Procedure of meiosis in grasshopper testis explains why testis of grasshopper is an ideal material for studying various stage of meiosis.
Aim of the Procedure
To study the different stages of meiosis in grasshopper testis through permanent grasshopper testis slide (Acetocarmine Stained).
Testis of Grasshopper
Testis of grasshopper is an ideal material for studying various stage of meiosis. Grasshopper is of good choice because it is easy available in lawns and fields. In addition is has fewer number of chromosomes. (Locally available species contain seventeen or twenty one chromosomes in males add number of chromosomes due to xx or xo sex chromosomes system). All chromosomes are of one type i.e acrocentric facilitating unambiguous of different stages.
Stains are used in microscopic studies to enhance the contrast of specific biological components in a sample. Acetocarmine is such a stain used to stain nucleic acid inside cells here its testis of grasshopper. As acetocarmine specifically stain chromosomes apart from the cytoplasm, it can be used to visualize chromosomes in mitotic studies.
1. Male Grasshopper
2. Insect Saline (0.67% NaCl)
3. 1:3 Acentomethanol Fixative
4. 70% And 90% Ethanol
5. 2% Acetocaremine Stain
6. 45% Acetic Acid
7. Slide Cover Glass
8. Sealing Wax or Nail Polish
10 g carmine, dissolved in 1 L glacial acetic acid at 45 percent. Reflux for 24 hours after adding aluminum granules. Filter and store in dark bottles at 4°C. By adding ferric chloride, the staining can be made more intense (add 5 mL of a 10 percent ferric chloride solution per 100 mL of percent acetocarmine).
Meiosis in Grasshopper Testis
1. Hold a male grasshopper in hand, give a small incision with scissors at the junction of thorax and abdomen and press the abdomen gently.
2. The testis covered in yellow fat bodies will pop out. Dissect them out and put in insect saline remove yellow fat with the help of forceps as much as possible.
3. A pair of testis (Each having a brunch of white tubules) will be seen. Transfer the tubules in a test tube and fix in acetomethanol fixative, close the test tube and leave it for overnight.
4. Remove the fixative and add 90% ethanol, leave for 2 hours. Decant 90% ethanol and add 70% ethanol for a long period of time. If the tube is lightly closed storing at 4° C is even better.
5. Stain the fixed testis in acetocarmine stain for 30 min. Take a drop of 45% acetic acid on slide place a few tubules of testis in the drop, leave for 1-2 minutes.
6. If acetic acid drop can be added. For squash preparation of grasshopper testis, place a cover glass on the tubules and squash using a rubber and pencil under the blotting paper.
7. Seal the edge of the cover glass with molten wax or with the nail polish. Immediately to prevent drying of acetic acid film and entry of air bubbles. The slide is ready for observation of meiosis in grasshopper testis under microscope.
Meiosis under Microscope
Meiosis in Grasshopper Testis Diagram: Different stages of meiosis in Grasshopper Testis. (1. Interphase, 2. Leptotene, 3. Zygotene , 4. Pachytene, 5. Diplotene, 6. Diakinese 7.Metaphase-I, 8. Anaphase-I, 9. Teleophase-I, 10. Prophase-II, 11. Metaphase-II, 12. Anaphase-II, 13. Telophase-II, 14. Spermatids (Sperms).)