Morphological distinctness despite large-scale phenotypic plasticity—analysis of wild and pond-bred juveniles of allopatric populations of Tropheus moorii

Cichlids are an excellent model to study explosive speciation and adaptive radiation. Their evolutionary success has been attributed to their ability to undergo rapid morphological changes related to diet, and their particular breeding biology. Relatively minor changes in morphology allow for exploitation of novel food resources. The importance of phenotypic plasticity and genetically based differences for diversification was long recognized, but their relationship and relative magnitude remained unclear. We compared morphology of individuals of four wild populations of the Lake Tanganyika cichlid Tropheus moorii with their pond-raised F1 offspring. The magnitude of morphological change via phenotypic plasticity between wild and pond-bred F1 fish exceeds pairwise population differences by a factor of 2.4 (mean Mahalanobis distances). The genetic and environmental effects responsible for among population differentiation in the wild could still be recognized in the pond-bred F1 fish. All four pond populations showed the same trends in morphological change, mainly in mouth orientation, size and orientation of fins, and thickness of the caudal peduncle. As between population differentiation was lower in the wild than differentiation between pond-raised versus wild fish, we suggest the narrow ecological niche and intense interspecific competition in rock habitats is responsible for consistent shape similarity, even among long-term isolated populations

Metabolic Effects of Acute Thiamine Depletion Are Reversed by Rapamycin in Breast and Leukemia Cells

Thiamine-dependent enzymes (TDEs) control metabolic pathways that are frequently altered in cancer and therefore present cancer-relevant targets. We have previously shown that the recombinant enzyme thiaminase cleaves and depletes intracellular thiamine, has growth inhibitory activity against leukemia and breast cancer cell lines, and that its growth inhibitory effects were reversed in leukemia cell lines by rapamycin. Now, we first show further evidence of thiaminase therapeutic potential by demonstrating its activity against breast and leukemia xenografts, and against a primary leukemia xenograft. We therefore further explored the metabolic effects of thiaminase in combination with rapamycin in leukemia and breast cell lines. Thiaminase decreased oxygen consumption rate and increased extracellular acidification rate, consistent with the inhibitory effect of acute thiamine depletion on the activity of the TDEs pyruvate dehydrogenase and 2-oxoglutarate dehydrogenase complexes; these effects were reversed by rapamycin. Metabolomic studies demonstrated intracellular thiamine depletion and the presence of the thiazole cleavage product in thiaminase-treated cells, providing validation of the experimental procedures. Accumulation of ribose and ribulose in both cell lines support the thiaminase-mediated suppression of the TDE transketolase. Interestingly, thiaminase suppression of another TDE, branched chain amino ketoacid dehydrogenase (BCKDH), showed very different patterns in the two cell lines: in RS4 leukemia cells it led to an increase in BCKDH substrates, and in MCF-7 breast cancer cells it led to a decrease in BCKDH products. Immunoblot analyses showed corresponding differences in expression of BCKDH pathway enzymes, and partial protection of thiaminase growth inhibition by gabapentin indicated that BCKDH inhibition may be a mechanism of thiaminase-mediated toxicity. Surprisingly, most of thiaminase-mediated metabolomic effects were also reversed by rapamycin. Thus, these studies demonstrate that acute intracellular thiamine depletion by recombinant thiaminase results in metabolic changes in thiamine-dependent metabolism, and demonstrate a previously unrecognized role of mTOR signaling in the regulation of thiamine-dependent metabolism

Differential gene expression of potential stem/progenitor cell markers in murine mammary epithelial cells (HC11)

Epithelial cells of the mammary gland have the ability to proliferate, differentiate and undergo apoptosis. A murine model system for studying mammary epithelial cell behavior is the HC11 cell line, which has some stem and/or progenitor cell characteristics. HC11 cells can be maintained, in response to special treatment conditions, as undifferentiated cells, competent cells capable of responding to lactogenic hormones, or they can be induced to differentiate. Based on data obtained from a gene array, the aim of this project is to investigate differentially expressed genes in HC11 cells, which might be stem/progenitor cell marker candidates and determine their functions in HC11 cells. Polymerase chain reaction (PCR) experiments revealed that Lgals1 and Ran were upregulated in undifferentiated compared to competent and induced HC11 cells. These findings were confirmed and quantified in this project with real-time PCR experiments. Western Blot experiments confirmed the upregulation of galectin-1 (Gal-1), the Lgals1 gene product, in undifferentiated compared to competent, induced and differentiated HC11 cells. Fluorescent activated cells sorting (FACS) analysis of undifferentiated HC11 cells revealed that 60.85% of the gated HC11 cells expressed stem cell antigen 1 (Sca1), 90.12% of the cells expressed Gal-1 and 60.77% of the gated HC11 cells expressed Gal-1 and Sca1. Galectin-1 positively influences cell proliferation and migration of certain cell types. Knockdown of Lgals1 in HC11 cells followed by functional assays measuring proliferation or migration might give further insight into how undifferentiated cells are regulated. In this study it has been shown that galectin-1 (Gal-1), the Lgals1 gene product, is upregulated in undifferentiated compared to competent, induced and differentiated HC11 cells, functional assays might reveal an important function of galectin-1 in HC11 cells, as well as in stem/progenitor cells of the mammary gland and FACS experiments revealed that galectin-1 might be used to enrich stem/progenitor cell populations of the mammary gland.9

Size variation between different species of <i>Parascolymia</i> and <i>Lithophyllia detrita</i>.

<p><i>Parascolymia vitiensis</i> (single calice specimens) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132243#pone.0132243.ref029" target="_blank">29</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132243#pone.0132243.ref037" target="_blank">37</a>], <i>Parascolymia ampla</i> (n = 13) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132243#pone.0132243.ref040" target="_blank">40</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132243#pone.0132243.ref042" target="_blank">42</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132243#pone.0132243.ref043" target="_blank">43</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132243#pone.0132243.ref057" target="_blank">57</a>], <i>Parascolymia (Circophyllia) farquharsoni</i> (n = 1) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132243#pone.0132243.ref051" target="_blank">51</a>], <i>Lithophyllia detrita</i> (n = 11) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132243#pone.0132243.ref039" target="_blank">39</a>]. The corallum of <i>P</i>. <i>vitiensis</i> is described without exact length measurements. The information that single calice specimens typically may reach 25 cm length has not been verified [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0132243#pone.0132243.ref036" target="_blank">36</a>]. Similarly, the length of <i>Lithophyllia detrita</i> is not documented.</p

<i>Parascolymia bracherti</i> sp. nov., columella.

<p>(A) detail view of the corallite center (mould). The irregular knobby structure likely represents sediment-sealed interstices between former lamellar linkages; (B) same as (A), but inverted grey-scales to create a positive image of the spongy columella.</p

<i>Parascolymia bracherti</i> sp. nov., holotype (NHMW 2014/0205/0001).

<p>(A) overview of the corallite mould; (B) inverted grey-scale image of (A) giving a three-dimensional impression of the original corallite structure.</p

<i>Parascolymia bracherti</i> sp. nov., septal dentation.

<p>(A) detail view of septa moulds; (B) grey-scale inversion image of (A) showing different outlines of lower and higher order septa; (C) schematic diagram illustrating the relationship between septum profile and septum height (1 = linear profile at the base of a septum, 2 = chain of ovals at the base of septal teeth, 3 = irregularly interrupted pattern at the tip of septal teeth).</p