African, Asian Lion Populations Genetically Diverse, Research Suggests

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[Asiatic_Lions] African, Asian Lion Populations Genetically Diverse,

Research Suggests

 

 

07-11-2008

 

African, Asian Lion Populations Genetically Diverse, Research Suggests

 

GenomeWeb News - NY,USA By a GenomeWeb staff reporter

 

http://www.genomewe b.com/issues/ news/150579- 1.html

 

NEW YORK (GenomeWeb News) – Lion populations contain unexpected genetic

diversity, according to a new study.

 

An

international team of researchers used a combination of mitochondrial

DNA, Y-chromosome, biparental nuclear DNA, and feline immunodeficiency

virus sequence data to characterize lion population genetics and

evolutionary history. Their work, appearing online today in PLoS

Genetics, suggests that existing lion populations fall into at least

eleven genetic groups, challenging the notion that African lions fall

into one large genetic group. That, in turn, provides insights into

potential lion conservation strategies.

 

“We

refute the hypothesis that African lions consist of a single panmictic

population,” senior author Warren Johnson, a staff scientist with the

National Cancer Institute’s Laboratory of Genetic Diversity, and his

colleagues wrote, “highlighting the importance of preserving

populations in decline rather than prioritizing larger-scale

conservation efforts.”

 

In the

past, lion fossils dating back millions of years have been unearthed in

eastern and southern Africa . The animals appear to have spread from

Africa to other parts of the continent and into Eurasia and the

Americas . These days, though, remaining free-ranging lion populations

are found in just a few primary regions, such as sub-Saharan Africa and

India ’s Gir Forest , where researchers estimate that there are fewer

than 50,000 lions remaining.

 

The team

compiled genetic data from 357 lions from Africa and Asia , focusing on

sequences from mitochondrial genes, the SRY-3’ UTR on the Y-chromosome,

two biparental nuclear genes, and 22 microsatellite markers.

 

They

also compared sequences from FIV samples, since the viruses vary

genetically from one lion population to the next. FIV genetics,

meanwhile, added another layer to the picture. The virus is endemic to

eight of the 11 lion populations, absent only in populations in India ,

Namibia , and the Botswana/Kalahari region.

 

Overall,

the team found eleven genetically distinct groups of lions: one each in

Namibia , South Africa ’s Kruger National Park , Tanzania ’s Ngorongoro

Crater , Kenya , Uganda , and Gir , India , two groups in Botswana ,

and three in the Serengeti National Park .

 

In

Botswana , the researchers found one distinct genetic cluster of lions

in northern Botswana and another in southern Botswana and the Kalahari

in South Africa . In the Serengeti region, on the other hand, three

genetic clusters were found in an overlapping region.

 

Along

with their assessment of existing lion populations, the researchers

were also able to make inferences about past migration events. Their

analysis of lion and FIV genetic data indicates that East African lions

are genetically older than other lions, supporting the notion that

lions were present in East Africa before spreading to other regions

sampled.

 

The

genetic patterns in each region also revealed information about some

past lion migration events. For instance, the team concluded that lion

populations living today originated in East and Southern Africa during

the Pleistocene period, between 169,000 and 324,000 years ago.

 

From

there, the researchers inferred that there were two major migration

events. The first migration, from southern and eastern Africa to

Central and North Africa and Asia , appears to have occurred during the

Late Pleistocene about 100,000 years ago. More recently, during the

Pleistocene/ Holocene transition (some 7,000 to 14,000 years ago),

lions appear to have migrated from Southern Africa towards East Africa

, inter-breeding with other lion populations on the way.

 

“[W]e

found substantial population subdivision, reduced gene flow, and large

differences in FIVPle sequence and sero-prevalence among lion

populations, as well as evidence of historic secondary contact between

populations,” the authors wrote.

 

Beyond

providing information about past lion populations, the team noted, the

findings could have implications for those designing lion conservation

schemes. Because there appears to be a substantial amount of genetic

diversity between different lion populations, genetic clusters could be

lost should individual lion populations disappear.

 

“[E]mploying

a bottom-up perspective that prioritizes populations, rather than

large-scale units (e.g. all African lions), might preserve and maintain

lion diversity and evolutionary processes most efficiently,” the

authors wrote.

 

Also see:

 

ASIATIC LION GROUP

http://pets.Asiatic_Lions/