Comparative chromosome painting of pronghorn (Antilocapra americana) and saola (Pseudoryx nghetinhensis) karyotypes with human and dromedary camel probes
- Equal contributors
1 Institute of Molecular and Cellular Biology, SB RAS and Novosibirsk State University, Novosibirsk, Russia
2 Genetics and Genome Biology Program, Hospital for Sick Children, Toronto, ON, Canada
3 Laboratory of Embryo Technology, Institute of Biotechnology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam
4 Institute of Animal Sciences, Swiss Federal Institute of Technology, (ETH), 8092 Zurich, Switzerland
5 BSP-CCR Genetics Core, Center for Cancer Research, 21702 Frederick, MD, USA
6 Laboratory of Animal Sciences Program, Leidos Biomedical Research, Inc., Frederick National Laboratory, 21702 Frederick, MD, USA
7 Laboratory of Genomic Diversity, National Cancer Institute, 21702 Frederick, MD, USA
BMC Genetics 2014, 15:68 doi:10.1186/1471-2156-15-68Published: 12 June 2014
Pronghorn (Antilocapridae, 2n = 58) and saola (Bovidae, 2n = 50) are members of Pecora, a highly diversified group of even-toed hoofed mammals. Karyotypes of these species were not involved in chromosome painting studies despite their intriguing phylogenetic positions in Pecora.
To trace the chromosome evolution during very fast radiation of main families from the common Pecoran ancestor, high-resolution comparative chromosome maps of pronghorn and saola with human (HSA) and dromedary camel (CDR) painting probes were established. The human and dromedary camel painting probes revealed 50 and 64 conserved segments respectively in the pronghorn genome, while 51 and 63 conserved segments respectively in the saola genome. Integrative analysis with published comparative maps showed that inversions in chromosomes homologous to CDR19/35/19 (HSA 10/20/10), CDR12/34/12 (HSA12/22/12/22), CDR10/33/10 (HSA 11) are present in representatives of all five living Pecoran families. The pronghorn karyotype could have formed from a putative 2n = 58 Pecoran ancestral karyotype by one fission and one fusion and that the saola karyotype differs from the presumed 2n = 60 bovid ancestral karyotype (2n = 60) by five fusions.
The establishment of high-resolution comparative maps for pronghorn and saola has shed some new insights into the putative ancestral karyotype, chromosomal evolution and phylogenic relationships in Pecora. No cytogenetic signature rearrangements were found that could unite the Antilocapridae with Giraffidae or with any other Pecoran families. Our data on the saola support a separate position of Pseudorigyna subtribe rather than its affinity to either Bovina or Bubalina, but the saola phylogenetic position within Bovidae remains unresolved.