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The mitochondrial DNA recovered from human remains originating
from the Merovingian necropolis in Jau Dignac et Loirac
appears globally well preserved because reliable partial or complete
mitochondrial HVR-I sequences could be easily replicated
from eight out of the nine samples analysed (89%). The good
macroscopic conservation of the remains lends favour to the positive
correlation between macroscopic conservation and ancient
DNA retrieval, as previously proposed in the literature (Cipollaro
et al., 1998). The recent sampling of the remains and their direct
storage at 20 C could also explain the high success rate obtained
because the sample conservation procedure can highly influence
the recovery of ancient DNA (Pruvost et al., 2007). However, no
autosomal STR typing could be obtained from the samples, confirming
that nuclear DNA preservation is difficult and requires
highly favourable environmental conditions.
No contamination was observed in our analyses, allowing us to
report mitochondrial sequences with a high degree of confidence in
terms of authenticity. Moreover, the history of the sampleswaswell
known, which allowed us to trace all potential contamination
sources and to determine the efficiency of the precautions followed
during all steps of the study. The results obtained in sarcophagus
169 permit us to confirm that careful contamination controls during
the initial sample collection and preparation are highly effective
in minimising the risk of false positive results (Yang and Watt,
2005). The authenticated results obtained for samples originating
from sarcophagi 170 and 171 (collected without gloves) would
support the idea that handling is not the main contaminating
process, at least if analyses are performed on teeth still fixed to the
jaw. Nevertheless, if the samples are highly contaminated before
the genetic analysis, the current authenticity criteria provide no
way to detect contamination (Gilbert et al., 2006). Therefore, the
samples should preferably not be handled, washed and/or repaired.
Our approach clearly identified six different mitochondrial lineages
(corresponding to five distinct haplogroups: J, H, K, X2 and
W) among eight human remains, indicating noticeable mitochondrial
diversity. During this period, the site might have been the
cemetery for a social group with significant genetic diversity. Such
mitochondrial diversity at a very local scale had already been
observed in Merovingian sepulchres from Dordogne (Peyrat site,
France, unpublished data), as well as in the first Christian cemetery
in Denmark (Rudbeck et al., 2005). It would be interesting to test
this high level of ancient mitochondrial diversity at the local/population
scale further using more numerous and representative
samples. Additionally, the haplotypes characterised from the Jau
Dignac site indicate genetic affinities with specific existing French
populations, such as those located in the Atlantic Pyrenees and
southeastern France. These observations suggest that specific gene
flow existed between these regions of southern France during or
since the High Middle Ages.
The palaeogenetic analyses conducted in our study allow us to
propose a maternal relationship between two individuals from
sarcophagus 169 and two individuals from sarcophagus 170. To our
knowledge, this study is the first to demonstrate kinship between
individuals deposited in the same sarcophagus in the Merovingian
funerary context. The fact that other individuals from the three
sarcophagi tested have distinct mitochondrial lineages does not
allowus to exclude any kinship other than maternal.We propose that
the reuse of the sarcophagi was a result of the individuals’ kinship.
Until now, the rare palaeogenetic studies conducted to test a link
between sepulchre structure and maternal relationships concluded
in the absence of a systematic correlation between both parameters
(Mooder et al., 2005; Rudbeck et al., 2005). In these studies, familial
groupingwas often specific to one structure or one particular zone of
the necropolis, indicating that the grouping of all individualswas not
systematically motivated by familial relationships. Consequently,
familial relationships between individuals grouped in a necropolis
(such as the ones encountered in sarcophagi 169 and 170 at the Jau
Dignac site) may not be systematic and may not be applied to the
necropolis as a whole, to the region and/or period as a whole.
The presence of an infant in sarcophagus 170 is particularly
striking because access to this type of funerary structure was
generally reserved for individuals beyond fifteen years of age during
the High Middle Ages. Combined to the maternal relationship
found between the two young women in the same sarcophagus,
one would have predicted that the child has been buried alongside
relatives. Therefore, the genetic demonstration that he was not
maternally related to either of the women buried in the same
sarcophagus was surprising. While speculative, different explanations
can be proposed for this observation, including (i) a kinship
between the women and infant undetectable by mtDNA; (ii) the
simultaneous death of both woman 170-2 and the infant (i.e., the
community took advantage of reopening the sarcophagus for the
woman’s burial and buried the infant); (iii) or a case of child
adoption, which was a common practice reported for the period
(Santinelli, 1998) (however, we cannot know if the infant, who
appeared to have been stillborn or died just after birth, had survived
long enough to be adopted).
Finally, the maternally related individuals buried in sarcophagi
169 and 170 are affiliated with distinct maternal lineages. This
result could indicate that sarcophagi were used or reserved for
distinct families. This point would be in accordance with the
archaeological and anthropological arguments that note that the
Jau-Dignac et Loirac necropolis may have grouped together the
members of a High Middle Ages familia (Le Jan 1995). For this
period, the familia represents a group of large family ties, bringing
together closely or distantly related individuals but also friends,
neighbours, and domestic staff of the domain. One possibility is
that sarcophagi were reused by closely related individuals in the
Jau-Dignac et Loira necropolis, whereas distinct sarcophagi were
reserved for distantly related groups inside the familia.
Journal of Archaeological Science 41 (2014) 399-405
from the Merovingian necropolis in Jau Dignac et Loirac
appears globally well preserved because reliable partial or complete
mitochondrial HVR-I sequences could be easily replicated
from eight out of the nine samples analysed (89%). The good
macroscopic conservation of the remains lends favour to the positive
correlation between macroscopic conservation and ancient
DNA retrieval, as previously proposed in the literature (Cipollaro
et al., 1998). The recent sampling of the remains and their direct
storage at 20 C could also explain the high success rate obtained
because the sample conservation procedure can highly influence
the recovery of ancient DNA (Pruvost et al., 2007). However, no
autosomal STR typing could be obtained from the samples, confirming
that nuclear DNA preservation is difficult and requires
highly favourable environmental conditions.
No contamination was observed in our analyses, allowing us to
report mitochondrial sequences with a high degree of confidence in
terms of authenticity. Moreover, the history of the sampleswaswell
known, which allowed us to trace all potential contamination
sources and to determine the efficiency of the precautions followed
during all steps of the study. The results obtained in sarcophagus
169 permit us to confirm that careful contamination controls during
the initial sample collection and preparation are highly effective
in minimising the risk of false positive results (Yang and Watt,
2005). The authenticated results obtained for samples originating
from sarcophagi 170 and 171 (collected without gloves) would
support the idea that handling is not the main contaminating
process, at least if analyses are performed on teeth still fixed to the
jaw. Nevertheless, if the samples are highly contaminated before
the genetic analysis, the current authenticity criteria provide no
way to detect contamination (Gilbert et al., 2006). Therefore, the
samples should preferably not be handled, washed and/or repaired.
Our approach clearly identified six different mitochondrial lineages
(corresponding to five distinct haplogroups: J, H, K, X2 and
W) among eight human remains, indicating noticeable mitochondrial
diversity. During this period, the site might have been the
cemetery for a social group with significant genetic diversity. Such
mitochondrial diversity at a very local scale had already been
observed in Merovingian sepulchres from Dordogne (Peyrat site,
France, unpublished data), as well as in the first Christian cemetery
in Denmark (Rudbeck et al., 2005). It would be interesting to test
this high level of ancient mitochondrial diversity at the local/population
scale further using more numerous and representative
samples. Additionally, the haplotypes characterised from the Jau
Dignac site indicate genetic affinities with specific existing French
populations, such as those located in the Atlantic Pyrenees and
southeastern France. These observations suggest that specific gene
flow existed between these regions of southern France during or
since the High Middle Ages.
The palaeogenetic analyses conducted in our study allow us to
propose a maternal relationship between two individuals from
sarcophagus 169 and two individuals from sarcophagus 170. To our
knowledge, this study is the first to demonstrate kinship between
individuals deposited in the same sarcophagus in the Merovingian
funerary context. The fact that other individuals from the three
sarcophagi tested have distinct mitochondrial lineages does not
allowus to exclude any kinship other than maternal.We propose that
the reuse of the sarcophagi was a result of the individuals’ kinship.
Until now, the rare palaeogenetic studies conducted to test a link
between sepulchre structure and maternal relationships concluded
in the absence of a systematic correlation between both parameters
(Mooder et al., 2005; Rudbeck et al., 2005). In these studies, familial
groupingwas often specific to one structure or one particular zone of
the necropolis, indicating that the grouping of all individualswas not
systematically motivated by familial relationships. Consequently,
familial relationships between individuals grouped in a necropolis
(such as the ones encountered in sarcophagi 169 and 170 at the Jau
Dignac site) may not be systematic and may not be applied to the
necropolis as a whole, to the region and/or period as a whole.
The presence of an infant in sarcophagus 170 is particularly
striking because access to this type of funerary structure was
generally reserved for individuals beyond fifteen years of age during
the High Middle Ages. Combined to the maternal relationship
found between the two young women in the same sarcophagus,
one would have predicted that the child has been buried alongside
relatives. Therefore, the genetic demonstration that he was not
maternally related to either of the women buried in the same
sarcophagus was surprising. While speculative, different explanations
can be proposed for this observation, including (i) a kinship
between the women and infant undetectable by mtDNA; (ii) the
simultaneous death of both woman 170-2 and the infant (i.e., the
community took advantage of reopening the sarcophagus for the
woman’s burial and buried the infant); (iii) or a case of child
adoption, which was a common practice reported for the period
(Santinelli, 1998) (however, we cannot know if the infant, who
appeared to have been stillborn or died just after birth, had survived
long enough to be adopted).
Finally, the maternally related individuals buried in sarcophagi
169 and 170 are affiliated with distinct maternal lineages. This
result could indicate that sarcophagi were used or reserved for
distinct families. This point would be in accordance with the
archaeological and anthropological arguments that note that the
Jau-Dignac et Loirac necropolis may have grouped together the
members of a High Middle Ages familia (Le Jan 1995). For this
period, the familia represents a group of large family ties, bringing
together closely or distantly related individuals but also friends,
neighbours, and domestic staff of the domain. One possibility is
that sarcophagi were reused by closely related individuals in the
Jau-Dignac et Loira necropolis, whereas distinct sarcophagi were
reserved for distantly related groups inside the familia.
Journal of Archaeological Science 41 (2014) 399-405