bluuebunny/crossref_metadata_2025_split huggingface dataset:
Body size and paternal investment in the genus Onthophagus (Coleoptera, Scarabaeoidea)
Authors: Palestrini Claudia , Rolando Antonio 
Published: July 2002

AbstractDuring reproduction, dung beetles of the genus Onthophagus typically bury portions of dung removed from the dung pad. Even though females are capable of successfully constructing and provisioning nests when unaccompanied by males, extensive levels of co‐operation between sexes have been reported. In some species, males show a clear dimorphism in body plan and only large horned males are known to assist females. In O. taurus this form of paternal investment is facultative and depends on social context (namely the presence of other males). We studied relationships between body size and paternal investment in five Onthophagus species (i.e. O. coenobita, O. fracticornis, O. illyricus, O. taurus and O. vacca). Two types of tests were established. In test A, a large and a small male were placed with a single, medium‐size female; in test B, a large and a small female were placed with a single large male. In controls one male was placed with one female. Individuals were maintained for 10 days. Then the enclosures were opened to assess the position of each beetle. When two mates were found in close vicinity or in the same tunnel provisioning dung, a co‐operative behaviour was assumed. In competitive tests, small males and small females never co‐operated with their potential mates whilst large and medium‐size individuals often co‐operated with mates inside the same tunnels. No differences in frequencies of co‐operation were found between large and medium‐size females. Small females and small males scarcely co‐operated with large or medium‐size mates in controls. These results suggest that large individuals outcompete the small ones. They also suggest that paternal investment depends on body size of both mates. Large males of all species assist medium‐size and large females, whereas small males do not. However, large males do not invest much parental effort on small females that, in fact, are poorly assisted. We assume that large individuals of both sexes are reproductively superior to small ones. The propensity of both small females and small males to excavate was lower than that of larger individuals; accordingly, digging capacity could be a proximate factor explaining facultative paternal investment in these species.
Asymmetrical gaits of juvenile Crocodylus johnstoni, galloping Australian crocodiles
Authors: Renous S. , Gasc J.‐P. , Bels V. L. , Wicker R. 
Published: July 2002

AbstractSeven juvenile individuals of the Australian species Crocodylus johnstoni from the Frankfurt Zoological Park were filmed on high‐speed video, at 250 fields s−1, whilst freely moving at various speeds in a long corridor. The sequences of locomotion were analysed to determine the various space and time parameters to characterize limb kinematics. We found that the animals use diverse patterns of asymmetrical gait, revealing great flexibility in limb co‐ordination. In all these gaits, the forelimb strikes the ground first, in the couple made by diagonally opposite fore‐ and hindlimbs. Among these gaits, rotary gallop offers probably a high level of manoeuvrability, whereas transverse gallop resulted in a higher level of stability. Speed increase is achieved by half‐bound and bound, the latter being the only gait used at velocities > 2 m s−1. Speed was increased mainly by increasing the stride length of the fore‐ and hindlimbs by simultaneously increasing both its components, the step and swing lengths. However, in bound, the step length of each forelimb increased more than the swing length, resulting in a stronger thrust action, whereas swing length increased more than step length for the hindlimb, causing the centre of mass to accelerate forwards during its ballistic phase. The asymmetrical gaits of crocodiles such as Crocodylus johnstoni are probably not functionally equivalent to the transitional asymmetrical gaits exhibited by lizards when building up into a bipedal run. These gaits are also not entirely equivalent to mammalian gaits, despite the use of vertical movements of the vertebral axis in these crocodiles, favouring an erect dynamic posture.
A review of reproductive strategies in cephalopods
Authors: ROCHA FRANCISCO , GUERRA ÁNGEL , GONZÁLEZ ÁNGEL F. 
Published: July 2002

ABSTRACTCephalopod reproductive strategies are reviewed in order to clarify their current, confusing status. Based on the type of ovulation, spawning pattern and growth between egg batches or spawning periods, five comprehensive and flexible cephalopod reproductive strategies are defined. Accordingly, with these three factors the following classification is proposed. (a) Spawning once (formerly semelparity) consisting of simultaneous terminal spawning, with synchronous ovulation, monocyclic spawning and absence of growth between egg batches. (b) Spawning more than once (formerly iteroparity) including: (i) polycyclic spawning with egg‐laying occurring in separate batches during the spawning season and growth occurring between production of egg batches and spawning seasons; (ii) multiple spawning, with group‐synchronous ovulation, monocyclic spawning and growth between egg batches; (iii) intermittent terminal spawning, with group‐synchronous ovulation, monocyclic spawning and no growth between egg batches; (iv) continuous spawning, with asynchronous ovulation, monocyclic spawning and growth between egg batches. Examples of species exhibiting each of these reproductive strategies are given. The large amount of inter‐species variation in several life‐history traits related to reproductive events is discussed.
Comparative Genome Sequence Analysis of the Bpa/Str Region in Mouse and Man
Authors: Mallon A.-M. , Platzer M. , Bate R. , Gloeckner G. , Botcherby M.R.M. , Nordsiek G. , Strivens M.A. , Kioschis P. , Dangel A. , Cunningham D. , Straw R.N.A. , Weston P. , Gilbert M. , Fernando S. , Goodall K. , Hunter G. , Greystrong J.S. , Clarke D. , Kimberley C. , Goerdes M. , Blechschmidt K. , Rump A. , Hinzmann B. , Mundy C.R. , Miller W. , Poustka A. , Herman G.E. , Rhodes M. , Denny P. , Rosenthal A. , Brown S.D.M. 
Published: July 2002

The progress of human and mouse genome sequencing programs presages the possibility of systematic cross-species comparison of the two genomes as a powerful tool for gene and regulatory element identification. As the opportunities to perform comparative sequence analysis emerge, it is important to develop parameters for such analyses and to examine the outcomes of cross-species comparison. Our analysis used gene prediction and a database search of 430 kb of genomic sequence covering the Bpa/Str region of the mouse X chromosome, and 745 kb of genomic sequence from the homologous human X chromosome region. We identified 11 genes in mouse and 13 genes and two pseudogenes in human. In addition, we compared the mouse and human sequences using pairwise alignment and searches for evolutionary conserved regions (ECRs) exceeding a defined threshold of sequence identity. This approach aided the identification of at least four further putative conserved genes in the region. Comparative sequencing revealed that this region is a mosaic in evolutionary terms, with considerably more rearrangement between the two species than realized previously from comparative mapping studies. Surprisingly, this region showed an extremely high LINE and low SINE content, low G+C content, and yet a relatively high gene density, in contrast to the low gene density usually associated with such regions.[The sequence data described in this paper have been submitted to EMBL under the following accession nos.: Mouse Genomic Sequence: Mouse contig A (AL021127), Mouse contig B (AL049866), BAC41M10 (AL136328), PAC303O11(AL136329). Human Genomic Sequence: Human contig 1 (U82671, U82670), Human contig 2 (U82695).]
A Small GTP-Binding Host Protein Is Required for Entry of Powdery Mildew Fungus into Epidermal Cells of Barley
Authors: Schultheiss Holger , Dechert Cornelia , Kogel Karl-Heinz , Hückelhoven Ralph 
Published: July 2002

Abstract
Small GTP-binding proteins such as those from the RAC family are cytosolic signal transduction proteins that often are involved in processing of extracellular stimuli. Plant RAC proteins are implicated in regulation of plant cell architecture, secondary wall formation, meristem signaling, and defense against pathogens. We isolated aRacB homolog from barley (Hordeum vulgare) to study its role in resistance to the barley powdery mildew fungus (Blumeria graminis f.sp.hordei). RacB was constitutively expressed in the barley epidermis and its expression level was not strongly influenced by inoculation with B. graminis.However, after biolistic bombardment of barley leaf segments withRacB-double-stranded RNA, sequence-specific RNA interference with RacB function inhibited fungal haustorium establishment in a cell-autonomous and genotype-specific manner. Mutants compromised in function of the Mlowild-type gene and the Ror1 gene (genotype mlo5 ror1) that are moderately susceptible to B. graminis showed no alteration in powdery mildew resistance uponRacB-specific RNA interference. Thus, the phenotype, induced by RacB-specific RNA interference, was apparently dependent on the same processes asmlo5-mediated broad resistance, which is suppressed byror1. We conclude that an RAC small GTP-binding protein is required for successful fungal haustorium establishment and that this function may be linked to MLO-associated functions.
Biosynthesis of Costunolide, Dihydrocostunolide, and Leucodin. Demonstration of Cytochrome P450-Catalyzed Formation of the Lactone Ring Present in Sesquiterpene Lactones of Chicory
Authors: de Kraker Jan-Willem , Franssen Maurice C.R. , Joerink Maaike , de Groot Aede , Bouwmeester Harro J. 
Published: July 2002

Abstract
Chicory (Cichorium intybus) is known to contain guaianolides, eudesmanolides, and germacranolides. These sesquiterpene lactones are postulated to originate from a common germacranolide, namely (+)-costunolide. Whereas a pathway for the formation of germacra-1(10),4,11(13)-trien-12-oic acid from farnesyl diphosphate had previously been established, we now report the isolation of an enzyme activity from chicory roots that converts the germacrene acid into (+)-costunolide. This (+)-costunolide synthase catalyzes the last step in the formation of the lactone ring present in sesquiterpene lactones and is dependent on NADPH and molecular oxygen. Incubation of the germacrene acid in the presence of18O2 resulted in the incorporation of one atom of 18O into (+)-costunolide. The label was situated at the ring oxygen atom. Hence, formation of the lactone ring most likely occurs via C6-hydroxylation of the germacrene acid and subsequent attack of this hydroxyl group at the C12-atom of the carboxyl group. Blue light-reversible CO inhibition and experiments with cytochrome P450 inhibitors demonstrated that the (+)-costunolide synthase is a cytochrome P450 enzyme. In addition, enzymatic conversion of (+)-costunolide into 11(S),13-dihydrocostunolide and leucodin, a guaianolide, was detected. The first-mentioned reaction involves an enoate reductase, whereas the formation of leucodin from (+)-costunolide probably involves more than one enzyme, including a cytochrome P450 enzyme.
The Interaction of Light and Abscisic Acid in the Regulation of Plant Gene Expression
Authors: Weatherwax S. C. , Ong M. S. , Degenhardt J. , Bray E. A. , Tobin E. M. 
Published: July 2002

Abstract
Extended dark treatments of light-grown plants of both Lemna gibba and Arabidopsis thaliana resulted in substantial increases in abscisic acid (ABA) concentrations. The concentration of ABA could be negatively regulated by phytochrome action in Lemna. As has been noted in other species, ABA treatment reduced Lemna rbcS and Lhcb RNA levels, which are positively regulated by phytochrome in many species. In view of these observations, the possibility that phytochrome effects on gene expression may be mediated primarily by changes in ABA was tested using a transient assay in intact plants. The phytochrome responsiveness of the Lemna Lhcb2*1 promoter was still apparent in the presence of exogenous ABA. Additionally, when 2-bp mutations were introduced into this promoter so that phytochrome responsiveness was lost, a response to exogenous ABA was still present. We conclude that phytochrome- and ABA-response elements are separable in the Lhcb2*1 promoter. We tested whether the effects of ABA on RNA abundance could be inhibited by treatment with gibberellin and found no evidence for such an inhibition. We have also found that the ABA-responsive Em promoter of wheat can be negatively regulated by phytochrome action. It is likely that this regulation is mediated at least in part by phytochrome-induced changes in ABA levels. Our results demonstrate that it is essential to take into account that dark treatments and the phytochrome system can affect ABA levels when interpreting studies of light-regulated genes.
Expressed Sequence Tags of Chinese Cabbage Flower Bud cDNA
Authors: Lim C. O. , Kim H. Y. , Kim M. G. , Lee S. I. , Chung W. S. , Park S. H. , Hwang I. , Cho M. J. 
Published: July 2002

Abstract
We randomly selected and partially sequenced cDNA clones from a library of Chinese cabbage (Brassica campestris L. ssp. pekinensis) flower bud cDNAs. Out of 1216 expressed sequence tags (ESTs), 904 cDNA clones were unique or nonredundant. Five hundred eighty-eight clones (48.4%) had sequence homology to functionally defined genes at the peptide level. Only 5 clones encoded known flower-specific proteins. Among the cDNAs with no similarity to known protein sequences (628), 184 clones had significant similarity to nucleotide sequences registered in the databases. Among these 184 clones, 142 exhibited similarities at the nucleotide level only with plant ESTs. Also, sequence similarities were evident between these 142 ESTs and their matching ESTs when compared using the deduced amino acid sequences. Therefore, it is possible that the anonymous ESTs encode plant-specific ubiquitous proteins. Our extensive EST analysis of genes expressed in floral organs not only contributes to the understanding of the dynamics of genome expression patterns in floral organs but also adds data to the repertoire of all genomic genes.
Phytochrome A Enhances the Promotion of Hypocotyl Growth Caused by Reductions in Levels of Phytochrome B in Its Far-Red-Light-Absorbing Form in Light-Grown Arabidopsis thaliana
Authors: Casal J. J. 
Published: July 2002

Abstract
We sought to determine if phytochrome B (phyB)-mediated responses to the red light (R)/far-red light (FR) ratio are affected by phytochrome A (phyA) activity in light-grown seedlings of Arabidopsis thaliana. Pulses of FR delayed into the dark period were less effective than end-of-day (EOD) FR in promoting hypocotyl growth over a given period in darkness. White light minus blue light interposed instead of darkness between the end of the white-light photoperiod and the FR pulse was sufficient to maintain responsivity to the decrease in phyB in FR-light-absorbing form in wild-type (WT) seedlings, but not in the phyA mutant. Compared with EOD R, hourly R+FR pulses provided throughout the night caused a stronger promotion of stem growth than a single EOD R+FR pulse in WT Arabidopsis, cucumber, mustard, sunflower, tobacco, and tomato, but not in phyA Arabidopsis or in the aurea mutant of tomato. WT seedlings of Arabidopsis responded to a range of high EOD R/FR ratios, whereas the phyA mutant required stronger reductions in the EOD R/FR ratio. In sunlight, phyA seedlings of Arabidopsis showed no response to the “early warning” signals of neighboring vegetation, and hypocotyl-growth promotion occurred at higher plant densities than in the WT. Thus, under a series of light conditions, the sensitivity or responsivity to reductions in the R/FR ratio were larger in WT than in phyA seedlings. A product of phyA is therefore proposed to enhance the hypocotyl-growth response to decreases in phyB in FR-light-absorbing form in light-grown seedlings.
Expansins in Deepwater Rice Internodes
Authors: Cho H. T. , Kende H. 
Published: July 2002

Abstract
Cell walls of deepwater rice (Oryza sativa L.) internodes undergo long-term extension (creep) when placed under tension in acidic buffers. This is indicative of the action of the cell wall-loosening protein expansin. Wall extension had a pH optimum of around 4.0 and was abolished by boiling. Acid-induced extension of boiled cell walls could be reconstituted by addition of salt-extracted rice or cucumber cell wall proteins. Cucumber expansin antibody recognized a single protein band of 24.5-kD apparent molecular mass on immunoblots of rice cell wall proteins. Expansins were partially purified by concanavalin A affinity chromatography and sulfopropyl (SP) cation-exchange chromatography. The latter yielded two peaks with extension activity (SP20 and SP29), and immunoblot analysis showed that both of these active fractions contained expansin of 24.5-kD molecular mass. The N-terminal amino acid sequence of SP20 expansin is identical to that deduced from the rice expansin cDNA Os-EXP1. The N-terminal amino acid sequence of SP29 expansin matches that deduced from the rice expansin cDNA Os-EXP2 in six of eight amino acids. Our results show that two expansins occur in the cell walls of rice internodes and that they may mediate acid-induced wall extension.
Molecular Cloning of Mannose-6-Phosphate Reductase and Its Developmental Expression in Celery
Authors: Everard J. D. , Cantini C. , Grumet R. , Plummer J. , Loescher W. H. 
Published: July 2002

Abstract
Compared with other primary photosynthetic products (e.g. sucrose and starch), little is known about sugar alcohol metabolism, its regulation, and the manner in which it is integrated with other pathways. Mannose-6-phosphate reductase (M6PR) is a key enzyme that is involved in mannitol biosynthesis in celery (Apium graveolens L.). The M6PR gene was cloned from a leaf cDNA library, and clonal authenticity was established by assays of M6PR activity, western blots, and comparisons of the deduced amino acid sequence with a celery M6PR tryptic digestion product. Recombinant M6PR, purified from Escherichia coli, had specific activity, molecular mass, and kinetic characteristics indistinguishable from those of authentic celery M6PR. Sequence analyses showed M6PR to be a member of the aldo-keto reductase superfamily, which includes both animal and plant enzymes. The greatest sequence similarity was with aldose-6-phosphate reductase (EC 1.1.1.200), a key enzyme in sorbitol synthesis in Rosaceae. Developmental studies showed M6PR to be limited to green tissues and to be under tight transcriptional regulation during leaf initiation, expansion, and maturation. These data confirmed a close relationship between the development of photosynthetic capacity, mannitol synthesis, and M6PR activity.
Effects of a Mechanical Stimulation on Localization of Annexin-Like Proteins in Bryonia dioica Internodes
Authors: Thonat C. , Mathieu C. , Crevecoeur M. , Penel C. , Gaspar T. , Boyer N. 
Published: July 2002

Abstract
Mechanical stimulation exerted by rubbing a young internode of Bryonia dioica plants inhibits its growth. Previous cellular and biochemical studies showed that this growth inhibition is associated with Ca2+ redistribution and profound modifications of plasma membrane characteristics. We extracted and purified Ca2+-dependent phospholipid-binding proteins from B. dioica internodes. Two main proteins, p33 and p35, and other minor bands were isolated and identified as annexin-like proteins because of their biochemical properties and their cross-reactions with antibodies against maize (Zea mays L.) annexins. Rabbit antiserum was obtained by injection of B. dioica p35. This antiserum was used for the immunocytolocalization of annexin-like proteins in internode parenchyma cells. It appeared that the distribution of annexin-like proteins was different before and 30 min after the mechanical stimulation. Western analysis of proteins in membrane fractions after separation by free-flow electrophoresis showed that p35 was present in most fractions, whereas p33 appeared mainly in plasmalemma-enriched fractions after the mechanical stimulation. It is hypothesized that a subcellular redistribution of these proteins might be involved in growth inhibition by mechanical stress.
Inositol 1,4,5-Trisphosphate-Sensitive Ca2+ Release across Nonvacuolar Membranes in Cauliflower
Authors: Muir S. R. , Sanders D. 
Published: July 2002

Abstract
Previous studies have indicated that the vacuole represents the major inositol 1,4,5-trisphosphate (InsP3)-mobilizable Ca2+ pool in higher plants. This finding is in contrast to animal cells, in which the endoplasmic reticulum and plasma membrane constitute the dominant InsP3-sensitive membranes. We used membrane vesicles prepared from cauliflower (Brassica oleracae L.) inflorescences that were separated on continuous sucrose gradients to demonstrate that cauliflower possesses at least two distinct membrane populations that are sensitive to InsP3. One of these membrane populations is nonvacuolar in origin and relies upon a Ca2+-ATPase to accumulate CA2+. In addition, we have shown that two polyclonal antibodies, raised against peptides corresponding to the animal type 1 InsP3 receptor, recognize immunologically related proteins in cauliflower, and that the distribution of immunoreactive proteins on a linear sucrose gradient reinforces the notion that cauliflower contains more than one membrane subtype that is sensitive to InsP3. To our knowledge, this is the first report describing an InsP3-sensitive Ca2+ store other than the vacuole in higher plant cells.
A Vacuole-Associated Annexin Protein, VCaB42, Correlates with the Expansion of Tobacco Cells
Authors: Seals D. F. , Randall S. K. 
Published: July 2002

Abstract
A Ca-dependent membrane-binding protein of the annexin family, VCaB42, has previously been shown to associate with vacuolar vesicles at physiological levels of Ca. In this study we used suspension-cultured cells of tobacco (Nicotiana tabacum BY-2) to show that VCaB42 is enriched 4.5-fold in intact vacuoles, whereas evacuolated protoplasts show a 12-fold reduction in VCaB42. VCaB42 distribution is thus comparable to that of the vacuole-associated H+-ATPase but is distinct from the endoplasmic reticulum-localized protein calnexin. Because VCaB42 is a vacuole-associated annexin, and given the putative function of annexins in vesicle fusion, we hypothesize a role for this protein in the vacuolation process of expanding cells. Consistent with this hypothesis, we show that VCaB42 levels correlate with age-associated and hormonally induced changes in cell volume in tobacco suspension cultures. The association of VCaB42 with vacuoles and its correlative pattern of expression relative to the expansion of cells is consistent with a possible role for VCaB42 in the early events of vacuole biogenesis.