Isolation and characterization of genes functionally involved in ovarian development of the giant tiger shrimp Penaeus monodon by suppression subtractive hybridization (SSH)

Suppression subtractive hybridization (SSH) libraries between cDNA in stages I (previtellogenic) and III (cortical rod) ovaries of the giant tiger shrimp (Penaeus monodon) were established. In all, 452 ESTs were unidirectionally sequenced. Sequence assembly generated 28 contigs and 201 singletons, 109 of which (48.0 percent) corresponding to known sequences previously deposited in GenBank. Several reproduction-related transcripts were identified. The full-length cDNA of anaphase promoting complex subunit 11 (PmAPC11; 600 bp with an ORF of 255 bp corresponding to a polypeptide of 84 amino acids) and selenoprotein M precursor (PmSePM; 904 bp with an ORF of 396 bp corresponding to a polypeptide of 131 amino acids) were characterized and reported for the first time in penaeid shrimp. Semiquantitative RT-PCR revealed that the expression levels of PmSePM and keratinocyte-associated protein 2 significantly diminished throughout ovarian development, whereas Ser/Thr checkpoint kinase 1 (Chk1), DNA replication licensing factor mcm2 and egalitarian were down-regulated in mature ovaries of wild P. monodon (p < 0.05). Accordingly, the expression profiles of PmSePM and keratinocyte-associated protein 2 could be used as biomarkers for evaluating the degree of reproductive maturation in domesticated P. monodon.

The detection of the death-associated protein kinase in oral squamous cell carcinoma by Semiquantitative RT-PCR / 实用口腔医学杂志

To investigate the relationship between the expression of death associated protein kinase (DAPK) gene and oral squamous cell carcinoma (OSCC). The expression of DAPK gene in OSCC was detected by semi-quantitive RT-PCR. The results showed that the expression of DAPK gene was down regulated significantly, which may relate to the tumorigenesis and development of OSCC. The detection of DAPK gene may act as an index in OSCC dignosis.

Molecular Characterization of Two Rice cDNAs Encoding GDP-Mannose-3', 5'-Epimerase and Their Expression Patterns / 生物化学与生物物理进展

GDP-mannose-3', 5' -epimerase (GME), which converts GDP-mannose into GDP-L-galactose, is essential for the biosynthesis of L-ascorbic acid in higher plants. The molecular characterization of two GME genes from rice has been reported. Firstly,both cDNAs were isolated from the rice mature leaves using RT-PCR technique. By comparing their sequences with homologues from other plants, it was found that GME genes were highly conserved among plant species, though phylogenetic study showed that all known GMEs could be divided into two distinct groups corresponding to monocots and dicots. Secondly, the genomic organization of rice OsGME genes was investigated, and a similarity of splice patterns was revealed. Finally, the expression patterns of the two cDNAs have been studied in various tissues and under different stress conditions by semiquantitative RT-PCR assay. The results showed that the OsGME1 transcript was up-regulated in response to cold stress, and gibberellin might regulate L-ascorbic acid levels by affecting transcription of both OsGME genes.

Methodologic Evaluation of EGFR Expression in Colorectal Cancer

PURPOSE: The epidermal growth factor receptor (EGFR) is a one of the transmembrane receptor proteins that play an important role in initiating tumor cell signaling and growth and is regarded as a promising target for cancer therapy. The EGFR expression rate has been reported to vary according to the detection method. The aims of this study were to evaluate the EGFR expression rate of a colorectal carcinoma by using immunohistochemical staining (IHC) and semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and to analyze the correlation between these methods. METHODS: EGFR expression was investigated in tissue sections from 33 patients with a colorectal adenocarcinoma by using IHC and semiquantitative RT-PCR. IHC was performed with antibodies in a 1:40 dilution and a 1:80 dilution. The results of the three detection methods were compared with one another. RESULTS: The mean age of the patients was 61.9+/-12.2 years, and the male-to-female ratio was 1.2:1. The EGFR expression rates were 93.9% (31/33) in IHC with a 1:40 dilution, 87.9% (29/33) in IHC with a 1:80 dilution, and 66.7% (22/33) in RT-PCR. The result of IHC with a 1:40 dilution significantly correlated with the result of IHC with a 1:80 dilution (Pearson correlation 0.684, P<0.01). There was no correlation between semiquantitative RT-PCR and IHC (1:40 dilution, 1:80 dilution). CONCLUSIONS: The EGFR expression obtained by using IHC was consistent with different antibody dilutions. The expression rate obtained by using RT-PCR was significantly lower than that obtained by using IHC, and there was no statistical correlation between the expressions of EGFR obtained by using RT-PCR and IHC. A standardization for EGFR detection methods is needed to draw any conclusion concerning their activity in colorectal cancer.

Semiquantitative RT-PCR analysis of apoptotic protease activating factor 1 in oral squamous cell carcinoma / 实用口腔医学杂志

Objective:To explore the relationship between apoptotic protease activating factor 1(APAF1) gene and oral squamous cell carcinoma (OSCC). Methods:The mRNA expression of APAF1 gene were detected with semiquantitative RT-PCR method in 18 cases of normal oral mucous membrane and 32 cases of OSCC tissues. Results:The expression of APAF1 gene was significantly decreased in OSCC tissues comparing with the normal oral mucous membrane(P