TY - JOUR
T1 - Independent introduction of two lactase-persistence alleles into human populations reflects different history of adaptation to milk culture.
AU - Enattah, Nabil Sabri
AU - Jensen, Tine G K
AU - Boyd, Mette
AU - Lewinski, Rikke
AU - Kuokkanen, Mikko
AU - Rasinpera, Heli
AU - El-Shanti, Hatem
AU - Seo, Jeong Kee
AU - Alifrangis, Michael
AU - Khalil, Insaf F
AU - Natah, Abdrazak
AU - Ali, Ahmed
AU - Natah, Sirajedin
AU - Comas, David
AU - Mehdi, S Qasim
AU - Groop, Leif
AU - Vestergaard, Else Marie
AU - Imtiaz, Faiqa
AU - Rashed, Mohamed S
AU - Meyer, Brian
AU - Troelsen, Jesper
AU - Peltonen, Leena
N1 - Keywords: Alleles; Animals; Camels; Culture; Evolution, Molecular; Haplotypes; Humans; Lactase; Lactose Tolerance Test; Middle East; Milk; Polymorphism, Single Nucleotide; Saudi Arabia
PY - 2008
Y1 - 2008
N2 - The T(-13910) variant located in the enhancer element of the lactase (LCT) gene correlates perfectly with lactase persistence (LP) in Eurasian populations whereas the variant is almost nonexistent among Sub-Saharan African populations, showing high prevalence of LP. Here, we report identification of two new mutations among Saudis, also known for the high prevalence of LP. We confirmed the absence of the European T(-13910) and established two new mutations found as a compound allele: T/G(-13915) within the -13910 enhancer region and a synonymous SNP in the exon 17 of the MCM6 gene T/C(-3712), -3712 bp from the LCT gene. The compound allele is driven to a high prevalence among Middle East population(s). Our functional analyses in vitro showed that both SNPs of the compound allele, located 10 kb apart, are required for the enhancer effect, most probably mediated through the binding of the hepatic nuclear factor 1 alpha (HNF1 alpha). High selection coefficient (s) approximately 0.04 for LP phenotype was found for both T(-13910) and the compound allele. The European T(-13910) and the earlier identified East African G(-13907) LP allele share the same ancestral background and most likely the same history, probably related to the same cattle domestication event. In contrast, the compound Arab allele shows a different, highly divergent ancestral haplotype, suggesting that these two major global LP alleles have arisen independently, the latter perhaps in response to camel milk consumption. These results support the convergent evolution of the LP in diverse populations, most probably reflecting different histories of adaptation to milk culture.
AB - The T(-13910) variant located in the enhancer element of the lactase (LCT) gene correlates perfectly with lactase persistence (LP) in Eurasian populations whereas the variant is almost nonexistent among Sub-Saharan African populations, showing high prevalence of LP. Here, we report identification of two new mutations among Saudis, also known for the high prevalence of LP. We confirmed the absence of the European T(-13910) and established two new mutations found as a compound allele: T/G(-13915) within the -13910 enhancer region and a synonymous SNP in the exon 17 of the MCM6 gene T/C(-3712), -3712 bp from the LCT gene. The compound allele is driven to a high prevalence among Middle East population(s). Our functional analyses in vitro showed that both SNPs of the compound allele, located 10 kb apart, are required for the enhancer effect, most probably mediated through the binding of the hepatic nuclear factor 1 alpha (HNF1 alpha). High selection coefficient (s) approximately 0.04 for LP phenotype was found for both T(-13910) and the compound allele. The European T(-13910) and the earlier identified East African G(-13907) LP allele share the same ancestral background and most likely the same history, probably related to the same cattle domestication event. In contrast, the compound Arab allele shows a different, highly divergent ancestral haplotype, suggesting that these two major global LP alleles have arisen independently, the latter perhaps in response to camel milk consumption. These results support the convergent evolution of the LP in diverse populations, most probably reflecting different histories of adaptation to milk culture.
U2 - 10.1016/j.ajhg.2007.09.012
DO - 10.1016/j.ajhg.2007.09.012
M3 - Journal article
C2 - 18179885
SN - 0002-9297
VL - 82
SP - 57
EP - 72
JO - American Journal of Human Genetics
JF - American Journal of Human Genetics
IS - 1
ER -