A repetitive probe for FISH analysis of bovine interphase nuclei

The purpose of this study was to generate repetitive DNA sequence probes fo r the analysis of interphase nuclei by fluorescent in situ hybridisation (F ISH). Such proles are useful for the diagnosis of chromosomal abnormalities in bovine preimplanted embryos. Of the seven probes (E1A, E4A, Ba, H1A, W1 8, W22, W5) that were generated and partially sequenced, five corresponded to previously described Bos taurus repetitive DNA (E1A, E4A, Ba, W18, W5), one probe (W22) shared Ilo homology with other DNA sequences and one (H1A) displayed a significant homology with Rattus norvegicus mRNA for secretin r eceptor transmembrane domain 3. Fluorescent in situ hybridisation was perfo rmed on metaphase bovine fibroblast cells and showed that five of the seven probes hybridised most centromeres (E1A, E4A, Ba, W18, W22), one labelled the arms of all chromosomes (W5) and the H1A probe was specific to three ch romosomes (ch14, ch20, and ch25). Moreover, FISH with H1A resulted ill inte rpretable signals on interphase nuclei in 88% of the cases, while the other probes yielded only dispersed overlapping signals.