TY - JOUR A1 - Signore, Anthony V. A1 - Paijmans, Johanna L. A. A1 - Hofreiter, Michael A1 - Fago, Angela A1 - Weber, Roy E. A1 - Springer, Mark S. A1 - Campbell, Kevin L. T1 - Emergence of a chimeric globin pseudogene and increased Hemoglobin Oxygen Affinity Underlie the evolution of aquatic specializations in Sirenia JF - Molecular biology and evolution N2 - As limits on O2 availability during submergence impose severe constraints on aerobic respiration, the oxygen binding globin proteins of marine mammals are expected to have evolved under strong evolutionary pressures during their land-to-sea transition. Here, we address this question for the order Sirenia by retrieving, annotating, and performing detailed selection analyses on the globin repertoire of the extinct Steller’s sea cow (Hydrodamalis gigas), dugong (Dugong dugon), and Florida manatee (Trichechus manatus latirostris) in relation to their closest living terrestrial relatives (elephants and hyraxes). These analyses indicate most loci experienced elevated nucleotide substitution rates during their transition to a fully aquatic lifestyle. While most of these genes evolved under neutrality or strong purifying selection, the rate of nonsynonymous/synonymous replacements increased in two genes (Hbz-T1 and Hba-T1) that encode the α-type chains of hemoglobin (Hb) during each stage of life. Notably, the relaxed evolution of Hba-T1 is temporally coupled with the emergence of a chimeric pseudogene (Hba-T2/Hbq-ps) that contributed to the tandemly linked Hba-T1 of stem sirenians via interparalog gene conversion. Functional tests on recombinant Hb proteins from extant and ancestral sirenians further revealed that the molecular remodeling of Hba-T1 coincided with increased Hb–O2 affinity in early sirenians. Available evidence suggests that this trait evolved to maximize O2 extraction from finite lung stores and suppress tissue O2 offloading, thereby facilitating the low metabolic intensities of extant sirenians. In contrast, the derived reduction in Hb–O2 affinity in (sub)Arctic Steller’s sea cows is consistent with fueling increased thermogenesis by these once colossal marine herbivores. KW - ancient DNA KW - aquatic adaptation KW - gene conversion KW - hemoglobin KW - oxygen affinity KW - molecular evolution KW - myoglobin KW - neuroglobin KW - cytoglobin KW - pseudogene Y1 - 2019 U6 - https://doi.org/10.1093/molbev/msz044 SN - 0737-4038 SN - 1537-1719 VL - 36 IS - 6 SP - 1134 EP - 1147 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Gonzalez-Fortes, Gloria M. A1 - Tassi, F. A1 - Trucchi, E. A1 - Henneberger, K. A1 - Paijmans, Johanna L. A. A1 - Diez-del-Molino, D. A1 - Schroeder, H. A1 - Susca, R. R. A1 - Barroso-Ruiz, C. A1 - Bermudez, F. J. A1 - Barroso-Medina, C. A1 - Bettencourt, A. M. S. A1 - Sampaio, H. A. A1 - Salas, A. A1 - de Lombera-Hermida, A. A1 - Fabregas Valcarce, Ramón A1 - Vaquero, M. A1 - Alonso, S. A1 - Lozano, Marina A1 - Rodriguez-Alvarez, Xose Pedro A1 - Fernandez-Rodriguez, C. A1 - Manica, Andrea A1 - Hofreiter, Michael A1 - Barbujani, Guido T1 - A western route of prehistoric human migration from Africa into the Iberian Peninsula JF - Proceedings of the Royal Society of London : B, Biological sciences N2 - Being at the western fringe of Europe, Iberia had a peculiar prehistory and a complex pattern of Neolithization. A few studies, all based on modern populations, reported the presence of DNA of likely African origin in this region, generally concluding it was the result of recent gene flow, probably during the Islamic period. Here, we provide evidence of much older gene flow from Africa to Iberia by sequencing whole genomes from four human remains from northern Portugal and southern Spain dated around 4000 years BP (from the Middle Neolithic to the Bronze Age). We found one of them to carry an unequivocal sub-Saharan mitogenome of most probably West or West-Central African origin, to our knowledge never reported before in prehistoric remains outside Africa. Our analyses of ancient nuclear genomes show small but significant levels of sub-Saharan African affinity in several ancient Iberian samples, which indicates that what we detected was not an occasional individual phenomenon, but an admixture event recognizable at the population level. We interpret this result as evidence of an early migration process from Africa into the Iberian Peninsula through a western route, possibly across the Strait of Gibraltar. KW - palaeogenome KW - Africa KW - Iberia KW - mitochondrial DNA KW - gene flow KW - admixture Y1 - 2019 U6 - https://doi.org/10.1098/rspb.2018.2288 SN - 0962-8452 SN - 1471-2954 VL - 286 IS - 1895 PB - Royal Society CY - London ER - TY - JOUR A1 - Sheng, Gui-Lian A1 - Basler, Nikolas A1 - Ji, Xue-Ping A1 - Paijmans, Johanna L. A. A1 - Alberti, Federica A1 - Preick, Michaela A1 - Hartmann, Stefanie A1 - Westbury, Michael V. A1 - Yuan, Jun-Xia A1 - Jablonski, Nina G. A1 - Xenikoudakis, Georgios A1 - Hou, Xin-Dong A1 - Xiao, Bo A1 - Liu, Jian-Hui A1 - Hofreiter, Michael A1 - Lai, Xu-Long A1 - Barlow, Axel T1 - Paleogenome reveals genetic contribution of extinct giant panda to extant populations JF - Current biology N2 - Historically, the giant panda was widely distributed from northern China to southwestern Asia [1]. As a result of range contraction and fragmentation, extant individuals are currently restricted to fragmented mountain ranges on the eastern margin of the Qinghai-Tibet plateau, where they are distributed among three major population clusters [2]. However, little is known about the genetic consequences of this dramatic range contraction. For example, were regions where giant pandas previously existed occupied by ancestors of present-day populations, or were these regions occupied by genetically distinct populations that are now extinct? If so, is there any contribution of these extinct populations to the genomes of giant pandas living today? To investigate these questions, we sequenced the nuclear genome of an similar to 5,000-year-old giant panda from Jiangdongshan, Teng-chong County in Yunnan Province, China. We find that this individual represents a genetically distinct population that diverged prior to the diversification of modern giant panda populations. We find evidence of differential admixture with this ancient population among modern individuals originating from different populations as well as within the same population. We also find evidence for directional gene flow, which transferred alleles from the ancient population into the modern giant panda lineages. A variable proportion of the genomes of extant individuals is therefore likely derived from the ancient population represented by our sequenced individual. Although extant giant panda populations retain reasonable genetic diversity, our results suggest that this represents only part of the genetic diversity this species harbored prior to its recent range contractions. Y1 - 2019 U6 - https://doi.org/10.1016/j.cub.2019.04.021 SN - 0960-9822 SN - 1879-0445 VL - 29 IS - 10 SP - 1695 EP - 1700 PB - Cell Press CY - Cambridge ER -