Chromosomes of Chironomus Larvae

bernhardinho · Post by **bernhardinho** » Tue Jan 09, 2007 2:58 pm

Hi folks,

this is a classic object of microscopy:

chromosomes from the salivary glands of chironomus larvae. The glands have been fixed in Carnoy, and dyed in carmin acetic acid. First pic is the head of the larva, accidently dyed under the coverglass:

chromosomes ( objective 50x, 0.95, plan, oil, eyepiece 10x Leitz periplan)

Bernhard

Ken Ramos · Post by **Ken Ramos** » Tue Jan 09, 2007 3:05 pm

Some interesting images Bernhard but I am a bit confused

. I thought that the chromosomes were found within the nuclei of cells and were in pairs. These seem a bit large for chromosomes, though I am not implying that they are not, they do look quite a bit like them. I don't know.

But, indeed some interesting images you have presented here.

bernhardinho · Post by **bernhardinho** » Tue Jan 09, 2007 3:20 pm

Hi Ken,

good question! The answer is: that's why they're a classic object for microscopy!!

In fact you find these chromosomes in the nuclei of the salivary glands.

Please let me remind you of Drosophila melanogaster! We have all learned at school that this fly has been the key to classical genetics. There are cases where the division of the chromatides does not take place as usual. In this cases the chromosomes get larger and larger because of failures in chromatides division during mitosis, they are then called giant chromosomes, or polytene chromosomes, thus becoming very accessable for research (and of course for the amateur as well!).

See here: http://en.wikipedia.org/wiki/Polytene_chromosome

Bernhard

Ken Ramos · Post by **Ken Ramos** » Tue Jan 09, 2007 3:37 pm

Well you learn something new everyday. Must have missed that along the way in biology class

Well that is something, I never knew that. Thanks Bernhard!