Function of lampbrush chromosomes: A hypothesis

✍ Scribed by Pedro E. León

• Book ID: 104155259
• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 762 KB
• Volume: 55
• Category: Article
• ISSN: 0022-5193
• DOI: 10.1016/s0022-5193(75)80095-6

✦ Synopsis

A hypothesis about lampbrush chromosome function is proposed which takes into account several aspects of their morphology and behavior. It is suggested that in lampbrusb loops, alterations of the deoxyribonucleoprotein fiber take place which reprogram the chromosome for development. Such reprogramming could involve exchange or enzymatic modification of regulatory molecules (i.e., non-histone proteins). Since inhibition of RNA synthesis causes the loops to collapse, it is possible that transcription largely occurs to generate and maintain the loop, allowing the DNP fiber to "enter" the nucleoplasm. Lampbrush chromosomes are also involved in the production of "masked" mRNAs for early development. The giant granular loops could either be the sites where such mRNAs are packaged or they could be sites where specific alterations of the deoxyribonucleoprotein fiber take place.