编辑MSTN半胱氨酸节基元促进两广小花猪肌肉生长

肌生长抑制素(myostatin,MSTN)是转化生长因子 β(transforming growth factor-β,TGF-β)家族成员之一,是一种肌肉生长抑制因子.解除MSTN的生长抑制功能是提高畜禽肌肉产量的一种有效途径.TGF-β 的半胱氨酸节结构基元(cystine knot motif)能够稳定MSTN...     

Stone artifacts and hominins in island Southeast Asia: new insights from Flores, eastern Indonesia

This study reexamines the current understanding of Pleistocene stone-artifact assemblages in island Southeast Asia. A differentiation has long been made between assemblages of large-sized "core tools" and assemblages of small-sized "flake tools." "Core tool" assemblages are often argued to be the handiwork of early hominin species such as Homo erectus, while small-sized "flake tool" assemblages have been attributed to Homo sapiens. We argue that this traditional Southeast Asian perspective on stone tools assumes that the artifacts recovered from a site reflect a complete technological sequence. Our analyses of Pleistocene-age artifact assemblages from Flores, Indonesia, demonstrate that large pebble-based cores and small flake-based cores are aspects of one reduction sequence. We propose that the Flores pattern applies across island Southeast Asia: large-sized "core tool" assemblages are in fact a missing element of the small-sized flake-based reduction sequences found in many Pleistocene caves and rock-shelters. We conclude by discussing the implications of this for associating stone-artifact assemblages with hominin species in island Southeast Asia.     

广西猕猴桃三个新变种

报道了广西猕猴桃属植物的三个新变种。     

Size, shape, and asymmetry in fossil hominins: the status of the LB1 cranium based on 3D morphometric analyses

The unique set of morphological characteristics of the Liang Bua hominins (Homo floresiensis) has been attributed to explanations as diverse as insular dwarfism and pathological microcephaly. This study examined the relationship between cranial size and shape across a range of hominin and African ape species to test whether or not cranial morphology of LB1 is consistent with the basic pattern of static allometry present in these various taxa. Correlations between size and 3D cranial shape were explored using principal components analysis in shape space and in Procrustes form space. Additionally, patterns of static allometry within both modern humans and Plio-Pleistocene hominins were used to simulate the expected cranial shapes of each group at the size of LB1. These hypothetical specimens were compared to LB1 both visually and statistically. Results of most analyses indicated that LB1 best fits predictions for a small specimen of fossil Homo but not for a small modern human. This was especially true for analyses of neurocranial landmarks. Results from the whole cranium were less clear about the specific affinities of LB1, but, importantly, demonstrated that aspects of facial morphology associated with smaller size converge on modern human morphology. This suggests that facial similarities between LB1 and anatomically modern humans may not be indicative of a close relationship. Landmark data collected from this study were also used to test the degree of cranial asymmetry in LB1. These comparisons indicated that the cranium is fairly asymmetrical, but within the range of asymmetry exhibited by modern humans and all extant African ape species. Compared to other fossil specimens, the degree of asymmetry in LB1 is moderate and readily explained by the taphonomic processes to which all fossils are subject. Taken together, these findings suggest that H. floresiensis was most likely the diminutive descendant of a species of archaic Homo, although the details of this evolutionary history remain obscure.     

Continuities in stone flaking technology at Liang Bua, Flores, Indonesia

This study examines trends in stone tool reduction technology at Liang Bua, Flores, Indonesia, where excavations have revealed a stratified artifact sequence spanning 95 k.yr. The reduction sequence practiced throughout the Pleistocene was straightforward and unchanging. Large flakes were produced off-site and carried into the cave where they were reduced centripetally and bifacially by four techniques: freehand, burination, truncation, and bipolar. The locus of technological complexity at Liang Bua was not in knapping products, but in the way techniques were integrated. This reduction sequence persisted across the Pleistocene/Holocene boundary with a minor shift favoring unifacial flaking after 11 ka. Other stone-related changes occurred at the same time, including the first appearance of edge-glossed flakes, a change in raw material selection, and more frequent fire-induced damage to stone artifacts. Later in the Holocene, technological complexity was generated by “adding-on” rectangular-sectioned stone adzes to the reduction sequence. The Pleistocene pattern is directly associated with Homo floresiensis skeletal remains and the Holocene changes correlate with the appearance of Homo sapiens. The one reduction sequence continues across this hominin replacement.     

The Liang Bua faunal remains: a 95 k.yr. sequence from Flores, East Indonesia

Excavations at Liang Bua, a limestone cave on the island of Flores, East Indonesia, have yielded a well-dated archaeological and faunal sequence spanning the last 95 k.yr., major climatic fluctuations, and two human species - H. floresiensis from 95 to 17 k.yr.¹, and modern humans from 11 k.yr. to the present. The faunal assemblage comprises well-preserved mammal, bird, reptile and mollusc remains, including examples of island gigantism in small mammals and the dwarfing of large taxa. Together with evidence from Early-Middle Pleistocene sites in the Soa Basin, it confirms the long-term isolation, impoverishment, and phylogenetic continuity of the Flores faunal community. The accumulation of Stegodon and Komodo dragon remains at the site in the Pleistocene is attributed to Homo floresiensis, while predatory birds, including an extinct species of owl, were largely responsible for the accumulation of the small vertebrates. The disappearance from the sequence of the two large-bodied, endemic mammals, Stegodon florensis insularis and Homo floresiensis, was associated with a volcanic eruption at 17 ka and precedes the earliest evidence for modern humans, who initiated use of mollusc and shell working, and began to introduce a range of exotic animals to the island. Faunal introductions during the Holocene included the Sulawesi warty pig (Sus celebensis) at about 7 ka, followed by the Eurasian pig (Sus scrofa), Long-tailed macaque, Javanese porcupine, and Masked palm civet at about 4 ka, and cattle, deer, and horse - possibly by the Portuguese within historic times. The Holocene sequence at the site also documents local faunal extinctions - a result of accelerating human population growth, habitat loss, and over-exploitation.     

夏石金花茶的核型研究

本文研究了夏石金花茶(Camellia xiashiensis S. Y. Liang et C. Z. Deng, sp. nov. ined)的核型。结果表明:其体细胞染色体数目为2n=30,具12对中部着丝点染色体.5对近中部着丝点染色体,第15对染色体具1对随体。根据Levan等的分类原则。其核型为2n=2x=24m(2SAT)+6sm。属于Stebbins核型的“2A”型。     

The biotrophy-associated secreted protein 4 (BAS4) participates in the transition of Magnaporthe oryzae from the biotrophic to the necrotrophic phase

The physiological and metabolic processes of host plants are manipulated and remodeled by phytopathogenic fungi during infection, revealed obvious signs of biotrophy of the hemibiotrophic pathogen. As we known that effector proteins play key roles in interaction of hemibiotrophic fungi and their host plants. BAS4 (biotrophy-associated secreted protein 4) is an EIHM (extrainvasive hyphal membrane) matrix protein that was highly expressed in infectious hyphae. In order to study whether BAS4 is involved in the transition of rice blast fungus from biotrophic to necrotrophic phase, The susceptible rice cultivar Lijiangxintuanheigu (LTH) that were pre-treated with prokaryotic expression product of BAS4 and then followed with inoculation of the blast strain, more serious blast disease symptom, more biomass such as sporulation and fungal relative growth, and lower expression level of pathogenicity-related genes appeared in lesion of the rice leaves than those of the PBS-pretreated-leaves followed with inoculation of the same blast strain, which demonstrating that BAS4 invitro changed rice defense system to facilitate infection of rice blast strain. And the susceptible rice cultivar (LTH) were inoculated withBAS4-overexpressed blast strain, we also found more serious blast disease symptom and more biomass also appeared in lesion of leaves inoculated with BAS4-overexpressed strain than those of leaves inoculated with the wild-type strain, and expression level of pathogenicity-related genes appeared lower in biotrophic phase and higher in necrotrophic phase of infection, indicating BAS4 maybe in vivo regulate defense system of rice to facilitate transition of biotrophic to necrotrophic phase. Our data demonstrates that BAS4 in vitro and in vivo participates in transition from the biotrophic to the necrotrophic phase of Magnaporthe oryzae.