title: Isolation and chromosomal localization of a germ line-specific highly repetitive DNA family in Acricotopus lucidus (Diptera, Chironomidae).
abstract: In the chironomid Acricotopus lucidus, parts of the genome, the germ line-limited chromosomes, are eliminated from the future soma cells during early cleavage divisions. A highly repetitive, germ line-specific DNA sequence family was isolated, cloned and sequenced. The monomers of the tandemly repeated sequences range in size from 175 to 184 bp. Analysis of sequence variation allowed the further classification of the germ line-restricted repetitive DNA into two related subfamilies, A and B. Fluorescence in situ hybridization to gonial metaphases demonstrated that the sequence family is highly specific for the paracentromeric heterochromatin of the germ line-limited chromosomes. Restriction analysis of genomic soma DNA of A. lucidus revealed another tandem repetitive DNA sequence family with monomers of about 175 bp in length. These DNA elements are found only in the centromeric regions of all soma chromosomes and one exceptional germ line-limited chromosome by in situ hybridization to polytene soma chromosomes and gonial metaphase chromosomes. The sequences described here may be involved in recognition, distinction and behavior of soma and germ line-limited chromosomes during the complex chromosome cycle in A. lucidus and may be useful for the genetic and cytological analysis of the processes of elimination of the germ line-limited chromosomes in the soma and germ line.
authors.affiliation: Institute of Genetics, University of Hohenheim, D-70593 Stuttgart, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Staiber
authors.forename: I
authors.initials: I
authors.lastname: Wech
authors.forename: A
authors.initials: A
authors.lastname: Preiss
mesh_terms: D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D002503:Centromere; D002683:Chironomidae / Q000235:genetics*; D002874:Chromosome Mapping; D003720:Densitometry; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics / Q000378:metabolism; D004587:Electrophoresis, Agar Gel; D005854:Germ Cells / Q000502:physiology*; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D012469:Salivary Glands / Q000502:physiology; D012689:Sequence Homology, Nucleic Acid; D013737:Testis / Q000502:physiology
chemical_list: D015252:Deoxyribonucleases, Type II Site-Specific; C027046:TCGA-specific type II deoxyribonucleases; C035594:TTTAAA -specific type II deoxyribonucleases