bluuebunny/crossref_metadata_2025_split huggingface dataset:
In developing Drosophila neurones the production of γ‐amino butyric acid is tightly regulated downstream of glutamate decarboxylase translation and can be influenced by calcium
Authors: Küppers Barbara , Sánchez‐Soriano Natalia , Letzkus Johannes , Technau Gerhard M. , Prokop Andreas 
Published: March 2003

AbstractThe presented work pioneers the embryonic Drosophila CNS for studies of the developmental regulation and function of γ‐amino butyric acid (GABA). We describe for the first time the developmental pattern of GABA in Drosophila and address underlying regulatory mechanisms. Surprisingly, and in contrast to vertebrates, detectable levels of GABA occur late during Drosophila neurogenesis, after essential neuronal proliferation and growth have taken place and synaptogenesis has been initiated. This timeline is almost unchanged when the GABA synthetase glutamate decarboxylase (GAD) is strongly misexpressed throughout the nervous system suggesting a tight post‐translational regulation of GABA expression. We confirmed such GABA control mechanisms in an independent model system, i.e. primary Drosophila cell cultures raised in elevated [K+]. The data suggest that, in both systems, GABA suppression occurs via control of GAD activity. Using developing embryos and cell cultures as parallel assay systems for pharmacological and genetic studies we show that the negative regulation of GAD can be overridden by drugs known to elevate intracellular free [Ca2+]. Our results provide the basis for investigations of genetic mechanisms underlying the observed phenomenon, and we discuss the potential implications of this work for Drosophila neurogenesis but also for a general understanding of GAD regulation.
The basic helix‐loop‐helix differentiation factor Nex1/MATH‐2 functions as a key activator of the GAP‐43 gene
Authors: Uittenbogaard Martine , Martinka Debra L. , Chiaramello Anne 
Published: March 2003

AbstractNex1/MATH‐2 is a neurogenic basic Helix‐Loop‐Helix (bHLH) transcription factor that belongs to the NeuroD subfamily. Its expression parallels that of the GAP‐43 gene and peaks during brain development, when neurite outgrowth and synaptogenesis are highly active. We previously observed a direct correlation between the levels of expression of Nex1 and GAP‐43 proteins, which resulted in extensive neurite outgrowth and neuronal differentiation of PC12 cells in the absence of nerve growth factor. Since the GAP‐43 gene is a target for bHLH regulation, we investigated whether Nex1 could regulate the activity of the GAP‐43 promoter. We found that among the members of the NeuroD subfamily, Nex1 promoted maximal activity of the GAP‐43 promoter. The Nex1‐mediated activity is restricted to the conserved E1–E2 cluster located near the major transcription start sites. By electrophoretic mobility shift assay and site‐directed mutagenesis, we showed that Nex1 binds as homodimers and that the E1 E‐box is a high affinity binding site. We further found that Nex1 released the ME1 E‐protein‐mediated repression in a concentration dependent manner. Thus, the E1–E2 cluster has a dual function: it can mediate activation or repression depending on the interacting bHLH proteins. Finally, a series of N‐terminal and C‐terminal deletions revealed that Nex1 transcriptional activity is linked to two distinct transactivation domains, TAD1 and TAD2, with TAD1 being unique to Nex1. Together, our results suggest that Nex1 may engage in selective interactions with components of the core transcriptional machinery whose assembly is dictated by the architecture of the GAP‐43 promoter and cellular environment.
Involvement of c‐Jun N‐terminal kinase in amyloid precursor protein‐mediated neuronal cell death
Authors: Hashimoto Yuichi , Tsuji Osahiko , Niikura Takako , Yamagishi Yohichi , Ishizaka Miho , Kawasumi Masaoki , Chiba Tomohiro , Kanekura Kohsuke , Yamada Marina , Tsukamoto Emi , Kouyama Keisuke , Terashita Kenzo , Aiso Sadakazu , Lin Anning , Nishimoto Ikuo 
Published: March 2003

AbstractAmyloid precursor protein (APP), the precursor of Aβ, has been shown to function as a cell surface receptor that mediates neuronal cell death by anti‐APP antibody. The c‐Jun N‐terminal kinase (JNK) can mediate various neurotoxic signals, including Aβ neurotoxicity. However, the relationship of APP‐mediated neurotoxicity to JNK is not clear, partly because APP cytotoxicity is Aβ independent. Here we examined whether JNK is involved in APP‐mediated neuronal cell death and found that: (i) neuronal cell death by antibody‐bound APP was inhibited by dominant‐negative JNK, JIP‐1b and SP600125, the specific inhibitor of JNK, but not by SB203580 or PD98059; (ii) constitutively active (ca) JNK caused neuronal cell death and (iii) the pharmacological profile of caJNK‐mediated cell death closely coincided with that of APP‐mediated cell death. Pertussis toxin (PTX) suppressed APP‐mediated cell death but not caJNK‐induced cell death, which was suppressed by Humanin, a newly identified neuroprotective factor which inhibits APP‐mediated cytotoxicity. In the presence of PTX, the PTX‐resistant mutant of Gαo, but not that of Gαi, recovered the cytotoxic action of APP. These findings demonstrate that JNK is involved in APP‐mediated neuronal cell death as a downstream signal transducer of Go.
Altered cAMP‐dependent protein kinase subunit immunolabeling in post‐mortem brain from patients with bipolar affective disorder
Authors: Chang Annisa , Li Peter P. , Warsh Jerry J. 
Published: March 2003

AbstractPrevious findings of reduced [3H]cAMP binding and increased activities of cAMP‐dependent protein kinase (PKA) in discrete post‐mortem brain regions from patients with bipolar affective disorder (BD) suggest that PKA, the major downstream target of cAMP, is also affected in this illness. As prolonged elevation of intracellular cAMP levels can modify PKA regulatory (R) and catalytic (C) subunit levels, we sought to determine whether these PKA abnormalities are related to changes in the abundance of PKA subunits in BD brain. Using immunoblotting techniques along with PKA subunit isoform‐specific polyclonal antisera, levels of PKA RIα, RIβ, RIIα, RIIβ and Cα subunits were measured in cytosolic and particulate fractions of temporal, frontal and parietal cortices of post‐mortem brain from BD patients and matched, non‐neurological, non‐psychiatric controls. Immunoreactive levels of cytosolic Cα in temporal and frontal cortices, as well as that of cytosolic RIIβ in temporal cortex, were significantly higher in the BD compared with the matched control brains. These changes were independent of age, post‐mortem interval or pH and unrelated to ante‐mortem lithium treatment or suicide. These findings strengthen further the notion that the cAMP/PKA signaling system is up‐regulated in discrete cerebral cortical regions in BD.
A critique of avianCHD‐based molecular sexing protocols illustrated by a Z‐chromosome polymorphism detected in auklets
Authors: Dawson Deborah A. , Darby Steven , Hunter Fiona M. , Krupa Andrew P. , Jones Ian L. , Burke Terry 
Published: March 2003

AbstractThe sexes of non‐ratite birds can be determined routinely by PCR amplification of theCHD‐ZandCHD‐Wgenes.CHD‐based molecular sexing of four species of auklets revealed the presence of a polymorphism in the Z chromosome. No deviation from a 1:1 sex ratio was observed among the chicks, though the analyses were of limited power. Polymorphism in theCHD‐Zgene has not been reported previously in any bird, but if undetected it could lead to the incorrect assignment of sex. We discuss the potential difficulties caused by a polymorphism such as that identified in auklets and the merits of alternativeCHD‐based sexing protocols and primers.
Highly polymorphic microsatellite loci for Speyeria idalia (Lepidoptera: Nymphalidae)
Authors: Williams Barry L. , Brawn Jeffrey D. , Paige Ken N. 
Published: March 2003

AbstractFour polymorphic microsatellite loci were identified in the butterfly Speyeria idalia. We constructed a phagemid library and screened approximately 120 000 inserts. Probing with GT15, we identified 36 positives and designed polymerase chain reaction (PCR) primers for 12 potential loci. Of those loci, only four consistently produced polymorphic, diallelic PCR products in the expected size range. These results are consistent with previous studies concerning the low frequency of microsatellite loci in the lepidoptera, although these four loci are highly polymorphic and therefore likely to provide information on the fine scale genetic structure among populations in this species.
Microsatellite loci for great white herons and great blue herons (Aves, Ardeidae, Ardea herodias)
Authors: McGuire Heather L. , Noor Mohamed A. F. 
Published: March 2003

AbstractWe used an enrichment technique to isolate 60 microsatellite loci in Ardea herodias. We developed primers for 17 loci, screened for variation in A. herodias and attempted to amplify these loci in three closely related species (A. alba, A. cinerea and A. cocoi). Fifteen loci were polymorphic in A. herodias. Observed heterozygosities ranged from 0.10 to 0.81. Two loci appeared to be monomorphic in A. herodias, but exhibited variation in product size among species within the genus. Our ability to amplify polymorphic products in closely related species suggests that these markers may be useful in other herons.
A set of polymorphic microsatellites for Vochysia ferruginea, a promising tree for land reclamation in the Neotropics
Authors: Lowe A. J. , Goodall‐Copestake W. P. , Caron H. , Kremer A. , Decroocq S. 
Published: March 2003

Abstract Vochysia ferruginea Mart. (Vochysiaceae) is a gap colonist of Neotropical forest. As a result of its high tolerance of low‐nutrient acidic conditions and high aluminium and iron concentrations, and its high potential seed and pollen dispersal, it is a promising timber species for commercial development as regenerated or reclaimed forest on degraded land. We present here the primer sequences for 10 polymorphic simple sequence repeat loci for use with V. ferruginea to assess fine‐scale genetic structure and gene flow dynamics.
Species‐diagnostic microsatellite loci for the fig wasp genus Pegoscapus
Authors: Molbo D. , Krieger M. J. B. , Herre E. A. , Keller L. 
Published: March 2003

AbstractTo obtain tools for the estimation of inbreeding and assignment of offspring to matrilines, we developed 13 microsatellite loci from the fig wasps that pollinate Ficus obtusifolia. Based on morphological studies, it was thought that a single species (Pegoscapus hoffmeyeri) pollinated this fig. However, our data revealed the presence of two coexisting cryptic species. Several diagnostic microsatellite markers may be used to distinguish these two cryptic species. The new microsatellites can be used across a wide range of fig‐pollinating wasp species for both evolutionary and population genetic studies.
Eight polymorphic microsatellite loci for bottlenose dolphin and other cetacean species
Authors: Caldwell Marthajane , Gaines Michael S. , Hughes Colin R. 
Published: March 2003

AbstractWe developed eight polymorphic microsatellite loci that can be used to elucidate population structure and aid management of bottlenose dolphins, Tursiops truncatus, in the northwest Atlantic. These loci averaged nine alleles, with no evidence for null alleles. Their cross‐species utility was examined in Cephalorhynchus commersonii, Delphinus delphis, Delphinapterus leucas, Eschrictius robustus, Globicephala macrorhynchus, Lagenorhynchus obliquidens, Orcinus orca, Steno bredanensis and Stenella clymene. On average, 75% of the loci were polymorphic in these species (range = 50–88%). Our results indicate that these loci will be useful for elucidating population structure of bottlenose dolphin as well as of other cetacean species.
Development and characterization of microsatellite markers for Liporrhopalum tentacularis Grandi, the pollinator fig wasp of Ficus montana Blume
Authors: Zavodna M. , Arens P. , Vosman B. , Van Dijk P. J. , Van Damme J. M. M. 
Published: March 2003

AbstractMicrosatellite markers for the pollinator fig wasp Liporrhopalum tentacularis were developed using genomic libraries enriched for di‐, tri‐ and tetranucleotide repeats. A subset of 31 positive clones was sequenced and primers were designed. Eleven primer pairs produced polymorphic amplification products in L. tentacularis. Eight markers gave unambiguously scorable patterns and were further characterized on 29 individuals collected from different fruits of the dioecious host fig Ficus montana in Indonesia. Three to 19 alleles per locus were detected in this set of samples. The observed heterozygosity ranged between 0.10 and 0.55.
Isolation and characterization of microsatellite loci in Lampsilis abrupta (Bivalvia: Unionidae) and cross‐species amplification within the genus
Authors: Eackles Michael S. , King Tim L. 
Published: March 2003

AbstractWe have documented the first microsatellites isolated from a unionid and demonstrated that these markers can be useful for surveys of neutral genetic variation in several Lampsilis species. We describe the isolation and characterization of 15 polymorphic microsatellite DNA loci for the endangered unionid Lampsilis abrupta. Among individuals from five collections, allelic diversity ranged from six to 17 alleles and averaged 10.4 alleles per locus. Individual heterozygosity was observed to range from 20.0% to 86.7% and averaged 46.9%. Cross‐species amplification was investigated in nine additional Lampsilis species. A high level of flanking sequence similarity was inferred as 13 of 15 loci amplified in at least seven species.
Characterization of microsatellite loci in Humboldt penguin (Spheniscus humboldti) and cross‐amplification in other penguin species
Authors: Schlosser J. A. , Garner T. W. J. , Dubach J. M. , McElligott A. G. 
Published: March 2003

AbstractThe Humboldt penguin (Spheniscus humboldti) was once very common throughout its range along the coast of Peru and Chile. Today, listed as endangered, it is crucial to gain an understanding of gene flow and levels of genetic variation between breeding colonies to protect this species effectively. We developed seven microsatellite primers to investigate gene flow and population structure among four colonies. Locus‐specific allelic diversity ranges from five to 11 alleles and observed heterozygosity ranges from 0.50 to 0.88. These markers cross‐amplify in eight penguin species over five genera.
Microsatellite loci for the eusocialLasioglossum malachurumand other sweat bees (Hymenoptera, Halictidae)
Authors: Paxton R. J. , Arévalo E. , Field J. 
Published: March 2003

AbstractSweat bees (family Halictidae) comprise a numerous and diverse group that are arguably among the most socially labile of all insect taxa. Given the lack of highly variable markers for eusocial species of the family, we developed a suite of dinucleotide and trinucleotide markers for one of its members, the EurasianLasioglossum malachurum, and used them to amplify DNA from other halictids. Loci were highly variable inL. malachurumand amplified DNA from many other halictids.
Adult survival and productivity of Hutton's Shearwaters
Authors: Cuthbert Richard , Davis Lloyd S. 
Published: March 2003

Accurate estimation of breeding and survival parameters is essential to assess the population viability of the endangered Hutton's ShearwaterPuffinus huttoni. This study investigated the accuracy of using field signs, an infrared ‘burrowscope’ and inspection hatches to monitor burrow occupancy and breeding success. Inspection hatches proved to be the most reliable means of measuring burrow occupancy and breeding success, and Hutton's Shearwaters appear to tolerate disturbance from this method. Data collected from inspection hatches over a 10‐year period indicate that breeding success has averaged 46.5%, and that 70.5% of burrows are occupied by an incubating bird at the start of the breeding season. This occupancy figure suggests that the population of Hutton's Shearwaters may be closer to 106 000 breeding pairs than the 134 000 pairs previously estimated. Annual adult survival is estimated to be 93.1%. These values of breeding success and adult survival are very similar to published data onPuffinusspecies breeding in environments free from introduced predators.
The pattern electroretinogram (PERG) with contralateral corneal reference
Authors: Aldebasi Y.H. , Drasdo N. , North R.V. , Morgan J.E. 
Published: March 2003

SummaryThe pattern electroretinogram (PERG) is a sensitive test for investigation of the proximal retina. For monocular recording, the contralateral corneal reference (CCR) electrode position has been suggested as a possible alternative to the conventional ipsilateral temporal reference (ITR). We therefore compared the effect of these electrode positions on 26 subjects (median age 45.5 years, IQR 24.5–61.5). The signals were recorded monocularly with DTL nylon fibre electrodes. The visual stimuli were high contrast 19′ black–white checkerboard patterns, reversing 4 times/s. PERG responses obtained from the CCR gave larger amplitudes and the increase in amplitude was statistically significant (P<0.001). Because the CCR signal is larger, new normative ranges must be established to avoid false negative results.
Interconverting the matrix and principal meridional representations of dioptric power in general including powers with nonorthogonal and complex principal meridians
Authors: Harris W.F. 
Published: March 2003

SummaryThe principal meridians of the powers of thick astigmatic systems, like the eye, are not necessarily at right angles. The consequence is a class of phenomena included in the category commonly described as irregular astigmatism. The conventional principal meridional representation of power, however, is unsuited to quantitative analysis. This paper presents equations for converting from the principal meridional form of power to a representation, the dioptric power matrix, which is amenable to quantitative analysis. It generalizes an earlier paper which treated only powers of a conventional form in which the principal meridians are always at right angles. It copes in particular with what are known as asymmetric powers. A routine is also presented for converting in the reverse direction, from the power matrix to the principal meridional form of power. The principal meridional form of power turns out not always to be unique, there being distinct powers (they are asymmetric) with the same principal powers andmeridians. Thus, in general, the dioptric power matrix is a satisfactory representation of power while the principal meridional representation is not.
The effect of perceived length on visuomotor localization
Authors: Fogt Nick , Ortman Jason 
Published: March 2003

Summary Purpose: The purpose of this experiment was to study visuomotor localization in the presence of either a horizontal array of equally spaced dots or a thin horizontal line. Methods: Pointing behavior was used to assess directional localization. In experiment 1, subjects were made myopic using a contact lens and then corrected with a spectacle lens. Subjects were tested in the presence and absence of a regularly spaced, horizontal array of dots with and without the contact lens/spectacle combination. In experiment 2, subjects wore the contact lens/spectacle in all cases. Some subjects were tested in the presence and then in the absence of a regularly spaced, horizontal array of dots while the order of conditions was reversed for other subjects. In experiments 3 and 4, subjects were tested without the contact lens/spectacle combination. In experiment 3, subjects were tested in the absence and then in the presence of a regularly spaced, horizontal arrays of dots. In experiment 4, subjects were tested in the absence and then in the presence of a thin horizontal line. Results: In experiment 1, in the absence of the array of dots, subjects undershot targets with the contact lens/spectacle combination. When the array was present, pointing with the contact lens/spectacle combination was accurate. In experiment 2, subjects undershot targets in the absence of the array of dots if this condition was performed first. If the array was present in the initial condition, the pointing undershoot in the second condition (array absent) was reduced. In all cases, the pointing undershoot was reduced in the presence of the array. In experiments 3 and 4, a pointing overshoot was found in the presence of an array of dots or a thin line. Conclusions: It is concluded that extraretinal eye position information is not the primary determinant of visuomotor localization in the presence of a horizontal contour. The overshoot produced by a horizontal contour may be related to a length illusion brought about by spatial filtering in the visual system or inaccurate distance judgments.
Influence of the luminance level on visual performance with a disposable soft cosmetic tinted contact lens
Authors: Albarrán Diego C. , Montés‐Micó R. , Pons A. M. , Artigas J. M. 
Published: March 2003

SummaryThe purpose of the present work was to study the effect on visual performance of wearing disposable soft tinted contact lenses for cosmetic purposes. Parameters such as contrast sensitivity (Vistech 6000), colour vision (Farnsworth‐Munsell 100‐Hue colour test), visual fields (static Goldmann perimetry) and subjective vision (what the wearer feels while wearing the lenses) were studied under different illumination levels in order to check for possible vision losses while wearing these contact lenses at low illumination levels. Sixteen emmetropic subjects were fitted consecutively with seven pairs of different colour lenses (Optima Colors® lenses by Bausch & Lomb), and the experimental parameters were measured under four different illumination levels (60, 6, 1, and 0.1 cd/m2; but 15 and 0.3 cd/m2 for the static perimetry) The results obtained showed no statistically significant differences in visual performance between wearing the lenses and not wearing them (p>0.01), except for the static perimetry, in which statistically significant differences (p<0.01) occur at eccentricities greater than 30°.