A molecular phylogeny of the bladed Bangiales (Rhodophyta) in China provides insights into biodiversity and biogeography of the genus Pyropia.

A molecular taxonomic study was undertaken for the first time of the bladed Bangiales of the mainland coast of China (Northwest Pacific) based on sequence data of 201 plastid rbcL and 148 nuclear 18S sequences of historical and contemporary specimens. The results revealed that only one genus of bladed Bangiales, Pyropia, was present along Chinese coast. Species delimitation was determined using two empirical methods: the Automatic Barcode Gap Discovery (ABGD) and General Mixed Yule Coalescence (GMYC) coupled with detection of monophyly in tree reconstruction. At least fourteen species of Pyropia were recovered. Six species were confirmed that had been recorded previously based on morphology (Py. suborbiculata, Py. yezoensis, Py. haitanensis, Py. katadae, Py. tenera and Py. acanthophora), three species were recorded from China for the first time (Py. kinositae, Py. pseudolinearis and Py. tanegashimensis), and five cryptic species that did not match any molecular sequences were also discovered. The phylogeny of the concatenated rbcL and 18S dataset resolved three singletons and four clades. Each clades has a strong trend towards occupying a biogeographic region, but they are not confined to them. A transoceanic and antitropical pattern of distribution was found for Pyropia at both the subgeneric and species level. This together with high biodiversity (ca. 30% of all known Pyropia species) indicates that the Northwest Pacific might act as a centre of origin for modern distribution of Pyropia since the early Cenozoic.

[Expression spectra of apoptosis-related gene pnas-2].

To explore the expression spectra of apoptosis-related gene pnas-2 in normal tissues and acute leukemia (AL) patient tissues, the expressions of pnas-2 gene in tissues including heart, brain, placenta, lung, liver, skeletal muscle, kidney, pancreas, spleen, lymph node, thymus, leukocyte, bone marrow and fetal liver were detected by Northern blot. The expressions of pnas-2 in samples including 44 de novo, 9 non-CR, 27 CR and 12 relapsed AL patients were measured by real-time RT-PCR and Northern blot, and the expression levels of pnas-2 in normal and tumor tissues from 31 patients with malignancies were also detected. The results showed that pnas-2 was not expressed in the most tissues except in placenta. The results of real-time PCR indicated that pnas-2 expressions in samples of de novo, non-CR and relapsed patients ware significantly higher than that in CR, tumor tissues and normal tissues. In serial monitoring of 7 AL patients, the expression level of pnas-2 was high at first visit examination, but remarkably decreased after remission, and the pnas-2 expression level increased again when relapsed. It is concluded that the pnas-2 is specifically up-regulated in acute leukemia patients, which might be an oncogene and participate in leukemogenesis.

[Correlation between expression of apoptosis-related gene pnas-2 and leukemia].

The study was purposed to explore the correlation between apoptosis-related gene pnas-2 and leukemia. The RT-PCR was performed to detect the expression levels of pnas-2 gene in NB4, K562, U937 cells before and after treatment with AS(4)S(4), and to analysis the expression change of pnas-2 gene in bone marrow cells from patients with acute leukemia before and after chemotherapy. The results showed that the expression of pnas-2 gene in arsenic sulfide treated NB4 cells was down regulated in time-dependent manner, but the same outcome in K562 and U937 cells after being treated with AS(4)S(4) was not found. The positive expression rate of pnas-2 in cells from untreated patients with acute leukemia was 100%, and was significantly higher than that in normal control group. After chemotherapy, the expression was negative in complete remission patients, whereas in no-remission patients there were no significant differences of expression of pnas-2 before and after treatment. It is concluded that the pnas-2 gene may be closely related with apotosis of arsenic sulfide treated APL cells, and may consider as a molecular biological remission marker in acute leukemia.

PNAS-2: a novel gene probably participating in leukemogenesis.

OBJECTIVE: As(4)S(4) is an effective drug for the treatment of acute promyelocytic leukemia but its mechanism of action remains largely unknown. In a previous study, we identified PNAS-2, a human apoptosis-related protein gene, using gene expression profiling. In this study, we tried to clarify the role of PNAS-2 in apoptosis and leukemogenesis. METHODS: NB4 and U937 leukemia cell lines and serial clinical samples were studied. RNA interference (RNAi) and RNA overexpression were used to address the potential role of PNAS-2 in apoptosis. PNAS-2 expression was examined using Northern blot in multiple tissues, and real-time PCR was applied to analyze PNAS-2 expression in various patient samples. RESULTS: Functional analyses of PNAS-2 by RNAi and RNA overexpression indicate PNAS-2 is an anti-apoptosis gene. PNAS-2 expression is significantly increased in de novo or relapsed acute leukemia, but in patients in complete remission PNAS-2 levels decrease to levels comparable to those found in normal controls. In carcinomas, PNAS-2 expression was not upregulated, indicating that PNAS-2 overexpression was specific for leukemia. CONCLUSION: Based on the preliminary data, we suggest that the PNAS-2 gene functions as an anti-apoptotic gene and probably participates in leukemogenesis.