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For a clade that includes Antilope, Gazella,Nanger and Eudorcas (Antilopinae), X;BTA5 translocation is a synapomorphy. Using a combination of fluorescence in situ hybridization (FISH) probes and polymerase chain reaction techniques, we provide (i) the first insight into the X;BTA5 architecture which differs in the species under study: Antilope cervicapra (genus Antilope), Gazella leptoceros (genus Gazella) and Nanger dama ruficollis (genus Nanger), (ii) determination of interstitial satellite DNA at the X;BTA5 junctions, and (iii) determination of repetitive sequences occupying constitutive heterochromatin of Xp arms in the studied species. The distribution of 2 repetitive DNA families in the centromeric regions of all chromosomes has been investigated by FISH with probes representing satellite I and satellite II DNA in all studied species. In this context, we discuss a markedly smaller centromere in the BTA5 (Y2) unfused chromosomes in males in the XY1Y2 determining system in comparison with other acrocentrics. An analysis of karyotypic data described in current published studies revealed a disparity with the data determined by FISH. In this report, we document chromosomal fusions in the 3 species mentioned resulting from FISH with painting probes prepared from cattle (Bos taurus). The number and chromosomal location of nucleolus organizer regions were determined by FISH. In the present study, we emphasize the importance of chromosomal rearrangement verification, particularly, if they are used for phylogenetic analysis. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Madoqua kirkii, a miniature African antelope, is noted for extensive chromosomal variation that has been categorized in four distinct cytotypes (A-D). In this investigation, we analyzed the A cytotype (2n = 46, FN = 48) using a suite of molecular cytogenetic approaches that entailed (i) whole chromosome and subchromosomal painting by fluorescence in situ hybridization (FISH), (ii) the study of Madoqua centromeric-specific DNA derived from pooled DNA obtained from the centromeric regions of the acrocentric chromosomes, and (iii) DNA from the telomere:centromere junctions of tandemly fused chromosomes. DNA from these sources was used to probe for the persistence of interstitial satellite DNA and residual centromeric sequences in the tandem and centric fusion junctions by PCR and FISH. The analyses show centromeric sequences at two of the six tandem fusion junctions. These data, and those of hybrid specimens (A × B cytotypes) in conjunction with published information permitted an interpretation of the probable sequence of chromosomal rearrangements among the M. kirkii cytotypes. We discuss the findings in the context of chromosomal evolution in these antelopes, and the implications that these hold for ex-situ breeding programs of the species. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The karyotypic evolution in the family Bovidae is based on centric fusions of ancestral acrocentric chromosomes. Here, the frequency and distribution of meiotic recombination was analyzed in pachytene spermatocytes from Bos taurus (2n = 60) and 3 wildebeest species (Connochaetes gnou, C. taurinus taurinus and C. t. albojubatus) (2n = 58) using immunofluorescence and fluorescence in situ hybridization. Significant differences in mean numbers of recombination events per cell were observed between B. taurus and members of the genus Connochaetes (47.2 vs. 43.7, p < 0.001). The number of MLH1 foci was significantly correlated with the length of the autosomal synaptonemal complexes. The average interfocus distance was influenced by interference. The male recombination maps of bovine chromosomes 2 and 25 and of their fused homologues in wildebeests were constructed. A significant reduction of recombination in the fused chromosome BTA25 was observed in wildebeests (p = 0.005). This was probably caused by interference acting across the centromere, which was significantly stronger than the intra-arm interference. This comparative meiotic study showed significant differences among the species from the family Bovidae with the same fundamental number of autosomal arms (FNa = 29) which differ by a single centric fusion. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The karyotype of the red river hog Potamochoerus porcus (2n = 34) differs from that of the domestic pig by the presence of 2 fusion chromosomes homologous to pig chromosomes 13/16 and 15/17. Moreover, chromosomes corresponding to pig chromosomes 13/16 and 1 are both acrocentric. Hybridization with region-specific painting probes confirmed tandem fusion of pig chromosomes 13 and 16, and a pericentric inversion of the pig chromosome 1p equivalent in P. porcus. The chromosome complement of the wart hog Phacochoerus africanus (2n = 34) differs from the pig karyotype in 2 centric fusions, 13/16 and 15/17. Karyotypic relationships among different Suidae species are discussed in the article. Besides fusions 13/16 and 15/17, which are common to several suids, another fusion of pig chromosomes 14 and 18 is suggested to exist in the karyotype of Sus cebifrons. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Chromosomes of fourteen captive-born mountain reedbucks (Redunca fulvorufula) have been investigated. The diploid chromosome number was 2n = 56 (FN = 60). The mountain reedbuck karyotype consists of 26 acrocentric and two biarmed chromosome pairs resulting from two centric fusions involving chromosomes 2 and 25, and 6 and 10, respectively. In some animals, 57 chromosomes were detected. Variation in the diploid number was found to be due to polymorphism for the centric fusion 6;10. Both X and Y chromosomes are large and acrocentric. The entire Y chromosome and the proximal part of the X chromosome consist of heterochromatin. The chromosomes X, 9 and 14 appeared to be of caprine type. Chromosome aberrations have been detected in two of the 14 animals investigated. A de novo formed Robertsonian translocation rob(6;13) was found in one female heterozygous for the fusion 6;10. CBG-banding revealed one block of centromeric heterochromatin in the de novo formed translocation rob(6;13) and also in the evolutionarily fixed centric fusions 6;10 and 2;25. One examined male homozygous for fusion 6;10, had a mosaic 56,XY/57,XYY karyotype, with 11% of analyzed cells containing two Y chromosomes. The findings were confirmed by cross-species fluorescence in situ hybridization (FISH) with bovine (Bos taurus L.) chromosome painting probes. The study demonstrates the relevance of cytogenetic screening in captive animals from zoological gardens. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]