Tracing the legacy of the early Hainan Islanders - a perspective from mitochondrial DNA

<p>Abstract</p> <p>Background</p> <p>Hainan Island is located around the conjunction of East Asia and Southeast Asia, and during the Last Glacial Maximum (LGM) was connected with the mainland. This provided an opportunity for the colonization of Hainan Island by modern human in the Upper Pleistocene. Whether the ancient dispersal left any footprints in the contemporary gene pool of Hainan islanders is debatable.</p> <p>Results</p> <p>We collected samples from 285 Li individuals and analyzed mitochondrial DNA (mtDNA) variations of hypervariable sequence I and II (HVS-I and II), as well as partial coding regions. By incorporating previously reported data, the phylogeny of Hainan islanders was reconstructed. We found that Hainan islanders showed a close relationship with the populations in mainland southern China, especially from Guangxi. Haplotype sharing analyses suggested that the recent gene flow from the mainland might play important roles in shaping the maternal pool of Hainan islanders. More importantly, haplogroups M12, M7e, and M7c1* might represent the genetic relics of the ancient population that populated this region; thus, 14 representative complete mtDNA genomes were further sequenced.</p> <p>Conclusions</p> <p>The detailed phylogeographic analyses of haplogroups M12, M7e, and M7c1* indicated that the early peopling of Hainan Island by modern human could be traced back to the early Holocene and/or even the late Upper Pleistocene, around 7 - 27 kya. These results correspond to both Y-chromosome and archaeological studies.</p

Effect of Ca2+ Channel Block on Glycerol Metabolism in Dunaliella salina under Hypoosmotic and Hyperosmotic Stresses

The effect of Ca2+ channel blockers on cytosolic Ca2+ levels and the role of Ca2+ in glycerol metabolism of Dunaliella salina under hypoosmotic or hyperosmotic stress were investigated using the confocal laser scanning microscope (CLSM). Results showed that intracellular Ca2+ concentration increased rapidly when extracellular salinity suddenly decreased or increased, but the increase could be inhibited by pretreatment of Ca2+ channel blockers LaCl3, verapamil or ruthenium red. The changes of glycerol content and G3pdh activity in D. salina to respect to hypoosmotic or hyperosmotic stress were also inhibited in different degrees by pretreatment of Ca2+ channel blockers, indicating that the influx of Ca2+ via Ca2+ channels are required for the transduction of osmotic signal to regulate osmotic responses of D. salina to the changes of salinity. Differences of the three blockers in block effect suggested that they may act on different channels or had different action sites, including influx of Ca2+ from the extracellular space via Ca2+ channels localized in the plasma membrane or from intracellular calcium store via the mitochondrial. Other Ca2+-mediated or non-Ca2+-mediated osmotic signal pathway may exist in Dunaliella in response to hypoosmotic and hyperosmotic stresses

Cell‐ and Gene‐Based Therapeutic Strategies for Periodontal Regenerative Medicine

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142086/1/jper1223.pd

ER Stress Induces Anabolic Resistance in Muscle Cells through PKB-Induced Blockade of mTORC1

Anabolic resistance is the inability to increase protein synthesis in response to an increase in amino acids following a meal. One potential mediator of anabolic resistance is endoplasmic reticulum (ER) stress. The purpose of the present study was to test whether ER stress impairs the response to growth factors and leucine in muscle cells

Measurement of the branching fraction for ψ(3686)→ωK+K-

With 1.06 × 108 ψ(3686) events collected with the BESIII detector, the branching fraction of ψ (3686) → ωK+K- is measured to be (1.54 ± 0.04 ± 0.11) × 10-4. This is the most precise result to date, due to the largest ψ(3686) sample, improved signal reconstruction efficiency, good simulation of the detector performance, and a more accurate knowledge of the continuum contribution. Using the branching fraction of J/ψ → ωK+K-, the ratio β(ψ(3868) → ωK+K-)/β(J/ψ → ωK+K-) is determined to be (18.4 ± 3.7)%. This constitutes a significantly improved test of the 12% rule, with the uncertainty now dominated by the J/ψ branching fraction

Human Angiostrongyliasis Outbreak in Dali, China

Angiostrongyliasis, caused by the rat lungworm Angiostrongylus cantonensis, is a potentially fatal food-borne disease. It is endemic in parts of Southeast Asia, the Pacific Islands, Australia, and the Caribbean. Outbreaks have become increasingly common in China due to the spread of efficient intermediate host snails, most notably Pomacea canaliculata. However, infections are difficult to detect since the disease has a rather long incubation period and few diagnostic clinical symptoms. Reliable diagnostic tests are not widely available. The described angiostrongyliasis epidemic in Dali, China lasted for eight months. Only 11 of a total of 33 suspected patients were clinically confirmed based on a set of diagnostic criteria. Our results demonstrate that the rapid and correct diagnosis of the index patient is crucial to adequately respond to an epidemic, and a set of standardized diagnostic procedures is needed to guide clinicians. Integrated control and management measures including health education, clinical guidelines and a hospital-based surveillance system, should be implemented in areas where snails are a popular food item

Systematic analysis of mitochondrial genes associated with hearing loss in the Japanese population: dHPLC reveals a new candidate mutation

<p>Abstract</p> <p>Background</p> <p>Variants of mitochondrial DNA (mtDNA) have been evaluated for their association with hearing loss. Although ethnic background affects the spectrum of mtDNA variants, systematic mutational analysis of mtDNA in Japanese patients with hearing loss has not been reported.</p> <p>Methods</p> <p>Using denaturing high-performance liquid chromatography combined with direct sequencing and cloning-sequencing, Japanese patients with prelingual (N = 54) or postlingual (N = 80) sensorineural hearing loss not having pathogenic mutations of m.1555A > G and m.3243A > G nor <it>GJB2 </it>were subjected to mutational analysis of mtDNA genes (<it>12S rRNA</it>, <it>tRNA</it>^{<it>Leu(UUR)</it>}, <it>tRNA</it>^{<it>Ser(UCN)</it>}, <it>tRNA</it>^<it>Lys</it>, <it>tRNA</it>^<it>His</it>, <it>tRNA</it>^{<it>Ser(AGY)</it>}, and <it>tRNA</it>^<it>Glu</it>).</p> <p>Results</p> <p>We discovered 15 variants in <it>12S rRNA </it>and one homoplasmic m.7501A > G variant in <it>tRNA</it>^{<it>Ser(UCN)</it>}; no variants were detected in the other genes. Two criteria, namely the low frequency in the controls and the high conservation among animals, selected the m.904C > T and the m.1105T > C variants in <it>12S rRNA </it>as candidate pathogenic mutations. Alterations in the secondary structures of the two variant transcripts as well as that of m.7501A > G in <it>tRNA</it>^{<it>Ser(UCN) </it>}were predicted.</p> <p>Conclusions</p> <p>The m.904C > T variant was found to be a new candidate mutation associated with hearing loss. The m.1105T > C variant is unlikely to be pathogenic. The pathogenicity of the homoplasmic m.7501T > A variant awaits further study.</p