Expression of common fragile sites in two Ceboidea species: Saimiri boliviensis and Alouatta caraya (Primates: Platyrrhini)

Abstract

Fragile sites are points of preferential breakage that may be involved in chromosome rearrangements. Induction of common fragile sites (c-fra) and spontaneous breakage were analyzed in two New World Monkeys species: Saimiri boliviensis (SBO) and Alouatta caraya (ACA). Spontaneous chromosome aberrations were analyzed on untreated lymphocyte cultures with Brögger's formula (1977). SBO presented a low level of spontaneous breakage, while higher frequencies were detected in ACA in which bands 1q23; 2q13 and 11q19 were significantly affected (p < 0.01). The populational distribution of c-fra was analyzed by the Chi2 test in FUdR plus caffeine treated cultures. A total of 21 c-fra was identified in SBO and 24 in ACA. Fragile sites A1q33, B1p21, B4p14, C3q23 and C5q22 were identified in all analyzed SBO specimens. The most frequent c-fra identified in ACA specimens were 1q23, 1q31, 1q33, 2q22, 8q14, 12q31, 13q22, 14q15 and Xq22. Fragile sites A1q31, A1q33, B1q14, B3q13, B4q21 and Xq22 identified in SBO and 1q31, 1q33, 2q22, 4q21, 6q13, 13q22 and Xq22 from ACA were the most conserved sites. A low coincidence between the location of c-fra and that of heterochromatin and breakpoints involved in euchromatic rearrangements known for these genera, was established.

Localisation of aphidicolin-induced break points in Holstein-Friesian cattle (Bos taurus) using RBG-banding

“…Also it has been proposed that interbands between heterochromatic and euchromatic regions may be more susceptible to breakage. On the contrary, Fundia et al [4], found no significant correlation between heterochromatic regions or structural changes and fragile sites, in two New World Monkey species.…”

“…APC is a diterpenoid mycotoxin, which specifically inhibits eukaryotic DNA polymerase alpha and beta [15]. APC induced fragile sites are well documented in humans but have been studied only sporadically in mammals and domestic animals, mainly in primates, pigs, cats, and cattle [4,6,9,12].…”

Expression of common fragile sites in two Ceboidea species: Saimiri boliviensis and Alouatta caraya (Primates: Platyrrhini)

“…Induction of fragile sites was also described in gorilla, chimpanzee and orangutan, showing an evolutionary conservation of these sites between the Great Apes and man and suggesting that fragile sites have been highly conserved during primate evolution [58,60,70]. In order to analyze the conservation of fragile sites in Ceboidea, the present data were compared to previous results on Cebus apella paraguayanus (CAP) chromosomes identifying 11 induced fragile sites (2q13, 2q26, 3q31, 5q22, 6q21, 11q15, 12q22, 19q13, 19q22, 20q13 and Xq22) [22,46]. Taking into account the chromosome homologies previously described in SBO, ACA and CAP [43], a homologous c-fra at band Xq22 was observed in all three species.…”

“…Since these six aberrations were located on different bands, no bands significantly involved in spontaneous breakage were found in SBO. On the other hand, spontaneous breakage analysis in ACA considering a haploid karyotype of 287 bands [21,22,46,47] demonstrated that any band with 2 or more lesions was non-randomly damaged (p < 0.01), identifying 3 bands: 1q23, 2q13 and 11q19 which were hot-spots for spontaneous breakage.…”

“…Slides with abnormal cells were destained and re-analyzed after sequential G-banding [59] to identify the breakpoints involved in CA. The karyotype of each species was considered following previously published works [21,22,25,[45][46][47]. Spontaneous CA were analyzed with Brögger's formula (1977) [4], and fragile sites were defined by the Chi2 test with Yates correction [27].…”