Relationships between lake ecology and morphological characters in Icelandic Arctic charr,Salvelinus alpinus

The common occurrence of parallel phenotypic patterns suggests that a strong relationship exists between ecological dynamics and micro‐evolution. Comparative studies from a large number of populations under varying sets of ecological drivers could contribute to a better understanding of this relationship. We used data on morphology of arctic charr (Salvelinus alpinus) and ecological factors from 35 Icelandic lakes to test the hypothesis that morphological patterns among monomorphic charr populations from different lakes are related to interlake variation in ecological characteristics. There is extensive phenotypic diversity among populations of Icelandic charr, and populations are easily distinguished based on overall body morphology. The results obtained in the present study showed that the morphological diversity of charr was related to large‐scale diversity in lake ecology. Variation in charr morphology was related to water origin (e.g. spring fed versus run‐off), bedrock age, and fish community structure. The present study shows how various ecological factors can shape the biological diversity that we observe. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 761–771.     

Nine new polymorphic microsatellite loci for the amplification of archived otolith DNA of Atlantic cod,Gadus morhua L.

Nine out of 22 microsatellite primers tested were successfully amplified on three samples of cod Gadus morhua L. (two contemporary and one archived otolith samples). All loci were polymorphic (5–23 alleles/locus). The average observed heterozygosity across loci and samples was 0.625, ranging from 0.294 to 0.895 at each locus. All loci were under Hardy–Weinberg equilibrium, except PGmo56 that showed significant excess of heterozygotes in all studied samples. The isolated loci were suitable for degraded DNA and therefore useful for conducting a long‐term temporal study with DNA obtained from archived otoliths of cod.     

小鼠月经生理模型的探讨

目的减少Finn CA于1984年首次报道的小鼠月经模型的观察时间点,以期为月经生理学研究提供一种较廉价且易操作的月经模型。方法应用成年雌性去势C57BL/6小鼠,给予续贯性激素处理,最末次激素处理后4～6h,实验组小鼠宫腔内注射花生油以诱导子宫内膜蜕膜化反应,对照组小鼠给予同样激素处理但无宫腔油剂注射。分别于油剂处理后31～35h(T3组)、56～70h(T4组)处死小鼠,称量子宫湿重,制作H&E组织切片,运用图像分析软件CAST2,计算全子宫横截面积(TUA)与子宫内膜横截面积(EA)。结果H&E染色子宫组织切片示在单纯雌激素作用下宫内膜呈单层立方上皮,核浆比较高,内膜基质疏松;雌孕激素联合处理后,分泌细胞易见,腺腔内可见分泌物。激素撤退后实验组T3观察到子宫内膜剥离,T4组示子宫内膜修复。对照组子宫内膜始终完整。子宫湿重在激素撤退后,实验组下降较慢。激素撤退后实验组T3的TUA继续上升而EA则维持原水平,T4组TUA与EA均明显下降。结论此模型在子宫内膜剥落期和早期修复期组织学特征与人类子宫内膜有一定的相似性。     

The effects of different decalcification protocols on TUNEL and general cartilage staining

Apoptosis is characterized by DNA strand breaks with a 3'-OH terminus, which are analyzed by terminal deoxy(d)-UTP nick end labeling (TUNEL). Proteinase K digestion is thought to be an essential step in the TUNEL procedure. The effects of decalcifying reagents on general staining and the TUNEL assay for cartilage sections are largely unknown. The effects of these reagents on retention and integrity of DNA in chondrocytes have not been described until now. We evaluated the effects of various decalcifying solutions, including 10% EDTA, 10% citric acid, 5% trichloroacetic acid, 5% acetic acid and a commercial hydrochloric acid-based reagent, on general cartilage staining and the TUNEL assay for cartilage. The effects of proteinase K on nucleus preservation were also examined. Decalcification with 10% EDTA gave the best result for general cartilage staining. Chondrocyte DNA was retained and intact after using this reagent. Decalcification with 10% EDTA is also the safest method of decalcification if the TUNEL assay is applied to cartilage. Proteinase K digestion may have adverse effects on nucleus preservation in cartilage. Awareness of these effects is important whenever the TUNEL assay is applied.     

Apolipoprotein E levels in cerebrospinal fluid and the effects of ABCA1 polymorphisms

Background

Animal studies suggest that brain apolipoprotein E (apoE) levels influence amyloid-β (Aβ) deposition and thus risk for Alzheimer's disease (AD). We have previously demonstrated that deletion of the ATP-binding cassette A1 transporter (ABCA1) in mice causes dramatic reductions in brain and cerebrospinal fluid (CSF) apoE levels and lipidation. To examine whether polymorphisms in ABCA1 affect CSF apoE levels in humans, we measured apoE in CSF taken from 168 subjects who were 43 to 91 years old and were either cognitively normal or who had mild AD. We then genotyped the subjects for ten previously identified ABCA1 single nucleotide polymorphisms (SNPs).

Results

In all subjects, the mean CSF apoE level was 9.09 μg/ml with a standard deviation of 2.70 μg/ml. Levels of apoE in CSF samples taken from the same individual two weeks apart were strongly correlated (r² = 0.93, p < 0.01). In contrast, CSF apoE levels in different individuals varied widely (coefficient of variation = 46%). CSF apoE levels did not vary according to AD status, APOE genotype, gender or race. Average apoE levels increased with age by ~0.5 μg/ml per 10 years (r² = 0.05, p = 0.003). We found no significant associations between CSF apoE levels and the ten ABCA1 SNPs we genotyped. Moreover, in a separate sample of 1225 AD cases and 1431 controls, we found no association between the ABCA1 SNP rs2230806 and AD as has been previously reported.

Conclusion

We found that CSF apoE levels vary widely between individuals, but are stable within individuals over a two-week interval. AD status, APOE genotype, gender and race do not affect CSF apoE levels, but average CSF apoE levels increase with age. Given the lack of association between CSF apoE levels and genotypes for the ABCA1 SNPs we examined, either these SNPs do not affect ABCA1 function or if they do, they do not have strong effects in the CNS. Finally, we find no evidence for an association between the ABCA1 SNP rs2230806 and AD in a large sample set.     

Molecular evolution of a multigene family in group A streptococci

The emm genes are members of a gene family in group A streptococci (GAS) that encode for antiphagocytic cell-surface proteins and/or immunoglobulin-binding proteins. Previously sequenced genes in this family have been named "emm," "fcrA," "enn," "arp," "protH," and "mrp"; herein they will be referred to as the "emm gene family." The genes in the emm family are located in a cluster occupying 3-6 kb between the genes mry and scpA on the chromosome of Streptococcus pyogenes. Most GAS strains contain one to three tandemly arranged copies of emm-family genes in the cluster, but the alleles within the cluster vary among different strains. Phylogenetic analysis of the conserved sequences at the 3' end of these genes differentiates all known members of this family into four evolutionarily distinct emm subfamilies. As a starting point to analyze how the different subfamilies are related evolutionarily, the structure of the emm chromosomal region was mapped in a number of diverse GAS strains by using subfamily-specific primers in the polymerase chain reaction. Nine distinct chromosomal patterns of the genes in the emm gene cluster were found. These nine chromosomal patterns support a model for the evolution of the emm gene family in which gene duplication followed by sequence divergence resulted in the generation of four major-gene subfamilies in this locus.      

Synthesis and evaluation of in vitro antioxidant capacities of some benzimidazole derivatives

New, except 1d, melatonin analogue benzimidazole derivatives were synthesized and characterized in the present study. The potential role of melatonin as an antioxidant by scavenging and detoxifying ROS raised the possibility that compounds that are analogous to melatonin can also be used for their antioxidant properties. Therefore the antioxidant effects of the newly synthesized compounds were investigated in vitro by means of their inhibitory effect on hydrogen peroxide-induced erythrocyte membrane lipid peroxidation (EMLP) and on various erythrocyte antioxidant enzymes viz. superoxide dismutase (SOD), catalase (CAT) and glucose-6-phosphate dehydrogenase (G6PD). The synthesized benzimidazole derivatives showed remarkable antioxidant activity in vitro in the H₂O₂-induced EMLP system. Furthermore their effects on various antioxidant enzymes are discussed and evaluated from the perspective of structure- activity relationships.     

Local host ant specificity of Phengaris (Maculinea) teleius butterfly,an obligatory social parasite of Myrmica ants

1. Phengaris butterflies are obligatory social parasites of Myrmica ants. Early research suggested that there is a different Myrmica host species for each of the five European Phengaris social parasites, but more recent studies have shown that this was an oversimplification. 2. The pattern of host ant specificity within a Phengaris teleius metapopulation from southern Poland is reported. A combination of studying the frequency distribution of Phengaris occurrence and morphometrics on adult butterflies were used to test whether use of different host species is reflected in larval development. 3. Phengaris teleius larvae were found to survive in colonies of four Myrmica species: M. scabrinodis, M. rubra, M. ruginodis, and M. rugulosa. Myrmica scabrinodis was the most abundant species under the host plant but the percentage of infested nests was similar to other host ant species at two sites and lower in comparison to nests of M. rubra and M. ruginodis at the other two sites. Morphometric measurements of adult butterflies reared by wild colonies of M. scabrinodis and M. ruginodis showed that wing size and number of wing spots were slightly greater for adults eclosing from nests of M. ruginodis. 4. Our results suggest that P. teleius in the populations studied is less specialised than previously suggested. The results are consistent with the hypothesis that P. teleius is expected to be the least specific of the European Phengaris species, as it has the largest and best defended fourth‐instar caterpillars and, as a predatory species, it spends less time in the central larval chambers of the host colonies. The fact that individuals reared by M. ruginodis had wider hind wings may suggest that P. teleius had better access to resources in M. ruginodis than in M. scabrinodis colonies.     

Disease-associated glycosylated molecular variants of human C-reactive protein activate complement-mediated hemolysis of erythrocytes in tuberculosis and Indian visceral leishmaniasis

Human C-reactive protein (CRP), as a mediator of innate immunity, removed damaged cells by activating the classical complement pathway. Previous studies have successfully demonstrated that CRPs are differentially induced as glycosylated molecular variants in certain pathological conditions. Affinity-purified CRPs from two most prevalent diseases in India viz. tuberculosis (TB) and visceral leishmaniasis (VL) have differential glycosylation in their sugar composition and linkages. As anemia is a common manifestation in TB and VL, we assessed the contributory role of glycosylated CRPs to influence hemolysis via CRP-complement-pathway as compared to healthy control subjects. Accordingly, the specific binding of glycosylated CRPs with erythrocytes was established by flow-cytometry and ELISA. Significantly, deglycosylated CRPs showed a 7–8-fold reduced binding with erythrocytes confirming the role of glycosylated moieties. Scatchard analysis revealed striking differences in the apparent binding constants (10⁴–10⁵ M⁻¹) and number of binding sites (10⁶–10⁷sites/erythrocyte) for CRP on patients’ erythrocytes as compared to normal. Western blotting along with immunoprecipitation analysis revealed the presence of distinct molecular determinants on TB and VL erythrocytes specific to disease-associated CRP. Increased fragility, hydrophobicity and decreased rigidity of diseased-erythrocytes upon binding with glycosylated CRP suggested membrane damage. Finally, the erythrocyte-CRP binding was shown to activate the CRP-complement-cascade causing hemolysis, even at physiological concentration of CRP (10 μg/ml). Thus, it may be postulated that CRP have a protective role towards the clearance of damaged-erythrocytes in these two diseases.