SUMMARYLateral organ growth in seed plants is controlled in part by members of the YABBY (YAB) and class III homeodomain/leucine zipper (HD-ZIPIII) families of transcription factors. HD-ZIPIII genes appear to play a conserved role in such organs, but YAB genes have diversified, with some members of the family having specialized functions in leaves, carpels or ovule integuments. The ancestral expression patterns and timing of divergence of the various classes of YAB genes remain to be established. We isolated and evaluated the expression of one HD-ZIPIII and five YAB genes representing the five major YAB gene classes from Cabomba caroliniana, a member of the earliest-diverging angiosperms. Consistent with observations in eudicots, the FILAMENTOUS FLOWER (FIL) and YABBY5 (YAB5) genes of C. caroliniana were expressed in the abaxial regions of the leaf where new laminar segments arise, and the patterns of expression were mutually exclusive to those of HD-ZIPIII, indicating that these expression patterns are ancestral. Expression of CRABS CLAW (CRC) in the abaxial carpel wall, and of INNER NO OUTER (INO) in the abaxial outer integument of ovules was also conserved between eudicots and C. caroliniana, indicating that these patterns are primitive. However, the CRC gene was also expressed in other floral organs in C. caroliniana, and expression in stamens was also observed in another early-diverging species, Amborella trichopoda, indicating that carpel-specific expression was acquired after divergence of the Nymphaeales. The expression data and phylogeny for YAB genes suggest that the ancestral YAB gene was expressed in proliferating tissues of lateral organs.

S100 protein A8 and A9 naturally form a stable heterocomplex. Recently, we have proved that S100A9 overexpression in various adenocarcinomas is associated with poor tumor differentiation. In this study, we examined the relationship between the expression of each protein and the pathological parameters that reflect the aggressiveness of carcinoma, in invasive ductal carcinoma (IDC) of the breast. Serial paraffin-embedded tissue sections from 101 IDC cases were immunostained with respective monoclonal antibodies, and the results were as follows: 1) A positive correlation of immunoreactivity between S100A8 and S100A9 was noticed (r=0.873 and P<0.0001); 2) The percentage of S100A9-positive tumor cells was higher than that of S100A8-positive tumor cells (P<0.001), and S100A8 alone was not detected in any case; 3) Overlap between S100A8 and S100A9 staining patterns was found in the corresponding tissue areas, but S100A9 positivity was also observed in S100A8-negative tumor cells; 4) The immunopositivity for each protein also correlated with the mitotic activity, MIB-1 index, HER2 overexpression, node metastasis, and poor pT categories and pStage (P<0.05); 5) Co-expression of both proteins was associated with poor tumor differentiation, vessel invasion, node metastasis, and poor pStage (P<0.05). Furthermore, co-expression of the proteins was also observed in MCF-7 cells, and it was suggested that the immunolocalization is related with cell cycle. Our conclusions are as follows: 1) It is suggested that S100A8 is S100A9-dependently expressed and acquires the protein stability by S100A8/A9 heterocomplex formation; 2) S100A8 and S100A9 overexpression should be considered marker of poor prognosis in IDC.

BackgroundThe evolution of oogamy from isogamy, an important biological event, can be summarized as follows: morphologically similar gametes (isogametes) differentiated into small “male” and large “female” motile gametes during anisogamy, from which immotile female gametes (eggs) evolved. The volvocine green algae represent a model lineage to study this type of sex evolution and show two types of gametic unions: conjugation between isogametes outside the parental colonies (external fertilization during isogamy) and fertilization between small motile gametes (sperm) and large gametes (eggs) inside the female colony (internal fertilization during anisogamy and oogamy). Although recent cultural studies on volvocine algae revealed morphological diversity and molecular genetic data of sexual reproduction, an intermediate type of union between these two gametic unions has not been identified.ResultsWe identified a novel colonial volvocine genus, Colemanosphaera, which produces bundles of spindle-shaped male gametes through successive divisions of colonial cells. Obligately anisogamous conjugation between male and female motile gametes occurred outside the female colony (external fertilization during anisogamy). This new genus contains 16- or 32-celled spheroidal colonies similar to those of the volvocine genera Yamagishiella and Eudorina. However, Colemanosphaera can be clearly distinguished from these two genera based on its sister phylogenetic position to the enigmatic flattened colonial volvocine Platydorina and external fertilization during anisogamy. Two species of Colemanosphaera were found in a Japanese lake; these species are also distributed in European freshwaters based on a published sequence of an Austrian strain and the original description of Pandorina charkowiensis from Ukraine.ConclusionsBased on phylogeny and morphological data, this novel genus exhibits a missing link between Platydorina and the typical spheroidal colonial volvocine members such as Pandorina or Yamagishiella. Considering the external obligate anisogamy, oogamy evolution may have been preceded by the transition from external to internal fertilization during anisogamy within the volvocine green algae.

Mass mortality of oak trees has been occurring in Japan since the late 1980s. The fungus Raffaelea quercivora has been frequently isolated from discoloured sapwood in dead or wilting trees and inoculation experiments have shown it to be capable of causing wilting and xylem discoloration in several oak species, notably Quercus crispula and Q. serrata. In this study, we inoculated seedlings of six Fagaceae species with R. quercivora and, after 56 days, measured the vertical length of the discoloration and the areas of discoloured and non-conducting sapwood on stem cross-sections. The sapwood discoloration and the water non-conduction areas were larger in Q. crispula and Q. serrata than in the other species.