Chromosomal rearrangements in�cattle and�pigs revealed by�chromosome microdissection and�chromosome painting

Abstract

-A pericentric inversion of chromosome 4 in a boar, as well as a case of (2q−;5p+) translocation mosaicism in a bull were analysed by chromosome painting using probes generated by conventional microdissection. For the porcine inversion, probes specific for p arms and q arms were produced and hybridised simultaneously on metaphases of a heterozygote carrier. In the case of the bovine translocation, two whole chromosome probes (chromosome 5, and derived chromosome 5) were elaborated and hybridised independently on chromosomal preparations of the bull who was a carrier of the mosaic translocation. The impossibility of differentiating chromosomes 2 and der(2) from other chromosomes of the metaphases did not allow the production of painting probes for these chromosomes. For all experiments, the quality of painting was comparable to that usually observed with probes obtained from flow-sorted chromosomes. The results obtained allowed confirmation of the interpretations proposed with G-banding karyotype analyses. In the bovine case, however, the reciprocity of the translocation could not be proven. The results presented in this paper show the usefulness of the microdissection technique for characterising chromosomal rearrangements in species for which commercial probes are not available. They also confirmed that the main limiting factor of the technique is the quality of the chromosomal preparations, which does not allow the identification of target chromosomes or chromosome fragments in all cases.

High-resolution comparative chromosome painting in the Arizona collared peccary (Pecari tajacu, Tayassuidae): a comparison with the karyotype of pig and sheep

“…The chromosome painting data confirm and extend previous findings showing that the main differences between pig and peccary chromosomes are translocations and fusion/ fission of large chromosome segments (Bosma et al 2004). Further, the data also confirm and extend assumptions that the pig has a highly derived karyotype compared to other Cetartiodactyla (Schmitz et al 1998, Froenicke & Wienberg 2001, and to primates (humans), serving as an outgroup (Froenicke et al 1996, Goureau et al 1996, Schmitz et al 1998, Pinton et al 2003, Biltueva et al 2004.…”

Chromosomal control of pig populations in France: 2002–2006 survey

“…For some particular rearrangements, the hypotheses concerning the chromosomes involved and/or the location of breakpoints on the chromosomes were verified using molecular cytogenetic techniques: chromosome painting (probes generated using flow-sorted or microdissected chromosomes [8,15,18]), fluorescent in situ hybridisation using probes generated from BAC clones [17]. [7]).…”

Comparison of male and female meiotic segregation patterns in translocation heterozygotes: a case study in an animal model (Sus scrofa domestica L.)

“…The same sets of probes and hybridization protocols were used for chromosome painting on metaphases of the boars obtained from lymphocyte cultures (Ducos et al, 2002b;Pinton et al, 2003) (Figures 1 and 2).…”

“…The probes were then re-suspended in 25 ml of conventional hybridization solution and 5 ml were placed (under a 22 mm £ 22 mm cover slip) on each preparation that had been previously denaturated (in 70% formamide at 708C for 2 min) and treated with proteinase K for 3 min. The biotin-labelled probes were revealed using a red Alexa 594 fluorochrome (Molecular Probes, Eugene, OR, USA), and the digoxigenin-labelled probes using a green Alexa 488 fluorochrome (Molecular Probes) as in the protocol described by Pinton et al, (2003).…”

“…For chromosomes 3, 12 and 14, the probes were produced from flow-sorted chromosomes amplified using priming authorizing random mismatches (PARM) -PCR (Schmitz et al, 1992;Yerle et al, 1993). The probe for chromosome 15 was produced by chromosomal microdissection followed by degenerate oligonucleotide-primed (DOP) -PCR amplification (Telenius et al, 1992) of the microdissected material (Pinton et al, 2003). Probe labelling was carried out either by PARM -PCR or DOP -PCR using 2 ml of amplified chromosomal products.…”