Most cited article - PubMed ID 23896647
Molecular cytogenetic insights to the phylogenetic affinities of the giraffe (Giraffa camelopardalis) and pronghorn (Antilocapra americana)
The family Cervidae groups a range of species with an increasing economic significance. Their karyotypes share 35 evolutionary conserved chromosomal segments with cattle (Bos taurus). Recent publication of the annotated red deer (Cervus elaphus) whole genome assembly (CerEla1.0) has provided a basis for advanced genetic studies. In this study, we compared the red deer CerEla1.0 and bovine ARS-UCD1.2 genome assembly and used fluorescence in situ hybridization with bovine BAC probes to verify the homology between bovine and deer chromosomes, determined the centromere-telomere orientation of the CerEla1.0 C-scaffolds and specified positions of the cervid evolutionary chromosome breakpoints. In addition, we revealed several incongruences between the current deer and bovine genome assemblies that were shown to be caused by errors in the CerEla1.0 assembly. Finally, we verified the centromere-to-centromere orientation of evolutionarily fused chromosomes in seven additional deer species, giving a support to previous studies on their chromosome evolution.
- Keywords
- BAC mapping, FISH, chromosome fission, chromosome fusion, comparative cytogenetics, genome assembly, karyotype,
- Publication type
- Journal Article MeSH
The Cervidae family comprises more than fifty species divided into three subfamilies: Capreolinae, Cervinae and Hydropotinae. A characteristic attribute for the species included in this family is the great karyotype diversity, with the chromosomal numbers ranging from 2n = 6 observed in female Muntiacus muntjak vaginalis to 2n = 70 found in Mazama gouazoubira as a result of numerous Robertsonian and tandem fusions. This work reports chromosomal homologies between cattle (Bos taurus, 2n = 60) and nine cervid species using a combination of whole chromosome and region-specific paints and BAC clones derived from cattle. We show that despite the great diversity of karyotypes in the studied species, the number of conserved chromosomal segments detected by 29 cattle whole chromosome painting probes was 35 for all Cervidae samples. The detailed analysis of the X chromosomes revealed two different morphological types within Cervidae. The first one, present in the Capreolinae is a sub/metacentric X with the structure more similar to the bovine X. The second type found in Cervini and Muntiacini is an acrocentric X which shows rearrangements in the proximal part that have not yet been identified within Ruminantia. Moreover, we characterised four repetitive sequences organized in heterochromatic blocks on sex chromosomes of the reindeer (Rangifer tarandus). We show that these repeats gave no hybridization signals to the chromosomes of the closely related moose (Alces alces) and are therefore specific to the reindeer.
The evolutionary clade comprising Nanger, Eudorcas, Gazella, and Antilope, defined by an X;BTA5 translocation, is noteworthy for the many autosomal Robertsonian fusions that have driven the chromosome number variation from 2n = 30 observed in Antilope cervicapra, to the 2n = 58 in present Eudorcas thomsoni and Eudorcas rufifrons. This work reports the phylogenetic relationships within the Antilopini using comprehensive cytogenetic data from A. cervicapra, Gazella leptoceros, Nanger dama ruficollis, and E. thomsoni together with corrected karyotypic data from an additional nine species previously reported in the literature. Fluorescence in situ hybridization using BAC and microdissected cattle painting probes, in conjunction with differential staining techniques, provide the following: (i) a detailed analysis of the E. thomsoni chromosomes, (ii) the identification and fine-scale analysis the BTA3 orthologue in species of Antilopini, and (iii) the location of the pseudoautosomal regions on sex chromosomes of the four species. Our phylogenetic analysis of the chromosomal data supports monophyly of Nanger and Eudorcas and suggests an affiliation between A. cervicapra and some of the Gazella species. This renders Gazella paraphyletic and emphasizes a closer relationship between Antilope and Gazella than what has previously been considered.
- MeSH
- Antelopes classification genetics MeSH
- Biological Evolution MeSH
- Centromere genetics MeSH
- Phylogeny MeSH
- Gene Rearrangement MeSH
- In Situ Hybridization, Fluorescence MeSH
- Karyotyping MeSH
- Cloning, Molecular MeSH
- Chromosome Painting MeSH
- Evolution, Molecular MeSH
- Sex Chromosomes genetics MeSH
- DNA, Satellite genetics MeSH
- Chromosomes, Mammalian genetics MeSH
- Cattle MeSH
- Translocation, Genetic MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Cattle MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA, Satellite MeSH
