Cross-species chromosome painting among camel, cattle, pig and human: further insights into the putative Cetartiodactyla ancestral karyotype

Abstract

The great karyotypic differences between camel, cattle and pig, three important domestic animals, have been a challenge for comparative cytogenetic studies based on conventional cytogenetic approaches. To construct a genome-wide comparative chromosome map among these artiodactyls, we made a set of chromosome painting probes from the dromedary camel (Camelus dromedarius) by flow sorting and degenerate oligonucleotide primed-PCR. The painting probes were first used to characterize the karyotypes of the dromedary camel (C. dromedarius), the Bactrian camel (C. bactrianus), the guanaco (Lama guanicoe), the alpaca (L. pacos) and dromedary x guanaco hybrid karyotypes (all with 2n = 74). These FISH experiments enabled the establishment of a high-resolution GTG-banded karyotype, together with chromosome nomenclature and idiogram for C. dromedarius, and revealed that these camelid species have almost identical karyotypes, with only slight variations in the amount and distribution patterns of heterochromatin. Further cross-species chromosome painting between camel, cattle, pig and human with painting probes from the camel and human led to the establishment of genome-wide comparative maps. Between human and camel, pig and camel, and cattle and camel 47, 53 and 53 autosomal conserved segments were detected, respectively. Integrated analysis with previously published comparative maps of human/pig/cattle enabled us to propose a Cetartiodactyla ancestral karyotype and to discuss the early karyotype evolution of Cetartiodactyla. Furthermore, these maps will facilitate the positional cloning of genes by aiding the cross-species transfer of mapping information.

Chromosome Evolution in Domestic Bovids as Revealed by Chromosome Banding and FISH-Mapping Techniques

“…1 ) and 'Bovinae' chromosomes 9 and 14 are present also in other families of advanced pecorans [Gallagher et al, 1994], it appears reasonable that the subfamily Bovinae is ancestral to all remaining bovid subfamilies. This hypothesis also agrees with the ancestral Cetartiodactyla karyotype (CAK) proposed by Balmus et al [2007] in which CAK6 and CAK15 are equivalent to BTA9 and BTA14, respectively, and homologous with HSA6q and HSA8q, respectively ( fig. 1 ).…”

“…According to Balmus et al [2007], the ancestral Cetartiodactyla karyotype (CAK) had 2n = 52. Transition from CAK to the ancestral pecoran karyotype (2n = 58) occurred by 9 fissions and 5 fusions.…”

Restriction of Porcine Endogenous Retrovirus by Porcine APOBEC3 Cytidine Deaminases

“…3B, lane 2). Thus, it is likely that the distantly related camel (3,70) carries an A3Z3 gene that has sequence homology to porcine A3Z3. No signal was found when genomic camel DNA was restricted with the enzyme BglII.…”

Reconstruction of the Putative Cervidae Ancestral Karyotype by Chromosome Painting of Siberian Roe Deer <i>(Capreolus pygargus)</i> with Dromedary Probes

“…In this study, we establish the comparative chromosome map of the Siberian roe deer and the dromedary by cross-species chromosome painting with dromedary chromosomespecific painting probes. This map has been integrated with the previously established dromedary-cattle homology map [Balmus et al, 2007] and supplemented with data on a comparison of the G-banding of roe deer and cattle karyotypes. Our results shed light into the karyotypic relationships of the 3 artiodactyl species and confirm the proposal on the Cervidae ancestral state of the roe deer karyotype.…”