Impact of different meadow mowing techniques on field invertebrates

Low‐input meadows are now recognized for their high biodiversity value and form an integral element of many agri‐environmental schemes in Europe. Meadow mowing techniques, however, have become highly mechanized in recent decades and scientific knowledge on the direct impacts of these techniques on field fauna is based on very few and often poorly replicated studies. Yet these studies, despite their limitations, suggest that such impacts can be considerable. With a view to providing a more comprehensive experimental assessment, we evaluated the direct impacts of four different mowing techniques (hand motor mower with cutter bar, rotary mower cut at 9 cm and rotary mower cut at 6 cm with and without a conditioner) on wax invertebrate models and real caterpillars. The size of the organisms, their microhabitat, the tractor wheel effect and the cutting height were also investigated as factors that could potentially affect mowing‐caused mortality. Rotary mowers were found to be more damaging than motor bar mowers on caterpillars (37% vs. 20%), but only on one type of invertebrate wax‐model. Conditioners more than doubled damage to all wax‐models in the vegetation (in average from 11% to 30%) and increased caterpillar mortality from 38% to 69%. Larger organisms were more vulnerable than smaller organisms and ground organisms were strongly impacted by tractor wheels. While conditioner should not be used in meadows where conservation of the inhabiting fauna is of concern, we also recognize that there is no damage‐free mowing technique. We therefore advocate the importance of leaving uncut areas as a refuge for invertebrates.     

Hybridisation between oilseed rape (Brassica napus) and tetraploid Brassica rapa under field conditions

Cross-compatible relatives of crop species contribute to the uncertainty regarding the potential risk of transgene escape from genetically modified varieties. The most successful crossing partner of oilseed rape (Brassica napus L.) is diploid Brassica rapa L. Variation of ploidy level among B. rapa cultivars has, until recently, been neglected in the context of gene flow and hybridisation with oilseed rape. We estimated the extent of hybridisation between autotetraploid B. rapa varieties (female) and B. napus (pollen donor) under experimental field conditions. Morphology, variation of relative DNA amount, and microsatellite markers were used to distinguish between intraspecific offspring of tetraploid B. rapa and interspecific hybrids with B. napus. Of 517 seed progenies of tetraploid B. rapa, 45 juvenile plants showed species specific morphological traits of oilseed rape. The detection of putative hybrids based on variation in relative DNA amounts was problematic due to the occurrence of aneuploidy. In total, 84 offspring showed relative DNA amounts deviating from tetraploid B. rapa, four of which were hexaploids. Of the 205 offspring analysed at three microsatellite loci, 67 had oilseed rape alleles. Based on molecular evidence a minimum hybridisation rate of 13.0% was estimated. A few mother plants accounted for the majority of hybrids. The mean pollen viability of hybrids between B. napus and tetraploid B. rapa (80.6%) was high in comparison with mean pollen viability of triploid hybrids between B. napus and diploid B. rapa. Therefore, the occurrence of tetraploid B. rapa should be taken into consideration when estimating the likelihood of gene flow from oilseed rape to close relatives at the landscape level. Tetraploid B. rapa is a common component of several seed mixtures and establishes feral populations in northwest Germany. Assuming a similar abundance of diploid and tetraploid B. rapa, gene flow from B. napus to tetraploid may be more likely than gene flow to diploid B. rapa.     

Cystathionine- -synthase gene transfer and 3-deazaadenosine ameliorate inflammatory response in endothelial cells

Although elevated levels of homocysteine (Hcy) known as hyperhomocysteinemia (HHcy) are associated with increased inflammation and vascular remodeling, the mechanism of Hcy-mediated inflammation and vascular remodeling is unclear. The matrix metalloproteinases (MMPs) and adhesion molecules play an important role in vascular remodeling. We hypothesized that HHcy induces inflammation by increasing adhesion molecules and matrix protein expression. Endothelial cells were supplemented with high methionine, and Hcy accumulation was measured by HPLC. Nitric oxide (NO) bioavailability was detected by a NO probe. The protein expression was measured by Western blot analysis. MMP-9 activity was detected by gelatin-gel zymography. We demonstrated that methionine supplement promoted upregulation of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) through increased Hcy accumulation. In addition, increased synthesis of collagen type-1 was also observed. MMP-9 gene expression and protein activity were increased in methionine supplement groups. 3-Deazaadenosine (DZA), an adenosine analogue, prevented high methionine-induced ICAM-1 and VCAM-1 expression and collagen type-1 synthesis. Transfection of endothelial cells with cystathionine-β-synthase (CBS) gene construct, which converts Hcy to cystathionine, reduced Hcy accumulation in high methionine-fed cells. CBS gene transfection reduced the inflammatory response, as evident by attenuated ICAM-1 and VCAM-1 expression. Furthermore, collagen type-1 expression and MMP-9 activity were dramatically attenuated with CBS gene transfection. These results suggested that methionine supplement increased Hcy accumulation, which was associated with inflammatory response and matrix remodeling such as collagen type-1 synthesis and MMP-9 activity. However, in vitro DZA and CBS gene therapy successfully treated the HHcy-induced inflammatory reaction in the methionine metabolism pathway. extracellular matrix; matrix metalloproteinase-9; intercellular cell adhesion molecule-1; vascular cell adhesion molecule-1; collagen type-1; hyperhomocysteinemia     

Mitotic inter-homologue junctions accumulate at damaged DNA replication forks in recQ mutants

Mitotic homologous recombination is utilised to repair DNA breaks using either sister chromatids or homologous chromosomes as templates. Because sister chromatids are identical, exchanges between sister chromatids have no consequences for the maintenance of genomic integrity unless they involve repetitive DNA sequences. Conversely, homologous chromosomes might differ in genetic content, and exchanges between homologues might lead to loss of heterozygosity and subsequent inactivation of functional genes. Genomic instability, caused by unscheduled recombination events between homologous chromosomes, is enhanced in the absence of RecQ DNA helicases, as observed in Bloom's cancer-prone syndrome. Here, we used two-dimensional gel electrophoresis to analyse budding yeast diploid cells that were modified to distinguish replication intermediates originating from each homologous chromosome. Therefore, these cells were suitable for analysing the formation of inter-homologue junctions. We found that Rad51-dependent DNA structures resembling inter-homologue junctions accumulate together with sister chromatid junctions at damaged DNA replication forks in recQ mutants, but not in the absence of Srs2 or Mph1 DNA recombination helicases. Inter-homologue joint molecules in recQ mutants are less abundant than sister chromatid junctions, but they accumulate with similar kinetics after origin firing under conditions of DNA damage. We propose that unscheduled accumulation of inter-homologue junctions during DNA replication might account for allelic recombination defects in recQ mutants.     

Dichloro(6-aminoethylaminopurine)platinum(II) and its hydroxy analogues: Synthesis and preliminary evaluation

The synthesis, chemical characterization and functional evaluation are reported for dichloro(6-aminoethylaminopurine)platinum(II) and dichloro(6-hydroxyethylaminopurine)platinum(II) and dichloro(6-hydroxyethylamethylaminopurine)platinum(II) (i.e. Pt(6-AEAP), Pt(6-HEAP) and Pt(6-MHEAP) new complexes of platinum(II). Certain reaction conditions favored the formation of the tripurine platinum complex, but the monopurine complex could be obtained either by hydrolysis of the tripurine or by reacting at reduced temperature and concentration. Although neither compound was as effective as cis-diamminedichloroplatinum(II) (i.e. DDP) at reducing tumor cell viability or proliferation, both were associated with much less renal toxicity than DDP in the mouse kidney (i.e. Pt(6-AEAP):～20 × less; Pt(6-MHEAP): ～100 × less).     

Corneal Curvature Radius and Associated Factors in Chinese Children: The Shandong Children Eye Study

PurposeTo investigate the distribution of the (CCR) and its associated factors in children.MethodsUsing a random cluster sampling method, the school-based, cross-sectional Shandong Children Eye Study included children aged 4 to 18 years from the rural county of Guanxian and the city of Weihai in the province of Shandong in East China. CCR was measured by ocular biometry.ResultsCCR measurements were available for 5913 (92.9%) out of 6364 eligible children. Mean age was 10.0±3.3 years, and mean CCR was 7.84±0.27 mm (range: 6.98 to 9.35 mm). In multivariate linear regression analysis, longer CCR (i.e. flatter cornea) was significantly associated with the systemic parameters of male sex (P<0001;standardized regression coefficient beta: -0.08;regression coefficient B:-0.04; 95% Confidence Interval (CI):-0.05,-0.03), younger age (P<0.001;beta:-0.37;B:-0.03;95%CI:-0.04,-0.03), taller body height (P = 0.002;beta:0.06;B:0.001;95%CI:0.000,0.001), lower level of education of the father (P = 0.001;beta:-0.04;B:-0.01;95%CI:-0.02,-0.01) and maternal myopia (P<0.001;beta:-0.07;B:-0.04;95%CI:-0.06,-0.03), and with the ocular parameters of longer ocular axial length (P<0.001;beta:0.59;B:0.13;95%CI:0.12,0.14), larger horizontal corneal diameter (P<0.001;beta:0.19;B:0.13;95%CI:0.11,0.14), and smaller amount of cylindrical refractive error (P = 0.001;beta:-0.09;B:-0.05;95%CI:-0.06,-0.04).ConclusionsLonger CCR (i.e., flatter corneas) (mean:7.84±0.27mm) was correlated with male sex, younger age, taller body height, lower paternal educational level, maternal myopia, longer axial length, larger corneas (i.e., longer horizontal corneal diameter), and smaller amount of cylindrical refractive error. These findings may be of interest for elucidation of the process of emmetropization and myopization and for corneal refractive surgery.     

Function and Evolutionary Origin of Unicellular Camera-Type Eye Structure

The ocelloid is an extraordinary eyespot organelle found only in the dinoflagellate family Warnowiaceae. It contains retina- and lens-like structures called the retinal body and the hyalosome. The ocelloid has been an evolutionary enigma because of its remarkable resemblance to the multicellular camera-type eye. To determine if the ocelloid is functionally photoreceptive, we investigated the warnowiid dinoflagellate Erythropsidinium. Here, we show that the morphology of the retinal body changed depending on different illumination conditions and the hyalosome manifests the refractile nature. Identifying a rhodopsin gene fragment in Erythropsidinium ESTs that is expressed in the retinal body by in situ hybridization, we also show that ocelloids are actually light sensitive photoreceptors. The rhodopsin gene identified is most closely related to bacterial rhodopsins. Taken together, we suggest that the ocelloid is an intracellular camera-type eye, which might be originated from endosymbiotic origin.     

Early Stress Causes Sex-Specific,Life-Long Changes in Behaviour,Levels of Gonadal Hormones,and Gene Expression in Chickens

Early stress can have long-lasting phenotypic effects. Previous research shows that male and female chickens differ in many behavioural aspects, and respond differently to chronic stress. The present experiment aimed to broadly characterize long-term sex differences in responses to brief events of stress experienced during the first weeks of life. Chicks from a commercial egg-laying hybrid were exposed to stress by inducing periods of social isolation during their first three weeks of life, followed by a broad behavioural, physiological and genomic characterization throughout life. Early stressed males, but not females, where more anxious in an open field-test, stayed shorter in tonic immobility and tended to have delayed sexual maturity, as shown by a tendency for lower levels of testosterone compared to controls. While early stressed females did not differ from non-stressed in fear and sexual maturation, they were more socially dominant than controls. The differential gene expression profile in hypothalamus was significantly correlated from 28 to 213 days of age in males, but not in females. In conclusion, early stress had a more pronounced long-term effect on male than on female chickens, as evidenced by behavioral, endocrine and genomic responses. This may either be attributed to inherent sex differences due to evolutionary causes, or possibly to different stress related selection pressures on the two sexes during commercial chicken breeding.     

Emotion Reactivity Is Increased 4-6 Weeks Postpartum in Healthy Women: A Longitudinal fMRI Study

Marked endocrine alterations occur after delivery. Most women cope well with these changes, but the postpartum period is associated with an increased risk of depressive episodes. Previous studies of emotion processing have focused on maternal–infant bonding or postpartum depression (PPD), and longitudinal studies of the neural correlates of emotion processing throughout the postpartum period in healthy women are lacking. In this study, 13 women, without signs of post partum depression, underwent fMRI with an emotional face matching task and completed the MADRS-S, STAI-S, and EPDS within 48 h (early postpartum) and 4–6 weeks after delivery (late postpartum). Also, data from a previous study including 15 naturally cycling controls assessed in the luteal and follicular phase of the menstrual cycle was used. Women had lower reactivity in insula, middle frontal gyrus (MFG), and inferior frontal gyrus (IFG) in the early as compared to the late postpartum assessment. Insular reactivity was positively correlated with anxiety in the early postpartum period and with depressive symptoms late postpartum. Reactivity in insula and IFG were greater in postpartum women than in non-pregnant control subjects. Brain reactivity was not correlated with serum estradiol or progesterone levels. Increased reactivity in the insula, IFG, and MFG may reflect normal postpartum adaptation, but correlation with self-rated symptoms of depression and anxiety in these otherwise healthy postpartum women, may also suggest that these changes place susceptible women at increased risk of PPD. These findings contribute to our understanding of the neurobiological aspects of the postpartum period, which might shed light on the mechanisms underlying affective puerperal disorders, such as PPD.