PMID- 22825842
OWN - NLM
STAT- MEDLINE
DCOM- 20130129
LR  - 20211021
IS  - 1573-6857 (Electronic)
IS  - 0016-6707 (Linking)
VI  - 140
IP  - 4-6
DP  - 2012 Jun
TI  - Sex chromosomes and associated rDNA form a heterochromatic network in the 
      polytene nuclei of Bactrocera oleae (Diptera: Tephritidae).
PG  - 169-80
AB  - The olive fruit fly, Bactrocera oleae, has a diploid set of 2n = 12 chromosomes 
      including a pair of sex chromosomes, XX in females and XY in males, but polytene 
      nuclei show only five polytene chromosomes, obviously formed by five autosome 
      pairs. Here we examined the fate of the sex chromosomes in the polytene 
      complements of this species using fluorescence in situ hybridization (FISH) with 
      the X and Y chromosome-derived probes, prepared by laser microdissection of the 
      respective chromosomes from mitotic metaphases. Specificity of the probes was 
      verified by FISH in preparations of mitotic chromosomes. In polytene nuclei, both 
      probes hybridized strongly to a granular heterochromatic network, indicating thus 
      underreplication of the sex chromosomes. The X chromosome probe (in both female 
      and male nuclei) highlighted most of the granular mass, whereas the Y chromosome 
      probe (in male nuclei) identified a small compact body of this heterochromatic 
      network. Additional hybridization signals of the X probe were observed in the 
      centromeric region of polytene chromosome II and in the telomeres of six polytene 
      arms. We also examined distribution of the major ribosomal DNA (rDNA) using FISH 
      with an 18S rDNA probe in both mitotic and polytene chromosome complements of B. 
      oleae. In mitotic metaphases, the probe hybridized exclusively to the sex 
      chromosomes. The probe signals localized a discrete rDNA site at the end of the 
      short arm of the X chromosome, whereas they appeared dispersed over the entire 
      dot-like Y chromosome. In polytene nuclei, the rDNA was found associated with the 
      heterochromatic network representing the sex chromosomes. Only in nuclei with 
      preserved nucleolar structure, the probe signals were scattered in the restricted 
      area of the nucleolus. Thus, our study clearly shows that the granular 
      heterochromatic network of polytene nuclei in B. oleae is formed by the 
      underreplicated sex chromosomes and associated rDNA.
FAU - Drosopoulou, Elena
AU  - Drosopoulou E
AD  - Department of Genetics, Development and Molecular Biology, School of Biology, 
      Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
FAU - Nakou, Ifigeneia
AU  - Nakou I
FAU - Sichova, Jindra
AU  - Sichova J
FAU - Kubickova, Svatava
AU  - Kubickova S
FAU - Marec, Frantisek
AU  - Marec F
FAU - Mavragani-Tsipidou, Penelope
AU  - Mavragani-Tsipidou P
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120724
PL  - Netherlands
TA  - Genetica
JT  - Genetica
JID - 0370740
RN  - 0 (DNA, Ribosomal)
SB  - IM
MH  - Animals
MH  - Cell Nucleolus/genetics
MH  - DNA, Ribosomal/*genetics
MH  - Female
MH  - In Situ Hybridization, Fluorescence
MH  - Male
MH  - Mitosis
MH  - *Polytene Chromosomes
MH  - *Sex Chromosomes
MH  - Tephritidae/*genetics
EDAT- 2012/07/25 06:00
MHDA- 2013/01/30 06:00
CRDT- 2012/07/25 06:00
PHST- 2012/02/22 00:00 [received]
PHST- 2012/07/11 00:00 [accepted]
PHST- 2012/07/25 06:00 [entrez]
PHST- 2012/07/25 06:00 [pubmed]
PHST- 2013/01/30 06:00 [medline]
AID - 10.1007/s10709-012-9668-3 [doi]
PST - ppublish
SO  - Genetica. 2012 Jun;140(4-6):169-80. doi: 10.1007/s10709-012-9668-3. Epub 2012 Jul 
      24.