Development of transgenic cucumber mosaic virus (CMV) resistant gerbera plants expressing CMV coat protein gene

Gerbera (Gerbera jamesonii L.) has its immense importance to the floriculture industry worldwide. The gerbera flower production has been hampered by various viruses, among them cucumber mosaic virus (CMV) has shown considerable damage.As natural resistance to CMV is absent in gerbera, here, we have made an attempt to develop transgenic gerbera plants expressing coat protein (CP) gene of CMV via Agrobacterium mediated transformation of base petiole explants for genetic resistance to CMV infection. Among the 44 putative transgenic gerbera plant acclimatized, 39 were found positive for integration of CP gene by polymerase chain reaction and southern hybridization assay using their specific primer and probe respectively. Northern hybridization assay using CP gene specific probe confirmed the transcription of transgene in all 39 transgenic plants. These plants showed translation of CP during DAS-ELISA when tested with antiserum specific to CP of CMV. These 39 plants when challenged by mechanical inoculations with CMV gerbera isolate showed virus resistance in 53% (21 out of 39) plants, virus tolerance (delayed mild symptom) in 33% (13/39) plants, while rest 12.8% (5/39) plants showed severe disease symptoms. The CP mediated resistance of CMV in transgenic gerbera is being reported for the first time from India.

Cardiopulmonary fitness test among Nepalese students

Background and Objectives: Maximum Oxygen uptake (VO2 max) is a good predictor of cardiopulmonary and muscle fitness. Maximum oxygen uptake is defined as the highest rate at which oxygen can be taken up and utilize by body during severe exercise. The present study aims to find out the level of VO2 max using Mc Ardle equation and to compare obtained values from Chatterjee’s equation in Nepalese population. Methodology: Maximum oxygen uptake was determined by using the Queen’s college step-stool of 16.25 inches and popular Mc Ardle equation. Stepping was done for a total duration of 3 minutes at the rate of 24 cycles per minute for males and 22 cycles per minute for females. After completion of the exercise, subjects remained standing while the carotid pulse rate was taken as heart rate. Maximum oxygen uptake was calculated using obtained heart rate. Results: Queen’s college step test (QCT) was used as a submaximal exercise and the estimated VO2 max in boys and girls was 48.8± 7.3 ml/kg/min and 37.4± 2.7 ml/kg/min respectively with Mc Ardle equation and the value was higher when compared with Chatterjee’s equations. The value of VO2 max was observed and found to be less in smokers and sedentary individuals. Conclusion: As the values of VO2 max obtained from different equations are different, this research strongly argues the need of developing a prediction equation specifically for the Nepalese population.

Haptoglobin polymorphism among the tribal groups of southern Gujarat.

BACKGROUND: Gujarat is located at the western most point of the Indian subcontinent. Valsad and Surat districts are part of the ‘tribal belt’of Gujarat and constitute 29.1% of total tribal population of Gujarat. These tribal populations are a rich source of gaining insights in the patterns of genetic diversity and genetico-environmental disorders against the back drop of their ecological, historical and ethnographic aspects. AIM: The objectives were to find out a) the genetic diversity among the tribes of Gujarat with reference to haptoglobin (Hp) locus b) the relationship between Hp polymorphism and sickle cell anemia/trait. MATERIALS AND METHODS: 431 individuals belonging to eight tribal groups were studied for Hp polymorphism using polyacrylamide disc gel electrophoresis (PAGE). Hb*S was screened by dithionate tube turbididy (DTT) test and confirmed using cellulose acetate membrane electrophoresis (CAME). STATISTICAL ANALYSIS: Allele frequency was calculated by direct gene counting method. Average heterozygosity and gene diversity were computed using software DISPAN. Analysis of molecular variance (AMOVA) was estimated using software ARLEQUIN version 3.1. RESULTS AND CONCLUSIONS: Pattern of allele frequency distribution showed preponderance of Hp2 allele in all the eight tribal groups, which is in accordance with its frequency in different populations of Indian subcontinent. Total average heterozygosity (HT) was found to be low (0.160) but the level of genetic differentiation (GST) was found to be moderately high (5.6%). AMOVA analysis indicated least among group variance between west and south Indian populations (-0.04%) indicating the affinities of the tribes of Gujarat with that of Dravidian speaking groups. Analysis of Hp phenotypes among sickle cell anemia/ trait individuals revealed a high frequency of Hp 0-0 phenotype (92.7%) among SS individuals as opposed to only 9.7% among AS individuals, reaffirming the selective advantage of HbAS state in relation to hemolytic disorders.

Haplotype diversity and linkage disequilibrium at the DRD2 locus among the tribes of western and southern regions of India.

BACKGROUND: Dopamine receptor D2 (DRD2) is an important gene having functional significance in the fields of neuropsychiatry and pharmacology and also has importance in evolutionary studies. MATERIALS AND METHODS: This study was undertaken to find out the haplotype distribution and linkage disequilibrium (LD) pattern for the three TaqI sites (TaqI ‘A’, TaqI ‘B’ and TaqI ‘D’) in the DRD2 gene in 232 unrelated individuals from five ethno-linguistically distinct endogamous tribal populations; Siddis and Gonds of Uttara Kannada district, Karnataka; Varli and Kolgha of Valsad district, Gujarat; and Dangi Konkana of Dang district, Gujarat. The genotype data obtained after molecular analysis of the three DRD2 sites was subjected to statistical analysis such as calculation of allele frequencies, haplotype frequencies among others. Subsequently, a neighbor-joining tree was also constructed from the data obtained. RESULTS: The three DRD2 sites were found to be polymorphic in all the populations. All the populations showed high levels of heterozygosities. Out of the eight possible haplotypes, most populations shared seven haplotypes. Of all the populations, Siddis showed the highest frequency of the ancestral haplotype B2D2A1 (11.4%). Significant LD was found to exist for TaqI ‘A’ and TaqI ‘B’ sites in both the populations. CONCLUSION: The findings are in concurrence with those from other Indian studies, especially from Dravidian-speaking South Indian populations. Similar pattern of diversity observed for ethnically and linguistically diverse populations in the present study is indicative of complex structure of Indian populations.

Aortic stenosis.

Valvular aortic stenosis in pediatric age group is mostly congenital in origin. The aortic valve may be unicuspid, bicuspid, tricuspid or rarely quadricuspid. Left ventricle undergoes concentric hypertrophy secondary to obstruction to its outflow tract. In neonatal aortic stenosis, left ventricle may be hypoplastic. The pathophysiology and clinical presentation vary with the age of onset and severity of obstruction. Echocardiography and Doppler are indispensible for the diagnosis of aortic stenosis and its severity. Cardiac catheterization is not necessary for the diagnosis, however it is performed as a part of balloon aortic valvuloplasty in severe cases. Balloon valvuloplasty is an effective alternative to surgery in pediatric age group. Some of these patients require surgical valve repair or replacement on follow-up. Neonates and young infants with critical aortic stenosis present with cardiogenic shock and need aggressive treatment with prostaglandin E1 infusion along with inotropic support. In experienced hands, balloon valvuloplasty is a safe procedure in neonates and infants with critical stenosis. Patients with mild and moderate aortic stenosis may be left on medical follow-up.

Stress response in pathogenic bacteria.

Bacterial pathogens survive under two entirely different conditions, namely, their natural environment and in their hosts. Response of these pathogens to stresses encountered during transition from the natural environment to human hosts has been described. The virulence determinants of pathogenic bacteria are under the control of transcriptional activators which respond to fluctuations in growth temperature, osmolarity, metal ion concentration and oxygen tension of the environment. The regulation of stress induced genes may occur at the level of transcription or translation or by post-translational modifications. Under certain stress conditions local changes in the superhelicity of DNA induce or repress genes. In addition to their role in survival of bacteria under stressful situations, the stress induced proteins are also implicated in the manifestation of pathogenicity of bacterial pathogens in vivo.