Sex-specific organisation of middle repetitive DNA sequences in the mealybug Planococcus lilacinus.
Differential organisation of homologous chromosomes is related to both sex determination and genomic imprinting in coccid insects, the mealybugs. We report here the identification of two middle repetitive sequences that are differentially organised between the two sexes and also within the same diploid nucleus. These two sequences form a part of the male-specific nuclease-resistant chromatin (NRC) fraction of a mealybug Planococcus lilacinus. To understand the phenomenon of differential organisation we have analysed the components of NRC by cloning the DNA sequences present, deciphering their primary sequence, nucleosomal organisation, genomic distri-bution and cytological localisation. Our observations suggest that the middle repetitive sequences within NRC are functionally significant and we discuss their probable involvement in male-specific chromatin organisation.
Khosla
S
S
Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560 012, India,
Augustus
M
M
Brahmachari
V
V
D000818:Animals; D001042:Aphids / Q000196:embryology / Q000235:genetics*; D015139:Blotting, Southern; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D003850:Deoxyribonuclease I / Q000378:metabolism; D005260:Female; D016678:Genome; D018392:Genomic Imprinting / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008836:Micrococcal Nuclease / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012727:Sex Characteristics; D019849:Sex Determination Processes
D002843:Chromatin; D003850:Deoxyribonuclease I; D008836:Micrococcal Nuclease