بسم الله الرحمن الرحيم. صلواة على سيدنا محمد وعلى آله وأصحابه أجمعين. و قل رب ادخلني مدخل صدق واخرجني مخرج صدق واجعل لي من لدنك سلطانا نصيرا
محمد علي نقوي
Mohammad Ali Naqvi
Phone # 647 300 1514
Please click on the title of a project for details
Vegetal Rotation in Xenopus laevis is an important force generating process during Gastrulation that plays an important part in tissue separation at the Brachet’s cleft, as well as in the internalization of the mesoderm. XRhoA plays a major role in vegetal rotation since a dominant-negative form thereof significantly blocks vegetal rotation. Inhibiting Rho-Activated Kinase (ROK) also causes the same effect. The blastopore never closes in these embryos. Here we show that the DN-XRhoA-induced phenotype can be partially rescued by countering the effects of the Dominant Negative with three times more amount of the Wildtype RNA. Moreover we also found that inhibiting myosin just before vegetal rotation has a weak effect on vegetal cell upwelling. This suggests the involvement of additional players downstream of ROK in the pathway that causes vegetal cell upwelling during gastrulation.
Vegetal Rotation in Xenopus laevis is an important force generating process during Gastrulation that plays an important part in tissue separation at the Brachet’s cleft, as well as in the internalization of the mesoderm. Here we show that XRhoA plays a major role in vegetal rotation since a dominant-negative form thereof significantly blocks vegetal rotation at low and intermediate doses and freezes the embryos in the blastula stage at higher doses with little or no development thereafter. The blastopore never closes in these embryos. Moreover we also show that inhibition of ROK, a kinase acting downstream of RhoA in many cell mobility pathways, produces a phenotype with respect to vegetal rotation that is strikingly similar to the phenotype produced by DN-XRhoA. This suggests a possible downstream role of ROK in RhoA signalling during vegetal rotation.
This project investigated the correlation between fitness and recombination (if any) in Drosophila melanogaster. The idea that there might be such a correlation came from the fact that adverse environmental conditions (such as a deviation from the optimal temperature, overcrowding, malnutrition etc.) have long been known to increase the rate of recombination. This increase in recombination, as theorized, copes with the environmental stress by generating a unique haplotype (in the next generation) that might carry the allelic combination perfectly equipped to comply with the environmental stress.
These earlier investigations led to our hypothesis that if an organism was subjected to stress by altering its genotype rather than by changing the environment, it would also have a similar increase in recombination as was observed with environmental stress in earlier studies. In other words, individuals with a “bad” genotype should have a higher recombination rate than those with “good” genotypes; because recombination in case of a bad genotype may serve to assemble a better haplotype, whereas in case of a good genotype, recombination may break apart an already good haplotype.
Here we assumed that having deleterious alleles would generate the same kind of effect on the overall physiology of the organism as was caused due to environmental stress. For example a mutation that debilitates the feeding apparatus will generate the same consequences as if the individual was subjected to malnutrition or food shortage……...
Recently, the molecular components of the BMP-Chordin system, that specifies the Dorsal/Ventral axis in Bilaterates, have also been found and characterized in the Radiate Nematostella vectensis. These morphogens, which are asymmetrically distributed in Bilaterates across the presumptive dorsal/ventral axis (which they specify), are also found to be asymmetrically distributed along an “invisible” directive axis in Nematostella. Moreover, these molecules have also been proved to be similar to their Bilaterate counterparts in sequence and function. This was revealed by studies employing sequence homologies to construct phylogenetic trees, and to test the effect of administering Radiate morphogens on developing vertebrate embryos…….
A significant number of diseases involve a gain of function. This gain of function is either due to a mutant gene, or due to loss of regulation of a gene. In addition, there are also diseases that require a specific component of the cellular machinery to propagate. In all of these cases, silencing a gene that is either itself responsible for the disease or is involved in its propagation, can serve to alleviate the disease symptoms. RNA interference is a naturally occurring phenomenon that the cells employ in order to regulate gene expression during development as well as in routine metabolism. This mechanism involves the use of anti-sense RNA to recognize the target mRNA, which is subsequently degraded. Recently, researchers developed gene-silencing approaches based on RNA interference by designing synthetic small interfering RNAs (siRNA), as well as DNA constructs that get transcribed to short hairpin RNAs (shRNA) in the cell. The shRNAs are in turn processed by cellular enzymes to siRNAs. RNA interference through shRNAs has proved to be an effective and long term silencing mechanism that can potentially be applied to many human disorders ranging from cancer and prion diseases to the diseases caused by viruses such as HIV & HPV…………….
The osprey is a large bird of prey about the size of a small eagle. The crown and upper nape are white, streaked with dark brown. The crown also bears a crest, which is not erectile but rides in the wind as the bird flies. The dorsal aspect of the bird's body is chocolate colored from the lower portion of nape, through the mantle, back, wings and rump, down to the tip of the tail. In contrast, the chin, throat, breast, belly, flanks, shins, undertail coverts, lesser underwing coverts and vent feathers are primarily white with sparse mottling, which is more pronounced in females than the males; males tend to be whiter on the underside than females……….