Genetic distance and phylogenetic studies of two Indian snakehead and one carp fish species

Aim: To study genetic distance and phylogenetic relationship of two different stock of three important fish species, i.e., Channa stewartii, C. striatus and Labeo gonius of Assam. Methodology: Three fish species, namely Channa stewartii, C. striatus and Labeo gonius were collected from two beels, i.e., Thekera and Samaguri beels of Assam, India. Standard procedures were followed for isolation of their DNA and sequencing. Thereafter, genetic distance and diversity and phylogenetic studies of three species were calculated using computer based softwares ClustalW and MEGA6. Results: In the present study, the pairwise genetic distance of three fish species ranged from 0 to 20.436. No pairwise distance was found between two stocks at different locations Thekera and Samaguri beels of Assam for each of three species C. stewartii, C. striatus and L. gonius. The highest values (20.436) of pairwise distance were found between C. striatus and L. gonius population of Thekera beel; Thekera and Samaguri beels; and L. gonius population of the Thekera and Samaguri beels. The overall average distance for the two populations of three fish species was 15.387. No significant intraspecific difference was observed in the phylogenetic studies of two stocks of three fish species. Interpretation: The overall average distance (15.387) of three fish species could be attributed to genetic distance from each other. The high value of coefficient of differentiation (1.000) for three fish species from two stocks indicated that all the species were different from each other. Overall genetic and phylogenetic studies revealed that C. stewartii, C. striatus and L. gonius. were less differentiated from each other.

Effects of single-dose atorvastatin on interleukin-6, interferon gamma, and myocardial no-reflow in a rabbit model of acute myocardial infarction and reperfusion

The mechanisms of statins relieving the no-reflow phenomenon and the effects of single-dose statins on it are not well known. This study sought to investigate the effects of inflammation on the no-reflow phenomenon in a rabbit model of acute myocardial infarction and reperfusion (AMI/R) and to evaluate the effects of single-dose atorvastatin on inflammation and myocardial no-reflow. Twenty-four New Zealand white male rabbits (5-6 months old) were randomized to three groups of eight: a sham-operated group, an AMI/R group, and an atorvastatin-treated group (10 mg/kg). Animals in the latter two groups were subjected to 4 h of coronary occlusion followed by 2 h of reperfusion. Serum levels of interleukin (IL)-6 were measured by enzyme-linked immunosorbent assay. The expression of interferon gamma (IFN-γ) in normal and infarcted (reflow and no-reflow) myocardial tissue was determined by immunohistochemical methods. The area of no-reflow and necrosis was evaluated pathologically. Levels of serum IL-6 were significantly lower in the atorvastatin group than in the AMI/R group (P<0.01). Expression of IFN-γ in infarcted reflow and no-reflow myocardial tissue was also significantly lower in the atorvastatin group than in the AMI/R group. The mean area of no-reflow [47.01% of ligation area (LA)] was significantly smaller in the atorvastatin group than in the AMI/R group (85.67% of LA; P<0.01). The necrosis area was also significantly smaller in the atorvastatin group (85.94% of LA) than in the AMI/R group (96.56% of LA; P<0.01). In a secondary analysis, rabbits in the atorvastatin and AMI/R groups were divided into two groups based on necrosis area (90% of LA): a small group (<90% of LA) and a large group (>90% of LA). There was no significant difference in the area of no-reflow between the small (61.40% of LA) and large groups (69.87% of LA; P>0.05). Single-dose atorvastatin protected against inflammation and myocardial no-reflow and reduced infarct size during AMI/R in rabbits. No-reflow was not dependent on the reduction of infarct size.

Prenatal diagnosis of the spinal muscular atrophy type I using genetic information from archival slides and paraffin-embedded tissues

Spinal muscular atrophy (SMA) type I is a common severe autosomal recessive inherited neuromuscular disorder that has been mapped to chromosome 5q11.2-13.3. The survival motor neuron (SMN) gene, a candidate gene, is known to be deleted in 96% of patients with SMA type I. Presently, PCR and single strand conformation polymorphism (PCR-SSCP) analyses have been made possible for application to both archival slides and paraffin-embedded tissues. Archival materials represent valuable DNA resources for genetic diagnosis. We applied these methods for the identification of SMN gene of SMA type I in archival specimens for the prenatal diagnosis. In this study, we performed the prenatal diagnosis with chorionic villus sampling (CVS) cells on two women who had experienced neonatal death of SMA type I. DNA extraction was done from archival slide and tissue materials and PEP-PCR was performed using CVS cells. In order to identify common deletion region of SMN and neuronal apoptosis-inhibitory protein (NAIP) genes, cold PCR-SSCP and PCR-restriction site assay were carried out. Case 1 had deletions of the exons 7 and 8, and case 2 had exon 7 only on the telomeric SMN gene. Both cases were found to be normal on NAIP gene. These results were the same for both CVS and archival biopsied specimens. In both cases, the fetuses were, therefore, predicted to be at very high risk of being affected and the pregnancy were terminated. These data clearly demonstrate that archival slide and paraffin-embedded tissues can be a valuable source of DNA when the prenatal genetic diagnosis is needed in case any source for genetic analysis is not readily available due to previous death of the fetus or neonate.