bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unraveling the Genetic Complexity of Drosophila stardust During Photoreceptor Morphogenesis and Prevention of Light-Induced Degeneration
Authors: Berger Sandra , Bulgakova Natalia A , Grawe Ferdi , Johnson Kevin , Knust Elisabeth 
Published: July 2007

Abstract
Drosophila Stardust, a membrane-associated guanylate kinase (MAGUK), recruits the transmembrane protein Crumbs and the cytoplasmic proteins DPATJ and DLin-7 into an apically localized protein scaffold. This evolutionarily conserved complex is required for epithelial cell polarity in Drosophila embryos and mammalian cells in culture. In addition, mutations in Drosophila crumbs and DPATJ impair morphogenesis of photoreceptor cells (PRCs) and result in light-dependent retinal degeneration. Here we show that stardust is a genetically complex locus. While all alleles tested perturb epithelial cell polarity in the embryo, only a subset of them affects morphogenesis of PRCs or induces light-dependent retinal degeneration. Alleles retaining particular postembryonic functions still express some Stardust protein in pupal and/or adult eyes. The phenotypic complexity is reflected by the expression of distinct splice variants at different developmental stages. All proteins expressed in the retina contain the PSD95, Discs Large, ZO-1 (PDZ), Src homology 3 (SH3), and guanylate kinase (GUK) domain, but lack a large region in the N terminus encoded by one exon. These results suggest that Stardust-based protein scaffolds are dynamic, which is not only mediated by multiple interaction partners, but in addition by various forms of the Stardust protein itself.
Molecular Differentiation at Nuclear Loci in French Host Races of the European Corn Borer (Ostrinia nubilalis)
Authors: Malausa Thibaut , Leniaud Laurianne , Martin Jean-François , Audiot Philippe , Bourguet Denis , Ponsard Sergine , Lee Siu-Fai , Harrison Richard G , Dopman Erik 
Published: July 2007

Abstract
French populations of the European corn borer consist of two sympatric and genetically differentiated host races. As such, they are well suited to study processes that could be involved in sympatric speciation, but the initial conditions of host-race divergence need to be elucidated. Gene genealogies can provide insight into the processes involved in speciation. We used DNA sequences of four nuclear genes to (1) document the genetic structure of the two French host races previously delineated with allozyme markers, (2) find genes directly or indirectly involved in reproductive isolation between host races, and (3) estimate the time since divergence of the two taxa and see whether this estimate is compatible with this divergence being the result of a host shift onto maize after its introduction into Europe ∼500 years ago. Gene genealogies revealed extensive shared polymorphism, but confirmed the previously observed genetic differentiation between the two host races. Significant departures from the predictions of neutral molecular evolution models were detected at three loci but were apparently unrelated to reproductive isolation between host races. Estimates of time since divergence between French host races varied from ∼75,000 to ∼150,000 years, suggesting that the two taxa diverged recently but probably long before the introduction of maize into Europe.
Concerted Evolution of rDNA in Recently Formed Tragopogon Allotetraploids Is Typically Associated With an Inverse Correlation Between Gene Copy Number and Expression
Authors: Matyášek Roman , Tate Jennifer A , Lim Yoong K , Šrubařová Hana , Koh Jin , Leitch Andrew R , Soltis Douglas E , Soltis Pamela S , Kovařík Aleš 
Published: July 2007

Abstract
We analyzed nuclear ribosomal DNA (rDNA) transcription and chromatin condensation in individuals from several populations of Tragopogon mirus and T. miscellus, allotetraploids that have formed repeatedly within only the last 80 years from T. dubius and T. porrifolius and T. dubius and T. pratensis, respectively. We identified populations with no (2), partial (2), and complete (4) nucleolar dominance. It is probable that epigenetic regulation following allopolyploidization varies between populations, with a tendency toward nucleolar dominance by one parental homeologue. Dominant rDNA loci are largely decondensed at interphase while silent loci formed condensed heterochromatic regions excluded from nucleoli. Those populations where nucleolar dominance is fixed are epigenetically more stable than those with partial or incomplete dominance. Previous studies indicated that concerted evolution has partially homogenized thousands of parental rDNA units typically reducing the copy numbers of those derived from the T. dubius diploid parent. Paradoxically, despite their low copy number, repeats of T. dubius origin dominate rDNA transcription in most populations studied, i.e., rDNA units that are genetic losers (copy numbers) are epigenetic winners (high expression).
Genetic Exchange Across a Species Boundary in the Archaeal Genus Ferroplasma
Authors: Eppley John M , Tyson Gene W , Getz Wayne M , Banfield Jillian F 
Published: July 2007

AbstractSpeciation as the result of barriers to genetic exchange is the foundation for the general biological species concept. However, the relevance of genetic exchange for defining microbial species is uncertain. In fact, the extent to which microbial populations comprise discrete clusters of evolutionarily related organisms is generally unclear. Metagenomic data from an acidophilic microbial community enabled a genomewide, comprehensive investigation of variation in individuals from two coexisting natural archaeal populations. Individuals are clustered into species-like groups in which cohesion appears to be maintained by homologous recombination. We quantified the dependence of recombination frequency on sequence similarity genomewide and found a decline in recombination with increasing evolutionary distance. Both inter- and intralineage recombination frequencies have a log-linear dependence on sequence divergence. In the declining phase of interspecies genetic exchange, recombination events cluster near the origin of replication and are localized by tRNAs and short regions of unusually high sequence similarity. The breakdown of genetic exchange with increasing sequence divergence could contribute to, or explain, the establishment and preservation of the observed population clusters in a manner consistent with the biological species concept.
Shs1 Plays Separable Roles in Septin Organization and Cytokinesis in Saccharomyces cerevisiae
Authors: Iwase Masayuki , Luo Jianying , Bi Erfei , Toh-e Akio 
Published: July 2007

Abstract
In Saccharomyces cerevisiae, five septins (Cdc3, Cdc10, Cdc11, Cdc12, and Shs1/Sep7) form the septin ring at the bud neck during vegetative growth. We show here that disruption of SHS1 caused cold-sensitive growth in the W303 background, with cells arrested in chains, indicative of a cytokinesis defect. Surprisingly, the other four septins appeared to form an apparently normal septin ring in shs1Δ cells grown under the restrictive condition. We found that Myo1 and Iqg1, two components of the actomyosin contractile ring, and Cyk3, a component of the septum formation, were either delocalized or mislocalized in shs1Δ cells, suggesting that Shs1 plays supportive roles in cytokinesis. We also found that deletion of SHS1 enhanced or suppressed the septin defect in cdc10Δ and cdc11Δ cells, respectively, suggesting that Shs1 is involved in septin organization, exerting different effects on septin-ring assembly, depending on the composition of the septin subunits. Furthermore, we constructed an shs1-100c allele that lacks the coding sequence for the C-terminal 32 amino acids. This allele still displayed the genetic interactions with the septin mutants, but did not show cytokinesis defects as described above, suggesting that the roles of Shs1 in septin organization and cytokinesis are separable.
Choline Transport and de novo Choline Synthesis Support Acetylcholine Biosynthesis in Caenorhabditis elegans Cholinergic Neurons
Authors: Mullen Gregory P , Mathews Eleanor A , Vu Mai H , Hunter Jerrod W , Frisby Dennis L , Duke Angie , Grundahl Kiely , Osborne Jamie D , Crowell John A , Rand James B 
Published: July 2007

Abstract
The cho-1 gene in Caenorhabditis elegans encodes a high-affinity plasma-membrane choline transporter believed to be rate limiting for acetylcholine (ACh) synthesis in cholinergic nerve terminals. We found that CHO-1 is expressed in most, but not all cholinergic neurons in C. elegans. cho-1 null mutants are viable and exhibit mild deficits in cholinergic behavior; they are slightly resistant to the acetylcholinesterase inhibitor aldicarb, and they exhibit reduced swimming rates in liquid. cho-1 mutants also fail to sustain swimming behavior; over a 33-min time course, cho-1 mutants slow down or stop swimming, whereas wild-type animals sustain the initial rate of swimming over the duration of the experiment. A functional CHO-1∷GFP fusion protein rescues these cho-1 mutant phenotypes and is enriched at cholinergic synapses. Although cho-1 mutants clearly exhibit defects in cholinergic behaviors, the loss of cho-1 function has surprisingly mild effects on cholinergic neurotransmission. However, reducing endogenous choline synthesis strongly enhances the phenotype of cho-1 mutants, giving rise to a synthetic uncoordinated phenotype. Our results indicate that both choline transport and de novo synthesis provide choline for ACh synthesis in C. elegans cholinergic neurons.
Epistasis Between Calpain 1 and Its Inhibitor Calpastatin Within Breeds of Cattle
Authors: Barendse W , Harrison B E , Hawken R J , Ferguson D M , Thompson J M , Thomas M B , Bunch R J 
Published: July 2007

Abstract
The calpain gene family and its inhibitors have diverse effects, many related to protein turnover, which appear to affect a range of phenotypes such as diabetes, exercise-induced muscle injury, and pathological events associated with degenerative neural diseases in humans, fertility, longevity, and postmortem effects on meat tenderness in livestock species. The calpains are inhibited by calpastatin, which binds directly to calpain. Here we report the direct measurement of epistatic interactions of causative mutations for quantitative trait loci (QTL) at calpain 1 (CAPN1), located on chromosome 29, with causative mutations for QTL variation at calpastatin (CAST), located on chromosome 7, in cattle. First we identified potential causative mutations at CAST and then genotyped these along with putative causative mutations at CAPN1 in &gt;1500 cattle of seven breeds. The maximum allele substitution effect on the phenotype of the CAPN1:c.947G&gt;C single nucleotide polymorphism (SNP) was 0.14 σp (P = 0.0003) and of the CAST:c.155C&gt;T SNP was also 0.14 σp (P = 0.0011) when measured across breeds. We found significant epistasis between SNPs at CAPN1 and CAST in both taurine and zebu derived breeds. There were more additive × dominance components of epistasis than additive × additive and dominance × dominance components combined. A minority of breed comparisons did not show epistasis, suggesting that genetic variation at other genes may influence the degree of epistasis found in this system.
Hand-Washing and Diapering Equipment Reduces Disease Among Children in Out-of-Home Child Care Centers
Authors: Kotch Jonathan B. , Isbell Patricia , Weber David J. , Nguyen Viet , Savage Eric , Gunn Elizabeth , Skinner Martie , Fowlkes Stephen , Virk Jasveer , Allen Jonnell 
Published: July 2007

OBJECTIVE. The objective of this study was to determine whether the installation of equipment for diaper-changing, hand-washing, and food preparation that is specifically designed to reduce the transmission of infectious agents would result in a decrease in the rate of diarrheal illness among children and their teachers in child care centers.METHODS. Twenty-three pairs of child care centers were matched on size and star-rated license level. One member of each pair was randomly assigned to an intervention group and the other to a control group. Intervention centers received new diaper-changing, hand-washing, and food-preparation equipment, and both intervention and control centers received hygiene and sanitation training with reinforcement and follow-up as needed. Families with children in participating classrooms were called biweekly to ascertain the frequency and severity of any diarrheal illness episodes. Staff attendance was monitored, and staff hygiene and sanitation behaviors were observed and recorded monthly.RESULTS. Although hygiene and sanitation behaviors improved in both intervention and control centers, there was a significant difference favoring the intervention centers with respect to frequency of diarrheal illness (0.90 vs 1.58 illnesses per 100 child-days in control centers) and proportion of days ill as a result of diarrhea (4.0% vs 5.0% in control centers) among the children. Staff in those same classrooms were reported to have a significantly lower proportion of days absent as a result of any illness (0.77% in treatment centers versus 1.73% in control centers).CONCLUSION. Diapering, hand-washing, and food-preparation equipment that is specifically designed to reduce the spread of infectious agents significantly reduced diarrheal illness among the children and absence as a result of illness among staff in out-of-home child care centers.
Screening and Treatment for Lipid Disorders in Children and Adolescents: Systematic Evidence Review for the US Preventive Services Task Force
Authors: Haney Elizabeth M. , Huffman Laurie Hoyt , Bougatsos Christina , Freeman Michele , Steiner Robert D. , Nelson Heidi D. 
Published: July 2007

OBJECTIVE. This was a systematic evidence review for the US Preventive Services Task Force, intended to synthesize the published evidence regarding the effectiveness of selecting, testing, and managing children and adolescents with dyslipidemia in the course of routine primary care.METHODS. Literature searches were performed to identify published articles that addressed 10 key questions. The review focused on screening relevant to primary care of children without previously identified dyslipidemias, but included treatment trials of children with dyslipidemia because some drugs have only been tested in that population.RESULTS. Normal values for lipids for children and adolescents are defined according to population levels (percentiles). Age, gender, and racial differences and temporal trends may alter these statistical cut points. Approximately 40% to 55% of children with elevated total cholesterol and low-density lipoprotein levels will continue to have elevated lipid levels on follow-up. Current screening recommendations based on family history will fail to detect substantial numbers (30%–60%) of children with elevated lipid levels. Drug treatment for dyslipidemia in children has been studied and shown to be effective only for suspected or proven familial monogenic dyslipidemias. Intensive dietary counseling and follow-up can result in improvements in lipid levels, but these results have not been sustained after the cessation of the intervention. The few trials of exercise are of fair-to-poor quality and show little or no improvements in lipid levels for children without monogenic dyslipidemias. Although reported adverse effects were not serious, studies were generally small and not of sufficient duration to determine long-term effects of either short or extended use.CONCLUSIONS. Several key issues about screening and treatment of dyslipidemia in children and adolescents could not be addressed because of lack of studies, including effectiveness of screening on adult coronary heart disease or lipid outcomes, optimal ages and intervals for screening children, or effects of treatment of childhood lipid levels on adult coronary heart disease outcomes.
Self-Reported Health Status and Health-Related Quality of Life of Teenagers Who Were Born Before 29 Weeks' Gestational Age
Authors: Gray Ron , Petrou Stavros , Hockley Christine , Gardner Frances 
Published: July 2007

OBJECTIVE. The objective of this study was to describe the self-reported health status and health-related quality of life of British teenagers who are in mainstream schooling and were born before 29 weeks' gestational age compared with British teenagers who were born at term.
METHODS. All surviving children who were born at &lt;29 weeks' gestation in the former Northern Region of England in 1983 and in the former Oxford Region of England and in Scotland in 1984 were eligible. A comparison group of teenagers who were born at term were also recruited. Children's responses to the Health Utilities Index Mark III were compared.
RESULTS. A total of 218 of the original 535 children who were born in the 3 regions during the study period were alive at 15 to 16 years of age. A complete Health Utilities Index Mark III record was available for 140 children in mainstream schools and for 108 control subjects. In 7 of the 8 attributes (vision, hearing, speech, emotion, pain, ambulation, and dexterity), there were no statistically significant differences in any functional impairment between the comparator groups. However, the preterm group did report a higher level of functional impairment in the cognition attribute (40.7% vs 25.0%). Although there was no difference in the median Health Utilities Index Mark III utility score between the 2 groups (0.93), there was a broader range of utility scores for the preterm group (0.07–1.0 vs 0.45–1.0 for the control group).
CONCLUSIONS. Despite objective evidence that children and teenagers who were born preterm have poorer health on average than term-born control subjects, this is not reflected in their own ratings of their health status and health-related quality of life at 15 to 16 years of age. The reasons for these differences need to be further explored.
Parental Ability to Discriminate the Weight Status of Children: Results of a Survey
Authors: Huang Jeannie S. , Becerra Karen , Oda Thaghar , Walker Edward , Xu Ronghui , Donohue Michael , Chen Iris , Curbelo Violeta , Breslow Adam 
Published: July 2007

OBJECTIVES. In this study we aimed to explore parents' weight perceptions of their children and of unrelated children.
METHODS. Parents of children ≤18 years of age who were attending pediatric clinics throughout San Diego County, California, were surveyed concerning their children's weight status and the weight status of unrelated children in various age groups. Height and weight were measured, and weight status was determined for both the parent and child. The influence of various demographic variables on parents' weight perceptions and the relationship between parents' perceptions of weight of their children and parents' perceptions of weight of unrelated children were evaluated. Multivariate regression modeling was applied to identify predictors of parents' perceptions of weight of their own children.
RESULTS. Of 1098 parents surveyed, 87% were women, 74% were white, and 46% reported Hispanic ethnicity. Seventy percent of the parents surveyed were overweight or obese, and 39% of their children were at risk for overweight or overweight. Sixty-one percent of parents correctly identified their children's weight status, and parents were able to correctly identify the weight status of unrelated children in 58% of reviewed photographs. Parents' weight perceptions of their children were not related to their ability to determine the weight status of unrelated children or to their ideal weight selections among unrelated children. In a multivariate logistic regression analysis, parental ability to correctly assess their child's weight status was associated with their child's age and weight status.
CONCLUSIONS. Parents' perceptions of their own children's weight status are influenced by their children's characteristics and do not seem to correspond with their weight perceptions of unrelated children. Parental recognition of weight issues in their offspring may be impeded by their inability to apply criteria used to ascertain the weight status of unrelated children to their own children.
Addressing Parents’ Concerns About Childhood Immunizations: A Tutorial for Primary Care Providers
Authors: Levi Benjamin H. 
Published: July 2007

BACKGROUND. Despite the dangers of vaccine-preventable infections and efforts by health care professionals to promote immunization, parents’ resistance to routine childhood immunizations continues to grow. This phenomenon can give rise to frustration among health care providers, as well as create barriers in providing medical care to children in need. In response, we developed a CD-ROM–based tutorial that (1) explains the nature and origins of parents’ concerns, (2) addresses clinical implications of resistance to immunization, (3) explores ethical and professional obligations that physicians have toward children and their parents, and (4) discusses how physicians can effectively address parents’ concerns.
OBJECTIVE. Our goals were to evaluate the tutorial's effectiveness in improving physicians’ (1) general knowledge about parents’ resistance to childhood immunizations, (2) knowledge of adverse effects of immunization, and (3) attitudes toward parents’ resistance to childhood immunization.
DESIGN/METHODS. After pretesting, expert review, and revision, the 45-minute Penn State Immunization Project tutorial was pilot tested with pediatric and family medicine residents at 7 training programs in 4 states (Pennsylvania, New York, Maryland, and Iowa). Knowledge and attitudes were assessed by using a 26-item pretest/posttest, the results of which were then analyzed by using standard statistical methods.
RESULTS. A total of 122 residents completed the pretest/posttest. Statistically and clinically significant improvements were seen in residents’ general knowledge, knowledge of adverse events, and all 5 attitudinal measures regarding childhood immunizations.
CONCLUSIONS. The tutorial Addressing Parents Concerns About Childhood Immunizations: A Tutorial for Primary Care Providers is effective in improving resident physicians’ general knowledge, knowledge of adverse events, and attitudes. As such, this tutorial has the potential to enhance communication between parents and primary care providers and, more generally, improve clinicians’ response to the growing resistance toward routine childhood immunizations.