Molecular characterization of mitochondrial Amerindian haplogroups and the amelogenin gene in human ancient DNA from three archaeological sites in Lambayeque - Peru.

Important pre-Inca civilizations, known by their great political and religious structures, inhabited the northern coast of Peru. Archeological and anthropological studies have shown that people from these villages have hierarchical strata, but the genetic structure has been poorly studied. Here, we aimed to perform a molecular characterization of the Amerindian maternal lineages and the amelogenin gene in skeletons collected from three archeological sites in Lambayeque. Ancient DNA (aDNA) samples were analyzed with conventional PCR to assess the nine-base pair (9 bp) deletion corresponding to mitochondrial haplogroup B and the identification of haplogroups A, C, and D were obtained with PCR-RFLP experiments. The sex was characterized via amplification of the AMEL(X/Y) locus. Haplogroup frequencies were compared with available data from other ancient and modern civilizations from the Peruvian coast and highlands using statistical methods. Our results showed that haplogroup C had the highest frequency, while haplogroup B showed variable diversity in the analyzed populations. The meta-analysis revealed a positive correlation among some coastal villages. We concluded that ancient populations analyzed in our study showed the presence of four Amerindian mitochondrial haplogroups, which is consistent with previous studies.

Characterization of a novel Drosophila melanogaster cis-regulatory module that drives gene expression to the larval tracheal system and adult thoracic musculature.

In a previous bioinformatics analysis we identified 10 conserved Drosophila melanogaster sequences that reside upstream from protein coding genes (CGs). Here we characterize one of these genomic regions, which constitutes a Drosophila melanogaster cis-regulatory module (CRM) that we denominate TT-CRM. The TT-CRM is 646 bp long and is located in one of the introns of CG32239 and resides about 3,500 bp upstream of CG13711 and about 620 bp upstream of CG12493. Analysis of 646 bp-lacZ lines revealed that TT-CRM drives gene expression not only to the larval, prepupal, and pupal tracheal system but also to the adult dorsal longitudinal muscles. The patterns of mRNA expression of the transgene and of the CGs that lie in the vicinity of TT-CRM were investigated both in dissected trachea and in adult thoraces. Through RT-qPCR we observed that in the tracheal system the pattern of expression of 646 bp-lacZ is similar to the pattern of expression of CG32239 and CG13711, whereas in the thoracic muscles 646 bp-lacZ expression accompanies the expression of CG12493. Together, these results suggest new functions for two previously characterized D. melanogaster genes and also contribute to the initial characterization of a novel CRM that drives a dynamic pattern of expression throughout development.