How do I distinguish an autosome from a s*x chromosome?

Question

i'm conducting a cytogenetic analysis on bugs, and I'm not sure how to differentiate the s*x chromosome from the autosomes at the diakinesis stage. what should I do?

Answer 1

First do you really mean bugs, or insects or arthropods?

If you mean insects, you will first have to find out what type of s*x determination the species uses. Some insects use an XX/XO system in which females have two X, males only one. Others use a ZW system in which the males have two Z and the females ZW. There are also haplo/diploid species in which haploid individuals are male and the diploids are generally female.

If it is XO then the male will have an odd number of chromosomes: the unpaired chromosome at metaphase I of meiosis will be the X. If it is XY then the male will show two unequal chromosomes at the same stage

Once you know which type they are you will need you need to look at chromosome spreads from both males and females to identify which of the chromosomes are showing the predicted pattern

Answer 2

You need to photograph the cell first. The s*x chromosomes are normally short and stubbed, and if you can identify the bug as male, you will see only one X or Y, of course, so you can know that it is the chromosome. But it is quite tedious to differentiate at first sight, and I would suggest you take time to compare.