The wide array of genetic tools available for genetic dissection of fruit fly drosophila melanogaster makes its undoubtedly the most preferred model organism when it comes to developmental and evolution puzzles.Balancer chromosomes forms a very important part of this repertoire. Balancer chromosome strains provide key advances for mutagenesis screens, for stock maintenance and for tracking quantitative traits.It was in 1918 Muller identified the first balanced mutation and later Sturtevant proposed that differences in the gene order in this region between different species of flies were due to an inversion in …

Drosophila melanogaster is a famous model system used to understand various aspects of life.This is largely due to various aspects of fruit fly like its fast development cycle, easy and cheap to culture in lab,wide array of genetic tool (various mutants available, markers,balancer chromosomes,UAS – GAL4 system,P element transformation for generating transgenic fly, UAS RNAI for gene Knock down) and fully sequenced genome.
Today we will know some basic stuff related to drosophila genetics like chromosomes in fruit fly, Nomenclature employed in writing genotypes and importance of virgin females in …

Yesterday while loading my PCR samples suddenly a thought struck,why is it always we run our DNA samples in horizontal manner and not horizontal like one employed for proteins.I discussed this stuff with my friends and googled the net out of curiosity.Below is some of the information regarding electrophoresis of DNA and Proteins samples.
Background:
Gel electrophoresis is a technique used for the separation of deoxyribonucleic acid, ribonucleic acid, or protein molecules using an electric current applied to a gel matrix.In most cases the gel is a crosslinked polymer whose composition and …

Chaperones are group of proteins that oversee proper folding and the assembly of other macromolecular structures without being components of the final structure. This means these chaperones do not occur in these structures when the latter are performing their normal biological functions.chaperone function as the prevention or reversal of incorrect interactions that may occur when reactive macromolecular surfaces are transiently exposed to the intracellular environment
The term `molecular chaperone` was first used by Ron Laskey to describe the function of a particular protein useful for nucleosome formation and the term was …

Cells form the building blocks of all animals and diversity in animal forms can be attributed to the way these building blocks arrange themselves while proliferating.These things depend on cross talk between cells and which is termed as Signalling.This language of cross talk involves a series of players,where one component relay the received signal to the one downstream to it ,forming a chain reaction or signalling pathway.
Signalling pathways transduce signal from external medium into the nucleus,which results in turning ON or OFF of concerned target genes of that pathway.Cells …

To define Segmentation in simple terms would be division of animal bodies into repetitive segments.Segments are comprised of a number of discrete structures developmentally derived from both ectoderm and mesoderm.Segmented animals are found in Annelida,Arthropoda and chordata phylas which are not closely related according to recent phylogenic data.Segmentation allows for a high degree of specialization of bodily regions.
Among Chordata, segmentation is well characterised in vertebrates.Segments or Somites in vertebrates are transient mesodermal structures that form sequentially along the anterior–posterior axis with a regular spatial and temporal periodicity.Molecular data available so …

Classification of Fossils is sometimes tricky as they do not follow systematics of living organisms and here come stem groups to the rescue.In order to know about stem groups we need to understand Crown Group also.
Stem groups:
Stem group organisms always lack one or more features that are present at the base of the crown group to which they are attached.

Archaeopteryx
Originally uploaded by Sebastian
Niedlich (Grabthar)

Crown Group:
A crown group is a living clade or monophyletic group which consists of the last common ancestor of all living examples and all of its descendants.But …