Microsatellite markers uncover cryptic species of Odontotermes (Termitoidae: Termitidae) from Peninsular Malaysia

Termites from the genus Odontotermes are known to contain numerous species complexes that are difficult to tell apart morphologically or with mitochondrial DNA sequences. We developed markers for one such cryptic species complex, that is, Odontotermes srinakarinensis sp. nov. from Maxwell Hill Forest Reserve (Perak, Malaysia), and characterised them using a sample of 41 termite workers from three voucher samples from the same area. We then genotyped 150 termite individuals from 23 voucher samples/colonies of this species complex from several sites in Peninsular Malaysia. We analysed their population by constructing dendograms from the proportion of shared-alleles between individuals and genetic distances between colonies; additionally, we examined the Bayesian clustering pattern of their genotype data. All methods of analysis indicated that there were two distinct clusters within our data set. After the morphologies of specimens from each cluster were reexamined, we were able to separate the two species morphologically and found that a single diagnostic character found on the mandibles of its soldiers could be used to separate the two species quite accurately. The additional species in the clade was identified as Odontotermes denticulatus after it was matched to type specimens at the NHM London and Cambridge Museum of Zoology.     

Intraspecific molecular phylogeny and phylogeography of the Meriones meridianus (Rodentia: Cricetidae) complex in northern China reflect the processes of desertification and the Tianshan Mountains uplift

The phylogeographical patterns and demographic history of mitochondrial DNA (cytochrome b, N = 327; D‐loop, N = 252) and nuclear DNA (IRBP gene, N = 235) haplotypes were studied for the Meriones meridianus complex in northern China, a desert‐dwelling gerbil species complex. The phylogenetic analyses, which were performed on the separate and combined (mitochondrial + nuclear) datasets, revealed two divergent clades (Clade A and Clade B) corresponding to distinct geographical regions. Clade A contained the haplotypes found mostly in individuals from the Tianshan Mountains area. Clade B contained haplotypes from populations located in other deserts in northern China. The divergence times indicated that the history of the M. meridianus complex was influenced by the uplift of the Tianshan Mountains and climate‐induced habitat fluctuations. In the Pleistocene, the expansion of forests and grasslands during interglacial period led to the isolation of the M. meridianus complex, which preferred to inhabit deserts. Hence, long geological isolation and the M. meridianus complex adaptation to local ecological conditions led to its genetic divergence. Clade A had long‐lasting demographic stability, most likely because the populations of this clade remained in a stable desert environment for a long time. However, the extension of other deserts and disappearance of palaeolakes during the last glacial period resulted in demographic expansion of Clade B. Furthermore, our genetic data indicated that two subspecies may exist within the M. meridianus complex. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110 , 362–383.     

Synthesis,angiopreventive activity,and in vivo tumor inhibition of novel benzophenone–benzimidazole analogs

Aim

The development of anticancer drugs with specific targets is of prime importance in modern biology. This study investigates the angiopreventive and in vivo tumor inhibition activities of novel synthetic benzophenone–benzimidazole analogs.

Main methods

The multistep synthesis of novel benzophenone–benzimidazole analogs (8a–n) allowing substitution with methoxy, methyl and halogen groups at different positions on the identical chemical backbone and the variations in the number of substituents were synthesized and characterized. The newly synthesized compounds were further evaluated for cytotoxic and antiproliferative effects against Ehrlich ascites carcinoma (EAC) cells. The potent lead compounds were further assessed for antiangiogenic effects in a CAM model and a tumor-induced vasculature in vivo model. The effect of angioprevention on tumor growth was verified in a mouse model.

Key findings

The cytotoxicity studies revealed that compounds 8f and 8n are strongly cytotoxic. Analyzing the structure–activity relationship, we found that an increase in the number of methyl groups in addition to methoxy substitution at the para position of the benzoyl ring in compound 8n resulted in higher potency compared to 8f. Furthermore, neovessel formation in in vivo systems, such as the chorioallantoic membrane (CAM) and tumor-induced mice peritoneum models, was significantly suppressed and reflected the tumor inhibition observed in mice.

Significance

These results suggest the potential clinical application of compound 8n as an antiangiogenic drug for cancer therapy.     

Brief communication: Evolution of a specific O allele (O1vG542A) supports unique ancestry of Native Americans

In this study, we explore the geographic and temporal distribution of a unique variant of the O blood group allele called O1v^G542A, which has been shown to be shared among Native Americans but is rare in other populations. O1v^G542A was previously reported in Native American populations in Mesoamerica and South America, and has been proposed as an ancestry informative marker. We investigated whether this allele is also found in the Tlingit and Haida, two contemporary indigenous populations from Alaska, and a pre‐Columbian population from California. If O1v^G542A is present in Na‐Dene speakers (i.e., Tlingits), it would indicate that Na‐Dene speaking groups share close ancestry with other Native American groups and support a Beringian origin of the allele, consistent with the Beringian Incubation Model. If O1v^G542A is found in pre‐Columbian populations, it would further support a Beringian origin of the allele, rather than a more recent introduction of the allele into the Americas via gene flow from one or more populations which have admixed with Native Americans over the past five centuries. We identified this allele in one Na‐Dene population at a frequency of 0.11, and one ancient California population at a frequency of 0.20. Our results support a Beringian origin of O1v^G542A, which is distributed today among all Native American groups that have been genotyped in appreciable numbers at this locus. This result is consistent with the hypothesis that Na‐Dene and other Native American populations primarily derive their ancestry from a single source population. Am J Phys Anthropol 151:649–657, 2013. © 2013 Wiley Periodicals, Inc.     

Cross-country variation in interracial marriage: a USA–Canada comparison of metropolitan areas

While black–white intermarriage is uncommon in the USA, blacks in Canada are just as likely to marry whites as to marry blacks. Asians, in contrast, are more likely to marry whites in the USA than in Canada. We test the claim that high rates of interracial marriage are indicative of high levels of social integration against Peter Blau's ‘macrostructural’ thesis that relative group size is the key to explaining differences in intermarriage rates across marriage markets. Using micro-data drawn from the American Community Survey and the Canadian census, we demonstrate that the relative size of racial groups accounts for over two-thirds of the USA–Canada difference in black–white unions and largely explains the cross-country difference in Asian–white unions. Under broadly similar social and economic conditions, a large enough difference in relative group size can become the predominant determinant of group differences in the prevalence of interracial unions.     

Molecular weight distribution and functional group profiles of TEMPO-oxidized lyocell fibers

The effects of TEMPO-mediated oxidation, performed with NaClO, a catalytic amount of NaBr, and 2,2′,6,6′-tetramethylpiperidine-1-oxy radical (TEMPO), were studied on lyocell fibers by means of GPC using multiple detection and group-selective fluorescence labeling according to the CCOA and FDAM methodology. The applied method determines functional group content as a sum parameter, as well as functional group profiles in relation to the molecular weight of the cellulose fibers. Both the CHO and COOH profiles, as well as molecular weight alterations, were analyzed. A significant decrease in the average molecular weight was obtained during the first hour of TEMPO-mediated oxidation, but prolonged oxidation time resulted in no strong additional chain scission. Significant amounts of COOH groups were introduced in the high molecular weight fractions by the oxidation with higher concentrations of NaClO (2.42–9.67 mmol NaClO/g fiber) after modification times of 1 h or longer.     

The Protohermes fruhstorferi species group (Megaloptera: Corydalidae: Corydalinae), with description of a new species from Vietnam

A new species group, the Protohermes fruhstorferi group of the dobsonfly genus Protohermes, is recognised. Three species belonging to the new species group are described and illustrated, including one new species from northern Vietnam.     

Focus Group Evaluation of Night Nurse Shiftwork Difficulties and Coping Strategies

Focus group interviews were performed on 45 intensive care nurses who worked 12-h shifts in a large metropolitan hospital. The purpose of this study was to identify nurses' perceptions of difficulties associated with shiftwork and coping strategies used to combat them. Overall, the findings were not different than those currently discussed in the literature. For example, nurses frequently utilized white noise, telephone answering machines, and light-darkening shades to improve the quality and quantity of day sleep. They also used exercise and increased early shift caffeine consumption to improve night work performance. However, the major incentive for performing night work for these nurses was a high shift differential that equaled approximately 20% of their hourly salary. Most nurses also felt that group educational interventions regarding shiftwork difficulties and coping strategies would be preferred to individual counseling. The most significant finding of this study was the discovery of an extremely high incidence (95%) of automobile-related injuries and near-accidents that occurred while driving to and from the workplace, potentially posing a significant public health risk. (Chronobiology International, 13(6), 457–463, 1996)     

Interaction of HMG proteins and H1 with hybrid PNA–DNA junctions

The objective of this study was to evaluate the effects of inserting peptide nucleic acid (PNA) sequences into the protein‐binding surface of an immobilized four‐way junction (4WJ). Here we compare the classic immobile DNA junction, J1, with two PNA containing hybrid junctions (4WJ‐PNA₁ and 4WJ‐PNA₃). The protein interactions of each 4WJ were evaluated using recombinant high mobility group proteins from rat (HMGB1b and HMGB1b/R26A) and human histone H1. In vitro studies show that both HMG and H1 proteins display high binding affinity toward 4WJ's. A 4WJ can access different conformations depending on ionic environment, most simply interpreted by a two‐state equilibrium between: (i) an open‐x state favored by absence of Mg²⁺, low salt, and protein binding, and (ii) a compact stacked‐x state favored by Mg²⁺. 4WJ‐PNA₃, like J1, shifts readily from an open to stacked conformation in the presence of Mg⁺², while 4WJ‐PNA₁ does not. Circular dichroism spectra indicate that HMGB1b recognizes each of the hybrid junctions. H1, however, displays a strong preference for J1 relative to the hybrids. More extensive binding analysis revealed that HMGB1b binds J1 and 4WJ‐PNA₃ with nearly identical affinity (K_Ds) and 4WJ‐PNA₁ with two‐fold lower affinity. Thus both the sequence/location of the PNA sequence and the protein determine the structural and protein recognition properties of 4WJs.     

Mhc‐linked survival and lifetime reproductive success in a wild population of great tits

Major histocompatibility complex (Mhc) genes are frequently used as a model for adaptive genetic diversity. Although associations between Mhc and disease resistance are frequently documented, little is known about the fitness consequences of Mhc variation in wild populations. Further, most work to date has involved testing associations between Mhc genotypes and fitness components. However, the functional diversity of the Mhc, and hence the mechanism by which selection on Mhc acts, depends on how genotypes map to the functional properties of Mhc molecules. Here, we test three hypotheses that relate Mhc diversity to fitness: (i) the maximal diversity hypothesis, (ii) the optimal diversity hypothesis and (iii) effect of specific Mhc types. We combine mark–recapture methods with analysis of long‐term breeding data to investigate the effects of Mhc class I functional diversity (Mhc supertypes) on individual fitness in a wild great tit (Parus major) population. We found that the presence of three different Mhc supertypes was associated with three different components of individual fitness: survival, annual recruitment and lifetime reproductive success (LRS). Great tits possessing Mhc supertype 3 experienced higher survival rates than those that did not, whereas individuals with Mhc supertype 6 experienced higher LRS and were more likely to recruit offspring each year. Conversely, great tits that possessed Mhc supertype 5 had reduced LRS. We found no evidence for a selective advantage of Mhc diversity, in terms of either maximal or optimal supertype diversity. Our results support the suggestion that specific Mhc types are an important determinant of individual fitness.