title: Gene mapping on chorionic villi chromosomes by hybridization in situ: localization of cholinesterase cDNA binding sites to chromosomes 3q21, 3q26-ter and 16q21.
abstract: To adapt the in-situ hybridization approach for use in very early fetal development, comparative in-situ hybridization was initiated on chromosomes from chorionic villus sampling (CVS). An additional aim was to refine the localization of the chromosomal sites binding butyrylcholinesterase (BuChE) cDNA by mapping them in parallel to previously mapped genes of close locations. BuChEcDNA was previously found to bind to the long arms of lymphocyte chromosomes 3 and 16, with a wide distribution of grains suggesting two separate sites on chromosome 3. When labelled with 35S and hybridized with CVS chromosomes, BuChEcDNA was bound to three distinct sites, designated CHEL1, CHEL2 and CHEL3. These peaked at 3q21, 3q26-ter and 16q21 respectively. Parallel hybridization with the cDNA encoding transferrin receptor (TFRC) refined its localization to 3q29, in agreement with previously published results and in a distal position to CHEL2, whereas haptoglobin cDNA (HPcDNA) was correctly mapped at 16q24, distal to CHEL3. In view of the published genetic linkage between the CHEL1 locus and the transferrin TF gene on 3q25, this study suggests that one of the three sites carrying BuChE-coding sequences, namely CHEL2, harbours the functional CHEL1 gene. Thus, in-situ hybridization provides a rapid and precise method for the localization of genes on CVS chromosomes, in comparison with known DNA markers.
authors.affiliation: Department of Obstetrics and Gynaecology, Edith Wolfson Medical Centre, Holon, Israel.
authors.forename: H
authors.initials: H
authors.lastname: Zakut
authors.forename: R
authors.initials: R
authors.lastname: Zamir
authors.forename: L
authors.initials: L
authors.lastname: Sindel
authors.forename: H
authors.initials: H
authors.lastname: Soreq
mesh_terms: D001665:Binding Sites; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002091:Butyrylcholinesterase / Q000235:genetics; D002802:Cholinesterases / Q000235:genetics*; D002824:Chorionic Villi / Q000648:ultrastructure*; D002874:Chromosome Mapping; D002885:Chromosomes, Human, Pair 16; D002893:Chromosomes, Human, Pair 3; D004247:DNA / Q000235:genetics* / Q000378:metabolism; D005260:Female; D006801:Humans; D008938:Mitosis; D009693:Nucleic Acid Hybridization; D013462:Sulfur Radioisotopes
chemical_list: D013462:Sulfur Radioisotopes; D004247:DNA; D002091:Butyrylcholinesterase; D002802:Cholinesterases; D001973:Bromodeoxyuridine