“We stand in the presence of riddles, but not without the hope of solving them. And riddles with the hope of solutions- what more can a scientist desire?”-Hans Spemann (Nobel Prize, 1935)

TH Morgan in his FLy Lab

One of the remarkable embryologists, Hans Spemann, truly said that. Speaking of embryology and developmental biology how one can not mention Drosophila melanogaster. It’s been nearly a century this organism is contributing to genetics research. Was it not for T H Morgan’s choice of model organism, who knew these fruit flies can open novel doors in genetics?

As a kid, I was always disgusted by these flies hovering over my favourite fruits. Never have I thought that one day I would work on the same flies for some research purpose.

So, why flies?

  • Size: Being approximately 3mm in size, they are neither microscopic nor big enough to occupy a large space in lab.
  • Reproductive cycle: Fruitfly has a short and simple reproductive cycle of 8-10 days. Hence, several generations can be obtained in months.
  • Maintenance: Flies are easy and inexpensive to maintain. Food requirement is a preparation of simple media of carbohydrates and proteins.
One of the robust and powerful tool in Genetics

The genetics:

  • Number of Chromosomes: Drosophila has a manageable number of chromosomes. Only 4 pairs of chromosomes present in contrast with humans, which are 23 pairs.
  • Genome: Full genome of Drosophila has been sequenced and it is found that 75% of disease causing genes in humans has a homologue in these flies.
  • Transgenic lines: It’s easier to create transgenic lines in fruitflies. Example: Green Fluorescent Protein (GFP) is easily expressed hence widely used in Drosophila
  • Polytene Chromosome: Polytene chromosomes are oversized chromosomes having barcode-like banding patterns of light and dark. This helps in understanding chromosomal rearrangements and deletions under microscope.
  • Balancer Chromosome: The most remarkable tool in fly work is use of balancer chromosome. It is a genetic tool preventing crossing over between homologous chromosomes. Hence, helps in carrying heterozygous mutations without constantly screening for the mutations.

All these advantages make these flies a powerful genetic tool. These days Drosophila is extensively used in neurodegeneration and ageing studies.

What excites me more is the recent development in Blood-Brain-Barrier (BBB) studies of Drosophila showing similarities with humans. Though Drosophila was largely ignored as a model system for mammalian BBB, this could possibly open doors for understanding formation of BBB and regulation and neuronal interactions in drug sensitivity.

http://www.geneticengg.com/wp-content/uploads/2017/03/white_eye1w.jpghttp://www.geneticengg.com/wp-content/uploads/2017/03/white_eye1w-150x150.jpgUpasana GuptaEvolutionary BiologyGeneticsBlood brain barrier,developmental biology,drosophila,Hans Spemann,TH Morgan“We stand in the presence of riddles, but not without the hope of solving them. And riddles with the hope of solutions- what more can a scientist desire?”-Hans Spemann (Nobel Prize, 1935) One of the remarkable embryologists, Hans Spemann, truly said that. Speaking of embryology and developmental biology how one...When Nature and Science meet, Magic happens !