A de novo reciprocal chromosomal translocation t(3;6)(p14;q26) in the black Lucano pig

Abstract

In the past two decades, several cytogenetic screening programmes identified different chromosome rearrangements in pig, most of which represented by reciprocal translocation (rcp). This chromosome abnormality does not involve the variation in the number of chromosomes, but only the rearrangement of genetic material, resulting in phenotypically normal carriers with fertility problems. During an occasional cytogenetic screening, a new reciprocal translocation was detected in the black Lucano pig native breed. We analysed 15 animals reared by a family‐run piggery in Basilicata region (Southern Italy). After karyotyping, four pigs (two boars and two sows) revealed two unpaired chromosomes. Analysis of the RBA karyotype and the dual‐colour FISH technique confirmed that these pigs showed the same reciprocal translocation involving the chromosomes SSC3 and SSC6. The precise location of breakpoints was identified by RBH‐FISH t(3;6)(p14;q26), whereas the analysis of the pedigree showed a case of Mendelian inheritance within a family, after the de novo occurrence of the new rcp. Considering the consequences of the rcp on the fertility, this study points out the importance of the cytogenetic screening in the native breeds for the safeguard of the genetic biodiversity and the sustainability of the rural areas.

Breeding and Economic Aspects of Cytogenetic Screening Studies of Pigs Qualified for Reproduction

“…It should be highlighted that the introduction of modern cytomolecular techniques into laboratory practice has considerably increased the diagnostic potential of the screening system, resulting in a marked increase in the number of karyotype abnormalities identified [92,103]. To date, cytogenetic screening of many pig populations around the world has resulted in the identification of over 220 structural karyotype defects, including almost 200 reciprocal translocations with a clear negative impact on fertility and economic efficiency of production [1,2,13,17,19,30,32,41,93,[98][99][100][103][104][105][106][107]. It seems that the elaboration and implementation of the next screening strategies will significantly intensify the detectability of reciprocal translocations, which are likely much more frequent in breeding populations than previously estimated.…”