A new rheophilic South American darter (Crenuchidae: Characidium) from the rio Juruena basin,Brazil, with comments on morphological adaptations to life in fast-flowing waters

Characidium iaquira, a new species from the upper rio Juruena, rio Tapajós basin, Brazil, is described. The new species can be promptly distinguished from all congeners by having a unique v-shaped dark mark lying along the caudal-fin extension, in medium- and large-sized specimens, and a remarkable iridescent green colouration in life. Characidium iaquira is closely related to Characidium crandellii and Characidium declivirostre by sharing unambiguous synapomorphies such as branchiostegal membranes united to each other across the isthmus, a scaleless area extending from the isthmus to the pectoral girdle, and dermal flaps surrounding anterior and posterior naris independent, but touching each other distally. Morphological specializations of the paired fins in the three riffle-dwellers species are discussed, including the wing-like shape, robustness, and inclination of the pectoral fin.     

The incidence of turnip yellows virus in oilseed rape crops (Brassica napus L.) in three different regions of England over three consecutive growing seasons and the relationship with the abundance of flying Myzus persicae

Turnip yellows virus (TuYV) is the most important virus infecting oilseed rape in the United Kingdom. The incidence and spatial distribution of TuYV in winter oilseed rape (WOSR) crops in three regions of England were determined over three growing seasons. Leaf samples were collected from three fields in each region, in autumn (November–December) and spring (April) of the three crop seasons and tested for virus presence by enzyme-linked immunosorbent assay. Infection was detected in all fields except one. Higher TuYV incidences were recorded in 2007–2008 (≤89%) and 2009–2010 (≤100%) crop seasons than in 2008–2009 (≤24%). Highest incidences were recorded in Lincolnshire (≤100%), followed by Warwickshire (≤88%), with lowest incidences in Yorkshire (1–74%). There was a significant increase in incidence detected between autumn and spring sampling in eight fields, a significant decrease in one field and no significant change in 18 fields. Rothamsted Insect Survey suction trap data for the aphid Myzus persicae in Lincolnshire, Warwickshire and Yorkshire revealed two peaks of flight activity in most years (2007–2009). The second peak (September–November) coincided with emergence of WOSR. The highest cumulative (August–November) trap catches in the three regions during the three crop seasons occurred in Lincolnshire and the lowest in Yorkshire; catches in autumn 2009 were highest and lowest in autumn 2008. Regression analysis revealed a highly significant association between the cumulative numbers of M. persicae caught in the suction traps closest to the crops between August and November each year and the incidence of TuYV detected in the WOSR crops in the autumn of each year. Results are discussed in the light of factors affecting the spread of TuYV and future possibilities for control.     

Apolipoprotein A-I Helsinki promotes intracellular acyl-CoA cholesterol acyltransferase (ACAT) protein accumulation

Reverse cholesterol transport is a process of high antiatherogenic relevance in which apolipoprotein AI (apoA-I) plays an important role. The interaction of apoA-I with peripheral cells produces through mechanisms that are still poorly understood the mobilization of intracellular cholesterol depots toward plasma membrane. In macrophages, these mechanisms seem to be related to the modulation of the activity of acyl-CoA cholesterol acyltransferase (ACAT), the enzyme responsible for the intracellular cholesterol ester biosynthesis that is stored in lipid droplets. The activation of ACAT and the accumulation of lipid droplets play a key role in the transformation of macrophages into foam cells, leading to the formation of atheroma or atherosclerotic plaque. ApoA-I Helsinki (or ?K107) is a natural apoA-I variant with a lysine deletion in the central protein region, carriers of which have increased atherosclerosis risk. We herein show that treatment of cultured RAW macrophages or CHOK1 cells with ?K107, but not with wild-type apoA-I or a variant containing a similar deletion at the C-terminal region (?K226), lead to a marked increase (more than 10 times) in the intracellular ACAT1 protein level as detected by western blot analysis. However, we could only detect a slight increase in cholesteryl ester produced by ?K107 mainly when Chol loading was supplied by low-density lipoprotein (LDL). Although a similar choline-phospholipid efflux is evoked by these apoA-I variants, the change in phosphatidylcholine/sphyngomyelin distribution produced by wild-type apoA-I is not observed with either ?K107 or ?K226.     

Routes into education and employment for young Pakistani and Bangladeshi women in the UK

The article examines the educational and employment experiences and aspirations of young Pakistani and Bangladeshi people living in Oldham, in Great Manchester. Many young people demonstrated high aspirations and high levels of participation, particularly in relation to the educational and occupational level of their parents. Explanatory factors include the cultural value of education among Asian groups, the desire by parents to ensure success for their children and the ethnic penalty which these young people incur in the labour market. However, not all Pakistani and Bangladeshi young people have these aspirations. Girls who wished to continue their education faced a more complex situation than boys; for girls it was important to avoid jeopardizing the family honour. Nonetheless, national statistics show a marked increase in the numbers of young Pakistani and Bangladeshi women in full-time undergraduate courses in recent years. Women with degree level qualifications showed considerable determination to combine paid employment with family life.     

Preconditioning of leaves by solar radiation and anoxia affects microbial colonisation and rate of leaf mass loss in an intermittent stream

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CHROMOSOMAL REARRANGEMENTS AND THE GENETICS OF REPRODUCTIVE BARRIERS IN MIMULUS (MONKEY FLOWERS)

Chromosomal rearrangements may directly cause hybrid sterility and can facilitate speciation by preserving local adaptation in the face of gene flow. We used comparative linkage mapping with shared gene‐based markers to identify potential chromosomal rearrangements between the sister monkeyflowers Mimulus lewisii and Mimulus cardinalis, which are textbook examples of ecological speciation. We then remapped quantitative trait loci (QTLs) for floral traits and flowering time (premating isolation) and hybrid sterility (postzygotic isolation). We identified three major regions of recombination suppression in the M. lewisii × M. cardinalis hybrid map compared to a relatively collinear Mimulus parishii × M. lewisii map, consistent with a reciprocal translocation and two inversions specific to M. cardinalis. These inferences were supported by targeted intraspecific mapping, which also implied a M. lewisii‐specific reciprocal translocation causing chromosomal pseudo‐linkage in both hybrid mapping populations. Floral QTLs mapped in this study, along with previously mapped adaptive QTLs, were clustered in putatively rearranged regions. All QTLs for male sterility, including two underdominant loci, mapped to regions of recombination suppression. We argue that chromosomal rearrangements may have played an important role in generating and consolidating barriers to gene flow as natural selection drove the dramatic ecological and morphological divergence of these species.     

Dual inhibition of DNA polymerase PolC and protein tyrosine phosphatase CpsB uncovers a novel antibiotic target

Increasing antibiotic resistance is making the identification of novel antimicrobial targets critical. Recently, we discovered an inhibitor of protein tyrosine phosphatase CpsB, fascioquinol E (FQE), which unexpectedly inhibited the growth of Gram-positive pathogens. CpsB is a member of the polymerase and histidinol phosphate phosphatase (PHP) domain family. Another member of this family found in a variety of Gram-positive pathogens is DNA polymerase PolC. We purified the PHP domain from PolC (PolC_PHP), and showed that this competes away FQE inhibition of CpsB phosphatase activity. Furthermore, we showed that this domain hydrolyses the 5′-p-nitrophenyl ester of thymidine-5′-monophosphate (pNP-TMP), which has been used as a measure of exonuclease activity. Finally, we showed that FQE not only inhibits the phosphatase activity of CpsB, but also ability of PolC_PHP to catalyse the hydrolysis of pNP-TMP. This suggests that PolC may be the essential target of FQE, and that the PHP domain may represent an as yet untapped target for the development of novel antibiotics.