Seaweeds are some of the principal primary producers of marine environments, and they are important ecological elements of coastal ecosystems. The effects of harmful chemicals on seaweeds may adversely affect coastal ecosystems, hence we aimed to develop a new phytotoxicity test using the gametophytes of a common temperate kelp species, Undaria pinnatifida (KU-1630), for the widely used antifouling chemical substances Cybutryne, Diuron, Cu2+, and Zn2+. Toxicity to gametophytes of U. pinnatifida was assessed by comparing the relative growth rate (RGR) at the logarithmic growth phase. Fragmentation method, initial algal biomass, photon irradiance, and adhesive period were investigated for developing optimal test conditions. Cybutryne exposure tests were performed with seven replicates and control, the RGR ranging from 0.17 to 0.19, while mean 7-day EC50 and no observed effect concentration (NOEC) were 5.1 μg/L and 1.8 μg/L, respectively. The 7-day EC50 for other antifoulants was 14 μg/L for Diuron, 17 μg/L for Cu2+, and 1500 μg/L for Zn2+. This test method demonstrated high sensitivity and reproducibility, and it may be added to the routine methods used for toxicity evaluation of hazardous chemicals.
Background: The tumor microenvironment and its stromal cells play an important role in cancer development and metastasis. Bone marrow-derived cells (BMDCs), a rich source of hematopoietic and mesenchymal stem cells, putatively contribute to this tumoral stroma. However their characteristics and roles within the tumor microenvironment are unclear. In the present study, BMDCs in the tumor microenvironment were traced using the green fluorescent protein (GFP) bone marrow transplantation model. Methods: C57BL/6 mice were irradiated and rescued by bone marrow transplantation from GFP-transgenic mice. Lewis lung cancer cells were inoculated into the mice to generate subcutaneous allograft tumors or lung metastases. Confocal microscopy, immunohistochemistry for GFP, α-SMA, CD11b, CD31, CD34 and CD105, and double-fluorescent immunohistochemistry for GFP-CD11b, GFP-CD105 and GFP-CD31 were performed. Results: Round and dendritic-shaped GFP-positive mononuclear cells constituted a significant stromal subpopulation in primary tumor peripheral area (PA) and metastatic tumor area (MA) microenvironment, thus implicating an invasive and metastatic role for these cells. CD11b co-expression in GFP-positive cells suggests that round/dendritic cell subpopulations are possibly BM-derived macrophages. Identification of GFP-positive mononuclear infiltrates co-expressing CD31 suggests that these cells might be BM-derived angioblasts, whereas their non-reactivity for CD34, CD105 and α-SMA implies an altered vascular phenotype distinct from endothelial cells. Significant upregulation of GFP-positive, CD31-positive and GFP/CD31 double-positive cell densities positively correlated with PA and MA (P<0.05). Conclusion: Taken together, in vivo evidence of traceable GFP-positive BMDCs in primary and metastatic tumor microenvironment suggests that recruited BMDCs might partake in cancer invasion and metastasis, possess multilineage potency and promote angiogenesis.
A taxonomic study of the genus Padina from Japan, Southeast Asia, and Hawaii based on morphology and gene sequence data (rbcL and cox3) resulted in the recognition of four new species, that is, Padina macrophylla and Padina ishigakiensis from Ryukyu Islands, Japan; Padina maroensis from Hawaii; and Padina usoehtunii from Myanmar and Thailand. All species are bistratose and morphologically different from one another as well as from any known taxa by a combination of characters relating to degree of calcification; the structure, position, and arrangement of hairlines (HLs) and reproductive sori; and the presence or absence of rhizoid-like groups of hairs and an indusium. Molecular phylogenetic analyses demonstrated a close relationship between P. ishigakiensis, P. macrophylla, P. maroensis, and Padina australis Hauck. The position of P. usoehtunii, however, was not fully resolved, being either sister to a clade comprising the other three new species and P. australis in the rbcL tree or more closely related to a clade comprising several other recently described species in the cox3 tree. The finding of the four new species demonstrates high species diversity particularly in southern Japan. The following characters were first recognized here to be useful for species delimitation: the presence or absence of small rhizoid-like groups of hairs on the thallus surface, structure and arrangement of HLs on both surfaces either alternate or irregular, and arrangement of the alternating HLs between both surfaces in equal or unequal distance. The evolutionary trajectory of these and six other morphological characters used in species delineation was traced on the phylogenetic tree.