Uniparental Genetic Heritage of Belarusians: Encounter of Rare Middle Eastern Matrilineages with a Central European Mitochondrial DNA Pool

Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups – a profile which is very similar to the two other eastern European populations – Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively

Stable nuclear transformation of Eudorina elegans

Lerche K, Hallmann A. Stable nuclear transformation of Eudorina elegans. BMC Biotechnology. 2013;13(1): 11.UNLABELLED: ABSTRACT: BACKGROUND: A fundamental step in evolution was the transition from unicellular to differentiated, multicellular organisms. Volvocine algae have been used for several decades as a model lineage to investigate the evolutionary aspects of multicellularity and cellular differentiation. There are two well-studied volvocine species, a unicellular alga (Chlamydomonas reinhardtii) and a multicellular alga with differentiated cell types (Volvox carteri). Species with intermediate characteristics also exist, which blur the boundaries between unicellularity and differentiated multicellularity. These species include the globular alga Eudorina elegans, which is composed of 16-32 cells. However, detailed molecular analyses of E. elegans require genetic manipulation. Unfortunately, genetic engineering has not yet been established for Eudorina, and only limited DNA and/or protein sequence information is available. RESULTS: Here, we describe the stable nuclear transformation of E. elegans by particle bombardment using both a chimeric selectable marker and reporter genes from different heterologous sources. Transgenic algae resistant to paromomycin were achieved using the aminoglycoside 3'-phosphotransferase VIII (aphVIII) gene of Streptomyces rimosus, an actinobacterium, under the control of an artificial promoter consisting of two V. carteri promoters in tandem. Transformants exhibited an increase in resistance to paromomycin by up to 333-fold. Co-transformation with non-selectable plasmids was achieved with a rate of 50 - 100%. The luciferase (gluc) gene from the marine copepod Gaussia princeps, which previously was engineered to match the codon usage of C. reinhardtii, was used as a reporter gene. The expression of gluc was mediated by promoters from C. reinhardtii and V. carteri. Heterologous heat shock promoters induced an increase in luciferase activity (up to 600-fold) at elevated temperatures. Long-term stability and both constitutive and inducible expression of the co-bombarded gluc gene was demonstrated by transcription analysis and bioluminescence assays. CONCLUSIONS: Heterologous flanking sequences, including promoters, work in E. elegans and permit both constitutive and inducible expression of heterologous genes. Stable nuclear transformation of E. elegans is now routine. Thus, we show that genetic engineering of a species is possible even without the resources of endogenous genes and promoters

Swapped green algal promoters: aphVIII-based gene constructs with Chlamydomonas flanking sequences work as dominant selectable markers in Volvox and vice versa

Hallmann A, Wodniok S. Swapped green algal promoters: aphVIII-based gene constructs with Chlamydomonas flanking sequences work as dominant selectable markers in Volvox and vice versa. Plant Cell Rep. 2006;25(6):582-591.Production of transgenic organisms is a well-established, versatile course of action in molecular biology. Genetic engineering often requires heterologous, dominant antibiotic resistance genes that have been used as selectable markers in many species. However, as heterologous 5' and 3' flanking sequences often result in very low expression rates, endogenous flanking sequences, especially promoters, are mostly required and are easily obtained in model organisms, but it is much more complicated and time-consuming to get appropriate sequences from less common organisms. In this paper, we show that aminoglycoside 3'-phosphotransferase gene (aphVIII) based constructs with 3' and 5' untranslated flanking sequences (including promoters) from the multicellular green alga Volvox work in the unicellular green alga Chlamydomonas and flanking sequences from Chlamydomonas work in Volvox, at least if a low expression rate is compensated by an enforced high gene dosage. This strategy might be useful for all investigators that intend to transform species in which genomic sequences are not available, but sequences from related organisms exist