Disease relevance of kl-5

• Region h1-h9 on YL, which carries the kl-3 and kl-5 loci, induces male sterility when present in three copies [1].

High impact information on kl-5

• The closest paralogs of kl-2, kl-3, and PRY (and also of kl-5) are autosomal and not X-linked, suggesting that the evolution of the Drosophila Y chromosome has been driven by an accumulation of male-related genes arising de novo from the autosomes [2].
• In the present study, we demonstrate that one of the dynein genes, Dhc-Yh3, is located in Y chromosome region h3, which is contained within kl-5, a locus required for male fertility [3].
• In situ hybridization to Drosophila testes shows Dhc-Yh3 is expressed in wild-type males but not in males missing the kl-5 region [3].
• Experiments using dosage variation and a temperature-sensitive sterile mutation in kl-5 suggest that the Y-chromosome regions contain the coding sequences for the polypeptides [4].
• In contrast, the kl-3 and kl-5 mutations had no effect on spermatid individualization despite the defect in the axonemes [1].

Biological context of kl-5

• Detailed mapping of satellite DNA sequences along the Y chromosome has recently shown that AA-GAC satellite repeats are a significant component of the kl-5 and ks-1 loop-forming regions [5].

Anatomical context of kl-5

• 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 [6].

Regulatory relationships of kl-5

• Use of a transgenic construct expressing TrxT fused to Enhanced Yellow Fluorescent Protein reveals a clear association of TrxT with the Y chromosome lampbrush loops ks-1 and kl-5 in primary spermatocytes [7].

Other interactions of kl-5

• Otherwise, there is evidence from genetic mapping and biochemical experiments that at least two of these loops, Threads in Drosophila hydei and kl-5 in D. melanogaster, colocalize with the genes for the axonemal dynein beta heavy chain proteins DhDhc7(Y) and Dhc-Yh3, respectively [8].

Analytical, diagnostic and therapeutic context of kl-5

• Moreover, preliminary sequence analysis and several other features support the hypothesis that DhDhc7(Y) on the lampbrush loops Threads in D. hydei and Dhc-Yh3 on the lampbrush loops kl-5 in Drosophila melanogaster on the heterochromatic Y chromosome of both species might indeed code for orthologous dynein beta heavy chain proteins [9].

References