[Research advances in the role of mesenchymal stem cells and their exosomes in treatment of liver diseases]

At present, liver transplantation remains the most effective treatment for acute liver failure and advanced cirrhosis, but its use and promotion are limited by insufficient organ donors, financial consideration, and requirements for lifelong immunosuppression. In recent years, stem cell transplantation has been recommended as an effective substitutive therapy for liver disease. Mesenchymal stem cells, also known as pluripotent interstitial stromal cells, are self-renewing cells that can be found in almost all postnatal organs and tissues, including the liver. Their potential to differentiate into hepatocytes and immunomodulatory properties provide new insights into the use of mesenchymal stem cells in the treatment of acute and chronic liver diseases. This article reviews the characteristics of mesenchymal stem cells, their mechanisms in the treatment of acute and chronic liver diseases, and related risks.

Characterization, expression analysis and localization pattern of toll-like receptor 1 (tlr1) and toll-like receptor 2 (tlr2) genes in grass carp Ctenopharyngodon idella

In this study, the toll-like receptor 1 (tlr1) and toll-like receptor 2 (tlr2) genes of grass carp Ctenopharyngodon idella were cloned and characterized. tlr1 and tlr2 were found to be highly expressed in immune system organs such as spleen, middle kidney and heart kidney. The expression level of tlr1 and tlr2 was found to be up-regulated at the later stage of viral challenge process. Moreover, subcellular localization indicated that Tlr1 and Tlr2 shared similar localization pattern and both of them may locate in the plasma membrane of transfected cells.

Clinical observation of umbilical cord mesenchymal stem cell treatment of severe systolic heart failure

The aim of this study was to evaluate the effectiveness of umbilical cord mesenchymal stem cells (MSCs) in the treatment of chronic systolic heart failure. Fifty-nine hospitalized patients with heart failure were randomly divided into a treatment group (30 patients) and a control group (29 patients). The treatment group received treatment with medication as well as intracoronary transplantation of umbilical cord MSCs, and the control group, only medication. The cardiac structure, function change, and rehospitalization and mortality rates of the 2 groups were observed before and 1 and 6 months after treatment. One month after the transplantation of umbilical cord MSCs, the incidence of fatigue, chest tightness, and dyspnea was high in the treatment group. The 6-min walking distance of the treatment group was found to be significantly higher than that of the control group (P < 0.05); in addition, the NT-proBNP level, left ventricular ejection fraction, and mortality rate of the treatment group were statistically lower than those of the control group (P < 0.05). Readmission rates showed a downward trend, but the difference was not statistically significant (P > 0.05). Using umbilical cord MSCs in the treatment of congestive heart failure can help improve cardiac remodeling and cardiac function and reduce the mortality rate.

Characterizations of four toll-like receptor 4s in grass carp Ctenopharyngodon idellus and their response to grass carp reovirus infection and lipopolysaccharide stimulation

In this study, the subcellular localization, tissue distribution and response to grass carp reovirus (GCRV) infection and lipopolysaccharide (LPS) stimulation of four grass carp Ctenopharyngodon idellus toll-like receptor 4 (tlr4) genes were investigated. All four genes were constitutively expressed in all tissues studied, but the subcellular localization and tissue exhibiting the highest expression differed for each protein. Following GCRV infection, all the four tlr4s were upregulated in all tissues examined, and stimulation of C. idellus kidney (CIK) cells with LPS resulted in downregulation of all four tlr4s. These results provide a foundation for further investigation of tlr4 genes in bony fishes.

Expression and diagnostic value of proteins in Mycobacterium tuberculosis

We constructed a prokaryotic expression vector expressing the Mycobacterium tuberculosis protein TB16.3, as well as 3 other proteins, including TB15.3, CFP-10, and Rv2626C, which were purified and analyzed for their effectiveness as detection antibodies. The TB16.3 genes of M. tuberculosis H37Rv genomic DNA were amplified by polymerase chain reaction, inserted into the expression vector pET-30a, and expressed in Escherichia coli. An enzyme-linked immunosorbent assay was used to detect the 4 M. tuberculosis antibodies. Engineered E. coli bacteria expressing TB16.3 and the 3 other proteins were constructed and found mainly to be soluble. For recombinant TB16.3 proteins, serum samples of 118 tuberculosis (TB) patients and 96 healthy controls were analyzed. Sensitivity, specificity, and adjusted concordance rate for the TB16.3 antibody were 72.9, 86.5, and 79.6%, respectively. The positive rate of Rv2626C antibody in TB patients (44.1%) was significantly lower than that in normal controls (75.0%, χ(2) = 20.8, P < 0.01). TB15.3 and TB16.3 were used for simultaneous detection and showed sensitivity, specificity, and repeatability rates of 69.4, 96.9, and 83.7%. The antibody positive rate and specificity for patients with lung disease was 9.6 and 90.4%, respectively. TB15.3 and TB16.3 were mixed and detected simultaneously. Combined with the results for TB15.3, the sensitivity, specificity, and concordance rates were 82.2, 95.9, and 88.9%, respectively. The concordance rate was the highest value observed. Target genes were cloned into a host strain and expressed successfully. The TB16.3 recombinant protein may be used as a new serological antigen for tuberculosis diagnosis.

Expression and serological diagnosis of Mycobacterium tuberculosis CFP-10 and Rv2626c proteins

We constructed a Mycobacterium tuberculosis vector expressing CFP-10 and Rv2626c to examine the expression of these proteins in Escherichia coli as well as their immunoreactivity. The CFP-10 and Rv2626c genes were amplified from tuberculosis H37Rv genomic DNA using polymerase chain reaction. They were ligated into the expression vector PET30a and expressed in E. coli. Histidine tag nickel column chromatography was used to purify the recombinant protein. An enzyme-linked immunosorbent assay (ELISA) was used for detection. In our E. coli-engineered bacteria containing a CFP10 and Rv2626c plasmid, the target protein was found mainly to be in the soluble form. We formed mixed antigens of the recombinant CFP10 and Rv2626c proteins. ELISA results showed that in 214 blood samples, the positive rate was 77.1%. The target gene was successfully expressed in the host strain. Mixed antigens of the recombinant CFP-10 and Rv2626c proteins can be used as a combination antigen in the serological diagnosis of tuberculosis.

Optoelectronic properties of CdSe0.75S0.25 nanocrystals assembled into micro-electrodes

CdSe0.75S0.25 semiconductor nanocrystals were synthesized by chemical colloidal route. The crystal structure, morphology and optical properties of synthesized CdSe0.75S0.25 nanocrystals were characterized by XRD, TEM and UV-Vis absorption spectroscopy respectively. The crystal structure of CdSe0.75S0.25 is face-centered Cubic sphalerite phase. The average size is about 7 nm in diameter. A gold tip-to-tip structure electrode with the gap size -20 microm was fabricated using conventional optical lithography technique followed by film deposition and standard lift-off process. An optoelectronics device was fabricated based on CdSe0.75S0.25 by assembling nanocrystals into electrodes by using dielectrophoresis (DEP) process. The electrical transport properties and opto-electrical transport properties of the fabricated device were measured at temperature range from 5 K to 305 K. The results show that the resistance of CdSe0.75S0.25 NCs increases with the temperature decreases, indicating a typical semiconductor behavior. An obvious photoconductive behavior was observed, demonstrated potential application in nano-optoelectronics devices. After data analyzing, the conductivity shows the 0.5 exponent of Efros-Shklovskii variable-range-hopping (ES-VRH) model.

Extrahepatic primary adrenal alveolar echinococcosis: a review

BACKGROUND

Primary echinococcosis, and especially primary alveolar echinococcosis (AE) is rare among adrenal lesions.

METHODS

We report a case of primary AE in a 28-year-old male with low backache and occasional upper limb pain lasting for six months, and review the pertinent but sparse literature on this disorder.

RESULTS

Evaluation of the patient revealed an abdominal mass as right adrenal AE. The adrenal gland is a rare extrahepatic site of occurrence of echinococcosis, and particularly of AE. Patients with adrenal echinococcosis usually have nonspecific clinical symptoms. Imaging examinations revealed clearly the features of AE and its surrounding pathology. Alveolar echinococcosis was seen as an inhomogeneous pseudotumor with irregular boundaries, an irregular central pseudocystic appearance, and infiltration into surrounding structures. On contrast-enhanced computed tomography, the periphery of the mass in AE may be enhanced and multicentric vesicles may be seen. Magnetic resonance imaging may show the multivesicular morphology of lesions. The definitive diagnosis of AE should be confirmed by pathologic or serologic examination. Radical surgical resection of the removable parasitic lesion, followed by anti-infective therapy with benzimidazoles, is the primary method for treating AE.

CONCLUSION

Although primary adrenal AE is rare, it should be included in the differential diagnosis of adrenal masses, especially in regions where AE is endemic.

Analysis of HLA-DM polymorphisms in the Chinese Han population

Non-classical human leukocyte antigen (HLA)-DM plays an important and unique role in the processing and presentation of exogenous antigens. Polymorphisms of certain genes and frequency of alleles in populations may indicate susceptibility to certain diseases. In this study, the analysis of HLA-DMA and HLA-DMB gene polymorphisms and haplotypes in the Chinese Han population was conducted to obtain population genetic data. HLA-DM typing has been performed previously by other groups by polymerase chain reaction (PCR)-restriction fragment length polymorphism and PCR-sequence-specific oligonucleotide probe techniques. In this study, we established a TaqMan PCR typing method as an alternative to these techniques to survey the frequency of DMA and DMB alleles in the population. Genotyping was conducted in 1000 unrelated individuals of Han nationality in South and North China using TaqMan PCR typing. Four different DMA alleles and six different DMB alleles were detected. All loci met the Hardy-Weinberg equilibrium principle that both allele and genotype frequencies in a population remain constant. We found that the DMA*01:01 (69.35%) and DMB*01:01 (52.5%) alleles were more frequent in Chinese Hans. Analysis of the haplotypes for two loci of DMA and DMB showed that a highly significant positive linkage disequilibrium (LD) presented for DMA*01:01-DMB*01:02, DMA*01:01-DMB*01:03, DMA*01:01-DMB*01:04, DMA*01:02-DMB*01:01, DMA*01:02-DMB*01:05, DMA*01:03-DMB*01:07, and DMA*01:04-DMB*01:01 haplotypes. Analysis of haplotypes for four loci associated with antigen processing (DMA-DMB-TAP1-TAP2) showed a highly significant LD in DMA*01:01-DMB*01:04-TAP1*02:01:01-TAP2*01:02, DMA*01: 02-DMB*01:05-TAP1*01:01-TAP2*01:01, and DMA*01:01-DMB*01:03-TAP1* 04:01-TAP2*01:01 haplotypes. The comparison between the Chinese Han population and non-Chinese populations showed that no significant differences were found at the HLA-DMA locus in the Chinese Han population compared with people of German nationality, whereas significant differences presented when compared with Turkish, American Caucasian, Japanese, French, and Italian nationalities. However, at the HLA-DMB locus, highly significant differences presented in the Chinese Han population compared with Germans and Italians. This study lays the foundations for further disease association analyses.

Small peripheral lung adenocarcinoma: CT and histopathologic characteristics and prognostic implications

Since the introduction of computed tomography (CT), detection of small lung cancer, especially small peripheral adenocarcinoma, is common. Recently, the morphological characteristics, including thin-section CT and pathologic findings, and prognosis of small peripheral lung adenocarcinomas have been studied extensively. The radiologic and microscopic findings correlate well with each other and are closely associated with tumour prognosis. Most importantly, some subtypes of small lung adenocarcinomas with specific CT or pathologic features are curable. Therefore, all defining characteristics (CT, pathologic and prognostic) of this kind of tumour should be integrated to improve our understanding, provide guidelines for management and accurately assess its prognosis.

The origin of the pseudogap in α-Ga

Density functional theory, the free-electron empty lattice approximation and the nearly free-electron approximation are employed to investigate the electronic properties of partially covalent α-Ga. Whereas free-electron-like properties are revealed over a large energy range, a deep pseudogap at the Fermi level is characteristic of α-Ga. We explain the origin of the pseudogap in terms of a delicate interplay between the electronic states and the specific Brillouin zone geometry.

[Anti-proliferative and anti-metastatic effects of curcumin on oral cancer cells]

OBJECTIVE

The purpose of this article is to examine the effect of curcumin on the proliferation and metastasis of human tongue squamous cell carcinoma and analyze its mechanism.

METHODS

SCC-4 were treated with curcumin of 0, 5, 10, 20, 30, 60, 100 micromol x L(-1) in 24 h. MTT assay, Matrigel invasion assay, flow cytometry and fluorescence microscopy were used to examine the effect of curcumin on the growth and metastasis of SCC-4. cDNA microarray and RT-PCR were employed to analyze the expression of genes treated by curcumin.

RESULTS

The results showed that curcumin could concentration-dependently inhibit SCC-4 cell proliferation at the concentration range from 20 to 100 micromol x L(-1). Furthermore, Matrigel invasion assay indicated that curcumin can reduce SCC-4 cell invasion under the dosage of 20, 30, 60 micromol x L(-1). Flow cytometry also showed that curcumin can influence the distribution of cell cycle of SCC-4 cell with the dosage of 20, 30, 60 micromol x L(-1). And the dosage of 30 micromol x L(-1) curcumin could lead to the recruitment of alpha-tubulin. cDNA microarray showed that 87 genes were activated and 198 genes were inhibited with the effect of curcumin. These results were validated by the real time quantitative RT-PCR.

CONCLUSION

According to the results, it suggests that curcumin has the potential as the leading compound for anti-cancer proliferation and invasion in oral cancer treatment, and cdc27, EGFR substrate 15, PPAR-alpha and H2A histone may play an important role among this multiple anticancer-targeting ability.

Mapping QTL for an adaptive trait: the length of caudal fin in Lates calcarifer

The caudal fin represents a fundamental design feature of fishes and plays an important role in locomotor dynamics in fishes. The shape of caudal is an important parameter in traditional systematics. However, little is known about genes involved in the development of different forms of caudal fins. This study was conducted to identify and map quantitative trait loci (QTL) affecting the length of caudal fin and the ratio between tail length and standard body length in Asian seabass (Lates calcarifer). One F1 family containing 380 offspring was generated by crossing two unrelated individuals. One hundred and seventeen microsatellites almost evenly distributed along the whole genome were genotyped. Length of caudal fin at 90 days post-hatch was measured. QTL analysis detected six significant (genome-wide significant) and two suggestive (linkage-group-wide significant) QTL on seven linkage groups. The six significant QTL explained 5.5-16.6% of the phenotypic variance, suggesting these traits were controlled by multiple genes. Comparative genomics analysis identified several potential candidate genes for the length of caudal fin. The QTL for the length of caudal fin detected for the first time in marine fish may provide a starting point for the future identification of genes involved in the development of different forms of caudal fins in fishes.

Comparative study of earthquake-related and non-earthquake-related head traumas using multidetector computed tomography

OBJECTIVE

The features of earthquake-related head injuries may be different from those of injuries obtained in daily life because of differences in circumstances. We aim to compare the features of head traumas caused by the Sichuan earthquake with those of other common head traumas using multidetector computed tomography.

METHODS

In total, 221 patients with earthquake-related head traumas (the earthquake group) and 221 patients with other common head traumas (the non-earthquake group) were enrolled in our study, and their computed tomographic findings were compared. We focused the differences between fractures and intracranial injuries and the relationships between extracranial and intracranial injuries.

RESULTS

More earthquake-related cases had only extracranial soft tissue injuries (50.7% vs. 26.2%, RR = 1.9), and fewer cases had intracranial injuries (17.2% vs. 50.7%, RR = 0.3) compared with the non-earthquake group. For patients with fractures and intracranial injuries, there were fewer cases with craniocerebral injuries in the earthquake group (60.6% vs. 77.9%, RR = 0.8), and the earthquake-injured patients had fewer fractures and intracranial injuries overall (1.5 + 0.9 vs. 2.5 +1.8; 1.3 + 0.5 vs. 2.1 + 1.1). Compared with the non-earthquake group, the incidences of soft tissue injuries and cranial fractures combined with intracranial injuries in the earthquake group were significantly lower (9.8% vs. 43.7%, RR = 0.2; 35.1% vs. 82.2%, RR = 0.4).

CONCLUSION

As depicted with computed tomography, the severity of earthquake-related head traumas in survivors was milder, and isolated extracranial injuries were more common in earthquake-related head traumas than in non-earthquake-related injuries, which may have been the result of different injury causes, mechanisms and settings.

Association of CYP1B1 gene polymorphisms and the positive expression of estrogen alpha and estrogen beta with endometrial cancer risk

To investigate the relationship between the CYP1B1 L432V polymorphism, ERalpha and ERbeta positivities and the incidence of endometrial cancer. The relationship between CYP1B1 L432V polymorphism, ERalpha and ERbeta positivities and endometrial cancer was investigated using the allele-specific polymerase chain reaction method to analyze gene polymorphism in exon 3 codon 432 (C-G) of CYP1B1. Our results are as follows: in endometrial cancer cases the prevalence rates of CYP1B1 L432V genotypes C/C, C/G, and G/G were 47.2%, 36.1%, and 16.7%, respectively, and 68.8%, 23.8% and 7.5% in the control group, respectively. The frequencies of CYP1B1 C and G alleles were 65.3% and 34.7% in endometrial cancer patients and 80.6% and 19.4% in the control group. A significant difference was found in the genotype distributions or allele frequencies of CYP1B1 L432V polymorphism between the two groups (p < 0.05). Compared with wild-type C/C, the susceptibility of endometrial cancer with homozygotic mutation G/G and heterozygotic mutation C/G increased by 3.235 (95%CI 1.111-9.425) and 2.214 (95% CI 1.067-4.593). Moveover, the positive expression of ERalpha in genotypes G/G and C/G was higher than in the wild genotype C/C (p < 0.05). In conclusion, allelic polymorphism of CYP1B1 L432V increases the risk of endometrial cancer and has a positive correlation with ERalpha expression.

Features of cranio-maxillofacial trauma in the massive Sichuan earthquake: analysis of 221 cases with multi-detector row CT

OBJECTIVE

In a massive earthquake, cranio-maxillofacial trauma was common. The present study was to determine the features of cranio-maxillofacial trauma sustained in the massive Sichuan earthquake by multi-detector row computed tomography (MDCT).

METHODS

The study included 221 consecutive patients (123 males and 98 females; age range, 1-83 years; median age, 35 years) with cranio-maxillofacial trauma in the Sichuan earthquake, who underwent cranio-maxillofacial MDCT scans. The image data were retrospectively reviewed focusing on the injuries of the cranio-maxillofacial soft tissue, facial bones and cranium.

RESULTS

All patients had soft tissue injuries frequently with foreign bodies. Ninety-seven (43.9%) patients had fractures (1.5 involved sites per patient, range from 1 to 8) including single cranial fractures in 36 (37.1%) cases, single maxillofacial fractures were seen in 48 (49.5%) and cranio-maxillofacial fractures in 13 (13.4%). Single bone fracture was more common than multiple bone fractures (p<0.05). Nasal, ethmoid bones and the orbits were the most commonly involved sites of the craniofacial region. Thirty-eight (17.2%) patients had intracranial injuries, the commonest being subarachnoid haemorrhage and the commonest sites were the temporal and frontal regions. Coexisting intracranial injuries were more common in patients with cranial fractures than in patients with maxillofacial fractures (p<0.05).

CONCLUSION

Our results indicate that the cranio-maxillofacial trauma arising from the massive Sichuan earthquake had some characteristic features, and a significant number of individuals had the potential for combined cranial and maxillofacial injuries, successful management of which required a multidisciplinary approach.

Characteristics of coronary artery disease in symptomatic type 2 diabetic patients: evaluation with CT angiography

BACKGROUND

Coronary artery disease (CAD) is a common and severe complication of type 2 diabetes mellitus (DM). The aim of this study is to identify the features of CAD in diabetic patients using coronary CT angiography (CTA).

METHODS

From 1 July 2009 to 20 March 2010, 113 consecutive patients (70 men, 43 women; mean age, 68 ± 10 years) with type 2 DM were found to have coronary plaques on coronary CTA. Their CTA data were reviewed, and extent, distribution and types of plaques and luminal narrowing were evaluated and compared between different sexes.

RESULTS

In total, 287 coronary vessels (2.5 ± 1.1 per patient) and 470 segments (4.2 ± 2.8 per patient) were found to have plaques, respectively. Multi-vessel disease was more common than single vessel disease (p < 0.001), and the left anterior descending (LAD) artery (35.8%) and its proximal segment (19.1%) were most frequently involved (all p < 0.001). Calcified plaques (48.8%) were the most common type (p < 0.001) followed by mixed plaques (38.1%). Regarding the different degrees of stenosis, mild narrowing (36.9%) was most common (p < 0.001); however, a significant difference was not observed between non-obstructive and obstructive stenosis (50.4% vs. 49.6%, p = 0.855). Extent of CAD, types of plaques and luminal narrowing were not significantly different between male and female diabetic patients.

CONCLUSIONS

Coronary CTA depicted a high plaque burden in patients with type 2 DM. Plaques, which were mainly calcified, were more frequently detected in the proximal segment of the LAD artery, and increased attention should be paid to the significant prevalence of obstructive stenosis. In addition, DM reduced the sex differential in CT findings of CAD.

[Changes of IL-8 and TNF-α in gingival crevicular fluid before and after treatment from chronic periodontitis]

AIM

To investigate the changes of IL-8 and TNF-α in gingival crevicular fluid (GCF) before and after treatment from chronic periodontitis.

METHODS

96 patients with chronic periodontitis were selected as study group and experienced initial periodontal therapy. 50 healthy people were selected as control group. Gingival crevicular fluid was collected before and after treatment. At the same time, the clinical parameters, including PLI, PD, SBI and AL were recorded, and the levels of IL-8 and TNF-α in GCF were measured by ELISA in two groups.

RESULTS

The levels of IL-8 and TNF-α in GCF after treatment were significantly lowered in study group as compared with those before treatment (P < 0.05), while PLI, PD, SBI and AL showed significant reduction (P < 0.05). The levels of IL-8 and TNF-α in GCF before and after treatment were significantly highered in study group as compared with those in control group (P < 0.05). There was significant correlation between PD and IL-8 in GCF (r = 0.486, P < 0.05) and between SBI, PD and TNF-α in GCF (r = 0.495, 0.648, P < 0.05).

CONCLUSION

IL-8 and TNF-α may be associated with the development and the severity of periodontitis.

Expression of c-kit and Slug correlates with invasion and metastasis of salivary adenoid cystic carcinoma

The overexpression of c-kit seems to be frequent and specific in salivary adenoid cystic carcinoma (ACC), however, there is little information on correlation between c-kit expression and the invasion and metastasis. Recently, the data showed that Slug, a transcription factor of epithelial-mesenchymal transitions (EMT), is a molecular target that contributes to the biological specificity of c-kit signaling pathway. In this study, the expression of c-kit and Slug was evaluated in two ACC cell lines and 121 patients with ACC. The results of real-time RT-PCR and Western blot showed that ACC-2 and ACC-M cell lines expressed c-kit and Slug mRNA and protein. The immunohistochemical assay in patients demonstrated that positive expression of c-kit and Slug was observed in 108/121 (89.26%) and 87/121 (71.90%) of cases, respectively, and that c-kit and Slug expression was significantly associated with tumor site, TNM stage, histological pattern, perineural invasion, local regional recurrence and distant metastasis of patients with ACC (P<0.05). Furthermore, there was a significant association between the positive expression of c-kit and that of Slug (P=0.046). These findings indicated that c-kit/Slug pathway might participate in the invasion and metastasis of salivary ACC.

[Central mucoepidermoid carcinoma of the jaws: a clinical and pathological analysis of eight cases]

OBJECTIVE

To report eight cases of central mucoepidermoid carcinoma of the jaws (CMCJ) and to analyze its clinical and pathological features.

METHODS

Eight cases of central mucoepidermoid carcinoma were diagnosed between 1989 and 2008. The clinical manifestation, radiological and histopathological changes were analyzed.

RESULTS

The mean age of this group of patients was 43.3 years, with 5 male and 3 female. Seven cases occurred in mandible, mainly in the molar, angle and ramus areas, and one in maxilla. The first complain usually was local swelling, pain or paraesthesia of the jaw and loosening and pain of the tooth. X-ray displayed unilocular or multilocular radiolucent lesion with distinct or ill-distinct border, and the light microscopic findings were similar to the mucoepidermoid carcinoma originated in the salivary gland.

CONCLUSIONS

To diagnose a CMCJ, it's necessary to synthetically analyze the case history, clinical examination, radiological and histopathological features. The treatment is wide local resection. Selective neck dissection and radiochemotherapy may improve curative effect and prognosis.

A standard panel of microsatellites for Asian seabass (Lates calcarifer)

Microsatellites are the most popular markers for parentage assignment and population genetic studies. To meet the demand for international comparability for genetic studies of Asian seabass, a standard panel of 28 microsatellites has been selected and characterized using the DNA of 24 individuals from Thailand, Malaysia, Indonesia and Australia. The average allele number of these markers was 10.82 +/- 0.71 (range: 6-19), and the expected heterozygosity averaged 0.76 +/- 0.02 (range: 0.63-1.00). All microsatellites showed Mendelian inheritance. In addition, eight standard size controls have been developed by cloning a set of microsatellite alleles into a pGEM-T vector to calibrate allele sizes determined by different laboratories, and are available upon request. Seven multiplex PCRs, each amplifying 3-5 markers, were optimized to accurately and rapidly genotype microsatellites. Parentage assignment using 10 microsatellites in two crosses (10 x 10 and 20 x 20) demonstrated a high power of these markers for revealing parent-sibling connections. This standard set of microsatellites will standardize genetic diversity studies of Asian seabass, and the multiplex PCR sets will facilitate parentage assignment.

Discovery of four natural clones in a crayfish species Procambarus clarkii

Self-cloning is quite rare in shrimp, lobsters, crayfish and crabs. Here we report the discovery of four natural clones of red swamp crayfish (Procambarus clarkii), each containing 2-6 genetically identical individuals, during the genotyping of 120 individuals with five microsatellites. The four clones were heterozygote at most of the five microsatellite loci. Phylogenetic analysis using microsatellite genotypes suggests recent origin of the four clones. Sequencing a part of the mitochondrial gene Cox I confirmed that the four clones were from the species Procambarus clarkii.