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Isolation and prominent aboriginal maternal legacy in the present-day population of La Gomera (Canary Islands).

Fregel R, Cabrera VM, Larruga JM, Hernández JC, Gámez A, Pestano JJ, Arnay M, González AM - Eur. J. Hum. Genet. (2014)

Bottom Line: This value is even greater than that observed in the extant population (44%), which in turn is the highest of all the seven Canary Islands.In contrast to previous results obtained for the aboriginal populations of Tenerife and La Palma, haplogroups related to secondary waves of migration were not detected in La Gomera aborigines, indicating that isolation also had an important role in shaping the current population.The rugged relief of La Gomera divided into several distinct valleys probably promoted subsequent aboriginal intra-insular differentiation that has continued after the European colonization, as seen in the present-day population structure observed on the island.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Genética, Facultad de Biología, Universidad de La Laguna, La Laguna, Tenerife, Spain.

ABSTRACT
The present-day population structure of La Gomera is outstanding in its high aboriginal heritage, the greatest in the Canary Islands. This was earlier confirmed by both mitochondrial DNA and autosomal analyses, although genetic drift due to the fifteenth century European colonization could not be excluded as the main factor responsible. The present mtDNA study of aboriginal remains and extant samples from the six municipal districts of the island indeed demonstrates that the pre-Hispanic colonization of La Gomera by North African people involved a strong founder event, shown by the high frequency of the indigenous Canarian U6b1a lineage in the aboriginal samples (65%). This value is even greater than that observed in the extant population (44%), which in turn is the highest of all the seven Canary Islands. In contrast to previous results obtained for the aboriginal populations of Tenerife and La Palma, haplogroups related to secondary waves of migration were not detected in La Gomera aborigines, indicating that isolation also had an important role in shaping the current population. The rugged relief of La Gomera divided into several distinct valleys probably promoted subsequent aboriginal intra-insular differentiation that has continued after the European colonization, as seen in the present-day population structure observed on the island.

No MeSH data available.


Related in: MedlinePlus

(a) PCA results based on haplogroup frequencies. (b) MDS plot based on Dest distance values. Population codes are as in Table 2. Black and gray icons correspond to ancient and present-day populations, respectively. Circles correspond to Gomeran populations, while squares indicate other Canary Islands samples. Dark and light gray ovals indicate Gomeran and non-Gomeran clusters.
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fig2: (a) PCA results based on haplogroup frequencies. (b) MDS plot based on Dest distance values. Population codes are as in Table 2. Black and gray icons correspond to ancient and present-day populations, respectively. Circles correspond to Gomeran populations, while squares indicate other Canary Islands samples. Dark and light gray ovals indicate Gomeran and non-Gomeran clusters.

Mentions: The subdivision of the total Gomeran population into municipalities allows refined comparisons with other islands. Tenerife is the population with the lowest genetic distance from La Gomera, the municipalities Agulo, Hermigua and Valle Gran Rey being the closest (Supplementary Table S4). This result is congruent with the geographical proximity of La Gomera to Tenerife (Figure 1). When all the islands are taken into account, the first component of PCA analysis (accounting for 17.2% of the variability) shows that the Gomeran municipalities and all the indigenous population are clustered to the left, whereas the other Canary Islands samples, including the eighteenth century population of Tenerife, are clustered to the right (Figure 2a). Congruently, San Sebastián, the main port and capital of La Gomera and therefore the most affected by external gene flow, is the closest to the right cluster. The main haplogroups responsible for the separation of the two clusters are the European U5b and H to the right and the Canarian autochthonous U6b1a to the left. It is clear that the aboriginal samples of Tenerife and La Palma are situated in the left cluster due to the strong indigenous component of the extant and prehistoric samples from La Gomera. The second component (12.8%) further separates San Sebastián and, to a lesser degree, Gran Canaria and Tenerife from the other populations, through their comparatively higher frequency of U5b2, L2a and K1b1a lineages. The MDS plot based on Dest distance values (Figure 2b) indicates that all the modern municipalities of La Gomera and the northern aboriginal samples are similar to each other and different from the cluster conformed by the rest of the archipelago, including the aboriginal samples from La Palma and Tenerife. In this case, the southern aboriginal sample from La Gomera behaves as an outlier of the Gomeran cluster, probably due to its higher frequency of U6b1a (~71%).


Isolation and prominent aboriginal maternal legacy in the present-day population of La Gomera (Canary Islands).

Fregel R, Cabrera VM, Larruga JM, Hernández JC, Gámez A, Pestano JJ, Arnay M, González AM - Eur. J. Hum. Genet. (2014)

(a) PCA results based on haplogroup frequencies. (b) MDS plot based on Dest distance values. Population codes are as in Table 2. Black and gray icons correspond to ancient and present-day populations, respectively. Circles correspond to Gomeran populations, while squares indicate other Canary Islands samples. Dark and light gray ovals indicate Gomeran and non-Gomeran clusters.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4538205&req=5

fig2: (a) PCA results based on haplogroup frequencies. (b) MDS plot based on Dest distance values. Population codes are as in Table 2. Black and gray icons correspond to ancient and present-day populations, respectively. Circles correspond to Gomeran populations, while squares indicate other Canary Islands samples. Dark and light gray ovals indicate Gomeran and non-Gomeran clusters.
Mentions: The subdivision of the total Gomeran population into municipalities allows refined comparisons with other islands. Tenerife is the population with the lowest genetic distance from La Gomera, the municipalities Agulo, Hermigua and Valle Gran Rey being the closest (Supplementary Table S4). This result is congruent with the geographical proximity of La Gomera to Tenerife (Figure 1). When all the islands are taken into account, the first component of PCA analysis (accounting for 17.2% of the variability) shows that the Gomeran municipalities and all the indigenous population are clustered to the left, whereas the other Canary Islands samples, including the eighteenth century population of Tenerife, are clustered to the right (Figure 2a). Congruently, San Sebastián, the main port and capital of La Gomera and therefore the most affected by external gene flow, is the closest to the right cluster. The main haplogroups responsible for the separation of the two clusters are the European U5b and H to the right and the Canarian autochthonous U6b1a to the left. It is clear that the aboriginal samples of Tenerife and La Palma are situated in the left cluster due to the strong indigenous component of the extant and prehistoric samples from La Gomera. The second component (12.8%) further separates San Sebastián and, to a lesser degree, Gran Canaria and Tenerife from the other populations, through their comparatively higher frequency of U5b2, L2a and K1b1a lineages. The MDS plot based on Dest distance values (Figure 2b) indicates that all the modern municipalities of La Gomera and the northern aboriginal samples are similar to each other and different from the cluster conformed by the rest of the archipelago, including the aboriginal samples from La Palma and Tenerife. In this case, the southern aboriginal sample from La Gomera behaves as an outlier of the Gomeran cluster, probably due to its higher frequency of U6b1a (~71%).

Bottom Line: This value is even greater than that observed in the extant population (44%), which in turn is the highest of all the seven Canary Islands.In contrast to previous results obtained for the aboriginal populations of Tenerife and La Palma, haplogroups related to secondary waves of migration were not detected in La Gomera aborigines, indicating that isolation also had an important role in shaping the current population.The rugged relief of La Gomera divided into several distinct valleys probably promoted subsequent aboriginal intra-insular differentiation that has continued after the European colonization, as seen in the present-day population structure observed on the island.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Genética, Facultad de Biología, Universidad de La Laguna, La Laguna, Tenerife, Spain.

ABSTRACT
The present-day population structure of La Gomera is outstanding in its high aboriginal heritage, the greatest in the Canary Islands. This was earlier confirmed by both mitochondrial DNA and autosomal analyses, although genetic drift due to the fifteenth century European colonization could not be excluded as the main factor responsible. The present mtDNA study of aboriginal remains and extant samples from the six municipal districts of the island indeed demonstrates that the pre-Hispanic colonization of La Gomera by North African people involved a strong founder event, shown by the high frequency of the indigenous Canarian U6b1a lineage in the aboriginal samples (65%). This value is even greater than that observed in the extant population (44%), which in turn is the highest of all the seven Canary Islands. In contrast to previous results obtained for the aboriginal populations of Tenerife and La Palma, haplogroups related to secondary waves of migration were not detected in La Gomera aborigines, indicating that isolation also had an important role in shaping the current population. The rugged relief of La Gomera divided into several distinct valleys probably promoted subsequent aboriginal intra-insular differentiation that has continued after the European colonization, as seen in the present-day population structure observed on the island.

No MeSH data available.


Related in: MedlinePlus