Welcome to the Y-chromosome loops section.

the above image is property of RP and originally developed and published
in the PhD Thesis, in 1999; an updated version can be found inside the manuscript
published by TheScientificWorldJOURNAL in 2010 (link below);
please do not reproduce without explicit permission

Primary spermatocyte nuclei of Drosophila melanogaster exhibit three giant lampbrush-like loops formed by the kl-5, kl-3 and ks-1 Y-chromosome fertility factors. These structures contain and abundantly transcribe highly repetitive, simple sequence DNAs and accumulate large amounts of non-Y-encoded proteins.The biological role of the Y-chromosome loops is still largely unknown.

A multidisciplinary approach is used to analyse Y loops. Antibodies against proteins bound to them, as well as FISH using DNA and RNA probes were used, and various collections of male sterile mutants were analysed to search those defective in Y loops development. Mutants were described cytologically and biochemically for the presence of high molecular weight polypeptides and for the proper development of loops. Also the evolutionary conservation of Y-loops had been investigated.

References

Meeting abstracts (see curriculum vitae).

Piergentili R., Bonaccorsi S., Raffa G. D., Pisano C., Hackstein J. P. and Mencarelli C. (2004)
Autosomal control of the Y chromosome kl-3 loop of Drosophila melanogaster.
Chromosoma 113(4):188-196

Piergentili R. (2006)
A simple method to prepare DNA fibres in male germ line.
Dros Info Serv 89:128-130

low resolution manuscript (136 Kb)

high resolution manuscript (10,800 Kb)

Piergentili R. (2007)
Evolutionary conservation of lampbrush-like loops in drosophilids.
BMC Cell Biol 8:35

Ceprani F., Raffa G. D., Petrucci R. and Piergentili R. (2008)
Autosomal mutations affecting Y chromosome loops in Drosophila melanogaster.
BMC Genet 9:32

Piergentili R. and Mencarelli C. (2008)
Drosophila melanogaster kl-3 and kl-5 Y-loops harbor triple-stranded nucleic acids.
J Cell Sci 121:1605-1612

Piergentili R. (2009)
The Y chromosome of Drosophila melanogaster and the enigma of 'functional heterochromatin'.
In: 'Sex Chromosomes: Genetics, Abnormalities, and Disorders'. New York: NovaScience Publishers inc. ISBN:978-1-60741-304-2

Piergentili R. (2010)
The heterochromatic component of the human Y chromosome: a genetic wasteland or something more? Suggestions from the fruitfly.
In: 'Human spermatozoa: maturation, capacitation and abnormalities'. New York: NovaScience Publishers inc. ISBN:978-1-60876-401-3

Piergentili R. (2010)
Multiple roles of the Y chromosome in the biology of Drosophila melanogaster.
TheScientificWorldJOURNAL 10:1749-1767