Cytogenetic investigation in two endangered pig breeds raised in Southern-Italy: Clinical and environmental aspects

Representative groups of animals of two endangered local pig breeds (Casertana and Nero Siciliano, both with black skin and raised in Southern-Italy) were cytogenetically investigated and compared to check for the presence of chromosomal abnormalities and to test their chromosome stability by sister chromatid exchange (SCE) test, in their normal breeding conditions. Forty-two Casertana pigs (22 males and 20 females, raised in 3 farms) and 39 Nero Siciliano pigs (19 males and 20 female, raised in 3 farms) were investigated. All animals showed normal CBA- and RBA-banded karyotypes (2n = 38), except for two Nero Siciliano boars (both from the same farm) which showed 2n = 37 being heterozygous carrier of rob (15;17). The translocation was confirmed by FISH-mapping with specific BAC-clones. Both animals were probably hybrids from crosses with the wild pig (2n = 36) present in the Nebrodi mountains where Nero Siciliano is reared with extensive or semi-extensive systems. SCE-test applied on all studied animals revealed no statistical differences between the SCE-mean number of Casertana (7.13 ± 3.20) and Nero Siciliano (6.87 ± 3.12) breeds. Statistical differences were found between SCEs mean values of males (7.26 ± 3.38) and females (6.59 ± 2.90) of Nero Siciliano breed, as well as between females of Casertana (7.24 ± 3.26) and Nero Siciliano (6.59 ± 2.90) breeds, while no statistical differences were found between SCE mean values of males of Casertana (6.98 ± 3.10) and Nero Siciliano (6.45 ± 2.97) breeds, as well as between males and females of Casertana breed.