bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimates of relatedness in groups of humpback whales (Megaptera novaeangliae) on two wintering grounds of the Southern Hemisphere
Authors: POMILLA CRISTINA , ROSENBAUM HOWARD C. 
Published: July 2006

AbstractGroup formation in humpback whales has been described in relation to different components of the migratory cycle, yet it is debated whether such groups represent real social bonding or ephemeral aggregations. Cooperative behaviours are exhibited during feeding activities, and it has been suggested that males may cooperate during competition for mates. Since most cooperative behaviours are expected to originate among kin, genetic relatedness represents a critical variable in the understanding of any social phenomenon, especially when cooperation cannot be confirmed unequivocally. Using an approach combining multi‐locus microsatellite genotyping and several genetic relatedness estimators, we analyzed whale associations for two different wintering grounds in the Southern Hemisphere. The analyses included 648 whales sampled from 292 groups off the coast of Gabon and Northeast Madagascar, and screened for eleven microsatellite loci. Through simulations, we assessed the performance of three pairwise relatedness estimators. The individuals were molecularly sexed and their associations were investigated in the context of sex and group type. No significant association among relatives was found with the exception of mother–offspring pairs, supporting previous indications of extended maternal care. The analysis from the Gabon population also suggests that related males may avoid each other during competitive activities. Our results demonstrate that if cooperative behaviours occur on wintering grounds they are not favoured by kin selection.
Farmers’ use of wild relative and sexual reproduction in a vegetatively propagated crop. The case of yam in Benin
Authors: SCARCELLI N. , TOSTAIN S. , VIGOUROUX Y. , AGBANGLA C. , DAÏNOU O. , PHAM J.‐L. 
Published: July 2006

AbstractThe impact of traditional farmers’ management on genetic diversity of vegetatively propagated crops is poorly documented. In this study, we analysed the impact of ennoblement of spontaneous yams, an original traditional farmers’ practice, on the genetic diversity of yam (Dioscorea sp.) in Benin. We used 11 microsatellite markers on yam tubers from a small village in northern Benin and demonstrated that wild × cultivated hybrids are spontaneously formed. Many of the spontaneous yams collected by farmers from surrounding savannah areas for ennoblement were shown to be of wild and hybrid genotypes. Moreover, we demonstrated that some yam varieties have a wild or hybrid signature. Lastly, we performed a broader ranging genetic analysis on yam material from throughout Benin and showed that this practice is used in different ecological and ethno‐linguistic regions. Through this practice, farmers create new varieties with new genetic combinations via sexual reproduction of wild and cultivated yams. This system, whereby a sexual cycle and asexual propagation are mixed, ensures potential large‐scale cultivation of the best genotypes while preserving the potential for future adaptation.
A novel high‐throughput genetic screen for stress‐responsive mutants of Arabidopsis thaliana reveals new loci involving stress responses
Authors: Rama Devi S. , Chen Xi , Oliver David J. , Xiang Chengbin 
Published: July 2006

SummaryActivation sequence‐1 (as‐1) cognate promoter elements are widespread in the promoters of plant defense‐related genes as well as in plant pathogen promoters, and may play important roles in the activation of defense‐related genes. The as‐1‐type elements are highly responsive to multiple stress stimuli such as jasmonic acid (JA), salicylic acid (SA), H2O2, xenobiotics and heavy metals, and therefore provide a unique opportunity for identifying additional signaling components and cross‐talk points in the various signaling networks. A single as‐1‐type cis‐element‐driven GUS reporter Arabidopsis line responsive to JA, SA, H2O2, xenobiotics and heavy metals was constructed for mutagenesis. A large‐scale T‐DNA mutagenesis has been conducted in the reporter background, and an efficient high‐throughput mutant screen was established for isolating mutants with altered responses to the stress chemicals. A number of mutants with altered stress responses were obtained, some of which appear to identify new components in the as‐1‐based signal transduction pathways. We characterized a mutant (Δ8L4) with a T‐DNA insertion in the coding sequence of the gene At4g24275. The as‐1‐regulated gene expression and GUS reporter gene expression were altered in the Δ8L4 mutant, but there was no change in the expression of genes lacking as‐1 elements in their promoters. The phenotype observed with the Δ8L4 mutant was further verified using RNAi plants for At4g24275 (8L4‐RNAi), suggesting the feasibility of use of this high‐throughput mutant screening in isolating stress‐signaling mutants.
Diverse phosphoregulatory mechanisms controlling cyclin‐dependent kinase‐activating kinases in Arabidopsis
Authors: Shimotohno Akie , Ohno Ryoko , Bisova Katerina , Sakaguchi Norihiro , Huang Jirong , Koncz Csaba , Uchimiya Hirofumi , Umeda Masaaki 
Published: July 2006

SummaryFor the full activation of cyclin‐dependent kinases (CDKs), not only cyclin binding but also phosphorylation of a threonine (Thr) residue within the T‐loop is required. This phosphorylation is catalyzed by CDK‐activating kinases (CAKs). In Arabidopsis three D‐type CDK genes (CDKD;1–CDKD;3) encode vertebrate‐type CAK orthologues, of which CDKD;2 exhibits high phosphorylation activity towards the carboxy‐terminal domain (CTD) of the largest subunit of RNA polymerase II. Here, we show that CDKD;2 forms a stable complex with cyclin H and is downregulated by the phosphorylation of the ATP‐binding site by WEE1 kinase. A knockout mutant of CDKD;3, which has a higher CDK kinase activity, displayed no defect in plant development. Instead, another type of CAK – CDKF;1 – exhibited significant activity towards CDKA;1 in Arabidopsis root protoplasts, and the activity was dependent on the T‐loop phosphorylation of CDKF;1. We propose that two distinct types of CAK, namely CDKF;1 and CDKD;2, play a major role in CDK and CTD phosphorylation, respectively, in Arabidopsis.
A simple in vitro RNA editing assay for chloroplast transcripts using fluorescent dideoxynucleotides: distinct types of sequence elements required for editing of ndh transcripts
Authors: Sasaki Tadamasa , Yukawa Yasushi , Wakasugi Tatsuya , Yamada Kyoji , Sugiura Masahiro 
Published: July 2006

SummaryRNA editing is found in various transcripts from land plant chloroplasts. In tobacco chloroplasts, C‐to‐U conversion occurs at 36 specific sites including two sites identified in this work. Our RNA editing assay system using chloroplast extracts facilitated biochemical analyses of editing reactions but required mRNAs labeled with 32P at specific sites. Here, we have improved the in vitro system using fluorescence‐labeled chain terminators, ddGTP and ddATP, and have measured the editing activity at 19 sites in ndh transcripts. Editing activities varied from site to site. It has been reported that one editing site in ndhA mRNAs is present in spinach but absent in tobacco, but a corresponding editing capacity had been found in vivo in tobacco using biolistic transformation. We confirmed biochemically the existence of this activity in tobacco extracts. Using the non‐radioactive assay, we examined sequences essential for editing within a 50‐nt mRNA region encompassing an editing site. Editing of the ndhB‐2 site requires a short sequence in front of the editing site, while that of the ndhF mRNA requires two separate regions, a sequence surrounding the editing site and a 5′ distal sequence. These results suggest that distinct editing mechanisms are present in chloroplasts.
Mycosphaerella species associated with leaf disease of Eucalyptus globulus in Ethiopia
Authors: Gezahgne Alemu , Roux J. , Hunter G. C. , Wingfield M. J. 
Published: July 2006

Summary Eucalyptus spp. are among the most widely planted exotic trees in Ethiopia. Several damaging leaf pathogens are known from Eucalyptus spp. worldwide. Of these, Mycosphaerella spp. are among the most important, causing the disease known as Mycosphaerella leaf disease (MLD). Characteristic symptoms of MLD include leaf spot, premature defoliation, shoot and twig dieback. Recent disease surveys conducted in Ethiopian Eucalyptus plantations have revealed disease symptoms similar to those caused by Mycosphaerella spp. These symptoms were restricted to E. globulus trees growing in several localities in south, south western and western Ethiopia. The aim of this study was to identify the fungi associated with this disease. This was achieved by examining ascospore germination patterns, anamorph associations and sequence data from the Internal Transcribed Spacer (ITS) region of the rRNA operon, for representative isolates. Several different ascospore germination patterns were observed, suggesting that more than one species of Mycosphaerella is responsible for MLD on E. globulus in Ethiopia. Analysis of sequence data showed that three Mycosphaerella spp., M. marksii, M. nubilosa and M. parva were present. This is the first report of these three species from Ethiopia and represents a valuable basis on which to build further studies in the region.
Polymorphism and chromosomal localization of the porcine signal transducer and activator of transcription 5B gene (STAT5B)
Authors: Ballester M. , Sardina M.T. , Folch J.M. 
Published: July 2006

SummarySignal transducers and activators of transcription (STATs) are a family of transcription factors. STAT5A and 5B are two highly related proteins encoded by two distinct genes. Transgenic knockout mice studies have indicated the importance of STAT5 proteins for the regulation of both lactation and growth performance. Moreover, different studies determine the role of STAT5 proteins in the modulation of adipocyte function. In this study, we sequenced one fragment of STAT5B gene from animals of six breeds (Duroc, Iberian, Landrace, Large White, Piétrain and Meishan) to identify genetic variants. A G/A single nucleotide polymorphism in intron 14 creates a polymorphic PstI restriction site and was genotyped by polymerase chain reaction restriction fragment length polymorphism in the six breeds. Allele G was only present in Large White, Piétrain and Meishan populations, detecting only G allele in this last pig breed. The STAT5B gene was located by radiation hybrid mapping to porcine chromosome 12, within the confidence interval for the fatty acid composition quantitative trait loci, previously identified in an Iberian × Landrace cross.
Strategy for applying genome‐wide selection in dairy cattle
Authors: Schaeffer L.R. 
Published: July 2006

SummaryAnimals can be genotyped for thousands of single nucleotide polymorphisms (SNPs) at one time, where the SNPs are located at roughly 1‐cM intervals throughout the genome. For each contiguous pair of SNPs there are four possible haplotypes that could be inherited from the sire. The effects of each interval on a trait can be estimated for all intervals simultaneously in a model where interval effects are random factors. Given the estimated effects of each haplotype for every interval in the genome, and given an animal's genotype, a ‘genomic’ estimated breeding value is obtained by summing the estimated effects for that genotype. The accuracy of that estimator of breeding values is around 80%. Because the genomic estimated breeding values can be calculated at birth, and because it has a high accuracy, a strategy that utilizes these advantages was compared with a traditional progeny testing strategy under a typical Canadian‐like dairy cattle situation. Costs of proving bulls were reduced by 92% and genetic change was increased by a factor of 2. Genome‐wide selection may become a popular tool for genetic improvement in livestock.
Effect of supplemental yeast culture and sodium bicarbonate on ruminal fermentation and blood variables in rams
Authors: Galıp Nurten 
Published: July 2006

SummaryA trial was conducted to evaluate the effect of sodium bicarbonate (BC) and Saccharomyces cerevisiae, live yeast culture (yea sacc1026, YS) on ruminal fermentation and blood variables. Four Kivircik rams with ruminal cannula were used in a Latin square design, during 27‐day periods (20 days for adaptation and 7 days for collection). They received 0 (control group), 5 g/day (i.e. 25 × 109 CFU) of YS or 10 g/day of sodium BC or 10 g/day of BC and 5 g/day of YS (BC + YS) (treatment groups). The cultures and sodium BC were added to the ration in a grain mix. The ration consisted of 70% grain mix and 30% lucerne hay. Rumen contents were collected before and 3 h and 6 h after morning feeding on days 1 and 7 in each collection period and were analyzed. Blood samples were also collected on the same days. Ruminal pH at 3 h (p ≤ 0.1) and 6 h (p ≤ 0.05) after feeding were higher when rams were fed BC and BC + YS than when they were fed CG and YS. Addition of YS to the diet did not modify the proportions of the different protozoa types; only Diplodinium at 0 h tended to be lower (p < 0.1) when rams were fed YS, BC and BC + YS than when they were fed CG. Plasma sodium value decreased by YS and BC + YS. Other biochemical and haematological variables were not affected by treatments. Also total volatile fatty acid, NH3‐N concentrations and protozoa counts in the ruminal fluid were not affected by treatments.
Effects of copper, zinc and selenium status on performance and health in commercial dairy and beef herds: retrospective study
Authors: Enjalbert F. , Lebreton P. , Salat O. 
Published: July 2006

SummaryA retrospective study using analysis of plasma copper and zinc, and erythrocyte glutathione peroxidase from 2 080 dairy and beef cow herds was conducted to evaluate the relationship between trace‐element status and production, reproduction and health in cows and their calves. Classification of the herd status as deficient, marginal, low‐adequate or high‐adequate was based on the lower tercile of individual values. Odds ratios for each disorder in herds were calculated by multivariable stepwise logistic regression. Inadequate copper status was not associated with adult disorders, but was an important risk factor for poor calf performance or health. Selenium deficient status was associated with most studied disorders in cows, and both deficient and marginal herd status were strongly associated with poor health of calves, particularly with increased risks of myopathy and infectious diseases. Zinc insufficiency was strongly associated with low milk production and impaired locomotion in dairy herds, and was also associated with diarrhoea and poor growth in calves. Because a low‐adequate status increased the risk of many disorders in adults and calves, we propose to classify herds as deficient and marginal when the lower terciles of plasma zinc concentration are below 12 and between 12 and 14 μmol/l respectively.
Neurotensin antagonist acutely and robustly attenuates locomotion that accompanies stimulation of a neurotensin‐containing pathway from rostrobasal forebrain to the ventral tegmental area
Authors: Reynolds Sheila M. , Geisler Stefanie , Bérod Anne , Zahm Daniel S. 
Published: July 2006

AbstractNeurotensin exerts complex effects on the mesolimbic dopamine system that alter motivation and contribute to neuroadaptations associated with psychostimulant drug administration. Activation of abundant neurotensin receptors in the ventral tegmental area (VTA) enhances dopamine neuron activity and associated release of dopamine in the nucleus accumbens (Acb) and cortex. In view of recent anatomical studies demonstrating that 70% of all neurotensin‐containing neurons projecting to the VTA occupy the lateral preoptic area–rostral lateral hypothalamus (LPH) and lateral part of the medial preoptic area (MPOA), the present study examined functionality in the LPH–MPOA neurotensinergic pathway in the rat. Disinhibition (resulting ultimately in stimulation‐like effects) of LPH–MPOA neurons with microinjected bicuculline (50 or 100 ng in 0.25 µL) produced locomotor activation that was considerably attenuated by systemic administration of the neurotensin antagonist SR 142948 A (0.03 and 0.1 mg/kg). In contrast, locomotion elicited in this manner was completely blocked by SR 142948 A infused directly into the VTA (5.0 and 15.0 ng in 0.25 µL). Baseline locomotion was unaffected by systemic or intra‐VTA administration of SR 142948 A and LPH–MPOA‐elicited locomotion was unaffected by infusion of SR 142948 A into the substantia nigra pars compacta and sites rostral and dorsal to the VTA. Locomotion was not elicited by infusions of bicuculline into the lateral hypothalamus at sites caudal to the LPH–MPOA, where neurotensin neurons projecting to the VTA are fewer. The results demonstrate the capacity of a neurotensin‐containing pathway from LPH–MPOA to VTA to modulate locomotion. This pathway may be important in linking hippocampal and mesolimbic mechanisms in normal behaviour and drug addiction.
Altered emotional behavioral responses in mice lacking brain‐type fatty acid‐binding protein gene
Authors: Owada Yuji , Abdelwahab Soha Abdelkawi , Kitanaka Noriko , Sakagami Hiroyuki , Takano Hiroshi , Sugitani Yoshinobu , Sugawara Minoru , Kawashima Hiroshi , Kiso Yoshinobu , Mobarakeh Jalal Izadi , Yanai Kazuhiko , Kaneko Kenya , Sasaki Hiroshi , Kato Hiroshi , Saino‐Saito Sachiko , Matsumoto Nozomu , Akaike Norio , Noda Tetsuo , Kondo Hisatake 
Published: July 2006

AbstractBrain‐type fatty acid‐binding protein (B‐FABP) belongs to a family of intracellular lipid‐binding proteins. B‐FABP exhibits a binding affinity to long‐chain fatty acids (FAs) whose effects on brain functions including development, emotion, learning and memory have been proposed. B‐FABP is localized in the ventricular germinal cells in embryonic brain and astrocytes in developing and mature brain of rodents. In the present study we generated the mouse harboring a null mutation in the B‐FABP gene and studied its phenotype. B‐FABP mutant mice exhibited the enhanced anxiety and increased fear memory as well as the decreased content of docosahexaenoic acid (DHA) in their brain during the neonatal period without detection of any histological changes in the brain. In the adult brain, B‐FABP was localized more numerously to the astrocytes in the amygdala and septal area than to those in the hippocampal area. Analysis of FA content in the amygdala of adult brain revealed that arachidonic and palmitic acids increased significantly in the mutant mice compared with wild‐type. Furthermore, the response of N‐methyl‐d‐aspartate receptor‐mediated current to DHA in isolated neurons from B‐FABP mutant brain was significantly decreased compared with that of wild‐type, while no significant differences were detected in behavioral responses related to the spatial learning/memory or in the hippocampal long‐term potentiation. These data indicate that B‐FABP is crucially involved in the fear memory and anxiety through its binding with FAs and/or its own direct effects on pertinent metabolism/signaling of FAs.
Progesterone reverses the spatial memory enhancements initiated by tonic and cyclic oestrogen therapy in middle‐aged ovariectomized female rats
Authors: Bimonte‐Nelson Heather A. , Francis Kevin R. , Umphlet Claudia D. , Granholm Ann‐Charlotte 
Published: July 2006

AbstractWhile some research has indicated that ovarian hormone therapy (HT) benefits memory and decreases risk of Alzheimer's disease in menopausal women, several newer studies have shown null or detrimental effects. Despite the null and negative cognitive findings, the numerous studies showing positive effects beg the question of what factors determine whether HT acts as a neuroprotectant or a risk factor for brain functioning. Using middle‐aged female rats, we directly compared six HTs. We evaluated the effects of ovariectomy, tonic low‐dose, tonic high‐dose and biweekly cyclic estradiol treatment, as well as whether progesterone altered the effectiveness of any one of these oestrogen regimens. Animals were tested on spatial and complex cued (intramaze patterns) reference memory using variants of the Morris maze. The tonic low‐dose and cyclic estradiol treatments improved spatial performance, while the addition of progesterone reversed these beneficial cognitive effects of estradiol. Additionally, all groups learned to locate the platform on the cued task; however, an egocentric circling strategy was used with sham ovary‐intact and hormone‐replacement groups showing the most efficient search strategy. Although the question of memory retention 8 weeks after the first cognitive assessment was addressed, a large number of animals died between the first and second test, rendering the retest uninterpretable for many group comparisons. Specifically, both doses of tonic estradiol dramatically increased the number of deaths during the 17‐week experiment, while the cyclic estradiol treatment did not. Progesterone decreased the number of deaths due to tonic estradiol treatment. Our findings suggest that the dose of estradiol replacement as well as the presence of progesterone influences the cognitive outcome of estradiol treatment. Further, there appears to be a dissociation between HT effects on cognition and mortality rates.
Selective rapid eye movement sleep deprivation impairs the maintenance of long‐term potentiation in the rat hippocampus
Authors: Ishikawa Akinori , Kanayama Yasuyo , Matsumura Hideki , Tsuchimochi Hirotsugu , Ishida Yoshiyuki , Nakamura Shoji 
Published: July 2006

AbstractRapid eye movement (REM) sleep deprivation (RSD) is known to impair learning and memory. Previous studies have demonstrated that RSD induces an impairment of hippocampal long‐term potentiation (LTP). In most of these studies, RSD was set up prior to LTP induction. In this work, we focused on RSD after LTP induction. We investigated the effect of RSD for 24–48 h after induction of LTP in the dentate gyrus on LTP maintenance and whether a REM rebound after 48 h RSD affected LTP. RSD rats were deprived of REM sleep by stroking their backs using a brush, whereas control rats were allowed to sleep freely. Another control group of rats was awoken during non‐REM sleep (NRS) under the same conditions (NRS group). REM‐deprived rats displayed a faster decay of population spike amplitudes compared with the control and NRS groups over a 24‐h recording time. After 48 h RSD, there was no difference in the population spike amplitudes before or after 4 h of release from RSD. These results suggest that REM sleep after LTP induction in the dentate gyrus plays an essential role in LTP maintenance, whereas a REM rebound does not restore the RSD‐induced impairment of LTP.