Lactase Persistence in Central Asia: Phenotype, Genotype, and Evolution

@inproceedings{Heyer2011LactasePI,
  title={Lactase Persistence in Central Asia: Phenotype, Genotype, and Evolution},
  author={Evelyne Heyer and Lionel Brazier and Laure S{\'e}gurel and Tatiana Hegay and Fr{\'e}d{\'e}ric Austerlitz and Llu{\'i}s Quintana-Murci and Myriam Georges and Patrick Pasquet and Michel Veuille},
  booktitle={Human biology},
  year={2011}
}
Abstract The aim of the present study is to document the evolution of the lactase persistence trait in Central Asia, a geographical area that is thought to have been a region of long-term pastoralism. [] Key Result Our results show a remarkable genetic-phenotypic correlation, with the causal polymorphism being the same than in Europe (-13.910C>T, rs4988235).
Why and when was lactase persistence selected for? Insights from Central Asian herders and ancient DNA
TLDR
It is proposed that Central Asian herders have adapted to milk consumption culturally, by fermentation, and/or by colonic adaptation, rather than genetically, which coincides well with the migration of steppe populations across and outside of Europe.
Lactase Persistence Variants in Arabia and in the African Arabs
TLDR
It is shown here that, in Arabia, -13,915*G frequency conforms to a partial clinal pattern and that this specific mutation has likely been spread from Arabia to Africa only recently from the sixth century AD onward by nomadic Arabs (Bedouins) looking for new pastures.
The evolutionary genetics of lactase persistence in seven ethnic groups across the Iranian plateau
TLDR
Soft selective sweep rather than hard selective sweep played a substantial role in the evolution of LP in Iranian populations, indicating the distribution ofLP in seven ethnic groups across the Iranian plateau.
On the Evolution of Lactase Persistence in Humans.
Lactase persistence-the ability of adults to digest the lactose in milk-varies widely in frequency across human populations. This trait represents an adaptation to the domestication of dairying
Sahelian pastoralism from the perspective of variants associated with lactase persistence.
TLDR
This is the first study showing that the "Eurasian" LP allele -13910*T is widespread both in northern Europe and in theSahel; however, it is limited to pastoralists in the Sahel.
A study of the molecular variants associated with lactase persistence in different Ecuadorian ethnic groups
TLDR
The aim of the study was to identify the molecular basis of LP in these admixed populations for the first time and determine the association between the T‐13910 marker and the European ancestry proportion of each ethnic group.
Polymorphism of the LCT gene regulatory region in Turkic-speaking populations of the Altay-Sayan region ( southern Siberia )
Retention of lactase activity in adulthood (lactase persistence) is one of the most important adaptive traits for human populations that consume fresh milk from domestic animals. At a
Evolution of Lactase Persistence: Turbo-Charging Adaptation in Growth Under the Selective Pressure of Maternal Mortality?
TLDR
It is proposed that the combination of consuming milk and lactase persistence could have reduced maternal mortality by promoting growth of the pelvis after weaning, while high calcium intake would reduce risk of pelvic deformities.
Adult-Type Hypolactasia in an Ethnic Uzbek Population
TLDR
The frequency of lactase deficiency in the selected adult Uzbek population was found to be high and high prevalence of hypolactasia is not associated with abstinence from milk intake.
Lactase persistence may have an independent origin in Tibetan populations from Tibet, China
TLDR
Three novel SNPs (−13838G/A, −13906T/A and −13908C/T) in Tibetans are identified and might be functional as it is located in the binding motif for HNF4α that acts as a transcription factor for intestinal gene expression.
...
...

References

SHOWING 1-10 OF 51 REFERENCES
Convergent adaptation of human lactase persistence in Africa and Europe
TLDR
A genotype-phenotype association study in Tanzanians, Kenyans and Sudanese and identified three SNPs that are associated with lactase persistence and that have derived alleles that significantly enhance transcription from the LCT promoter in vitro, providing a marked example of convergent evolution due to strong selective pressure resulting from shared cultural traits.
The Origins of Lactase Persistence in Europe
TLDR
It is inferred that the −13,910*T allele first underwent selection among dairying farmers around 7,500 years ago in a region between the central Balkans and central Europe, possibly in association with the dissemination of the Neolithic Linearbandkeramik culture over Central Europe.
A worldwide correlation of lactase persistence phenotype and genotypes
TLDR
Lactase persistence genotype data is currently insufficient to explain lactase persistence phenotype frequency in much of western and southern Africa, southeastern Europe, the Middle East and parts of central and southern Asia, and it is suggested that further studies of genetic variation in these regions should reveal additional nucleotide variants that are associated with lactases persistence.
A novel polymorphism associated with lactose tolerance in Africa: multiple causes for lactase persistence?
TLDR
A cohort study of lactose digester and non-digester Sudanese volunteers shows there is no association of -13910*T or the A haplotype with lactase persistence, and reveals the complexity of this phenotypic polymorphism and highlights the limitations of C-13910T as a diagnostic test for lact enzyme persistence status, at least for people with non-European ancestry.
Microsatellite variation and evolution of human lactase persistence
TLDR
This study shows that a limited number of microsatellite loci may provide sufficient resolution to reconstruct key aspects of the evolutionary history of lactase persistence, providing an alternative to approaches based on large numbers of SNPs.
Impact of Selection and Demography on the Diffusion of Lactase Persistence
TLDR
The results show that gene-culture coevolution is a likely hypothesis in Africa as high LCT*P frequencies are preferentially found in pastoral populations and selection pressure on lactase persistence has been very high in the North-western part of the continent.
In the heartland of Eurasia: the multilocus genetic landscape of Central Asian populations
TLDR
The results suggest that the recurrent expansions of eastern nomadic groups did not result in the complete replacement of local populations, but rather into partial admixture, which reveals that Central Asian diversity is mainly shaped by linguistic affiliation.
The lactase persistence/non-persistence polymorphism is controlled by a cis-acting element.
TLDR
This work exploited known DNA 'marker' polymorphisms within the exons of the lactase gene to examine the expression of the individual lactase mRNA transcripts from persistent and non-persistent individuals in order to determine whether the regulation is in cis or trans.
Beja and Nilotes: nomadic pastoralist groups in the Sudan with opposite distributions of the adult lactase phenotypes.
TLDR
The Beja are the first nomadic desert population in North Africa in whom a high prevalence of lactase persistence has been demonstrated on a numerically sufficient sample, and fits into a converging gradient of lactose gene frequencies along the Nile Valley.
...
...