NOR and nucleolus in the spermatogenesis of acridoid grasshoppers

✍ Scribed by J. S. Rufas; P. Esponda; J. Gosálvez

• Book ID: 104638209
• Publisher: Springer Netherlands
• Year: 1985
• Tongue: English
• Weight: 922 KB
• Volume: 66
• Category: Article
• ISSN: 0016-6707
• DOI: 10.1007/bf00139718

✦ Synopsis

By means of silver staining procedures of light microscopy the characteristics of the nucleolus and the NO Rs have been investigated in meiocytes of different grasshopper species. Our results show that: (1) Two is the most common number of chromosomes per haploid genome carrying active NORs although this number may vary from one up to five; (2) NOR activity is preferentially located on medium and short chromosomes but the X and the megameric chromosome are involved in nucleolar organization in a high proportion of the species studied; (3) The NOR location is normally restricted to one end in acro-telocentrics and to the short arm, near the centromere region, in metacentrics; (4) A marked correlation is observed between the number of nucleoli present in the spermatogonial cells and in the first meiotic prophase of a given species; (5) In some cases, the nucleoli are associated to chromosomes during spermatogonial premetaphases.