germination, root elongation, and stomatal movement and had decreased tolerance to high salinity and water deficiency. Overexpression of NPC4 renders plants more sensitive to ABA and more …


Marine Natural Products, The Halogenated 1'-Methyl-1,2'-Bipyrroles, Biomagnify In A Northwestern Atlantic Food Web., Kristin C. Pangallo, Christopher M. Reddy Jun 2010

Marine Natural Products, The Halogenated 1'-Methyl-1,2'-Bipyrroles, Biomagnify In A Northwestern Atlantic Food Web., Kristin C. Pangallo, Christopher M. Reddy

Kristin Pangallo

Halogenated 1′-methyl-1,2′-bipyrroles (MBPs) are putative marine natural products that accumulate in marine mammal blubber in similar concentrations and patterns to biomagnifying organic pollutants. Here we measure concentrations of MBPs and 2,2′,4,4′,5,5′-hexachlorobiphenyl (CB-153) in 40 samples composed of eight fish species, two squid species, and six species of marine mammals. To determine their trophic positions and to further investigate influence of prey preference, we also measured the stable carbon and nitrogen isotopic compositions of all samples. Our results show that lipid-normalized MBP concentrations increase with increasing trophic level; therefore, MBPs qualify as another class of biomagnifying marine natural products. The presence …