Maternal responsiveness of sows towards piglet's screams during the first 24 h postpartum

In this study we focused on sow responsiveness towards piglet screams which are proposed to have an important link to posture changes and early piglet crushing. A sow's responsiveness to screams of her piglets was investigated along the first 24 h after birth, the period of highest mortality, in 15 lactating sows housed in farrowing crates. We compared the sow's response to playbacks of screams of trapped piglets to her response to a control sound during birth, 8–12 h postpartum and 20–24 h postpartum. We did the same with playbacks of screams of fighting piglets during nursings 8–12 h postpartum and 20–24 h postpartum. The sow’ responsiveness to screams of own trapped piglets was analyzed within the whole 24 h and to screams of fighting piglets 30 min between 8 and 12 h postpartum and 30 min between 20 and 24 h postpartum. A sow was scored as responsive if she changed her posture in response to the stimuli. Sows had a four times higher response towards playbacks with screams than towards the control stimulus. The proportion of the sows’ responsiveness to screams (44%) of trapped piglets did not change significantly between birth, 8–12 h postpartum and 20–24 h postpartum. Sows responded to 28% of playbacks of fighting piglets by terminating a nursing independently from the time after birth. Playbacks and real screams of own piglets were similarly effective in evoking a response for both types of screams. There was no significant association between the sows’ responsiveness to screams of trapped piglets and piglet mortality nor between screams of fighting piglets and weight gain. In conclusion our results indicate that sows maintained their responsiveness towards piglet screams during trapping and during fighting for teats within the first 24 h. Playbacks and real screams were similarly effective in evoking a response. We discuss the importance of the sound characteristics of piglet screams related to the sows’ response.     

Factors affecting piglet mortality during the first 24 h after the onset of parturition in large litters: effects of farrowing housing on behaviour of postpartum sows

The present study aimed to identify the factors that affect immediate (within 24 h after farrowing onset) postnatal piglet mortality in litters with hyperprolific sows, and investigate their associations with behaviour of postpartum sows in two different farrowing housing systems. A total of 30 sows were housed in: (1) CRATE (n=15): the farrowing crate closed (0.80×2.20 m) within a pen (2.50×1.70 m), and (2) OPEN (n=15): the farrowing crate open (0.80×2.20×1.80 m) within a pen (2.50×2.40 m) with a provision of 20 ls of hay in a rack. A total of 518 live born piglets, produced from the 30 sows, were used for data analyses during the first 24 h after the onset of parturition (T24). Behavioural observations of the sows were assessed via video analyses during T24. Total and crushed piglet mortality rates were higher in OPEN compared with CRATE (P<0.01, for both). During T24, the OPEN sows tended to show higher frequency of postural changes (P=0.07) and duration of standing (P=0.10), and showed higher frequencies of bar-biting (P<0.05) and piglet trapping (P<0.01), when compared with the CRATE sows. During T24, the mortality rates caused by crushing were correlated with the piglet trapping event (r=0.93, P<0.0001), postural changes (r=0.37, P<0.01), duration of standing (r=0.32, P<0.01) and frequency of bar-biting behaviour (r=0.51, P<0.01) of the sows (n=30). In conclusion, immediate postnatal piglet mortality, mainly due to crushing, may be associated with potential increases in frequency of postural changes, duration of standing and incidence of piglet trapping in postpartum sows in the open crate system with large litters.     

Effects of deer,mice and dwarf bamboo on the emergence,survival and growth of <Emphasis Type="Italic">Abies homolepis</Emphasis> (Piceaceae) seedlings

In the subalpine mixed forest of Mt. Ôdaigahara, mid-western Japan, the understory is dominated by dwarf bamboo (Sasa nipponica), which is the major forage of overly populous sika deer (Cervus nippon). In the present study, we monitored the survival and growth of Abies homolepis seedlings over 5years to determine how they responded to the experimental removal of dwarf bamboo and to the exclusion of sika deer and mice (Apodemus argenteus and A.speciosus). Deer and dwarf bamboo reduced the survival of seedlings but had different effects on growth. The stems of seedlings were shorter in the presence of deer, indicating that taller seedlings were apt to be browsed by deer, whereas the diameters of seedlings were smaller in the presence of dwarf bamboo, mainly owing to its shading effect. The presence of mice decreased the number of seedlings germinating in a particular site, but had no effect on seedling survival after germination. There was no significant indirect effect whereby the survival of seedlings was predicted to be facilitated by the decreased biomass of bamboo because of grazing by deer. We supposed that this might be because the direct negative effect of deer was so large as to conceal the positive indirect effect.     

The comparative amino acid sequences, substrate specificities and gene or cDNA nucleotide sequences of some prokaryote and eukaryote amidinotransferases: implications for evolution

The amino acid sequences of the amidinotransferases and the nucleotide sequences of their genes or cDNA from four Streptomyces species (seven genes) and from the kidneys of rat, pig, human and human pancreas were compared. The overall amino acid and nucleotide sequences of the prokaryotes and eukaryotes were very similar and further, three regions were identified that were highly identical. Evidence is presented that there is virtually zero chance that the overall and high identity regions of the amino acid sequence similarities and the overall nucleotide sequence similarities between Streptomyces and mammals represent random match. Both rat and lamprey amidinotransferases were able to use inosamine phosphate, the amidine group acceptor of Streptomyces. We have concluded that the structure and function of the amidinotransferases and their genes has been highly conserved through evolution from prokaryotes to eukaryotes. The evolution has occurred with: (1) a high degree of retention of nucleotide and amino acid sequences; (2) a high degree of retention of the primitive Streptomyces guanine+cytosine (G+C) third codon position composition in certain high identity regions of the eukaryote cDNA; (3) a decrease in the specificities for the amidine group acceptors; and (4) most of the mutations silent in the regions suggested to code for active sites in the enzymes.     

The influence of domestic piglets' (<Emphasis Type="Italic">Sus scrofa</Emphasis>) age and test experience on the preference for the replayed maternal nursing vocalisation in a modified open-field test

The nursing vocalisation of lactating sows is an important part of the complex nursing and suckling behaviour of domestic pigs (Sus scrofa). It helps to lead the young through the several phases of a nursing episode. A total of 135 suckling piglets were investigated regarding their reactions to different vocalisations and sounds successively replayed in combined choice/open-field experiments. Two piglet samples were used to determine the impact of age (sample 1: weeks 1 and 5, n=93) and previous test experience of naive older piglets (sample 2: week 5, n=42) on their behavioural responses. In the 1st week after birth, the nursing vocalisation of sows released an initial generalised approach and contact response in the young, indicating high motivation to gain nutritional or social support. Close to the sound source, the piglets then strongly preferred the nursing vocalisation produced by their own mothers compared to that produced by another, unrelated and unfamiliar sow, or an artificial sound composed of similar frequencies as the nurse grunting, or a control without sound. However, at the end of the suckling period (5-week-old piglets) no clear differences in the reactions to the sounds could be identified. Moreover, the lack of a clear response at week 5 seems largely independent of any earlier test experience of the piglets. As well in the 1st as in the 5th week the piglets showed a decrease in open-field activity when sow grunting was present, indicating that the replay of the nursing vocalisation might have some calming effect. Communicated by K. Kotrschal     

Phylogenetic analysis of Asian<Emphasis Type="Italic"> Symplocos</Emphasis> (Symplocaceae) based on nuclear and chloroplast DNA sequences

Thirty species and one variety of Symplocos (Symplocaceae), including all taxa distributed in Japan, were phylogenetically analyzed with DNA sequence data. The evolution of morphological characters is discussed on the basis of the phylogenetic relationships obtained. All species were Asian, except one, S. austromexicana, from Mexico. The nuclear ribosomal internal transcribed spacer (ITS) region and two intergenic spacer regions, between trnL and trnF, and between trnH and psbA of chloroplast DNA were used. The topologies of trees obtained from ITS and the chloroplast intergenic spacers are largely congruent. S. sonoharae, the representative of the subgenus Symplocos in Asia, was sister to all other species. The position of the American species, S. austromexicana, which also belongs to the subgenus Symplocos, was not well resolved. The phylogenetic tree based on combined sequence data largely supports the monophyletic origin of the infrageneric sections proposed earlier. However, the phylogenetic relationship between them is not well resolved, probably due to rapid diversification. The section Palura, a deciduous group, is well defined in the DNA analysis, suggesting its independent status in the genus Symplocos. In spite of their morphological divergence, the three endemic species of the Bonin Islands are monophyletic. The occurrence of curved seeds seems to be homoplastic, scattered over the phylogenetic tree without showing a particular infrageneric relationship.     

Patterns of importin-α expression during Drosophila spermatogenesis

Importin-α proteins do not only mediate the nuclear import of karyophilic proteins but also regulate spindle assembly during mitosis and the assembly of ring canals during Drosophila oogenesis. Three importin-α genes are present in the genome of Drosophila. To gain further insights into their function we analysed their expression during spermatogenesis by using antibodies raised against each of the three Importin-α proteins identified in Drosophila, namely, Imp-α1, -α2, and -α3. We found that each Imp-α is expressed during a specific and limited period of spermatogenesis. Strong expression of Imp-α2 takes place in spermatogonial cells, persists in spermatocytes, and lasts up to the completion of meiosis. In growing spermatocytes, the intracellular localisation of Imp-α2 appears to be dependent upon the rate of cell growth. In pupal testes Imp-α2 is essentially present in the spermatocyte nucleus but is localised in the cytoplasm of spermatocytes from adult testes. Both Imp-α1 and -α3 expression initiates at the beginning of meiosis and ends during spermatid differentiation. Imp-α1 expression extends up to the onset of the elongation phase, whereas that of Imp-α3 persists up to the completion of nuclear condensation when the spermatids become individualised. During meiosis Imp-α1 and -α3 are dispersed in the karyoplasm where they are partially associated with the nuclear spindle, albeit not with the asters. At telophase they aggregate around the chromatin. During sperm head differentiation, both Imp-α1 and -α3 are nuclear. These data indicate that each Imp-α protein carries during Drosophila spermatogenesis distinct, albeit overlapping, functions that may involve nuclear import of proteins, microtubule organisation, and other yet unknown processes.     

Lefty acts as an essential modulator of Nodal activity during sea urchin oral-aboral axis formation

Nodal is a key player in the process regulating oral–aboral axis formation in the sea urchin embryo. Expressed early within an oral organizing centre, it is required to specify both the oral and aboral ectoderm territories by driving an oral–aboral gene regulatory network. A model for oral–aboral axis specification has been proposed relying on the self activation of Nodal and the diffusion of the long-range antagonist Lefty resulting in a sharp restriction of Nodal activity within the oral field. Here, we describe the expression pattern of lefty and analyse its function in the process of secondary axis formation. lefty expression starts at the 128-cell stage immediately after that of nodal, is rapidly restricted to the presumptive oral ectoderm then shifted toward the right side after gastrulation. Consistently with previous work, neither the oral nor the aboral ectoderm are specified in embryos in which Lefty is overexpressed. Conversely, when Lefty's function is blocked, most of the ectoderm is converted into oral ectoderm through ectopic expression of nodal. Reintroducing lefty mRNA in a restricted territory of Lefty depleted embryos caused a dose-dependent effect on nodal expression. Remarkably, injection of lefty mRNA into one blastomere at the 8-cell stage in Lefty depleted embryos blocked nodal expression in the whole ectoderm consistent with the highly diffusible character of Lefty in other models. Taken together, these results demonstrate that Lefty is essential for oral–aboral axis formation and suggest that Lefty acts as a long-range inhibitor of Nodal signalling in the sea urchin embryo.     

Spleen size variations and reproduction in a Mediterranean population of wild boar (<Emphasis Type="Italic">Sus scrofa</Emphasis>)

We analysed spleen size variations of free-ranging wild boars from the west-central Iberian Peninsula during the hunting season (autumn and winter) in relation to the rut, the gestation effort and the attainment of sexual maturity by males and females. Females had larger spleens than males once they reached their sexual maturity. Individuals shot in winter had larger spleens than those shot in autumn, the start of the rutting period. In contrast to other reports, we found no influence of the reproductive status of adult females on their spleen sizes. Our findings may point to an influence of sex hormones, and possibly also stress hormones, and environmental factors on spleen development, mainly in adult and subadult males.     

Efficient generation of transgenic barley: The way forward to modulate plant–microbe interactions

Stable genetic transformation represents the gold standard approach to the detailed elucidation of plant gene functions. This is particularly relevant in barley, an important experimental model widely employed in applied molecular, genetic and cell biological research, and biotechnology. Presented are details of the establishment of a protocol for Agrobacterium-mediated gene transfer to immature embryos, which enables the highly efficient generation of transgenic barley. Advancements were achieved through comparative experiments on the influence of various explant treatments and co-cultivation conditions. The analysis of representative numbers of transgenic lines revealed that the obtained T-DNA copy numbers are typically low, the generative transmission of the recombinant DNA is in accordance with the Mendelian rules and the vast majority of the primary transgenics produce progeny that expresses the respective transgene product. Moreover, the newly established protocol turned out to be useful to transform not only the highly amenable cultivar (cv.) ‘Golden Promise’ but also other spring and winter barley genotypes, albeit with substantially lower efficiency. As a major result of this study, a very useful tool is now available for future functional gene analyses as well as genetic engineering approaches. With the aim to modify the expression of barley genes putatively involved in plant–fungus interactions, numerous transgenic plants have been generated using diverse expression cassettes. These plants represent an example of how transformation technology may contribute to further our understanding of important biological processes.     

Spatial avoidance of littoral and pelagic invertebrate predators by <Emphasis Type="Italic">Daphnia</Emphasis>

Studies on spatial avoidance behaviour of predators by prey often ignored the fact that prey typically face multiple predators which themselves interact and show a spatial pattern in abundance and predation rates (PRs). In a series of laboratory experiments, we investigated predation risk (PRI) and horizontal migration of the cladoceran Daphnia magna between open water and vegetation in response to two important invertebrate predators with a contrasting spatial distribution: pelagic Choaborus and vegetation-associated Ischnura. As expected, PRI by Chaoborus was higher in open water due to higher numbers and higher PRs of Chaoborus, while for Ischnura, PRI was highest in the vegetation due to higher densities, despite lower PRs of Ischnura. In accordance with this, Daphnia moved into the vegetation in the presence of the pelagic Chaoborus alone. In the presence of Ischnura alone, however, Daphnia showed no response. We hypothesize this may be the result of a constitutive behaviour of Daphnia to avoid pelagic fish, which impedes a response to the open water. In the combined predator treatment, Daphnia migrated to the open water zone. The increased risk of predation in the vegetation, due to a facilitating effect of Chaoborus on Ischnura PRs is believed to have caused this migration of the Daphnia. This response of Daphnia declined through time and Daphnia moved toward the vegetation. A decline in the activity of the Ischnura larvae through time may have switched the risk balance in favour of the vegetation environment.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of the genus <Emphasis Type="Italic">Clivia</Emphasis>

We have developed a protocol for the in vitro propagation of the genus Clivia. Shoots were regenerated when fragments of the peduncle-pedicel junction (PP junction) from young inflorescences were used as explants. The optimal media for PP junction were Murashige and Skoog (MS)-based medium containing 10 M of 6-benzyladenine (BA) and 10 M of 2,4-dichlorophenoxyacetic acid (2,4-D) or MS supplemented with 5 M BA, 10 M -naphthaleneacetic acid (NAA), 250 mg l^-1 glutamine and 500 mg l^–1 casein hydrolysate and their usage depended on the breeding lines. Multiplication from initiations and in vitro seedlings was the best when the explants were cut longitudinally through the meristem and placed on MS plus 44 M BA. Plantlets were transferred on to hormone -free MS medium with charcoal for rooting.     

Nucleolus activation in pea cotyledonary buds during 24 hours after decapitation of the main stem: Cytochemical studies

Summary Several cytochemical techniques and routine electron microscopy were used to detect changes in the pea cotyledonary bud nucleolus, from the G_0–1 resting state until the first mitoses (24th hour) following removal of the main stem. In the G_0–1 nucleus the fibrillar RNP nucleolus, shaped like a hollow sphere, possessed clumps of DNA connected to the compact peripheral nuclear chromatin by DNA fibres. The large central space, surrounded by the fibrillar component, showed the characteristics of a heterogeneous fibrillar center. By the 6th hour, this heterogeneous fibrillar center broke up, into small scattered elements in which DNA was detected. Between the 9th and 12th hours, RNA maturation produced a granular zone. Inter- and peri-chromatin granules of RNP were then present. In the bud, which was either in the resting state or in the process of reactivation, Ag-NOR proteins were located throughout the nucleolar mass, but were heavily concentrated in its peripheral region; they constituted a binding network between the various nucleolar components. The role and importance of the G_0–1 nuclei karyosome, present until the 9th hour, is discussed.     

Glycotope analysis in miracidia and primary sporocysts of Schistosoma mansoni: Differential expression during the miracidium-to-sporocyst transformation

Fucosylated carbohydrate epitopes (glycotopes) expressed by larval and adult schistosomes are thought to modulate the host immune response and possibly mediate parasite evasion in intermediate and definitive hosts. While previous studies showed glycotope expression is developmentally and stage-specifically regulated, relatively little is known regarding their occurrence in miracidia and primary sporocysts. In this study, previously defined monoclonal antibodies were used in confocal laser scanning microscopy, standard epifluorescence microscopy and Western blot analyses to investigate the developmental expression of the following glycotopes in miracidia and primary sporocysts of Schistosoma mansoni: GalNAcβ1-4GlcNAc (LDN), GalNAcβ1-4(Fucα1-3)GlcNAc (LDN-F), Fucα1-3GalNAcβ1-4GlcNAc (F-LDN), Fucα1-3GalNAcβ1-4(Fucα1-3)GlcNAc (F-LDN-F), GalNAcβ1-4(Fucα1-2Fucα1-3)GlcNAc (LDN-DF), Fucα1-2Fucα1-3GalNAcβ1-4(Fucα1-2Fucα1-3)GlcNAc (DF-LDN-DF), Galβ1-4(Fucα1-3)GlcNAc (Lewis X) and the truncated trimannosyl N-glycan Manα1-3(Manα1-6)Manβ1-4GlcNAcβ1-4GlcNAcβ1-Asn (TriMan). All but Lewis X were variously expressed by miracidia and sporocysts of S. mansoni. Most notably, α3-fucosylated LDN (F-LDN, F-LDN-F, LDN-F) was prominently expressed on the larval surface and amongst glycoproteins released during larval transformation and early sporocyst development, possibly implying a role for these glycotopes in snail–schistosome interactions. Interestingly, Fucα2Fucα3-subsituted LDN (LDN-DF, DF-LDN-DF) and LDN-F were heterogeneously surface-expressed on individuals of a given larval population, particularly amongst miracidia. In contrast, LDN and TriMan primarily localised in internal somatic tissues and exhibited only minor surface expression. Immunoblots indicate that glycotopes occur on overlapping but distinct protein sets in both larval stages, further demonstrating the underlying complexity of schistosome glycosylation. Additionally, sharing of specific larval glycotopes with Biomphalaria glabrata suggests an evolutionary convergence of carbohydrate expression between schistosomes and their snail host.     

Dynamics of potentially harmful microalgae in a confined Mediterranean Gulf—Assessing the risk of bloom formation

The population dynamics of potentially harmful microalgae was investigated in the semi-enclosed shallow Gulf of Kalloni, Greece (Aegean Sea, Eastern Mediterranean), during a 2-year period from August 2004 to March 2006. A total of 21 potentially harmful microalgae (bloom-forming and/or toxic) were identified including 3 diatoms and 18 dinoflagellates. The densities of each species were analyzed in time and space and in relation to environmental parameters. Some species such as Alexandrium insuetum, Heterocapsa circularisquama, Karlodinium veneficum, Scrippsiella trochoidea, and Ceratium spp. developed high cell concentrations, particularly during a Pseudo-nitzschia calliantha winter bloom. Other species such as Dinophysis caudata, Ostreopsis ovata, Prorocentrum minimum, and Protoperidinium crassipes were rare or appeared in small numbers. Densities of the most abundant species were closely associated with freshwater nutrient-rich inputs during winter, being negatively correlated with temperature and salinity and positively correlated with nitrogen. The spatial distribution of the abundant species exhibited a marked increase towards the inner part of the gulf, close to the main freshwater inputs, whereas some species were mainly concentrated in the dilute surface layer (1 m depth). Examination of the abundance–occupancy relationship revealed that the species more prone to bloom are those with wide spatial distribution and frequent presence throughout the year such as the diatom P. calliantha. Although blooms of cyst-forming species are rarer, an increased risk can be foreseen under favorable resource supply and environmental conditions during winter.     

Non-target effects of neonicotinoid seed treatments; mortality of coccinellid larvae related to zoophytophagy

Third and fourth instar Harmonia axyridis Pallas larvae feed directly on corn seedlings; therefore they may be at risk if the seedlings are chemically treated. Neonicotinoids are broad-spectrum systemic insecticides that are frequently applied to corn seeds prior to planting to protect seedlings from early-season root and leaf-feeding. In this study, H. axyridis larvae were exposed for 360 min to corn seedlings that had been grown from seeds treated with either thiamethoxam or clothianidin. Neurotoxic symptoms (trembling, paralysis, and loss of coordination) were observed in 72% of the H. axyridis larvae; recovery following neurotoxic symptoms rarely occurred (7%). Starvation of larvae for 48 h prior to seedling exposure may increase tissue consumption; however, there was no difference in the number of starved or satiated larvae that displayed neurotoxic symptoms and died. Neurotoxic symptoms and larval mortality were significantly more likely to occur if larvae were exposed to seedlings grown from seeds treated with neonicotinoids compared to the control. In addition, clothianidin resulted in significantly greater larval mortality (80%) compared to thiamethoxam (53%). Symptoms and mortality were rarely observed if seedlings were not treated with a neonicotinoid seed treatment (3% and 3%, respectively). Coccinellids are abundant in agroecosystems in which neonicotinoid seed treatments are likely to be applied. Therefore, the use of neonicotinoids may have negative effects on these non-target species if early-season leaf-feeding occurs in the field.     

Effect of retinoic acid signaling on Wnt/β-catenin and FGF signaling during body axis extension

Cell–cell signaling regulated by retinoic acid (RA), Wnt/β-catenin, and fibroblast growth factor (FGF) is important during body axis extension, and interactions between these pathways have been suggested. At early somite stages, Wnt/β-catenin and FGF signaling domains exist both anterior and posterior to the developing trunk, whereas RA signaling occurs in between in the trunk under the control of the RA-synthesizing enzyme retinaldehyde dehydrogenase-2 (Raldh2). Previous studies demonstrated that vitamin A deficient quail embryos and Raldh2^−/− mouse embryos lacking RA synthesis exhibit ectopic expression of Fgf8 and Wnt8a in the developing trunk. Here, we demonstrate that Raldh2^−/− mouse embryos display an expansion of FGF signaling into the trunk monitored by Sprouty2 and Pea3 expression, and an expansion of Wnt/β-catenin signaling detected by expression of Axin2, Tbx6, Cdx2, and Cdx4. Following loss of RA signaling, the caudal expression domains of Fgf8, Wnt8a, and Wnt3a expand anteriorly into the trunk, but no change is observed in caudal expression of Fgf4 or Fgf17 plus caudal expression of Fgf18 and Cdx1 is reduced. These findings suggest that RA repression of Fgf8, Wnt8a, and Wnt3a in the developing trunk functions to down-regulate FGF signaling and Wnt/β-catenin signaling as the body axis extends.