Early Holocene human skeletal remains from Santana do Riacho,Brazil: implications for the settlement of the New World

In this study we compare the cranial morphology of several late Paleoindian skeletons uncovered at Santana do Riacho, Central Brazil, with worldwide human cranial variation. Mahalanobis Distance and Principal Component Analysis are used to explore the extra-continental morphological affinities of the Brazilian Paleoindian sample. Santana do Riacho is a late Paleoindian burial site where approximately 40 individuals were recovered in varying states of preservation. The site is located at Lagoa Santa/Serra do Cipó, State of Minas Gerais. The first human activities in this rockshelter date back to the terminal Pleistocene, but the burials are bracketed between circa 8200 and 9500BP. The collection contains only six skulls well-enough preserved to be measured. The Santana do Riacho late Paleoindians present a cranial morphology characterized by long and narrow neurocrania, low and narrow faces, with low nasal apertures and orbits. The multivariate analyses show that they exhibit strong morphological affinities with present day Australians and Africans, showing no resemblance to recent Northern Asians and Native Americans. These findings confirm our long held opinion that the settlement of the Americas was more complicated in terms of biological input than has been widely assumed. The working hypothesis is that two very distinct populations entered the New World by the end of the Pleistocene, and that the transition between the cranial morphology of the Paleoindians and the morphology of later Native Americans, which occurred around 8-9ka, was abrupt. This, in our opinion, is a more parsimonious explanation for the diversity detected than a long, local microevolutionary process mediated by selection and drift. The similarities of the first South Americans with sub-Saharan Africans may result from the fact that the non-Mongoloid Southeast Asian ancestral population came, ultimately, from Africa, with no major modification in the original cranial bau plan of the first modern humans.     

Genetic heterogeneity among the Negroid and Arab tribes of the Sudan

Genetic distance analysis was carried out among seven tribes of the Sudan comprising three Negroid (Nuba, Fur, and Nilotes) and four Arab tribes (Beja, Gaalin, Hawazma, and Messeria) on the basis of six polymorphic loci (ABO and Rhesus blood groups; haemoglobin and red cell glucose-6-phosphate dehydrogenase; serum haptoglobin and transferrin polymorphisms) controlling 21 alleles and compared with the Arab and Negroid populations in neighbouring countries. The Nuba and Nilotes have been found to have Negroid genetic characteristics, while the Fur are intermediate between the Arabs and Negroids. The Beja and Gaalin tribes have more pronounced Arab genetic characteristics than the Hawazma and Messeria, who have a great deal of Negroid admixture.     

Evolution of the RNA-dependent RNA polymerase (RdRP) genes: Duplications and possible losses before and after the divergence of major eukaryotic groups

Eukaryotic RNA-dependent RNA polymerases (RdRPs, encoded by RDR genes) play critical roles in developmental regulation, maintenance of genome integrity, and defense against foreign nucleic acids. However, the phylogenetic relationship of RDRs remains unclear. From available genome sequences, we identified 161 putative RDR genes from 56 eukaryotes, ranging from protists to multicellular organisms, including plants, fungi and invertebrate animals, such as nematodes, lancelet and sea anemone. On the other hand, we did not detect RDR homologs in vertebrates and insects, even though RNA interference functions in these organisms. Our phylogenetic analysis of the RDR genes suggests that the eukaryotic ancestor might have had three copies, i.e. RDRα, RDRβ and RDRγ. These three ancient copies were also supported by the patterns of protein sequence motifs. Further duplication events after the divergence of major eukaryotic groups were supported by the phylogenetic analyses, including some that likely occurred before the separation of subgroups within each kingdom. We present a model for a possible evolutionary history of RDR genes in eukaryotes.     

Variation of DNA fingerprints among accessions within maize inbred lines and implications for identification of essentially derived varieties: II. Genetic and technical sources of variation in AFLP data and comparison with SSR data

Accuracy and reproducibility of genetic distances (GDs) based on molecular markers are crucial issues for identification of essentially derived varieties (EDVs). Our objectives were to investigate (1) the amount of variation for amplified fragment length polymorphism (AFLP) markers found among different accessions within maize inbreds and doubled haploid (DH) lines, (2) the proportion attributable to genetic and technical components and marker system specific sources, (3) its effect on GDs between maize lines and implications for identification of EDVs, and (4) the comparison to published SSR data from the same plant materials. Two to five accessions from nine inbred lines and five DH lines were taken from different sources of maintenance breeding or drawn as independent samples from the same seed lot. Each of the 41 accessions was genotyped with 20 AFLP primer combinations revealing 988 AFLP markers. Map positions were available for 605 AFLPs covering all maize chromosomes. On average, six (0.6%) AFLP bands were polymorphic between different accessions of the same line. GDs between two accessions of the same line averaged 0.013 for inbreds and 0.006 for DH lines. The correlation of GDs based on AFLPs and SSRs was tight (r = 0.97**) across all 946 pairs of accessions but decreased (r = 0.55**) for 43 pairs of accessions originating from the same line. On the basis of our results, we recommend specific EDV thresholds for marker systems with different degree of polymorphism. In addition, precautions should be taken to warrant a high level of homogeneity for DNA markers within maize lines before applying for plant variety protection.     

Glutamine-Fructose-6-Phosphate Transaminase 2 (GFPT2) Is Upregulated in Breast Epithelial–Mesenchymal Transition and Responds to Oxidative Stress

Breast cancer cells that have undergone partial epithelial–mesenchymal transition (EMT) are believed to be more invasive than cells that have completed EMT. To study metabolic reprogramming in different mesenchymal states, we analyzed protein expression following EMT in the breast epithelial cell model D492 with single-shot LFQ supported by a SILAC proteomics approach. The D492 EMT cell model contains three cell lines: the epithelial D492 cells, the mesenchymal D492M cells, and a partial mesenchymal, tumorigenic variant of D492 that overexpresses the oncogene HER2. The analysis classified the D492 and D492M cells as basal-like and D492HER2 as claudin-low. Comparative analysis of D492 and D492M to tumorigenic D492HER2 differentiated metabolic markers of migration from those of invasion. Glutamine-fructose-6-phosphate transaminase 2 (GFPT2) was one of the top dysregulated enzymes in D492HER2. Gene expression analysis of the cancer genome atlas showed that GFPT2 expression was a characteristic of claudin-low breast cancer. siRNA-mediated knockdown of GFPT2 influenced the EMT marker vimentin and both cell growth and invasion in vitro and was accompanied by lowered metabolic flux through the hexosamine biosynthesis pathway (HBP). Knockdown of GFPT2 decreased cystathionine and sulfide:quinone oxidoreductase (SQOR) in the transsulfuration pathway that regulates H₂S production and mitochondrial homeostasis. Moreover, GFPT2 was within the regulation network of insulin and EGF, and its expression was regulated by reduced glutathione (GSH) and suppressed by the oxidative stress regulator GSK3-β. Our results demonstrate that GFPT2 controls growth and invasion in the D492 EMT model, is a marker for oxidative stress, and associated with poor prognosis in claudin-low breast cancer.     

Pinus uncinata Ramond taxonomy based on needle characters

 11 needle characters of Pinus uncinata Ramond from the Spanish Pyrenees, P. mugo Turra from the Tatra Mountains, and P. sylvestris L. from N.E. Poland were analysed. It was shown that P. uncinata is much more closely related to P. mugo than to P. sylvestris. Nevertheless P. uncinata remains distinct from both in a number of the characters examined. The species differs from P. mugo especially in the length of the needles and in the distance between the vascular bundles. It differs from P. sylvestris in such characters as the number of resin canals, thickness of epidermis cells and the distance between the vascular bundles. Width of epidermis cells was similar in all taxa studied. Received May 31, 2000 Accepted February 13, 2001     

A nonparametric distance analysis of biochemical genetic data from the Åland Islands,Finland

Biochemical genetic data from 3272 individuals from the Åland Islands, Finland, are analyzed using a recently developed set of nonparametric genetic distance measures. These measures are more robust than the traditional methods used in previous studies of this population. While there was general agreement in the results of the traditional and nonparametric approaches, some important differences were seen. In these cases, the nonparametric methods gave results more congruent with population history, geographic propinquity, and migration patterns. Heterozygosity measures were also calculated for the Åland Islands population and compared to values obtained for Jewish populations. The total heterozygosity values were very similar.     

Ruellia sect.Urceolata (Acanthaceae), a novel species complex from southern Mexico

A new section in MexicanRuellia, R. sect.Urceolata comprising three species (includingR. cedilloi, spec. nova), endemic to Mexico, is described and illustrated. The taxonomic relationship and differentiation of the species are discussed. Evolution in Mexican Ruellas seems to be occurring at the diploid level.     

The Chipaya of Bolivia: Dermatoglyphics and ethnic relationships

Dermatoglyphic data on 15 traits (digital arches, digital radial loops, digital ulnar loops, digital whorls, I loops, I_r loops, H loops, ? loops, III loops, IV loops, mainline C absence, total ridge count, a-b ridge count, atd angle, and mainline index) are presented for 141 Chipaya Indians of Bolivia. Ethnic relationships of these Indians to nine South American Indian tribes (Alacaluf, Atacameño, Aymara, Cashinahua, Chácobo, Chama, Chané, Quechua, and Sirionó) are explored by means of a genetic distance analysis using 21 alleles. Genetic distances are complemented with linguistic and geographic distances between the Chipaya and the other tribes. Genetic distances were found not to be significantly correlated with linguistic and geographic distances. Combining the information available, it is concluded that the Chipaya are most likely ethnically related to the Arawak speakers of the tropical forest.