Isolation of a new germ line-specific repetitive DNA family in Acricotopus by microdissection of polytenized germ line-limited chromosome sections from a permanent larval salivary gland preparation.
In Acricotopus lucidus (Diptera, Chironomidae) the germ line-limited chromosomes (Ks) have developed from the soma chromosomes (Ss) by endoreduplication, rearrangements and accumulation of germ line-specific repetitive sequences. For molecular analysis of specific small K sections, microdissection of metaphase Ks generally yields very limited amounts of DNA. In this study, K-specific DNA was microdissected from defined polytenized K sections of X-ray induced K-S-rearrangements of permanent salivary gland chromosome preparations and was then amplified by DOP-PCR. A new germ line-specific tandem repetitive DNA family was isolated by this way from a heterochromatic K segment, characterized and localized on the Ks by FISH. The repetitive elements are related to sequences of earlier described K-specific tandem repetitive DNA families in A. lucidus, but are located mainly in terminal heterochromatin bands of the two largest Ks and only to a limited degree in the paracentromeric K heterochromatin. This demonstrates that a collection of permanent preparations of K-S-rearrangements with polytenized heterochromatic and S-homologous K sections of A. lucidus can be used as a source for obtaining K sequences of defined K parts to investigate the molecular evolution of the Ks.
Staiber
W
W
Institute of Genetics, University of Hohenheim, Stuttgart, Germany. wstaiber@uni-hohenheim.de
D000818:Animals; D001483:Base Sequence; D002683:Chironomidae / Q000235:genetics* / Q000254:growth & development; D002874:Chromosome Mapping; D002875:Chromosomes / Q000648:ultrastructure; D004247:DNA / Q000302:isolation & purification; D004210:Dissection; D015321:Gene Rearrangement; D005854:Germ Cells; D006570:Heterochromatin; D007814:Larva / Q000033:anatomy & histology / Q000235:genetics; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D012469:Salivary Glands / Q000601:surgery; D016415:Sequence Alignment; D012730:Sex Chromosomes
D006570:Heterochromatin; D004247:DNA