When staining the salivary glands of the Drosophila larvae What was the purpose of the squashing step?
In this case salivary glands were dissected directly in a dilute formaldehyde solution, soaked in 50% glycerol, and squashed in 50% glycerol in order to mimic the viscosity of the nucleus to help preserve chromosomal morphology during spreading.
Why are polytene chromosomes in salivary glands?
In insects, they are commonly found in the salivary glands when the cells are not dividing. They are produced when repeated rounds of DNA replication without cell division forms a giant chromosome.
What is salivary gland in Drosophila?
Drosophila salivary glands consist of two major cell types: secretory cells and duct cells. Secretory cells are columnar epithelial cells that synthesize and secrete high levels of protein. Duct cells are cuboidal epithelial cells that form the simple tubes connecting the secretory cells to the larval mouth.
Why is Drosophila called fruit fly?
Drosophila derived from the Greek word drósos means dew loving. They belong to the Droso–philidae family; and are most frequently known as fruit flies or often called vinegar, wine or pomace flies. Their main distinguishing character is to stay on fruits, which are ripped or rotten.
Why do we isolate salivary glands from insects?
Components within the saliva of mosquito vectors facilitate blood feeding, modulate host responses, and allow efficient transmission of pathogens, such as Dengue, Zika, yellow fever, West Nile, Japanese encephalitis, and chikungunya viruses, as well as Plasmodium parasites, among others.
Which organ is generally used to find the polytene chromosome in Drosophila?
Further, the polytene chromosome located within the larval salivary glands of Drosophila, provide scientists the unique ability to directly visualize structural changes that result from the epigenetic modifications of chromatin [10,11].
What Are salivary glands?
Salivary glands make saliva, which aids in digestion, keeps your mouth moist and supports healthy teeth. You have three pairs of major salivary glands under and behind your jaw — parotid, sublingual and submandibular.
Why do the fruit fly larvae need polytene chromosomes?
Polytene Chromosomes As the fly larva grows, it keeps the same number of cells, but needs to make much more gene product. The result is that the cells get much bigger and each chromosome divides hundreds of times, but all the strands stay attached to each other.
Why is Drosophila called Cinderella of genetics?
It is used by the scientist for experimental studies because of the short life cycle, easy to culture, single reproduction produces large number of progeny, the genome can be mutated easily. The genome of Drosophila has only four chromosomes typically in a haploid set useful in genetic studies.
Why is Drosophila used in genetics?
75 per cent of the genes that cause disease in humans are also found in the fruit fly. Drosophila have a short, simple reproduction cycle. Fruit fly are small (3 mm long) but not so small that they can’t be seen without a microscope. This allows scientists to keep millions of them in the laboratory at a time.
What is the function of salivary reservoir in cockroach?
It is concluded that the primary function of the salivary reservoir is to store salivary secretion for moistening and digesting food. Secondarily, when water is not available, the reservoir contents serve to partially satisfy the water requirements of the cockroach.