Why lampbrush chromosomes are absent in mammals?

Why lampbrush chromosomes are not found in mammals?

Answer :- Human and other mammalian chromosomes do not form recognizable lampbrush chromosomes in their own oocytes or in any somatic cells.

In which animals lampbrush chromosomes can be found?

Lampbrush chromosomes (LBCs) are transcriptionally active chromosomes found in the germinal vesicle (GV) of large oocytes of many vertebrate and invertebrate animals and also in the giant single-celled alga Acetabularia. These cells are all in prophase of the first meiotic division.

Who discovered Lampbrush chromosome in amphibian oocytes?

Lampbrush chromosomes were discovered in sala- mander egg cells (Ambystoma mexicanum) by Flemming in 1882. Ten years later, LBCs were identified in shark egg cells and described by Rückert in 1982.

Why Lampbrush chromosome is called?

Lampbrush Chromosomes (LBCs) are present in the oocytes of birds, lower vertebrata and invertebrates during the prolonged prophase of the first meiotic division. Their name stems from their similarity to bottle brushes. Lampbrush chromosome of the early prophase is a bivalent, made up of two conjugating homologues.

What is the difference between Lampbrush chromosome and polytene chromosome?

The main difference between polytene and lampbrush chromosome is that polytene chromosomes occur in the salivary glands and other tissues of insects whereas lampbrush chromosomes occur in the oocytes of vertebrates except for mammals and some invertebrates.

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What are the functions of Lampbrush chromosome?

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.

Who introduced Lampbrush chromosome?

Lampbrush chromosomes (LBCs) are giant meiotic chromosomes first described more than 100 years ago from the oocyte nucleus or germinal vesicle (GV) of the axolotl (Flemming 1882) and a shark (Rückert 1892).

Do humans have Lampbrush chromosome?

Human and other mammalian chromosomes do not form recognizable lampbrush chromosomes in their own oocytes or in any somatic cells.

What do you mean by Lampbrush?

: a greatly enlarged diplotene chromosome that has apparently filamentous granular loops extending from the chromomeres and is characteristic of some animal oocytes.