Journals
2013 EN
Bernardi Giacomo
The field of speciation has seen much renewed interest in the past few years, with theoretical and empirical advances that have moved it from a descriptive field to a predictive and testable one. The goal of this review is to provide a general background on research on speciation as it pertains to fishes. Three major components to the question are first discussed: the spatial, ecological and sexual factors that influence speciation mechanisms. We then move to the latest developments in the field of speciation genomics. Affordable and rapidly available, massively parallel sequencing data allow speciation studies to converge into a single comprehensive line of investigation, where the focus has shifted to the search for speciation genes and genomic islands of speciation. We argue that fish present a very diverse array of scenarios, making them an ideal model to study speciation processes.
Journals
2013 EN
Sakuma Shun · Pourkheirandish Mohammad · Hensel Goetz
+8 more
Summary Barley ( H ordeum vulgare ) spikes are developmentally switched from two‐rowed to six‐rowed by a single recessive gene, six‐rowed spike 1 ( vrs1 ), which encodes a homeodomain‐leucine zipper I class transcription factor. Vrs1 is a paralog of HvHox2 and both were generated by duplication of an ancestral gene. HvHox2 is conserved among cereals, whereas Vrs1 acquired its current function during the evolution of barley. It was unclear whether divergence of expression pattern or protein function accounted for the functionalization of Vrs1 . Here, we conducted a comparative analysis of protein functions and gene expression between HvHox2 and Vrs1 to clarify the functionalization mechanism. We revealed that the transcriptional activation activity of H v HOX 2 and VRS 1 was conserved. In situ hybridization analysis showed that HvHox2 is localized in vascular bundles in developing spikes, whereas Vrs1 is expressed exclusively in the pistil, lemma, palea and lodicule of lateral spikelets. The transcript abundance of Vrs1 was > 10‐fold greater than that of HvHox2 during the pistil developmental stage, suggesting that the essential function of Vrs1 is to inhibit gynoecial development. We demonstrated the quantitative function of Vrs1 using RNA i transgenic plants and Vrs1 expression variants. Expression analysis of six‐rowed spike mutants that are nonallelic to vrs1 showed that Vrs1 expression was up‐regulated by Vrs4 , whereas HvHox2 expression was not. These data demonstrate that the divergence of gene expression pattern contributed to the neofunctionalization of Vrs1 .
Journals
2013 EN
Liu Hui · Kishimoto Sanae · Yamamizo Chihiro
+2 more
Eustoma grandiflorum is one of the leading cut‐flowers in Japan. There are market demands for cultivars with deep‐yellow flowers, but they have never been bred successfully. By investigating the carotenoid accumulation and carotenogenic gene expressions, this study attempted to explore the reasons that block the formation of deep‐yellow colour in Eustoma. High performance liquid chromatography analysis showed that the carotenoid compositions in petals were similar to those in leaves, accumulating mainly lutein, violaxanthin and β‐carotene. The total carotenoid contents decreased as the petals matured in all the cultivars tested. Quantitative real‐time PCR analysis showed that the expression levels of PSY , LCYB , ZDS and LCYE showed significant differences between white and pale‐yellow petals or between petals and leaves, indicating that these enzymes may play a key role in the carotenoid biosynthesis in E. grandiflorum . The expression levels of CCD 4 were high in both pale‐yellow and white petals during development, suggesting that carotenoid degradation activity is high in the petals. We then conclude that the total carotenoid accumulation level could be determined by the balance between carotenoid biosynthesis and degradation activities.
Journals
2013 EN
Ohmiya Akemi · Tanase Koji · Hirashima Masumi
+2 more
Carnation ( D ianthus caryophyllus L .) belongs to the family C aryophyllaceae in the order C aryophyllales. Plants in this order do not accumulate carotenoids in petals. To understand how carotenoid accumulation is controlled in carnation petals, we analysed the expression of genes related to carotenoid accumulation. Petals at an early stage of development accumulated small amounts of carotenoids. As petals matured, their carotenoid content decreased to extremely low levels. In contrast, carnation leaves contained substantial amounts of carotenoids that are essential for photosynthesis. Most of the carotenogenic genes were expressed in petals at levels similar to those in leaves, and the expression levels of these genes increased during petal development. Genes encoding phytoene synthase and lycopene ε‐cyclase were exceptions. Their expression levels in petals were very low compared with those in leaves. Expression of the gene encoding carotenoid cleavage dioxygenase 4 was detected in neither leaves nor petals. These data suggest that the low levels of carotenoids in carnation petals are caused not by enzymatic degradation but rather by low rates of carotenoid biosynthesis.
Journals
2013 EN
Campagna Cinzia · Tassinari Davide · Neri Iria
+1 more
M ycoplasma pneumoniae , the major pathogen of primary atypical pneumonia, is reported as the most common infectious agent associated with S tevens– J ohnson syndrome ( SJS ) in children. For that reason it is important to consider mycoplasma infection also in the absence of classical pulmonary symptoms. SJS is a rare and acute, self‐limited disease, characterized by severe inflammation and necrosis of two or more mucous membranes. We report the case of a 12‐year‐old boy with a diagnosis of SJS induced by M . pneumoniae infection. The patient's SJS relapsed 8 months after discharge. When the condition is recurrent, it is important early on to identify the cause of a single episode to optimize care and therapeutic choices.
Journals
2013 EN
Lombardi Lara · Faoro Franco · Luti Simone
+6 more
The cerato‐platanin ( CP ) family consists of fungal‐secreted proteins involved in various stages of the host–fungus interaction and acting as phytotoxins and elicitors of defense responses. The founder member of this family is CP , a non‐catalytic protein with a six‐stranded double‐ψβ‐barrel fold. Cerato‐populin (Pop1) is an ortholog showing low sequence identity with CP . CP is secreted by Ceratocystis platani , the causal agent of the canker stain of plane. Pop1 is secreted by Ceratocystis populicola , a pathogen of poplar. CP and Pop1 have been suggested to act as PAMPs (pathogen‐associated molecular patterns) because they induce phytoalexin synthesis, transcription of defense‐related genes, restriction of conidia growth and cell death in various plants. Here, we treated plane leaves with CP or Pop1, and monitored defense responses to define the role of these elicitors in the plant interactions. Both CP and Pop1 were able to induce mitogen‐activated protein kinases ( MAPKs ) phosphorylation, production of reactive oxygen species and nitric oxide, and overexpression of defense related genes. The characteristic DNA fragmentation and the cytological features indicate that CP and Pop1 induce cell death by a mechanism of programmed cell death. Therefore, CP and Pop1 can be considered as two novel, non‐catalytic fungal PAMPs able to enhance primary defense. Of particular interest is the observation that CP showed faster activity compared to Pop1. The different timing in defense activation could potentially be due to the structural differences between CP and Pop1 (i.e. different hydrophobic index and different helix content) therefore constituting a starting point in unraveling their structure–function relationships.
Journals
2013 EN
Gaggini TS · Perin J · Arend LS
+3 more
Contents This study investigated the effect of altrenogest treatment on the farrowing development of sows, and birth weight ( BW ) and piglet survival until the third day of life. Three control groups were used: (i) sows that farrowed spontaneously before 114 day of gestation ( CONT 0.05) in farrowing duration, BW , coefficient of variation ( CV ) of BW , stillborn piglets, mummified foetuses, percentage of light piglets and survival until Day 3 between sows with and without cloprostenol treatment, in both control ( CONT ≥114 vs CONTCLOPR ) and altrenogest‐treated sows ( ALT vs ALTCLOPR ). Further comparisons were performed taking into account three groups: sows with early delivery ( CONT 0.05), but higher than in CONT 0.05) between groups in farrowing duration, CV of BW , and percentages of stillborn piglets and mummified foetuses. Sows of CONT <114 group had a larger litter size and a lower BW than sows of the other two groups (p < 0.05). Sows of CONT <114 group had a higher percentage of lighter piglets and a lower piglet survival rate (p < 0.05) than ALT sows. In conclusion, altrenogest treatment proved to be an efficient method to avoid early parturition in 3–5 parity sows resulting in heavier piglets at birth.
Journals
2013 EN
Kummer ABHP · Gaggini TS · Bernardi ML
+4 more
Contents This study investigates the association of semen traits with boar fertility. The fertility outcome (farrowing rate – FR and total piglets born – TB ) of 14 boars was obtained from a field trial conducted during 10 week of breeding period on a commercial farm using multiparous sows (n = 948) through single‐sire mating with 2 × 10 9 motile sperm cells per artificial insemination (AI) dose. Sperm motion parameters, evaluated with computer‐assisted semen analysis system in raw and stored semen at 17°C for 240 h, in addition to morphological sperm defects, measured on the collection day, were included in the analysis to determine which semen traits were important to discriminate the fertility potential of ejaculates from these boars. The data underwent multivariate cluster, canonical and discriminant analyses. Four clusters of boars were formed based on fertility outcome. One boar, with the lowest FR and TB values (89.7% and 11.98), and two boars, with the highest FR and TB values (97.8% and 14.16), were placed in different clusters. The other boars were separated in two distinct clusters (four and seven boars), including boars with intermediate TB (12.64 and 13.22) but divergent values for FR (95.9% vs 91.8%). Semen traits with higher discriminatory power included total motility, progressive motility, amplitude of lateral head displacement and cytoplasmatic droplets. Through multivariate discriminant analysis, more than 80% of the 140 ejaculates were correctly classified into their own group, showing that this analysis may be an efficient statistical tool to improve the discrimination of potential fertility of boars. Nevertheless, the validation of the relationship between fertility and semen traits using this statistical approach needs to be performed on a larger number of farms and with a greater number of boars.
Journals
2013 EN
Raccanello Daniela · Brondino Margherita · Bernardi Bianca
The present work investigates students' representation of achievement emotions, focusing in context‐specific situations in terms of settings and subject‐domains, as a function of grade level. We involved 527 fourth‐, seventh‐, and eleventh‐graders, who evaluated ten discrete emotions through questionnaires, with reference to verbal language and mathematics, and different settings (class, homework, tests). Confirmatory multitrait‐multimethod analyses indicated higher salience of subject‐domains rather than settings for all the emotions; however, complexity of reality was best explained when also settings were accounted for. Analyses of variance revealed higher intensity of positive emotions for younger students, and the opposite pattern for older students; significant differences for most of the emotions based on the evaluative nature of settings, moderated by class levels; more intense positive emotions for mathematics and more intense negative emotions for Italian. Results are discussed considering their theoretical and applied relevance, corroborating previous literature on domain‐specificity.
Journals
2013 EN
Sekine Daisuke · Ohnishi Takayuki · Furuumi Hiroyasu
+4 more
Summary A post‐zygotic hybridization barrier is often observed in the endosperm of seeds produced by interspecific or interploidy crosses. In A rabidopsis thaliana , for example, hybrid endosperm from both types of cross shows altered timing of cellularization and an altered rate of nuclear divisions. Therefore, it has been proposed that interspecific and interploidy crosses share common molecular mechanisms for establishment of an effective species barrier. However, these two types of hybridization barrier may be initiated by different intrinsic cues: the interspecific cross barrier arises after hybridization of genomes with differences in DNA sequences, while the interploidy cross barrier arises after hybridization of genomes with the same DNA sequences but differences in ploidy levels. In this study, we performed interploidy crosses to identify components of the post‐hybridization barrier in the endosperm of rice. We performed an intra‐cultivar cross of autotetraploid (4 n ) × diploid (2 n ) rice, and found precocious cellularization and a decreased rate of nuclear division in the syncytial endosperm. By contrast, seeds from the reciprocal cross showed delayed cellularization and an increased rate of nuclear division. This differential effect on nuclear division rates contrasts with the outcome of rice interspecific crosses, which were previously shown to have altered timing of cellularization without any change in nuclear division rates. Thus, we propose that the post‐zygotic hybridization barrier in rice endosperm has two separable components, namely control of the timing of cellularization and control of the nuclear division rates in the syncytial stage of endosperm development.