Amplification success rate of DNA from museum skin collections: a case study of stoats from 18 museums

There are large museum collections of mammalian skins and we wished to determine their usefulness for DNA‐based evolutionary and conservation studies. Methods derived from the ancient DNA approach were used to process samples from skins of the stoat (Mustela erminea) from 18 museums in 11 countries. Successful polymerase chain reaction (PCR) amplification was achieved in 56%, 46% and 40% of all samples for 0.65‐, 0.70‐ and 0.78‐kb PCR products of mitochondrial DNA, respectively. Some of the best‐preserved skin samples were those in tight‐fitting containers in a dry and cold environment. With care in their preservation, mammalian skin collections may be a good source of DNA.     

Anti-inflammatory effect of rosiglitazone is not reflected in expression of NFκB-related genes in peripheral blood mononuclear cells of patients with type 2 diabetes mellitus

Background

The aim of this study is to perform a cost-effectiveness comparison between palpation-guided thyroid fine-needle aspiration biopsies (P-FNA) and ultrasound-guided thyroid FNA biopsies (USG-FNA).

Methods

Each nodule was considered as a case. Diagnostic steps were history and physical examination, TSH measurement, Tc^99m thyroid scintigraphy for nodules with a low TSH level, initial P-FNA versus initial USG-FNA, repeat USG-FNA for nodules with initial inadequate P-FNA or USG-FNA, hemithyroidectomy for inadequate repeat USG-FNA. American Thyroid Association thyroid nodule management guidelines were simulated in estimating the cost of P-FNA strategy. American Association of Clinical Endocrinologists guidelines were simulated for USG-FNA strategy. Total costs were estimated by adding the cost of each diagnostic step to reach a diagnosis for 100 nodules. Strategy cost was found by dividing the total cost to 100. Incremental cost-effectiveness ratio (ICER) was calculated by dividing the difference between strategy cost of USG-FNA and P-FNA to the difference between accuracy of USG-FNA and P-FNA. A positive ICER indicates more and a negative ICER indicates less expense to achieve one more additional accurate diagnosis of thyroid cancer for USG-FNA.

Results

Seventy-eight P-FNAs and 190 USG-FNAs were performed between April 2003 and May 2008. There were no differences in age, gender, thyroid function, frequency of multinodular goiter, nodule location and diameter (median nodule diameter: 18.4 mm in P-FNA and 17.0 mm in USG-FNA) between groups. Cytology results in P-FNA versus USG-FNA groups were as follows: benign 49% versus 62% (p = 0.04), inadequate 42% versus 29% (p = 0.03), malignant 3% (p = 1.00) and indeterminate 6% (p = 0.78) for both. Eleven nodules from P-FNA and 18 from USG-FNA group underwent surgery. The accuracy of P-FNA was 0.64 and USG-FNA 0.72. Unit cost of P-FNA was 148 Euros and USG-FNA 226 Euros. The cost of P-FNA strategy was 534 Euros and USG-FNA strategy 523 Euros. Strategy cost includes the expense of repeat USG-FNA for initial inadequate FNAs and surgery for repeat inadequate USG-FNAs. ICER was -138 Euros.

Conclusion

Universal application of USG-FNA for all thyroid nodules is cost-effective and saves 138 Euros per additional accurate diagnosis of benign versus malignant thyroid nodular disease.

Trial registration

ClinicalTrials.gov, NCT00571090     

A new cytochrome b phylogroup of the common vole (Microtus arvalis) endemic to the Balkans and its implications for the evolutionary history of the species

The phylogeographic architecture of the common vole, Microtus arvalis, has been well‐studied using mitochondrial DNA and used to test hypotheses relating to glacial refugia. The distribution of the five described cytochrome b (cyt b) lineages in Europe west of Russia has been interpreted as a consequence of postglacial expansion from both southern and central European refugia. A recently proposed competing model suggests that the ‘cradle’ of the M. arvalis lineages is in western central Europe from where they dispersed in different directions after the Last Glacial Maximum. In the present study, we report a new cyt b lineage of the common vole from the Balkans that is not closely related to any other lineage and whose presence might help resolve these issues of glacial refugia. The Balkan phylogroup occurs along the southern distributional border of M. arvalis in central and eastern Bosnia and Herzegovina, Montenegro, and eastern Serbia. Further north and west in Slovenia, Bosnia and Herzegovina, and Serbia, common voles belong to the previously‐described Eastern lineage, whereas both lineages are sympatric in one site in Bosnia and Herzegovina. The Balkan phylogroup most reasonably occupied a glacial refugium already known for various Balkan endemic species, in contrast to the recently proposed model. South‐east Europe is an absolutely crucial area for understanding the postglacial colonization history of small mammals in Europe and the present study adds to the very few previous detailed phylogeographic studies of this region. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 788–796.     

Multiple refugia and barriers explain the phylogeography of the Valais shrew,Sorex antinorii (Mammalia: Soricomorpha)

The aim of the present study was to investigate the genetic structure of the Valais shrew (Sorex antinorii) by a combined phylogeographical and landscape genetic approach, and thereby to infer the locations of glacial refugia and establish the influence of geographical barriers. We sequenced part of the mitochondrial cytochrome b (cyt b) gene of 179 individuals of S. antinorii sampled across the entire species' range. Six specimens attributed to S. arunchi were included in the analysis. The phylogeographical pattern was assessed by Bayesian molecular phylogenetic reconstruction, population genetic analyses, and a species distribution modelling (SDM)‐based hindcasting approach. We also used landscape genetics (including isolation‐by‐resistance) to infer the determinants of current intra‐specific genetic structure. The phylogeographical analysis revealed shallow divergence among haplotypes and no clear substructure within S. antinorii. The starlike structure of the median‐joining network is consistent with population expansion from a single refugium, probably located in the Apennines. Long branches observed on the same network also suggest that another refugium may have existed in the north‐eastern part of Italy. This result is consistent with SDM, which also suggests several habitable areas for S. antinorii in the Italian peninsula during the LGM. Therefore S. antinorii appears to have occupied disconnected glacial refugia in the Italian peninsula, supporting previous data for other species showing multiple refugia within southern refugial areas. By coupling genetic analyses and SDM, we were able to infer how past climatic suitability contributed to genetic divergence of populations. The genetic differentiation shown in the present study does not support the specific status of S. arunchi. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 864–880.     

Ecomorphometric variation and sexual dimorphism in the common shrew (Sorex araneus)

We investigated the evolution of the biomechanics of the mandible in island and mainland populations of the common shrew on the west coast of Scotland. We predicted that climatic differences between populations should cause differences in prey composition leading to changes in the mechanical potential (MP) of the mandible. In females, MP was correlated with climate, with greater MP in warmer and drier habitats. In males, MP was significantly greater than in females but there was no relationship between male MP and climate. This led to increased sexual dimorphism in colder and wetter climates. The same pattern was found after a phylogenetic least squares analysis was conducted to account for shared phylogenetic history. We discuss possible reasons for this pattern, including male–male combat and the greater necessity of females to feed as efficiently as possible to meet their extremely high energy requirements during lactation.     

黄檗丛枝菌根真菌鉴定

目的：利用形态学特征与Nested-PCR技术鉴定黄檗丛枝菌根真菌。方法：采用酸性品红染色法挑选黄檗丛枝菌根。同时,利用湿筛法获得AM真菌孢子,进行形态学鉴定。运用Nested-PCR技术,对黄檗粗提DNA进行特异性扩增,采用blastn进行序列相似性比较。并构建系统进化树,确定侵染黄檗根系的AM真菌。结果：编号为HDAM-1的AM真菌孢子,形态特征与G．intraradices的特征描述一致。Nested-PCR检测到约455bp的目的片段,其序列与G．intraradices（DQ469118）相似性最高,达97．8％,有11个碱基的差异。系统进化树显示该序列在基于25S rDNA的进化树中与G．intraradices（DQ469118．1）处于同一分支,确定G．intraradices侵染黄檗根系。结论：将形态学特征与Nested-PCR技术相结合鉴定AM真菌,不仅简易、经济,而且能够提高研究结果的可靠性。     

半夏蛋白在小鼠早期妊娠子宫结合部位的检测

利用辣根过氧化物酶标记定位技术对半夏蛋白抗小鼠早期妊娠的作用原理进行了探讨。结果显示小鼠子宫内膜和腺管上皮以及胚胎外胚盘锥体部分呈现明显的酶棕显色颗粒,它们的产生能被未经酶标半夏蛋白所抑制。子宫内膜和胚胎的其他部分均未见与半夏蛋白有专一性的结合。本文对半夏蛋白的抗生育机理进行了简略的讨论。