No abstract

No abstract

Because plants do not possess a proper germline, deleterious somatic mutations can beThe copyright holder for this preprint (which was . http://dx.doi.org/10.1101/149203 doi: bioRxiv preprint first posted online Jun. 13, 2017; 3 the Lausanne University campus, on their way to conquer Italy. At the time of sample harvest 49 for our study, the dividing apical meristems of this magnificent tree (Figure 1 not peer-reviewed) is the author/funder. All rights reserved. No reuse allowed without permission.The copyright holder for this preprint (which was . http://dx.doi.org/10.1101/149203 doi: bioRxiv preprint first posted online Jun. 13, 2017; 4 conservative estimate, we are likely to have missed no more than 18 further such sites (17 75 candidates and 1 false negative, see Supplementary Methods). 76All 17 confirmed SNVs were heterozygous, as expected for novel somatic mutations. Table 2). The functional impact of exchanging a positively charged arginine with a non-82 charged and smaller glycine residue is unknown and deserves further analysis. 83Having confidently established 17 SNVs, we then assessed their occurrence 84 throughout the tree. We used Sanger sequencing to genotype the remaining 24 terminal 85 branches sampled from other parts of the tree and checked for the presence of each SNV. Napoleon Oak may be difficult to reconstruct, our SNV analysis generated a nested set of 92 lineages supported by derived mutations, analogous to a phylogenetic tree. 93The spontaneous mutation rate in plants has been estimated to range from 5 X 10 -9 to 94 30 X 10 -9 substitutions/site/generation, based on mutations accumulated during divergence 95 between monocots and dicots 8 . Values for mutation accumulation lines of Arabidopsis 96 thaliana maintained in the laboratory range between 7.0 and 7.4 X 10 -9 , which corresponds to 97 ~1 mutation/genome/generation 9,10 . Arabidopsis is an annual plant that reaches 98 approximately 30 cm in height before producing seeds. In contrast, the physical distance 99 traced along branches between the terminal branches we sequenced for the Napoleon Oak is 100 not peer-reviewed) is the author/funder. All rights reserved. No reuse allowed without permission.The copyright holder for this preprint (which was . http://dx.doi.org/10.1101/149203 doi: bioRxiv preprint first posted online Jun. 13, 2017; 5 about 40 m (Figure 1 Our original hypothesis is thus not supported by the data and another mechanism has to be 110 invoked.). Assuming similar cell sizes between oak and Arabidopsis, 111Classical studies of shoot apical meristem organization have reported that the most 112 distal zone has a significantly lower rate of cell division than more basal regions of the apex, 113 and might therefore be relatively protected from replication errors 12,13 . In a recent study that It thus seems reasonable to suppose that the growth pattern described in Arabidopsis and 126 not peer-reviewed) is the author/funder. All rights reserved. No reuse allowed without permission.The copyright holder for thi...

Here, we present 12 loci paternal haplotypes (Y-STR profiles) against the backdrop of the Y-SNP marker system of Bantu males from the Maputo Province of Southeast Africa, a region believed to represent the southeastern fringe of the Bantu expansion. Our Maputo Bantu group was analyzed within the context of 27 geographically relevant reference populations in order to ascertain its genetic relationship to other Bantu and non Bantu (Pygmy, Khoisan and Nilotic) sub-equatorial tribes from West and East Africa. This study entails statistical pair wise comparisons and multidimensional scaling based on YSTR Rst distances, network analyses of Bantu (B2a-M150) and Pygmy (B2b-M112) lineages as well as an assessment of Y-SNP distribution patterns. Several notable findings include the following: 1) the Maputo Province Bantu exhibits a relatively close paternal affinity with both east and west Bantu tribes due to high proportion of Bantu Y chromosomal markers, 2) only traces of Khoisan (1.3%) and Pygmy (1.3%) markers persist in the Maputo Province Bantu gene pool, 3) the occurrence of R1a1a-M17/M198, a member of the Eurasian R1a-M420 branch in the population of the Maputo Province, may represent back migration events and/or recent admixture events, 4) the shared presence of E1b1b1-M35 in all Tanzanian tribes examined, including Bantu and non-Bantu groups, in conjunction with its nearly complete absence in the West African populations indicate that, in addition to a shared linguistic, cultural and genetic heritage, geography (e.g., east vs. west) may have impacted the paternal landscape of sub-Saharan Africa, 5) the admixture and assimilation processes of Bantu elements were both highly complex and region-specific.

No abstract

No abstract

No abstract