The muskox suffered a loss of genetic diversity at the Pleistocene/Holocene transition

October 05, 2005

The tundra muskox, one of the few large northern mammals to have survived to the present day, saw its genetic diversity decrease greatly at the end of the Pleistocene period, around 10,000 years ago. A study published in the open access journal BMC Evolutionary Biology reveals that the muskox (Ovibus moschatus) was genetically much more diverse before the Pleistocene/Holocene transition, the period that witnessed the extinction of other great mammals such as the mammoth.

Ross MacPhee and Alex Greenwood, from the American Museum of Natural History in New York, USA, collaborated with colleagues from Russia and the Netherlands to sequence samples of muskox ancient mitochondrial DNA (hypervariable region and cytochrome b sequences) and compared the data with DNA sequences from modern muskoxen. The ancient DNA samples dated from the late Pleistocene to the late Holocene and were collected in the Arctic Archipelago of North America, Yukon, and the Arctic periphery of Siberia in northeastern Asia. Modern samples came from northern North America and Greenland - the only regions where muskoxen can be found today.

The authors identified two groups of haplotypes (haploid genotypes, or gene sets associated on single chromosomes) within the analysed sequences. 'Extinct haplotypes' (EHs), or haplotypes which no longer occur in modern muskoxen, were recovered only in northern Asia where the muskox is now extinct. Such haplotypes were found in a number of specimens dated from ~44,000 to ~18,000 years ago.

'Surviving haplotypes' (SHs) include all other known haplotypes, which are closely related, or identical, to modern haplotypes. Some northern Asian fossil specimens, dating from up to ~22,000 years ago, yielded sequences conforming to known SHs. So did the last known Asian muskoxen, which died out on the Taimyr Peninsula of Siberia about 2000 years ago. This evidence shows that SHs and EHs coexisted for at least several thousand years and probably much longer.

In accordance with previous research, their results show that SH samples from both continents show little to no genetic variation. By contrast, EHs in Pleistocene samples were found to diverge by several substitutions from one another as well as from modern muskoxen, for both cytochrome b and the hypervariable region.

The authors write, "Ovibos, one of the few high-latitude megafaunal mammals to have survived into recent times, has clearly done so with reduced genetic variability [...] at what point before the present this variability was lost cannot be satisfactorily established with existing data".
-end-
Article:
Late Quaternary Loss of Genetic Diversity in Muskox (Ovibos)
Ross D. E. MacPhee, Alexei N. Tikhonov, Dick Mol and Alex D. Greenwood
BMC Evolutionary Biology 2005, 5:49 (6 October 2005)

BioMed Central

Related Haplotypes Articles from Brightsurf:

Spring-run and fall-run Chinook salmon aren't as different as they seem
Historically, spring-run and fall-run Chinook salmon have been considered as separate subspecies, races, ecotypes, or even as separate species of fish.

Coronavirus mutations show early safety measures and restrictions limited viral spread
Scientists analyzed genomic information from over 6,000 samples of SARS-CoV-2, the coronavirus behind the COVID-19 pandemic.

Unlocking the secrets of plant genomes in high resolution
Resolving genomes, particularly plant genomes, is a very complex and error-prone task.

DNA metabarcoding detects ecological stress within freshwater species
Metabarcoding allows scientists to extract DNA from the environment, in order to rapidly detect species inhabiting a particular habitat.

Genetic differences between global American Crocodile populations identified in DNA analysis
A genetic analysis of the American crocodile (Crocodylus acutus) has re-established our understanding of its population structure, aiding its conservation.

Patterns in crop data reveal new insight about plants and their environments
A new study unearthed patterns in datasets collected on rice plants across Asia that allowed researchers to develop a matrix to predict the traits of rice plants depending on their genetics and environment.

Individual genetic variation in immune system may affect severity of COVID-19
Genetic variability in the human immune system may affect susceptibility to, and severity of infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the coronavirus disease (COVID-19).

Study reveals an inherited origin of prostate cancer in families
Vanderbilt researchers have identified haplotypes, ancestral fragments of DNA, that are associated with hereditary prostate cancer (HPC) in a first-of-its-kind genomic study made possible by the study of prostate cancer patients with family histories of the disease.

Red panda population genomics confirms two phylogenetic species and different evolutionary histories
A research team led by Prof. WEI Fuwen from the Institute of Zoology of the Chinese Academy of Sciences, used population genomics methods to analyze the genome resequencing data of 65 wild red pandas from seven geographical populations; mitochondrial genomes of 49 red pandas; and Y chromosome single-nucleotide polymorphism (SNP) data from 49 male individuals.

Modern Africans and Europeans may have more Neanderthal ancestry than previously thought
Neanderthal DNA sequences may be more common in modern Africans than previously thought, and different non-African populations have levels of Neanderthal ancestry surprisingly similar to each other, finds a study publishing Jan.

Read More: Haplotypes News and Haplotypes Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.