Towards a physical map of the fertility genes on the heterochromatic Y chromosome of Drosophila hydei: Families of repetitive sequences transcribed on the lampbrush loops Nooses and Threads are organized in extended clusters of several hundred kilobases

The understanding of structure and function of the so-called fertility genes of Drosophila is very limited due to their unusual size — several megabases — and their location on the heterochromatic Y chromosome. Since mapping of these genes has mainly been done by classical cytogenetic analyses using a small number of cytologically visible lampbrush loops as… (More)