Lactase persistence in Tunisia as a result of admixture with other Mediterranean populations
Abstract Background The ability to digest lactose after weaning, namely, lactase persistence (LP), is encoded by polymorphisms in the MCM6 gene and varies widely in frequency among different human populations. Although, evolution of LP-related genetic variants was investigated in many groups of Sub-...
| Main Authors: | , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2017-08-01
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| Series: | Genes & Nutrition |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s12263-017-0573-3 |
| _version_ | 1828751617882587136 |
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| author | Yosra Ben Halima Rym Kefi Marco Sazzini Cristina Giuliani Sara De Fanti Chokri Nouali Majdi Nagara Giacomo Mengozzi Sahar Elouej Abdelmajid Abid Henda Jamoussi Lotfi Chouchane Giovanni Romeo Sonia Abdelhak Donata Luiselli |
| author_facet | Yosra Ben Halima Rym Kefi Marco Sazzini Cristina Giuliani Sara De Fanti Chokri Nouali Majdi Nagara Giacomo Mengozzi Sahar Elouej Abdelmajid Abid Henda Jamoussi Lotfi Chouchane Giovanni Romeo Sonia Abdelhak Donata Luiselli |
| author_sort | Yosra Ben Halima |
| collection | DOAJ |
| description | Abstract Background The ability to digest lactose after weaning, namely, lactase persistence (LP), is encoded by polymorphisms in the MCM6 gene and varies widely in frequency among different human populations. Although, evolution of LP-related genetic variants was investigated in many groups of Sub-Saharan African, Middle Eastern, and European ancestry, only few studies have focused on populations from North Africa and no data are especially available from the Tunisian one. For this reason, there is an urgent need to investigate the frequency patterns at these loci in Tunisia since this adaptive trait is implicated in health. Methods Forty SNPs covering the LCT/MCM6 genes and including the two functional variants − 13,910 C > T and − 22,018 G > A were genotyped in 117 Tunisian individuals using the Sequenom Mass Array technology. The observed nucleotide and haplotype patterns of variation were then compared with those of several African, European, and Mediterranean human groups for which comparable data were publicly available. Admixture analysis on a 5 Mb genomic region surrounding the LCT/MCM6 loci was also performed by extracting genotypes from a previously generated genome-wide dataset in order to deepen the reconstruction of the evolutionary history of these loci. Results We found that lactase non-persistence (LNP)-related alleles and haplotypes were predominantly present in the examined population. A clear differentiation between Tunisian, African, and North European/North Italian samples was found, while the Tunisian population showed more genetic affinity to Central and South Italian groups. Conclusions Our study provided a first report of LP-associated alleles and haplotypes in the Tunisian population. We highlighted a gradient followed by LP diffusion from Europe to North Africa. Based on the rich historic background of Tunisia, we suggest that this adaptive trait was introduced in that geographic region by a relatively recent gene flow. |
| first_indexed | 2024-12-10T20:56:17Z |
| format | Article |
| id | doaj.art-b541615b7f054027885f5ea339ee95ec |
| institution | Directory Open Access Journal |
| issn | 1555-8932 1865-3499 |
| language | English |
| last_indexed | 2024-12-10T20:56:17Z |
| publishDate | 2017-08-01 |
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| series | Genes & Nutrition |
| spelling | doaj.art-b541615b7f054027885f5ea339ee95ec2022-12-22T01:33:57ZengBMCGenes & Nutrition1555-89321865-34992017-08-0112111010.1186/s12263-017-0573-3Lactase persistence in Tunisia as a result of admixture with other Mediterranean populationsYosra Ben Halima0Rym Kefi1Marco Sazzini2Cristina Giuliani3Sara De Fanti4Chokri Nouali5Majdi Nagara6Giacomo Mengozzi7Sahar Elouej8Abdelmajid Abid9Henda Jamoussi10Lotfi Chouchane11Giovanni Romeo12Sonia Abdelhak13Donata Luiselli14Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de TunisLaboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de TunisLaboratory of Molecular Anthropology and Centre for Genome Biology, Department of Biological, Geological and Environmental Sciences (BiGeA), University of BolognaLaboratory of Molecular Anthropology and Centre for Genome Biology, Department of Biological, Geological and Environmental Sciences (BiGeA), University of BolognaLaboratory of Molecular Anthropology and Centre for Genome Biology, Department of Biological, Geological and Environmental Sciences (BiGeA), University of BolognaLaboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de TunisLaboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de TunisLaboratory of Molecular Anthropology and Centre for Genome Biology, Department of Biological, Geological and Environmental Sciences (BiGeA), University of BolognaLaboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de TunisLaboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de TunisLaboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de TunisLaboratory of Genetic Medicine and Immunology, Weill Cornell Medical College in Qatar, Qatar FoundationMedical Genetics Unit, Department of Medical and Surgical Sciences, Polyclinic S. Orsola-Malpighi, University of BolognaLaboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur de TunisLaboratory of Molecular Anthropology and Centre for Genome Biology, Department of Biological, Geological and Environmental Sciences (BiGeA), University of BolognaAbstract Background The ability to digest lactose after weaning, namely, lactase persistence (LP), is encoded by polymorphisms in the MCM6 gene and varies widely in frequency among different human populations. Although, evolution of LP-related genetic variants was investigated in many groups of Sub-Saharan African, Middle Eastern, and European ancestry, only few studies have focused on populations from North Africa and no data are especially available from the Tunisian one. For this reason, there is an urgent need to investigate the frequency patterns at these loci in Tunisia since this adaptive trait is implicated in health. Methods Forty SNPs covering the LCT/MCM6 genes and including the two functional variants − 13,910 C > T and − 22,018 G > A were genotyped in 117 Tunisian individuals using the Sequenom Mass Array technology. The observed nucleotide and haplotype patterns of variation were then compared with those of several African, European, and Mediterranean human groups for which comparable data were publicly available. Admixture analysis on a 5 Mb genomic region surrounding the LCT/MCM6 loci was also performed by extracting genotypes from a previously generated genome-wide dataset in order to deepen the reconstruction of the evolutionary history of these loci. Results We found that lactase non-persistence (LNP)-related alleles and haplotypes were predominantly present in the examined population. A clear differentiation between Tunisian, African, and North European/North Italian samples was found, while the Tunisian population showed more genetic affinity to Central and South Italian groups. Conclusions Our study provided a first report of LP-associated alleles and haplotypes in the Tunisian population. We highlighted a gradient followed by LP diffusion from Europe to North Africa. Based on the rich historic background of Tunisia, we suggest that this adaptive trait was introduced in that geographic region by a relatively recent gene flow.http://link.springer.com/article/10.1186/s12263-017-0573-3Lactase persistenceNorth AfricaAdmixtureTunisiaNatural selectionLCT |
| spellingShingle | Yosra Ben Halima Rym Kefi Marco Sazzini Cristina Giuliani Sara De Fanti Chokri Nouali Majdi Nagara Giacomo Mengozzi Sahar Elouej Abdelmajid Abid Henda Jamoussi Lotfi Chouchane Giovanni Romeo Sonia Abdelhak Donata Luiselli Lactase persistence in Tunisia as a result of admixture with other Mediterranean populations Genes & Nutrition Lactase persistence North Africa Admixture Tunisia Natural selection LCT |
| title | Lactase persistence in Tunisia as a result of admixture with other Mediterranean populations |
| title_full | Lactase persistence in Tunisia as a result of admixture with other Mediterranean populations |
| title_fullStr | Lactase persistence in Tunisia as a result of admixture with other Mediterranean populations |
| title_full_unstemmed | Lactase persistence in Tunisia as a result of admixture with other Mediterranean populations |
| title_short | Lactase persistence in Tunisia as a result of admixture with other Mediterranean populations |
| title_sort | lactase persistence in tunisia as a result of admixture with other mediterranean populations |
| topic | Lactase persistence North Africa Admixture Tunisia Natural selection LCT |
| url | http://link.springer.com/article/10.1186/s12263-017-0573-3 |
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