Are three colonies of Neostromboceros albicomus,a candidate biological control agent for Lygodium microphyllum,the same host biotype?

Three colonies of Neostromboceros albicomus, a candidate biological control agent of Lygodium microphyllum, were barcoded using the D2 expansion domain, to determine which of two biotypes they represented. The first colony, collected in 2005 and 2007, was used for the initial host range testing. Colonies collected in 2012 and 2014 are currently being used to finalise this testing. All three colonies were collected in Trat Province, Thailand and all three populations show identical sequences to the N. albicomus biotype which prefers L. microphyllum as its host plant. The N. albicomus biotype that uses L. flexuosum as its host plant differs by a single nucleotide, a difference which may reflect cryptic speciation.     

Genetic implications of phylogeographical patterns in the conservation of the boreal wetland butterfly Colias palaeno (Pieridae)

The boreo‐montane wetland butterfly species Colias palaeno has a European distribution from the Alps to northern Fennoscandia. Within its European range, the species’ populations have shrunk dramatically in recent historical times. Therefore, detailed baseline knowledge of the genetic makeup of the species is pivotal in planning potential conservation strategies. We collected 523 individuals from 21 populations across the entire European range and analyzed nuclear (20 allozyme loci) and mitochondrial (600 bp of the cytochrome c oxidase subunit I gene) genetic markers. The markers revealed contrasting levels of genetic diversity and divergence: higher in allozymes and lower in mitochondrial sequences. Five main groups were identified by allozymes: Alps, two Czech groups, Baltic countries, Fennoscandia, and Poland. The haplotype mitochondrial network indicates a recent range expansion. The most parsimonious interpretation for our results is the existence of a continuous Würm glacial distribution in Central Europe, with secondary disjunction during the Last Glacial Maximum into a south‐western and a north‐eastern fragment and subsequent moderate differentiation. Both groups present signs of postglacial intermixing in the Czech Republic. However, even a complete extinction in this region would not considerably affect the species’ genetic basis, as long as the source populations in the Alps and in northern Europe, comprising the most relevant evolutionary units for conservation, are surviving.     

Spindle assembly checkpoint genes reveal distinct as well as overlapping expression that implicates MDF-2/Mad2 in postembryonic seam cell proliferation in Caenorhabditis elegans

Background

The spindle assembly checkpoint (SAC) delays anaphase onset by inhibiting the activity of the anaphase promoting complex/cyclosome (APC/C) until all of the kinetochores have properly attached to the spindle. The importance of SAC genes for genome stability is well established; however, the roles these genes play, during postembryonic development of a multicellular organism, remain largely unexplored.

Results

We have used GFP fusions of 5' upstream intergenic regulatory sequences to assay spatiotemporal expression patterns of eight conserved genes implicated in the spindle assembly checkpoint function in Caenorhabditis elegans. We have shown that regulatory sequences for all of the SAC genes drive ubiquitous GFP expression during early embryonic development. However, postembryonic spatial analysis revealed distinct, tissue-specific expression of SAC genes with striking co-expression in seam cells, as well as in the gut. Additionally, we show that the absence of MDF-2/Mad2 (one of the checkpoint genes) leads to aberrant number and alignment of seam cell nuclei, defects mainly attributed to abnormal postembryonic cell proliferation. Furthermore, we show that these defects are completely rescued by fzy-1(h1983)/CDC20, suggesting that regulation of the APC/C^CDC20 by the SAC component MDF-2 is important for proper postembryonic cell proliferation.

Conclusion

Our results indicate that SAC genes display different tissue-specific expression patterns during postembryonic development in C. elegans with significant co-expression in hypodermal seam cells and gut cells, suggesting that these genes have distinct as well as overlapping roles in postembryonic development that may or may not be related to their established roles in mitosis. Furthermore, we provide evidence, by monitoring seam cell lineage, that one of the checkpoint genes is required for proper postembryonic cell proliferation. Importantly, our research provides the first evidence that postembryonic cell division is more sensitive to SAC loss, in particular MDF-2 loss, than embryonic cell division.     

Use of C-banding for identifying radiation induced micronuclei

Differentiation of micronuclei (MN) caused by ionizing radiation from those caused by chemicals is a crucial step for managing treatment of individuals exposed to radiation. MN in binucleated lymphocytes in peripheral blood are widely used as biomarkers for estimating dose of radiation, but they are not specific for ionizing radiation. MN induced by ionizing radiation originate predominantly as a result of chromosome breaks (clastogenic action), whereas MN caused by chemical agents are derived from the loss of entire chromosomes (aneugenic action). C-banding highlights centromeres, which might make it possible to distinguish radiation induced MN, i.e., as a byproduct of acentric fragments, from those caused by the loss of entire chromosomes. To test the use of C-banding for identifying radiation induced MN, a blood sample from a healthy donor was irradiated with 3 Gy of Co-60 gamma rays and cultured. Cells were harvested and dropped onto slides, divided into a group stained directly with Giemsa and another processed for C banding, then stained with Giemsa. The frequency of MN in 500 binucleated cells was scored for each method. In preparations stained with Giemsa directly, the MN appeared as uniformly stained structures, whereas after C banding, some MN exhibited darker regions corresponding to centromeres that indicated that they were not derived from acentric fragments. The C-banding technique enables differentiation of MN from acentric chromosomal material. This distinction is useful for improving the specificity of the MN assay as a biomarker for ionizing radiation.     

Estrogen receptor alpha (ERS1) SNPs c454-397T>C (PvuII) and c454-351A>G (XbaI) are risk biomarkers for breast cancer development

There are several risk factors related to Breast Cancer (BC) risks and response to chemotherapy with SERMs. Recently some single nucleotide polymorphisms (SNPs) on ESR1 gene have been associated to this disease. However, data are still inconclusive. The present study aimed to investigate the association of SNPs c454-397T>C (also called PvuII) and c454-351A>G (so called XbaI) to incidence of sporadic BC; ERα expression in BC; tamoxifen hormonetherapy (HT-TMX) responsiveness. To do so, a cohort of BC patients was analyzed through retrospective data collection, immunohistochemistry to ERα protein, and genotyping for PvuII and XbaI SNPs by PCR–RFLP, confirmed by sequencing. Significant difference in PvuII alleles frequencies were found BC patients when compared to control samples. Patients with P allele have a 5.14-fold increased BC risk. We found higher P and X alleles frequencies in ERα positive BC and the pp and xx genotypes were observed exclusively in patients with HT-TMX-responsive BC. Taken together, data indicates that P allele as a novel sporadic BC biomarker whereas p and x alleles enhanced chemotherapy responsiveness.     

Can genomics clarify the origins of Boreioglycaspis melaleucae in California,USA?

The Australian psyllid Boreioglycaspis melaleucae is a biological control agent of Melaleuca quinquenervia in Florida (USA) but was observed attacking M. quinquenervia trees in southern California (USA). Genotyping revealed the California population matched three of eight Australian haplotypes and all three Florida haplotypes. It remains unclear if the California psyllid population arrived directly from Australia or via Florida.     

A reliable and rapid procedure to estimate drug partitioning in biomembranes

A direct method using derivative spectrophotometry was developed for determining membrane-water molar partition coefficients (Kp) of the anticancer drugs tamoxifen (TAM) and 4-hydroxytamoxifen (OHTAM). This method explores a shift in the absorption spectra of the drugs when removed from the aqueous phase to a hydrophobic environment. Partition of TAM and OHTAM depends on membrane composition and on drug concentration, temperature and presence of cholesterol. Unlike OHTAM, partition of TAM in DMPC bilayers, liposomes of sarcoplasmic reticulum (SR) lipids and native membranes of SR and mitochondria decreases linearly with drug concentration. Additionally, the partition of these drugs is higher in SR native membranes than in liposomes of SR lipids. The partition also depends on membrane type, being higher in mitochondria than in SR membranes. Maximal partitionings in DMPC are observed at temperatures in the range of the main phase transition. Cholesterol strongly affects the incorporation of drugs and maximal inhibition was observed in DMPC bilayers.     

Is filament clipping an effective tool for tissue sampling in <Emphasis Type="Italic">Hippocampus guttulatus</Emphasis>?

Examining genetic diversity, population structure, and geographic distribution has become an important part in the conservation strategies of endangered populations. However, these studies rely on tissue samples collection for DNA analysis which may be problematic for species with a sensitive conservation status. Partial fin-clipping has been employed for tissue collection, due to the increased popularity of DNA-based analysis for ecological and fisheries studies, however, fin clipping can potentially affect behavior, swimming performance, predator avoidance and the ability to find and capture prey. This study aimed to test the effects of filament clipping using captive breed seahorses (Hippocampus guttulatus) as an alternative tool for tissue sample. Clipped filaments regrew on average 0.05?±?0.02 mm/day for 3 months and no mortality or disease was observed during the experiment. Filaments provided enough tissue for DNA analysis. This study provided valuable information regarding a new sampling technique that does not impair the seahorse locomotion. This methodology may be used in population’s genetic studies of other species that have skin filaments as a morphological trait.