Drosophila melanogaster kl-3 and kl-5 Y-loops harbor triple-stranded nucleic acids

Drosophila melanogaster kl-3 and kl-5 Y-loops harbor triple-stranded nucleic acids.

Primary spermatocyte nuclei of Drosophila melanogaster contain three prominent lampbrush-like loops. The development of these structures has been associated with the transcription of three fertility factors located on the Y chromosome, named kl-5, kl-3 and ks-1. These loci have huge physical dimensions and contain extremely long introns. In addition, kl-3 and kl-5 were shown to encode two putat...

Y chromosomal fertility factors kl-2 and kl-3 of Drosophila melanogaster encode dynein heavy chain polypeptides.

The molecular identity and function of the Drosophila melanogaster Y-linked fertility factors have long eluded researchers. Although the D. melanogaster genome sequence was recently completed, the fertility factors still were not identified, in part because of low cloning efficiency of heterochromatic Y sequences. Here we report a method for iterative blast searching to assemble heterochromatic...

Atomic force microscopy of long and short double-stranded, single-stranded and triple-stranded nucleic acids.

Atomic force microscopy (AFM, also called scanning force microscopy) is proving to be a useful technique for imaging DNA. Thus it is important to push the limits of AFM imaging in order to explore both what types of DNA can be reliably imaged and identified and also what substrates and methods of sample preparation are suitable. The following advances in AFM of DNA are presented here. (i) DNA m...

Lecture 3 : KL - divergence and connections

1 Recap Recall some important facts about entropy and mutual information from the previous lecture: • H(X,Y ) = H(X) + H(Y |X) = H(Y ) + H(X|Y ) • I(X;Y ) = H(X)−H(X|Y ) = H(Y )−H(Y |X) = H(X) + H(Y )−H(X,Y ) • I(X;Y |Z) = H(X|Z)−H(X|Y,Z) • I(X;Y ) = 0 if X and Y are independent • I(X;Y ) ≥ 0 or, equivalently, H(X) ≥ H(X|Y ) Exercise 1.1 Prove that H(X|Y ) = 0 if and only if X = g(Y ) for some ...

2 J Urgen Kl Uners