Rapid detection of chromosome 18 aneuploidies in amniocytes by using primed in situ labeling （PRINS） technique

This paper presents a feasible method for rapid detection of the interphase nuclei of uncultured amniocytes for chromosomes 18 by using our modified primed in situ labeling (PRINS) technique. A total of 262 independent, uncultured amniotic fluid samples were analysed in a blind fashion before the karyotype was available. In addition, 62 samples were examined by fluorescence in situ hybridization (FISH) for comparison. In more than 95% of the samples PRINS reactions with primer 18cen were successfully induced. Two samples were properly identified and correctly scored as trisomic 18. PRINS reaction could be performed automatically in less than one hour with a programmable thermocycler. Our studies showed that the PRINS technique is simple, rapid and cost effective. It is as sensitive and specific as FISH; can enhance the accuracy of standard cytogenetic analysis; and allows identification of chromosomes 18 aneuploidies in uncultured amniocytes in significantly less time.

Primed In Situ Labeling Technique for Subtelomeric Rearrangements in 70 Children with Idiopathic Mental Retardation

Subtelomeric rearrangements contribute to idiopathic mental retardation （MR）, but most children with idiopathic MR do not show any chromosome abnormalities with standard cytogenetic analysis. The primed in situ labeling （PRINS） technique, using an oligonucleotide primer complementary to the telemetric repeat sequences （TTAGGG）, can identify chromosome telomeric abnormality （deletion） in idiopathic MR children. In this study, seventy children with idiopathic MR were enrolled and subjected to PR1NS. The results showed normal karyotype in all the children, subtelomeric rearrangements （lq del and 4q del） in 2 cases, which was confirmed by fluorescence in situ hybridization （FISH）. It was concluded that PRINS is effective for the detection of subtelomeric rearrangements and may become a routine technique for cytogenetical abnormality screening.

Cytogenetic analysis in two scallops (Bivalvia:Pectinidae) by PRINS and PI banding

Cytogenetic analysis was performed for the bay scallop （Argopecten irradians Lamarck 1819） and the Japanese scallop （Patinopecten yessoensis Jay 1857 ） by primed in situ labeling （PRINS） and propidium iodide （PI） banding techniques. The PRINS analysis revealed that major rRNA genes were clustered in two loci on the telomeric regions of the short arms on two acrocentric chromosome pairs in A. irradians and on two submetacentric pairs in P. yessoensis. The histone H3 gene sites differed in number and location between these two species. The C-band-like patterns revealed by PI staining varied considerably between these two species. A. irradians displayed terminal bands at long arms on all chromosomes, centromeric bands on some pairs and interstitial bands on five pairs. P. yessoensis exhibited only centromeric bands on all chromosomes. These results would contribute to the better understanding of karyotype evolution in A. irradians and P. yessoensis.