Embryo sac isolation inArabidopsis thaliana: A simple and efficient technique for structure analysis and mutant selection

Arabidopsis thaliana has been widely used as a model plant in gene function analysis. However, its tiny flower and curved embryo sac make it difficult to study gene expression during megagametogenesis, fertilization, and early embryogenesis, especially in the screening of mutants from those developmental processes. The techniques currently available are sectioning and whole-mount clearing of ovules; however, sectioning is time consuming and laborious for quantitative analysis, and whole-mount clearing, makes clear cytological observation impossible. Reported here is a simple and efficient method based on enzymatic isolation of embryo sacs that enables both quantitative analysis and elaborate cytological observation for gene expression investigation and mutant screening.     

SDX on the X chromosome is required for male sex determination

Dear Editor, Sex determination is one of the most fundamental develop-ment processes,as gender is the first and most important identity of human.In most mammals...     

Intratumoral expression of IL-17 and its prognostic role in gastric adenocarcinoma patients

In this study, we characterized the intratumoral expression of IL-17 and CD8(+) TILs in gastric adenocarcinoma patients after resection and determined the correlation between the survival probability of gastric adenocarcinoma patients and the expression of IL-17 in tumor. Expression of IL-17 and CD8 was assessed by immunohistochemistry, and the prognostic effects of intratumoral IL-17 expression and CD8(+) TILs were evaluated by Cox regression and Kaplan-Meier analysis. Immunohistochemical detection revealed the presence of IL-17 and CD8(+) cells in gastric adenocarcinoma tissue samples (90.6%, 174 out of 192 patients and 96.9%, 186 out of 192 patients, respectively). We have also found that intratumoral IL-17 expression was significantly correlated with age (p=0.004) and that the number of CD8(+)TILs was significantly correlated with UICC staging (p=0.012) and the depth of tumor invasion (p=0.022). The five-year overall survival probability among patients intratumorally expressing higher levels of IL-17 was significantly better than those expressing lower levels of IL-17 (p=0.036). Multivariate Cox proportional hazard analyses revealed that intratumoral IL-17 expression (HR: 0.521; 95% CI: 0.329-0.823; p=0.005) was an independent factor affecting the five-year overall survival probability. We conclude that low levels of intratumoral IL-17 expression may indicate poor prognosis in gastric adenocarcinoma patients.     

Primary structure and expression of a sodium channel characteristic of denervated and immature rat skeletal muscle

The alpha subunit of a voltage-sensitive sodium channel characteristic of denervated rat skeletal muscle was cloned and characterized. The cDNA encodes a 2018 amino acid protein (SkM2) that is homologous to other recently cloned sodium channels, including a tetrodotoxin (TTX)-sensitive sodium channel from rat skeletal muscle (SkM1). The SkM2 protein is no more homologous to SkM1 than to the rat brain sodium channels and differs notably from SkM1 in having a longer cytoplasmic loop joining domains 1 and 2. Steady-state mRNA levels for SkM1 and SkM2 are regulated differently during development and following denervation: the SkM2 mRNA level is highest in early development, when TTX-insensitive channels predominate, but declines rapidly with age as SkM1 mRNA increases; SkM2 mRNA is not detectable in normally innervated adult skeletal muscle but increases greater than 100-fold after denervation; rat cardiac muscle has abundant SkM2 mRNA but no detectable SkM1 message. These findings suggest that SkM2 is a TTX-insensitive sodium channel expressed in both skeletal and cardiac muscle.