Abdominal pigmentation and growth temperature in Indian Drosophila melanogaster: Evidence for genotype-environment interaction

Phenotypic variability for abdominal pigmentation in females of an Indian natural population ofDrosophila melanogaster was studied using isofemale lines and by rearing the larvae and pupae at 4 different temperatures ranging from 20–30°C. The dark pigmented area was found to increase in all the three segments when the growth temperature decreases. A significant positive correlation was detected for the occurrence of dark pigmentation in the 5th and 6th segments in each growth temperature but for other comparisons the correlation was not regular. Analysis of variance (ANOVA) was carried out both for individual segments over different growth temperatures and also for each temperature over the three abdominal segments and in all cases found to be statistically significant. The results are quite different from the earlier observation in FrenchDrosophila melanogaster and suggest that genes controlling pigmentation are temperature dependent; temperature could affect post-transitional events involved in pigmentation. The present findings also clearly indicate that significant genotype-environment interaction exists, responsible for the production of desired phenotype at the opportune moment during the life span of a species.     

Laser-assisted targeted gene delivery to degenerated retina improves retinal function

Delivery of therapeutic genes into retina is proving to reverse degeneration and restore vision, however, viral vector-based gene delivery is prone to immunorejection, inflammatory/immune-response and nontargeted. Here, we report nonviral gene delivery and expression of opsin encoding genes in mouse retina in-vitro and in-vivo by use of pulsed femtosecond laser microbeam. In-vitro patch-clamp recording of the opsin-sensitized retinal cells and visually evoked in-vivo electrical recording from laser-transfected eye of mouse with degenerated retina showed functional response. The ultrafast laser-based naked gene delivery showed minimal damage and reliable expression of therapeutic opsin in cell membrane of the selected cells and in targeted retinal region. Laser-based “naked DNA gene therapy” in a spatially targeted manner will pave the way for treatment of inherited retinal diseases.     

Kinetics of SO4−2 reduction under different growth media by sulfate reducing bacteria

Sulfate Reducing Bacteria (SRB) were used to reduce the SO₄ ^–2 concentration in waste water. The growth pattern of SRB was found by varying the concentration of nutrients and the biomass. The specific reaction constant was evaluated in each case.     

Diurnal variation of the acid phosphatase activity in the leaves of Cowpea

Summary The activity of acid phosphatases (glycerophosphatase, phenylphosphatase and pyrophosphatase) in Cowpea (Vigna catjang) leaves has been studied at different hours of the day and a marked diurnal variation has been observed. The phosphatase activity in leaves collected between 10 A.M. to 2 P.M. was always higher than in leaves collected earlier in the morning and late at evening. Pyrophosphatase activity exhibited greater variation than phenylphosphatase and glycerophosphatase activity. The significance of the increased phosphatase activity is discussed in relation to the production of carbohydrates from organic acids in light.