Abstract
The W chromosome of the codling moth, Cydia pomonella, like that of most Lepidoptera species, is heterochromatic and forms a female-specific sex chromatin body in somatic cells. We collected chromatin samples by laser microdissection from euchromatin and W-chromatin bodies. DNA from the samples was amplified by degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR) and used to prepare painting probes and start an analysis of the W-chromosome sequence composition. With fluorescence in situ hybridization (FISH), the euchromatin probe labelled all chromosomes, whereas the W-chromatin DNA proved to be a highly specific W-chromosome painting probe. For sequence analysis, DOP-PCR-generated DNA fragments were cloned, sequenced, and tested by Southern hybridization. We recovered single-copy and low-copy W-specific sequences, a sequence that was located only in the W and the Z chromosome, multi-copy sequences that were enriched in the W chromosome but occurred also elsewhere, and ubiquitous multi-copy sequences. Three of the multi-copy sequences were recognized as derived from hitherto unknown retrotransposons. The results show that our approach is feasible and that the W-chromosome composition of C. pomonella is not principally different from that of Bombyx mori or from that of Y chromosomes of several species with an XY sex-determining mechanism. The W chromosome has attracted repetitive sequences during evolution but also contains unique sequences.
| Original language | English |
|---|---|
| Journal | Chromosoma |
| Volume | 116 |
| Issue number | 2 |
| Pages (from-to) | 135-145 |
| Number of pages | 11 |
| ISSN | 0009-5915 |
| DOIs | |
| Publication status | Published - 01.04.2007 |
Funding
Acknowledgement Our thanks are due to Dr. Ken Sahara (Hokkaido University, Sapporo, Japan) for KAIKOBLAST search. The technical assistance of Marie Korchová (Institute of Entomology, České Budějovice, Czech Republic), Heidemarie Riechers and Constanze Reuter (Insitut für Biologie, Universität zu Lübeck, Germany) is highly appreciated. This work was funded from the Entomology Institute project Z50070508, by Research Contract No. 12055/R of the International Atomic Energy Agency, Vienna, Austria, and by grants A6007307 of the Grant Agency of the Academy of Sciences of the Czech Republic (till 2005) and 206/06/1860 of the Grant Agency of the Czech Republic (since 2006), both Prague. I. F. and M. V. acknowledge the support of their Ph.D. program from the grant 521/03/H160 of the Grant Agency of the Czech Republic. S. K. was supported from a project MZE 0002716201 of the Grant Agency of the Ministry of Agriculture of the Czech Republic, Prague.
