Polyploidy before and after domestication of crop species.

Recent advances in the genomics of polyploid species answer some of the long-standing questions about the role of polyploidy in crop species. Here, we summarize the current literature to reexamine scenarios in which polyploidy played a role both before and after domestication. The prevalence of polyploidy can help to explain environmental robustness in agroecosystems. This review also clarifies the molecular basis of some agriculturally advantageous traits of polyploid crops, including yield increments in polyploid cotton via subfunctionalization, modification of a separated sexuality to selfing in polyploid persimmon via neofunctionalization, and transition to a selfing system via nonfunctionalization combined with epistatic interaction between duplicated S-loci. The rapid progress in genomics and genetics is discussed along with how this will facilitate functional studies of understudied polyploid crop species.

Dynamic Pruritus Score: Evaluation of the Validity and Reliability of a New Instrument to Assess the Course of Pruritus.

Currently valid itch intensity scales, such as the visual analogue scale (VAS), are indispensable, but they can be influenced by the patient's overall health status. The aim of this study was to evaluate the reliability and validity of the Dynamic Pruritus Score (DPS), a new instrument comparing reduction in current pruritus with a defined earlier time-point. Eighty-one randomly selected adults (50 females, mean age 53.9 years) recorded their pruritus at visit 1 and repeatedly at visit 2 on the DPS, VAS, numerical rating scale, and on health status questionnaires (EuroQol; EQ-5D), skin-related quality of life (Dermatology Life Quality Index; DLQI), anxiety and depression (Hospital Anxiety and Depression Scale; HADS) and patient benefit (Patient Benefit Index; PBI). Intraclass correlation showed high reliability for both DPS and VAS (r < 0.9, p < 0.001), while the DPS has shown higher concurrent validity (rDPS to PBI = 0.570; p < 0.001). The DPS can then be considered an alternative instrument to the VAS for assessment of pruritus in adults. Further research is needed to confirm these results with a more representative sample size.

Enhanced cardiac perception is associated with benefits in decision-making.

In the present study we provide the first empirical evidence that viscero-sensory feedback from an internal organ is associated with decision-making processes. Participants with accurate vs. poor perception of their heart activity were compared with regard to their performance in the Iowa Gambling Task. During this task, participants have to choose between four card decks. Decks A and B yield high gains and high losses, and if played continuously, result in net loss. In contrast, decks C and D yield small gains and also small losses, but result in net profit if they are selected continuously. Accordingly, participants have to learn to avoid the net loss options in favor of the net gain options. In our study, participants with good cardiac perception chose significantly more of the net gain and fewer of the net loss options. Our findings document the substantial role of visceral feedback in decision-making processes in complex situations.

Effects of cyanobacterial toxins and cyanobacterial cell-free crude extract on germination of alfalfa (Medicago sativa) and induction of oxidative stress.

Cyanobacterial toxins have adverse effects on both terrestrial and aquatic plants. Microcystins are cyclic heptapeptides and an important group of cyanotoxins. When lake water contaminated with cyanobacterial blooms is used for spray irrigation, these toxins can come in contact with agricultural plants. During the exposure to these toxins, reactive oxygen species can form. These reactive oxygen species have a strong reactivity and are able to interact with other cellular compounds (lipids, protein, and DNA). Plants have antioxidative systems that will limit the negative effects caused by reactive oxygen species. These systems consist of enzymes, such as superoxide dismutase, catalase, and ascorbate peroxidase, and nonenzymatic substances, such as reduced glutathione or vitamins. The aim of the present study was to investigate the effects of cyanobacterial toxins (microcystins and anatoxin-a) and cyanobacterial cell-free crude extract on alfalfa (Medicago sativa) seedlings. Inhibition of germination and root growth was observed with toxin concentrations of 5.0 microg/L. Also, oxidative damage, such as lipid peroxidation, was detected after the exposure of alfalfa seedlings to the toxin. Reactive oxygen detoxifying enzymes were elevated, showing a marked response in alfalfa to oxidative stress caused by the exposure to cyanobacterial metabolites that might influence the growth and development of these plants negatively.

Insect epidermis: disturbance of supracellular tissue polarity does not prevent the expression of cell polarity.

The insect integument displays planar tissue polarity in the uniform orientation of polarized cuticular structures. In a body segment, for example, the denticles and bristles produced by the constituent epidermal cells point posteriorly. Colchicine can abolish this uniform orientation while still allowing individual cells to form orientated cuticular structures and thereby to express cell polarity. This suggests that an individual cell in a sheet can establish planar polarity without reference to some kind of covert supracellular cue (such as a morphogen gradient) in the epidermis as a whole. The results also indicate that colchicine interferes - directly or indirectly - with the mechanisms involved in aligning the polarity axes of individual cells into a common orientation, thereby generating supracellular or tissue polarity.

Pattern control in insect segments: superimposed features of the pattern may be subject to different control mechanisms.

The integument of an insect segment displays two distinct pattern features which are based on different properties of the constituent epidermal cells. Normally, the uniform orientation of epidermal cell polarities ("polarity pattern") is strictly correlated with the sequence of differentiated cells ("differentiation pattern"). Here it is reported that in the integument of the cotton bug Dysdercus epidermal cells can adopt orientations that do not correlate with the pigmentation pattern and which are not compatible with the gradient model. The results indicate that different features of a composite pattern can be independently controlled.

Pattern stability in the insect segment : II. The intersegmental region.

1. InDysdercus the abdominal segments are isolated from each other by an intersegmental region which can be distinguished on the basis of morphological and physiological criteria. 2. The intersegmental region (ISR) consists of the visible segment border and narrow strips of cells anterior and posterior to it. 3. The anterior strip (w-ISR) is white and merges with the white segment region (wS) in front of it, and the posterior strip (r-ISR) is red and merges posteriorly with the red segment region (rS). The wS and the rS meet in the middle of the segment; together they form the segment proper. 4. Grafts from the ISR have been transplanted to various positions within a segment. The reactions of graft and host, respectively, can be distinguished in combinations involving a colour mutant and/or individuals of different sexes. 5. The results show that cells of the r-ISR and the w-ISR each have some adhesiveness towards those tissues which they border in situ, and less adhesiveness towards other tissues. That is, the w-ISR is adhesive towards the r-ISR and wS and is usually rejected by tissue of the rS, whereas the r-ISR is adhesive towards tissue of the w-ISR and rS, but is rejected by tissue of the wS. 6. The role which the ISR plays as a barrier between adjacent segments can essentially be interpreted on the basis of differences in cell adhesiveness. 7. Besides these adhesiveness properties the two parts of the ISR show a long-range influence on polarity and pigment synthesis in surrounding segment tissue. 8. The adhesiveness properties of the r-ISR and w-ISR can explain why the segment boundary forms such a straight line and why the ISR tends to grow between tissues from non-contiguous segment levels. This property can explain the hitherto not understood healing capacity of the ISR which even after wounding prevents cellular interactions between adjacent segments so effectively.

Pattern stability in the insect segment : I. Pattern reconstitution by intercalary regeneration and cell sorting inDysdercus intermedius Dist.

1. The mechanisms of pattern reconstitution in the abdominal segment of insects were studied by transplantations between the wild type and a colour mutant of the bugDysdercus intermedius. In this species, anterior and posterior regions of the segment differ in pigmentation. Thus transplants are marked by donor genotype and by region-specific pigmentation. Moreover, the translucent cuticle allows direct and continuous observation of the behaviour of host and transplant cells. 2. Transplants rotated by 90° re-rotate so as to approach or even restore the original relations with their surroundings, whereas transplants completely surrounded by cells from another segment region tend to contract. Both observations indicate differences in adhesiveness between cells from different regions of a segment. 3. When transplants rotated by 180° or shifted to different antero-posterior levels in a segment cannot approach their original situations by rerotation, then conspicuous folds appear before moults in the regions where cells from different segment levels meet, and these regions become pigmented according to the levels which were lacking in between. This indicates that an intercalary regenerate is formed which eliminates the discontinuity in positional values created by transplantation. 4. The intercalary regenerate forms essentially from cells representing the more posterior segment level, irrespective of whether these are host or transplant cells. 5. It is suggested that pattern reconstitution in the abdominal segment can be explained in terms of cell behaviour, assuming cell sorting and intercalary regeneration. 6. This interpretation is discussed in the light of a current hypothesis which assumes that displaced cells are re-programmed in situ under the influence of a diffusible morphogen.