bluuebunny/crossref_metadata_2025 huggingface dataset:
Circadian desynchronization of core body temperature and sleep stages in the rat
Authors: Cambras Trinitat , Weller John R. , Anglès-Pujoràs Montserrat , Lee Michael L. , Christopher Andrea , Díez-Noguera Antoni , Krueger James M. , de la Iglesia Horacio O.
Published: April 2007

Proper functioning of the human circadian timing system is crucial to physical and mental health. Much of what we know about this system is based on experimental protocols that induce the desynchronization of behavioral and physiological rhythms within individual subjects, but the neural (or extraneural) substrates for such desynchronization are unknown. We have developed an animal model of human internal desynchrony in which rats are exposed to artificially short (22-h) light–dark cycles. Under these conditions, locomotor activity, sleep–wake, and slow-wave sleep (SWS) exhibit two rhythms within individual animals, one entrained to the 22-h light–dark cycle and the other free-running with a period >24 h (τ
>24 h
). Whereas core body temperature showed two rhythms as well, further analysis indicates this variable oscillates more according to the τ
>24 h
rhythm than to the 22-h rhythm, and that this oscillation is due to an activity-independent circadian regulation. Paradoxical sleep (PS), on the other hand, shows only one free-running rhythm. Our results show that, similarly to humans, (
i
) circadian rhythms can be internally dissociated in a controlled and predictable manner in the rat and (
ii
) the circadian rhythms of sleep–wake and SWS can be desynchronized from the rhythms of PS and core body temperature within individual animals. This model now allows for a deeper understanding of the human timekeeping mechanism, for testing potential therapies for circadian dysrhythmias, and for studying the biology of PS and SWS states in a neurologically intact model.
Poor prognosis in carcinoma is associated with a gene expression signature of aberrant PTEN tumor suppressor pathway activity
Authors: Saal Lao H. , Johansson Peter , Holm Karolina , Gruvberger-Saal Sofia K. , She Qing-Bai , Maurer Matthew , Koujak Susan , Ferrando Adolfo A. , Malmström Per , Memeo Lorenzo , Isola Jorma , Bendahl Pär-Ola , Rosen Neal , Hibshoosh Hanina , Ringnér Markus , Borg Åke , Parsons Ramon
Published: April 2007

Pathway-specific therapy is the future of cancer management. The oncogenic phosphatidylinositol 3-kinase (PI3K) pathway is frequently activated in solid tumors; however, currently, no reliable test for PI3K pathway activation exists for human tumors. Taking advantage of the observation that loss of PTEN, the negative regulator of PI3K, results in robust activation of this pathway, we developed and validated a microarray gene expression signature for immunohistochemistry (IHC)-detectable PTEN loss in breast cancer (BC). The most significant signature gene was
PTEN
itself, indicating that
PTEN
mRNA levels are the primary determinant of PTEN protein levels in BC. Some PTEN IHC-positive BCs exhibited the signature of PTEN loss, which was associated to moderately reduced
PTEN
mRNA levels cooperating with specific types of
PIK3CA
mutations and/or amplification of
HER2
. This demonstrates that the signature is more sensitive than PTEN IHC for identifying tumors with pathway activation. In independent data sets of breast, prostate, and bladder carcinoma, prediction of pathway activity by the signature correlated significantly to poor patient outcome. Stathmin, encoded by the signature gene
STMN1
, was an accurate IHC marker of the signature and had prognostic significance in BC. Stathmin was also pathway-pharmacodynamic
in vitro
and
in vivo
. Thus, the signature or its components such as stathmin may be clinically useful tests for stratification of patients for anti-PI3K pathway therapy and monitoring therapeutic efficacy. This study indicates that aberrant PI3K pathway signaling is strongly associated with metastasis and poor survival across carcinoma types, highlighting the enormous potential impact on patient survival that pathway inhibition could achieve.
Regulation of AID expression in the immune response
Authors: Crouch Elizabeth E. , Li Zhiyu , Takizawa Makiko , Fichtner-Feigl Stefan , Gourzi Polyxeni , Montaño Carolina , Feigenbaum Lionel , Wilson Patrick , Janz Siegfried , Papavasiliou F. Nina , Casellas Rafael
Published: April 2007

The B cell–specific enzyme activation-induced cytidine deaminase (AID) has been shown to be essential for isotype switching and affinity maturation of antibody genes during the immune response. Conversely, AID activity has also been linked to autoimmunity and tumorigenesis. Determining how AID expression is regulated in vivo is therefore central to understanding its role in health and disease. Here we use phylogenetic footprinting and high-resolution histone acetylation mapping to accurately demarcate AID gene regulatory boundaries. Based on this strategy, we identify a novel, positive regulatory element required for AID transcription. Furthermore, we generate two AID indicator mouse strains using bacterial artificial chromosomes that faithfully recapitulate endogenous AID expression. The first strain uses a green fluorescent protein reporter to identify B cells that actively express AID during the immune response. In the second strain, AID transcription affects the permanent expression of a yellow fluorescent protein reporter in post–germinal center and terminally differentiated lymphocytes. We demonstrate the usefulness of these novel strains by resolving recent contradictory observations on AID expression during B cell ontogeny.
Mature natural killer cell and lymphoid tissue–inducing cell development requires Id2-mediated suppression of E protein activity
Authors: Boos Markus D. , Yokota Yoshifumi , Eberl Gerard , Kee Barbara L.
Published: April 2007

The Id2 transcriptional repressor is essential for development of natural killer (NK) cells, lymphoid tissue–inducing (LTi) cells, and secondary lymphoid tissues. Id2 was proposed to regulate NK and LTi lineage specification from multipotent progenitors through suppression of E proteins. We report that NK cell progenitors are not reduced in the bone marrow (BM) of Id2−/− mice, demonstrating that Id2 is not essential for NK lineage specification. Rather, Id2 is required for development of mature (m) NK cells. We define the mechanism by which Id2 functions by showing that a reduction in E protein activity, through deletion of E2A, overcomes the need for Id2 in development of BM mNK cells, LTi cells, and secondary lymphoid tissues. However, mNK cells are not restored in the blood or spleen of Id2−/−E2A−/− mice, suggesting a role for Id2 in suppression of alternative E proteins after maturation. Interestingly, the few splenic mNK cells in Id2−/− and Id2−/−E2A−/− mice have characteristics of thymus-derived NK cells, which develop in the absence of Id2, implying a differential requirement for Id2 in BM and thymic mNK development. Our findings redefine the essential functions of Id2 in lymphoid development and provide insight into the dynamic regulation of E and Id proteins during this process.
Expression of lymphotoxin-αβ on antigen-specific T cells is required for DC function
Authors: Summers-deLuca Leslie E. , McCarthy Douglas D. , Cosovic Bojana , Ward Lesley A. , Lo Calvin C. , Scheu Stefanie , Pfeffer Klaus , Gommerman Jennifer L.
Published: April 2007

During an immune response, activated antigen (Ag)-specific T cells condition dendritic cells (DCs) to enhance DC function and survival within the inflamed draining lymph node (LN). It has been difficult to ascertain the role of the tumor necrosis factor (TNF) superfamily member lymphotoxin-αβ (LTαβ) in this process because signaling through the LTβ-receptor (LTβR) controls multiple aspects of lymphoid tissue organization. To resolve this, we have used an in vivo system where the expression of TNF family ligands is manipulated only on the Ag-specific T cells that interact with and condition Ag-bearing DCs. We report that LTαβ is a critical participant required for optimal DC function, independent of its described role in maintaining lymphoid tissue organization. In the absence of LTαβ or CD40L on Ag-specific T cells, DC dysfunction could be rescued in vivo via CD40 or LTβR stimulation, respectively, suggesting that these two pathways cooperate for optimal DC conditioning.
Type I interferon signaling is required for activation of the inflammasome during Francisella infection
Authors: Henry Thomas , Brotcke Anna , Weiss David S. , Thompson Lucinda J. , Monack Denise M.
Published: April 2007

Francisella tularensis is a pathogenic bacterium whose virulence is linked to its ability to replicate within the host cell cytosol. Entry into the macrophage cytosol activates a host-protective multimolecular complex called the inflammasome to release the proinflammatory cytokines interleukin (IL)-1β and -18 and trigger caspase-1–dependent cell death. In this study, we show that cytosolic F. tularensis subspecies novicida (F. novicida) induces a type I interferon (IFN) response that is essential for caspase-1 activation, inflammasome-mediated cell death, and release of IL-1β and -18. Extensive type I IFN–dependent cell death resulting in macrophage depletion occurs in vivo during F. novicida infection. Type I IFN is also necessary for inflammasome activation in response to cytosolic Listeria monocytogenes but not vacuole-localized Salmonella enterica serovar Typhimurium or extracellular adenosine triphosphate. These results show the specific connection between type I IFN signaling and inflammasome activation, which are two sequential events triggered by the recognition of cytosolic bacteria. To our knowledge, this is the first example of the positive regulation of inflammasome activation. This connection underscores the importance of the cytosolic recognition of pathogens and highlights how multiple innate immunity pathways interact before commitment to critical host responses.
Patterns of Using Complementary and Alternative Medicine by Stroke Patients at Two University Hospitals in Korea
Authors: Shin Yong-Il , Yang Chung-Yong , Joo Min-Cheol , Lee Sam-Gyu , Kim Jae-Hyung , Lee Myeong Soo
Published: April 2007

This study measured the prevalence of complementary and alternative medicine (CAM) use among Korean stroke patients. Questionnaire‐based 20‐min interviews were conducted at the hospitals by a trained nurse after an outpatient visit. It included questions on demographic information, clinical information and the utilization of CAM. Of 304 stroke‐patient respondents, 164 (54%) had used CAM, of which 66% had started taking CAM products following suggestions from family members and other relatives. Of the 57% of users who felt that CAM was effective, 84% considered that it improved the symptoms of stroke and 16% felt it was effective in achieving psychological relaxation. Of the eight CAM categories used by respondents, 92% used traditional Oriental medical treatments, 36% used plant‐ and animal‐derived over‐the‐counter health care products, 24% used minerals and vitamins, and 11% used manual therapies. The majority of stroke patients (68%) were trying a new type of CAM, and half of the respondents (45%) relied on the knowledge of their general practitioner about CAMs when deciding whether to use them. Most of the stroke patients in this study used CAM, and a half of them reported beneficial effects. Despite the presence of adverse side effects, they tended to be used without discussion with chief physicians, and hence physicians should be actively involved in the usage of CAM.
Chondroprotective Potential of Fruit Extracts of Phyllanthus emblica in Osteoarthritis
Authors: Sumantran Venil N. , Kulkarni Asavari , Chandwaskar Rucha , Harsulkar Abhay , Patwardhan Bhushan , Chopra Arvind , Wagh Ulhas V.
Published: April 2007

There is a need for effective nutraceuticals for osteoarthritis care. The fruit of Phyllanthus emblica is used as a powerful rejuvenator in Ayurvedic medicine. This study measured the chondroprotective potential of P. emblica (‘Amalaki’) fruits in vitro. We used aqueous extracts of unprocessed P. emblica fruit powder (powder A), and the powder obtained after hot water extraction and drying of powder A (powder B). Chondroprotection was measured in three different assay systems. First, we tested the effects of both fruit powders on the activities of the enzymes hyaluronidase and collagenase type 2. Second, an in vitro model of cartilage degradation was set‐up with explant cultures of articular knee cartilage from osteoarthritis patients. Cartilage damage was assayed by measuring glycosaminoglycan release from explants treated with/without P. emblica fruit powders. Aqueous extracts of both fruit powders significantly inhibited the activities of hyaluronidase and collagenase type 2 in vitro. Third, in the explant model of cartilage matrix damage, extracts of glucosamine sulphate and powder B (0.05 mg/ml) exhibited statistically significant, long‐term chondroprotective activity in cartilage explants from 50% of the patients tested. This result is important since glucosamine sulphate is the leading nutraceutical for osteoarthritis. Powder A induced a statistically significant, short‐term chondroprotective activity in cartilage explants from all of the patients tested. This is the first study to identify and quantitate new chondroprotective activities of P. emblica fruits. These data provide pilot pre‐clinical evidence for the use of P. emblica fruits as a chondroprotective agent in osteoarthritis therapy.
Loop anchor modification causes the population of an alternative native state in an SH3‐like domain
Authors: Knappenberger Jane A. , Lecomte Juliette T.J.
Published: April 2007

Many stably folded proteins are proposed to contain long, unstructured loops. A series of hybrid proteins (EbE1–4) containing the folded scaffold of photosystem I accessory protein E (PsaE), an SH3‐like protein, and the 40‐residue heme‐binding loop of cytochrome b5 was created to inspect the dependence of thermodynamic and kinetic parameters on the residues at the interface of folded and flexible regions. Compared to the simplest hybrid (EbE1), the chimeras differed by Gly insertions (EbE2, EbE3) or an asymmetric four‐residue restructuring of loop termini (EbE4). NMR spectroscopy indicated that the chimeras retained the PsaE topology; native and unfolded state solubilities, however, were affected to varying degrees. Thermal and chemical denaturation experiments revealed that the EbE2 and EbE1 constructs resulted in a modest destabilization of the PsaE core, whereas apparent stability was increased by >5 kJ/mol in EbE4. EbE3 aggregated at μM concentrations and was not studied in detail. EbE4 populated two native states (N1 and N2), which differed by hydrophobic core packing and C‐terminal interactions. At room temperature, the population ratio (∼3–4:1) favored the state whose spectroscopic properties most resembled those of PsaE (N1). EbE4 also demonstrated altered folding kinetics, displaying multiple slow phases related to the population of intermediates and possibly N2. It was concluded that loop anchors can affect protein properties, including stability, via short‐range effects on local structure and long‐range communication with the packed hydrophobic core. Modification of the attachment points appears to be a possible stepping stone in the transition from one three‐dimensional structure to another.
Expression of proteins with dimethylarginines in Escherichia coli for protein–protein interaction studies
Authors: Hsieh Cheng‐Hsilin , Huang San‐Yuan , Wu Yu‐Ching , Liu Li‐Fan , Han Chau‐Chung , Liu Yi‐Chen , Tam Ming F.
Published: April 2007

Protein arginine methylation often modulates protein–protein interactions. To isolate a sufficient quantity of proteins enriched in methyl arginine(s) from natural sources for biochemical studies is laborious and difficult. We describe here an expression system that produces recombinant proteins that are enriched in ω‐NG,NG‐asymmetry dimethylarginines. A yeast type I arginine methyltransferase gene (HMT1) is put on a plasmid under the control of the Escherichia coli methionine aminopeptidase promoter for constitutive expression. The protein targeted for post‐translational modification is put on the same plasmid behind a T7 promoter for inducible expression of His6‐tagged proteins. Sbp1p and Stm1p were used as model proteins to examine this expression system. The 13 arginines within the arginine‐glycine‐rich motif of Sbp1p and the RGG sequence near the C terminus of Stm1p were methylated. Unexpectedly, the arginine residue on the thrombin cleavage site (LVPRGS) of the fusion proteins can also be methylated by Hmt1p. Sbp1p and Sbp1p/hmt1 were covalently attached to solid supports for the isolation of interacting proteins. The results indicate that arginine methylation on Sbp1p exerts both positive and negative effects on protein–protein interaction.
Molecular architecture of DesV from Streptomyces venezuelae: A PLP‐dependent transaminase involved in the biosynthesis of the unusual sugar desosamine
Authors: Burgie E. Sethe , Thoden James B. , Holden Hazel M.
Published: April 2007

Desosamine is a 3‐(dimethylamino)‐3,4,6‐trideoxyhexose found in certain macrolide antibiotics such as the commonly prescribed erythromycin. Six enzymes are required for its biosynthesis in Streptomyces venezuelae. The focus of this article is DesV, which catalyzes the PLP‐dependent replacement of a 3‐keto group with an amino functionality in the fifth step of the pathway. For this study the three‐dimensional structures of both the internal aldimine and the ketimine intermediate with glutamate were determined to 2.05 Å resolution. DesV is a homodimer with each subunit containing 12 α‐helical regions and 12 β‐strands that together form three layers of sheet. The structure of the internal aldimine demonstrates that the PLP‐cofactor is held in place by residues contributed from both subunits (Asp 164 and Gln 167 from Subunit I and Tyr 221 and Asn 235 from Subunit II). When the ketimine intermediate is present in the active site, the loop defined by Gln 225 to Ser 228 from Subunit II closes down upon the active site. The structure of DesV is similar to another sugar‐modifying enzyme referred to as PseC. This enzyme is involved in the biosynthesis of pseudaminic acid, which is a sialic acid‐like nonulosonate found in the flagellin of Helicobacter pylori. In the case of PseC, however, the amino group is transferred to the C‐4 rather than the C‐3 position. Details concerning the structural analysis of DesV and a comparison of its molecular architecture to that of PseC are presented.
The 2.0 Å crystal structure of the ERα ligand‐binding domain complexed with lasofoxifene
Authors: Vajdos Felix F. , Hoth Lise R. , Geoghegan Kieran F. , Simons Samuel P. , LeMotte Peter K. , Danley Dennis E. , Ammirati Mark J. , Pandit Jayvardhan
Published: April 2007

Lasofoxifene is a new and potent selective estrogen receptor modulator (SERM). The structural basis of its interaction with the estrogen receptor has been investigated by crystallographic analysis of its complex with the ligand‐binding domain of estrogen receptor α at a resolution of 2.0 Å. As with other SERMs, lasofoxifene diverts the receptor from its agonist‐bound conformation by displacing the C‐terminal AF‐2 helix into the site at which the LXXLL motif of coactivator proteins would otherwise be able to bind. Lasofoxifene achieves this effect by occupying the space normally filled by residue Leu 540, as well as by modulating the conformation of residues of helix 11 (His 524, Leu 525). A well‐defined salt bridge between lasofoxifene and Asp 351 suggests that charge neutralization in this region of the receptor may explain the some of the antiestrogenic effects of lasofoxifene. The results suggest general features of ERα/SERM recognition, and add a new dimension to efforts to rationalize differences between the biological activity profiles exhibited by these important pharmacological agents.
Behavioural responses of larval container mosquitoes to a size‐selective predator
Authors: KESAVARAJU BANUGOPAN , ALTO BARRY W. , LOUNIBOS L. PHILIP , JULIANO STEVEN A.
Published: April 2007

Abstract1. The hypothesis that size‐selective predation and species‐specific prey behaviours facilitate the coexistence between larvae of invasiveAedes albopictus(Skuse) and U.S.A.‐nativeOchlerotatus triseriatus(Say) was tested experimentally with the predatorCorethrella appendiculata(Grabham).

2. Larval behaviours associated with a higher risk of predation were identified, and prey behavioural responses were tested in either the physical presence of predators or in water containing predation cues. Larvae that thrashed on container bottoms had a higher risk of being captured by fourth instarC. appendiculatathan did larvae resting on the water surface.Ochlerotatus triseriatus, but notA. albopictus, adopted low‐risk behaviours in response to water‐borne cues to predation. Both prey species reduced risky behaviours in the physical presence of the predator, butO. triseriatusshowed a stronger response.

3. The vulnerability of 2nd and 3rd instar prey to predation was compared, and behavioural responses were correlated with prey vulnerability. Second instars of both species were more vulnerable to predation byC. appendiculatathan were 3rd instars, and the 3rd instarA. albopictuswas more vulnerable thanO. triseriatusof the same stage. All instars ofO. triseriatusshowed a similar reduction of risky behaviours in response to the presence ofC. appendiculatadespite 4th instar prey being relatively invulnerable to size‐selective predation.

4. Weaker predator avoidance, coupled with superior competitive ability, of invasiveA. albopictusis likely to contribute to its coexistence withO. triseriatusin containers of the south‐eastern U.S.A., whereC. appendiculatacan be abundant.
Scanning electron microscopic examination of different cleaners: surface contaminant removal from dentures
Authors: KULAK Y. , ARIKAN A. , ALBAK S. , OKAR I. , KAZAZOĞLU E.
Published: April 2007

summary
Dentures were examined by scanning electron microscopy to evaluate removal of surface contaminants. Five complete dentures were obtained during patient appointments. The palatal surface of each denture was divided into eight pieces (1 cm2) then each sample cleaned with Corega®, Dentipur®, Fittydent®, sodium hypochloride, Savlon®, Ipanol®, brushing methods and one sample was also kept as a control. They were prepared for SEM examination and photographed at X500. One photograph of each sample was evaluated in random order by three judges for a total of 120 observations. Photographs were compared with one of a clean denture sample. Statistical analysis of the results showed that soaking dentures in sodium hypochloride and Savlon® removed significantly more contaminants than any of the other methods used in this study.
Re‐examination of the surface EMG activity of the masseter muscle in young adults during chewing of two test foods
Authors: KARKAZIS H.C. , KOSSIONI A.E.
Published: April 2007

summary
The purpose of this study was to investigate the effect of the texture of food on the masseter EMG activity during chewing. Fresh raw carrots and non‐adhesive chewing gums of similar size and weight were used as representing a hard and a soft food respectively. The mean values for the IEMG activity, the duration of the chewing cycle, the chewing rate and the relative contraction time during chewing were significantly higher for the carrots while no significant difference was found in the chewing burst duration between the two test foods. Finally a strong inverse correlation was found between chewing rate and cycle duration. It was concluded that the texture of food has an obvious effect on EMG activity during chewing and that adjustments to changes in food consistency are made mainly by altering the chewing rate, the duration of the chewing cycle and the IEMG activity
Characteristics of chief complaints of patients with temporomandibular disorders in a Brazilian population
Authors: LUZ J.G.C. , MARAGNO I.C. , MARTIN M.C.
Published: April 2007

summary
A retrospective survey of 894 patients with temporomandibular disorders was conducted in order to analyse the characteristics of chief complaints. The patients presented complaints of pain (82.1%), functional disturbance (12.3%), articular sounds (5.0%) and swelling (0.6%). Unilateral occurrence (66.5%) was more frequent than bilateral. The most frequent location of pain was the temporomandibular joint (TMJ) (82.1%) followed by ear (10.8%), face (2.3%), head (2.3%), mandible (1.0%), neck (0.9%), temporal (0.4%) and frontal (0.1%) areas. Pain in the TMJ occurred in isolation (87.9%) or associated to other locations. The most frequent functional disturbance was limitation of jaw opening (32.1%).
Polygyny and polyandry in small ant societies
Authors: KELLNER K. , TRINDL A. , HEINZE J. , D’ETTORRE P.
Published: April 2007

Social insects, ants in particular, show considerable variation in queen number and mating frequency resulting in a wide range of social structures. The dynamics of reproductive conflicts in insect societies are directly connected to the colony kin structure, thus, the study of relatedness patterns is essential in order to understand the evolutionary resolution of these conflicts. We studied colony kin structure and mating frequencies in two closely related Neotropical ant species Pachycondyla inversa and Pachycondyla villosa. These represent interesting model systems because queens found new colonies cooperatively but, unlike many other ant species, they may still co‐exist when the colony becomes mature (primary polygyny). By using five specific and highly variable microsatellite markers, we show that in both species queens usually mate with two or more males and that cofounding queens are always unrelated. Polygynous and polyandrous colonies are characterized by a high genetic diversity, with a mean relatedness coefficient among worker nestmates of 0.27 (± 0.03 SE) for P. inversa and 0.31 (± 0.05 SE) for P. villosa. However, relatedness among workers of the same matriline is high (0.60 ± 0.03 in P. inversa, 0.62 ± 0.08 in P. villosa) since males that mated with the same queen are on average closely related. Hence, we have found a new taxon in social Hymenoptera with high queen‐mating frequencies and with intriguing mating and dispersal patterns of the sexuals.
Case studies and mathematical models of ecological speciation. 2. Palms on an oceanic island
Authors: GAVRILETS SERGEY , VOSE AARON
Published: April 2007

A recent study of a pair of sympatric species of palms on the Lord Howe Island is viewed as providing probably one of the most convincing examples of sympatric speciation to date. Here we describe and study a stochastic, individual‐based, explicit genetic model tailored for this palms system. Overall, our results show that relatively rapid (< 50 000 generations) colonization of a new ecological niche, and sympatric or parapatric speciation via local adaptation and divergence in flowering periods are theoretically plausible if (i) the number of loci controlling the ecological and flowering period traits is small; (ii) the strength of selection for local adaptation is intermediate; and (iii) an acceleration of flowering by a direct environmental effect associated with the new ecological niche is present. We discuss patterns and time‐scales of ecological speciation identified by our model, and we highlight important parameters and features that need to be studied empirically in order to provide information that can be used to improve the biological realism and power of mathematical models of ecological speciation.
Population structure and genetic diversity in tristylousNarcissus triandrus: insights from microsatellite and chloroplast DNA variation
Authors: HODGINS KATHRYN A. , BARRETT SPENCER C. H.
Published: April 2007

We investigated cpDNA sequence and nuclear microsatellite variation among populations of the wild daffodilNarcissus triandrusto examine the role of historical vs. contemporary forces in shaping population structure, morphological differentiation and sexual‐system evolution. This wide‐ranging heterostylous species of the Iberian Peninsula is largely composed of two allopatric varieties (vars.cernuusandtriandrus), and populations with either stylar trimorphism or dimorphism. Dimorphic populations only occur in var.triandrus, are mainly restricted to the northwestern portion of the species range, and uniformly lack the mid‐styled morph (M‐morph). Chloroplast DNA (cpDNA) sequence variation revealed strong geographical structuring and evidence for a fragmentation event associated with differentiation of the two varieties. In var.triandrus,population fragmentation, restricted gene flow and isolation‐by‐distance were also inferred. Significant differences in genetic diversity and population structure between the two varieties likely reflect historical and contemporary differences in demography and gene flow among populations. Discordance between cpDNA markers and both microsatellite and morphological variation indicate that hybridization has occurred between the two varieties at contact zones. There were no differences in genetic diversity or population structure between dimorphic and trimorphic populations, and chloroplast haplotypes were not associated with either sexual system, indicating transitions in morph structure within each maternal lineage. M‐morph frequencies were positively correlated with differentiation at microsatellite loci, indicating that the evolutionary processes influencing these neutral markers also influence alleles controlling the style morphs.
Glacial survival and local adaptation in an alpine leaf beetle
Authors: MARGRAF NICOLAS , VERDON ALINE , RAHIER MARTINE , NAISBIT RUSSELL E.
Published: April 2007

The challenge in defining conservation units so that they represent evolutionary entities has been to combine both genetic properties and ecological significance. Here we make use of the complexity of the European Alps, with their genetic landscape shaped by geographical barriers and postglacial colonization, to examine the correlation between ecological and genetic divergence. Montane species, because of the fragmentation of their present habitat, constitute extreme cases in which to test if genetically distinct subgroups based on neutral markers are also ecologically differentiated and show local adaptation. In the leaf beetle Oreina elongata, populations show variation in host plant use and a patchy distribution throughout the Alps and Apennines. We demonstrate that despite very strong genetic isolation (FST = 0.381), variation in host plant use has led to differences in larval life‐history traits between populations only as a secondary effect of host defence chemistry, and not through physiological adaptation to plant nutritional value. We also establish that populations that are more ecologically different in terms of larval performance are also more genetically divergent. In addition, morphological variation used to define subspecies appears to be mirrored in the population genetics of this species, resulting in almost perfect clustering based on microsatellite data. Finally, we argue from their strong genetic structure and congruent distribution that the subspecies of O. elongata were divided among the same glacial refugia within the Alps that have been proposed for alpine plants.
Egg production and individual genetic diversity in lesser kestrels
Authors: ORTEGO JOAQUÍN , CALABUIG GUSTAU , CORDERO PEDRO J. , APARICIO JOSÉ MIGUEL
Published: April 2007

Fecundity is an important component of individual fitness and has major consequences on population dynamics. Despite this, the influence of individual genetic variability on egg production traits is poorly known. Here, we use two microsatellite‐based measures, homozygosity by loci and internal relatedness, to analyse the influence of female genotypic variation at 11 highly variable microsatellite loci on both clutch size and egg volume in a wild population of lesser kestrels (Falco naumanni). Genetic diversity was associated with clutch size, with more heterozygous females laying larger clutches, and this effect was statistically independent of other nongenetic variables such as female age and laying date, which were also associated with fecundity in this species. However, egg volume was not affected by female heterozygosity, confirming previous studies from pedigree‐based breeding experiments which suggest that this trait is scarcely subjected to inbreeding depression. Finally, we explored whether the association between heterozygosity and clutch size was due to a genome‐wide effect (general effect) or to single locus heterozygosity (local effect). Two loci showed a stronger influence but the correlation was not fully explained by these two loci alone, suggesting that a main general effect underlies the association observed. Overall, our results underscore the importance of individual genetic variation for egg production in wild bird populations, a fact that could have important implications for conservation research and provides insights into the study of clutch size evolution and genetic variability maintenance in natural populations.
The maize (Zea mays L.) RTCS gene encodes a LOB domain protein that is a key regulator of embryonic seminal and post‐embryonic shoot‐borne root initiation
Authors: Taramino Graziana , Sauer Michaela , Stauffer Jay L. , Multani Dilbag , Niu Xiaomu , Sakai Hajime , Hochholdinger Frank
Published: April 2007

Maize has a complex root system composed of different root types formed during different stages of development. The rtcs (rootless concerning crown and seminal roots) mutant is impaired in the initiation of the embryonic seminal roots and the post‐embryonic shoot‐borne root system. The primary root of the mutant shows a reduced gravitropic response, while its elongation, lateral root density and reaction to exogenously applied auxin is not affected. We report here the map‐based cloning of the RTCS gene which encodes a 25.5 kDa LOB domain protein located on chromosome 1S. The RTCS gene has been duplicated during evolution. The RTCS‐LIKE (RTCL) gene displays 72% sequence identity on the protein level. Both genes are preferentially expressed in roots. Expression of RTCS in coleoptilar nodes is confined to emerging shoot‐borne root primordia. Sequence analyses of the RTCS and RTCL upstream genomic regions identified auxin response elements. Reverse transcriptase‐PCR revealed that both genes are auxin induced. Microsynteny analyses between maize and rice genomes revealed co‐linearity of 14 genes in the RTCS region. We conclude from our data that RTCS and RTCL are auxin‐responsive genes involved in the early events that lead to the initiation and maintenance of seminal and shoot‐borne root primordia formation.
Convergent evolution in the BAHD family of acyl transferases: identification and characterization of anthocyanin acyl transferases from Arabidopsis thaliana
Authors: Luo Jie , Nishiyama Yasutaka , Fuell Christine , Taguchi Goro , Elliott Katherine , Hill Lionel , Tanaka Yoshikazu , Kitayama Masahiko , Yamazaki Mami , Bailey Paul , Parr Adrian , Michael Anthony J. , Saito Kazuki , Martin Cathie
Published: April 2007

Members of the BAHD family of plant acyl transferases are very versatile catalytically, and are thought to be able to evolve new substrate specificities rapidly. Acylation of anthocyanins occurs in many plant species and affects anthocyanin stability and light absorption in solution. The versatility of BAHD acyl transferases makes it difficult to identify genes encoding enzymes with defined substrate specificities on the basis of structural homology to genes of known catalytic function alone. Consequently, we have used a modification to standard functional genomics strategies, incorporating co‐expression profiling with anthocyanin accumulation, to identify genes encoding three anthocyanin acyl transferases from Arabidopsis thaliana. We show that the activities of these enzymes influence the stability of anthocyanins at neutral pH, and some acylations also affect the anthocyanin absorption maxima. These properties make the BAHD acyl transferases suitable tools for engineering anthocyanins for an improved range of biotechnological applications.
Within/between population crosses reveal genetic basis for siring success in Silene latifolia (Caryophyllaceae)
Authors: JOLIVET C. , BERNASCONI G.
Published: April 2007

Abstract Divergence at reproductive traits can generate barriers among populations, and may result from several mechanisms, including drift, local selection and co‐adaptation between the sexes. Intersexual co‐adaptation can arise through sexually antagonistic co‐evolution, a timely hypothesis addressed in animals but, to our knowledge, not yet in flowering plants. We investigated whether male and female population of origin affected pollen competition success, offspring fitness and sex ratio in crosses within/between six genetically differentiated populations of the white campion, Silene latifolia. Each female was crossed with pollen from one focus male from the same population, and pollen from two focus males from two distinct populations, both as single‐donor and two‐donor crosses against a fixed tester male with a 2‐h interpollination interval (n = 288 crosses). We analysed paternity with microsatellite DNA. Male populations of origin significantly differed for siring success and in vitro pollen germination rates. In vitro pollen germination rate was heritable. Siring success also depended on sex ratio in the female family of origin, but only in between‐population crosses. In some female populations, two‐donor crosses produced less female‐biased sex ratios compared with single‐donor crosses, yet in other female populations the reverse was true. Offspring sex ratio varied with donor number, depending on the female population. Within/between population crosses did not differ significantly in seed set or offspring fitness, nor were siring success and offspring fitness significantly correlated. Altogether this suggests reproductive divergence for traits affecting pollen competition in S. latifolia.
Elastic plasma protein film blended with platelet releasate accelerates healing of diabetic mouse skin wounds
Authors: Tanaka R. , Ichioka S. , Sekiya N. , Ohura N. , Uchino S. , Ojima A. , Itoh Y. , Ishihara O. , Nakatsuka T. , Ikebuchi K.
Published: April 2007

Background and Objectives  The growth factors derived from platelets and plasma proteins mediate the wound‐healing process that is characterized by the sequential migration and differentiation of several cell populations that give rise to angiogenesis, collagen synthesis, wound contraction, and re‐epithelialization. To evaluate the efficacy of the blood‐derived factors in wound healing, we examined a novel wound dressing consisting of concentrated human plasma proteins and platelet releasate (CPPP).

Materials and Methods  To generate CPPP, plasma proteins and platelets in the peripheral blood (n = 5) were concentrated with the cold ethanol precipitation method. The thrombin obtained from the same blood unit and calcium chloride (CaCl2) were mixed to a concentrate. The CPPP has enough strength to dress cutaneous wounds and contains large amounts of cytokines and fibronectin. We applied the CPPP to excisional skin wounds in genetically healing‐impaired model mice (n= 5) and the wounds were evaluated 10 days after the operation.

Results  The area of CPPP‐treated wounds decreased significantly compared with that of the control wounds (65% vs. 94% of the original size, respectively, P= 0·032). The immunostained section revealed a striking effect of CPPP on vascularization compared with the control wounds (13·2 vs. 2·7 vessels per mm2 as mean vascular density observed in the sections, respectively, P= 0·013).

Conclusions  Our results suggest that CPPP is a promising biologically active dressing for full‐thickness skin wounds. CPPP can be an entirely autologous biological dressing, suggesting that it is free from the risk of transmission of pathogens through blood products.
The Evolution of Exploitation in Humans: ‘Surrounded by Strangers I Thought Were My Friends’1
Authors: Jones Clara B.
Published: April 2007

Early humans were obligately social, living in nested kin groups or close associations of related individuals. Theoretical and empirical research has demonstrated that group life is characterized by both costs (e.g. increased likelihood of disease transmission) and benefits (e.g. enhanced predator defense). This paper addresses the evolution of exploitation in humans (e.g. slavery, infanticide) as a response to within‐group competition for limiting resources (e.g. food, mates), a potential cost of living in groups. Exploitation is defined as one individual's use of another for selfish ends, in particular, the acquisition and/or use of another's resources for the optimization of inclusive fitness. It is argued that exploitation is most likely to occur in relationships characterized by asymmetries such as dependence, intimacy, and/or differential access to resources. A simple mathematical treatment assesses exploitation as a facultative response to local competition among relatives, providing insights into the conditions favorable and adverse to exploitation of conspecifics. Possible applications of the formulations are discussed, including the conditions under which intraspecific exploitation may be beneficial to both actor and recipient(s). Constraints on the evolution of exploitation in humans are identified, and suggestions are made for testing hypotheses related to the differential costs and benefits of exploitation to conspecifics. Future studies may promote the mitigation of exploitation's deleterious effects inHomo sapiens, a body of research which may apply, as well, to other social mammals.
Sex Allocation in Response to Maternal Condition: Different Tactics of Care‐Giving by Male and Female Zebra Finches
Authors: Foster Valerie S. , Burley Nancy Tyler
Published: April 2007

While behavioral ecologists have studied sex allocation for 30 yr, almost nothing is known about the roles of male vs. female parents in making secondary allocation decisions in species with bi‐parental care. To investigate possible sex differences in tactics in zebra finches, we manipulated the condition of one cohort of females by trimming their flight feathers; a second cohort of females and all males were left intact. Focal observations of feeding behavior revealed that manipulated females did not reduce their feeding time, but rather focused their efforts on rearing sons, while control females allocated effort to rearing daughters. Males mated to manipulated females tended to focus effort to daughters, while control males showed no consistent response. Manipulated females experienced a lower reproductive rate, primarily because of a low daughter rate, relative to control females. Manipulated females also laid smaller clutches and had longer inter‐clutch intervals, which suggest that their ability to metabolize and allocate essential proteins from pectoral muscle mass during the egg‐laying period was impaired. To our knowledge, this study is the first to show that parents of both sexes make active sex allocation decisions when the physiological condition of one parent is manipulated; males do not simply adopt female allocation patterns, but make complementary adjustments. Our results have implications for interpretation of handicapping studies that seek to understand the dynamics of inter‐sexual negotiations of care‐giving. Investigation of sex differences in sex allocation tactics in species with limited dietary protein, such as granivorous birds, is a potentially important direction for future research.
Large subunit rDNA and rbcL gene sequence data place Petrohua bernabei gen. et sp. nov. in the Batrachospermales (Rhodophyta), but do not provide further resolution among taxa in this order
Authors: Vis Morgan L. , Harper James T. , Saunders Gary W.
Published: April 2007

The phylogenetic relationship among 12 previously described batrachospermalean taxa and a novel member of the order were investigated using the LSU and rbcL genes separately and in combination. The primary goal of this research was to establish the phylogenetic placement of a previously undescribed freshwater red alga from Chile. The results showed that the new entity with pseudoparenchymatous tube morphology is a member of the Batrachospermales and Petrohua bernabei gen. et sp. nov. is described herein. This is the first record to our knowledge of a Lemanea‐like alga from Chile. It would appear that this thallus construction has evolved at least three times in the Batrachospermales and that the switch from a Batrachospermum‐like construction to a pseudoparenchymatous construction may be a repeated adaptive response to turbulent waterfall habitats. In addition to providing information about a new freshwater red alga, this study sought to determine whether combining the data from two genes would produce a more robust phylogeny, particularly for intermediate nodes, to resolve familial relationships within the order. As with previous analyses, the Batrachospermales was resolved as a clade and support was high for relationships resolved among relatively recent nodes. Unfortunately, combining the LSU and rbcL data did not have the desired effect of more fully resolving intermediate nodes among the Batrachospermales.
Possible surface carbohydrates involved in signaling during conjugation process in Zygnema cruciatum monitored with fluorescein isothiocyanate‐lectins (Zygnemataceae, Chlorophyta)
Authors: Kim Gwang Hoon , Yoon Minchul , West John A. , Klochkova Tatyana A. , Kim Sung‐Ho
Published: April 2007

The changes of cell surface carbohydrates were examined with FITC (fluorescein isothiocyanate)‐labeled lectins during the conjugation process of the green alga Zygnema cruciatum. The Ulex europaeus agglutinin (UEA)‐specific materials were detected consistently on the surface of vegetative cells, but were absent on the surface of protruding papillae or conjugation tube. The tips of male and female papillae were labeled with soybean agglutinin (SBA) and peanut agglutinin (PNA) during conjugation. The SBA‐ and PNA‐specific materials appeared first at the tip of male papillae and began to accumulate on the surface of female papillae. No labeling of these lectins was detected on the surface of vegetative filaments throughout the conjugation process. FITC‐ConA (Concanavalin A) and FITC‐RCA (Ricinus communis agglutinin) did not label the vegetative filaments of Z. cruciatum, but a trace labeling of these lectins was observed on the surface of some swollen papillae occasionally. Blocking experiments with various lectins showed that these SBA‐ and PNA‐specific glycoconjugates might be involved in the signaling between male and female papillae.