Cortical bone mapping: An application to hand and foot bones in hominoids

Bone form reflects both the genetic profile and behavioural history of an individual. As cortical bone is able to remodel in response to mechanical stimuli, interspecific differences in cortical bone thickness may relate to loading during locomotion or manual behaviours during object manipulation. Here, we test the application of a novel method of cortical bone mapping to the third metacarpal (Mc3) and talus of Pan, Pongo, and Homo. This method of analysis allows measurement of cortical thickness throughout the bone, and as such is applicable to elements with complex morphology. In addition, it allows for registration of each specimen to a canonical surface, and identifies regions where cortical thickness differs significantly between groups. Cortical bone mapping has potential for application to palaeoanthropological studies; however, due to the complexity of correctly registering homologous regions across varied morphology, further methodological development would be advantageous.     

脑水肿干湿重法的测定条件分析

目的：分析干湿重法测定脑水肿的温度条件和时间条件,探讨优化测量方案。方法：健康SD大鼠随机分为3组（n=4）：取脑组织称其湿重,分别连续烘烤16 h,用于不同温度条件下60℃、90℃、110℃的干湿重法脑水肿测定,检测不同时间点脑组织重量变化以及重量差值变化情况。结果：在不同温度下,随着时间的延长,脑组织重量逐渐减轻;温度在110℃条件下,9 h两次称量干重之差小于0.0002 g,已经烘烤至恒重;90℃温度条件下12 h至恒重;60℃温度条件下15.5 h至恒重。结论：干湿重法测量脑水肿的优化方案为110℃ 9 h、90℃ 12 h、60℃ 15.5 h,为脑水肿的测定提供实验依据。     

现代人的出现与扩散——中国的化石证据

自2002年在周口店附近的田园洞发现大约4万年前的现代人化石以来,相继在湖北郧西黄龙洞、广西崇左智人洞等地点发现了早期现代人化石。这些化石发现证实大约10万年前早期现代人在华南地区已经出现。最近在湖南道县福岩洞发现的人类牙齿化石及相关研究进一步揭示具有完全现代形态的人类8万-12万年前在华南局部地区已经出现;而在这个时间段的华北地区,以许家窑人为代表的人类化石形态仍较原始,其演化尚未进入早期现代人阶段。这些研究发现提示,在中国地区,华南是现代人形成与扩散的中心区域,早期现代人以及完全现代类型的人类都可能首先在华南地区出现,然后向华北地区扩散。现有的化石形态证据显示,更新世晚期华南地区人类具有较大的演化变异,可能同时生存有几种不同的演化类群。智人洞属于从古老型智人向现代人演化的过渡类型,而道县则代表着演化进入完全现代类型的人类。基于前人研究及本文的分析,作者认为柳江、资阳、丽江、田园洞等更新世晚期人类化石特征比较进步,在演化上属于与道县相似的现代类型人类。值得注意的是,这些研究进展在引起对现代人在东亚地区出现和扩散关注的同时,古人类学界对其中涉及的许多问题还存在争论。本文在回顾分析这些研究进展的基础上,就相关问题进行了讨论。     

瘤背石磺的形态、习性和生殖行为

2003年5月～2004年5月研究了上海崇明瘤背石磺(Onchidium struma)的形态特征、生活习性,分别对其消化、呼吸、循环、排泄、生殖、神经等六大系统进行了阐述。结果表明,瘤背石磺生活在潮间带高潮区滩涂的芦苇丛里,摄食泥滩上的有机质和单胞藻类;雌雄同体、异体交配、卵生。生殖系统包括生殖器和雌、雄交接器三部分：生殖器由两性腺、卵黄腺和蛋白腺组成;雄性交接器由输精管、附性腺、阴茎、刺激器等组成,雄性生殖孔位于右侧第一触角中部;雌性交接器由输卵管、受精囊、阴道等组成,雌性生殖孔位于肛门右侧约5．0mm处的腹足与外套膜的交界处。本文并详细描述了石磺的交配行为。     

Phylogenetic relationships of Middle American cichlids (Cichlidae, Heroini) based on combined evidence from nuclear genes, mtDNA, and morphology

Heroine cichlids are the second largest and very diverse tribe of Neotropical cichlids, and the only cichlid group that inhabits Mesoamerica. The taxonomy of heroines is complex because monophyly of most genera has never been demonstrated, and many species groups are without applicable generic names after their removal from the catch-all genus Cichlasoma (sensu Regan, 1905). Hence, a robust phylogeny for the group is largely wanting. A rather complete heroine phylogeny based on cytb sequence data is available [Concheiro Pérez, G.A., Říčan O., Ortí G., Bermingham, E., Doadrio, I., Zardoya, R. 2007. Phylogeny and biogeography of 91 species of heroine cichlids (Teleostei: Cichlidae) based on sequences of the cytochrome b gene. Mol. Phylogenet. Evol. 43, 91–110], and in the present study, we have added and analyzed independent data sets (nuclear and morphological) to further confirm and strengthen the cytb-phylogenetic hypothesis. We have analyzed a combined cytb-nuclear (RAG1 and two S7 introns) data set of 48 species representing main heroine lineages to achieve further resolution of heroine higher taxonomic levels and a combined cytb-morphological data set of 92 species to stabilize generic taxonomy. The recovered phylogenies supported the circumamazonian—CAM—Heroini (sensu Concheiro Peréz et al., 2007) as a monophyletic group, that could be divided into six main clades: (1) australoheroines (the southernmost heroine genus Australoheros), (2) nandopsines (the Antillean genus Nandopsis), (3) caquetaines (including the north western Amazonian genera Caquetaia and Heroina), (4) astatheroines (including Astatheros, Herotilapia and Rocio), (5) amphilophines (including Amphilophus and related genera), and (6) herichthyines (including Herichthyis and related genera). Nuclear and mitochondrial data partitions arrived at highly congruent topologies. Suprageneric relationships were influenced mainly by the nuclear signal, as well as the most basal phylogenetic position of Australoheros within CAM heroines. The new phylogeny of the tribe Heroini provides robust framework to stabilize the taxonomy of the group and for future comparative studies on these morphologically and ecologically diverse freshwater fishes. Morphology was mostly informative at the genus level and aid in determining the monophyly and composition of heroine genera. Upon acceptance of all putative genera, as recovered in this study, the Heroini would be with 35 genera the most genus-rich clade of Neotropical cichlids.     

Morphological differences between larvae and in vitro-cultured adults of Anisakis simplex (sensu stricto) and Anisakis pegreffii (Nematoda: Anisakidae)

Proper identification of Anisakis species infecting host fishes is very important to both human health and fish disease diagnosis. The foremost problem in the identification of Anisakis larvae in fishes is that L3 larvae cannot be easily differentiated morphologically, especially between A. simplex (sensu stricto) (s.s.) (Rudolphi, 1809) and A. pegreffii Campana-Rouget et Biocca, 1955. Instead, molecular means such as allozyme, mitochondrial DNA (mtDNA) cox2 region and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses had been successfully used. In this study, morphological differences of L3 larvae collected from fishes and in vitro-cultured L4 larvae and adult A. simplex (s.s.) and A. pegreffii were evaluated. Anisakis larvae were collected from 7 different host fishes within Japan. Undamaged A. simplex (s.s.) and A. pegreffii collected from Oncorhynchus keta (Walbaum) and Scomber japonicus Houttuyn, respectively, were used for in vitro-culture in order to obtain L4 and adult stages. Species identification was confirmed by PCR-RFLP analysis of the ITS region (ITS1-5.8S-ITS2) of ribosomal DNA and by mtDNA cox2 gene sequencing. Results revealed that L3, L4 and adult stages of A. simplex (s.s.) and A. pegreffii are morphologically distinguishable based on ventriculus length, wherein the former has longer ventriculus (0.90–1.50 mm) than the latter (0.50–0.78 mm). For oesophagus/ventriculus ratio, these two species are distinguishable only during L4 and adult stages. Also, adult male A. simplex (s.s.) and A. pegreffii were found to be distinguishable by differences in the distribution pattern of the caudal papillae, particularly the 3rd pair of distal papillae.     

NMR insights into a megadalton-size protein self-assembly

Protein self-association is critical to many biological functions. However, atomic-level structural characterization of these assemblies has remained elusive. In this report we present insights into the mechanistic details of the process of self-association of the 136-residue GTPase effector domain (GED) of the endocytic protein dynamin into a megadalton-sized soluble mass. Our approach is based on NMR monitoring of regulated folding and association through Gdn-HCl titration. The results suggest the evolution of a sequence–self-association paradigm. Equally significantly, the study demonstrates an elegant bottom-up strategy that can render large protein self-assemblies accessible to NMR investigations that have remained difficult to date.     

Plant cover estimation based on the beta distribution in grassland vegetation

Cover is the most frequently used measure of abundance in vegetation surveys of grasslands, and various qualitative and semi-quantitative methods have been developed for visual estimation of this metric. Field survey is usually made with a point-grid plate. The frequency distributions of cover derived from point-grid counts follow a beta distribution. Combining point-grid counts from a field survey and the beta distribution for a statistical analysis, we developed an effort-saving cover-measurement method. Cover is measured with a transparent plastic plate on which, for example, 10 × 10 = 100 points are arranged in a lattice with 1-cm grid spacing (thus, one point count represents 1 cm² of cover). N quadrats are set out at randomly dispersed sites in a grassland, and, in each, the plastic plate is used for making counts. The number of grid points located above a given species is counted in every quadrat until the number of counted points reaches a given value c, which is determined in advance. If the number of counted points reaches c in a quadrat, the count is stopped and the quadrat is classified in the category “>c”. In quadrats where c is not attained, full point counts above the species bodies are made. Let g be the number of observed quadrats whose cover is ≤c. Using these g cover measurements and the number of quadrats (N − g) with cover >c, we can quantitatively estimate cover for each species and the spatial pattern index value based on the maximum likelihood method. In trial counts using this method, the time savings varied between 5% and 41%, depending on the shape of the cover frequency distribution. The mean cover value estimates agreed well with conventional measures without a stopping point (i.e., based on full counts of all points in each quadrat).     

Morphological and functional characterization of BcMF13 in the antisense-silenced plants of Brassica campestris ssp. chinensis var. parachinensis

The gene Brassica campestris male fertility 13 (BcMF13, GenBank accession number EF158459) was isolated as a reproductive organ-specific gene from Chinese cabbage (Brassica campestris L. ssp. chinensis Makino, syn. B. rapa ssp. chinensis). It is exclusively expressed in stage four and five flower buds of fertile lines and is most strongly expressed in stamens. Here, we report a functional characterization of this BcMF13 gene in the antisense-silenced plants. The inflorescence of the BcMF13 mutant was compacted with anthers curved outside. The fertility of this mutant was greatly reduced with less than 5 seeds per silique. Under scanning electron microscopy, the mutant demonstrated numerous shriveled pollen grains with deep invaginations. The frequency of normal pollen grains was just 45.34%. The pollen mother cell, the tetrad, and the mature pollen of the BcMF13 mutant were abnormal resulting in the poor pollen vitality. Germination test in vivo suggested BcMF13 delayed the pollen tubes’ extension in the style. All these indicated BcMF13 had a vital role in pollen development of Chinese cabbage.     

Photosynthetic electron transport and proton flux under moderate heat stress

Moderate heat stress has been reported to increase PSI cyclic electron flow (CEF). We subjected leaves of Arabidopsis (Arabidopsis thaliana) mutants disrupted in the regulation of one or the other pathway of CEF flow—crr2 (chlororespiratory reduction, deficient in regulation of chloroplast NAD(P)H dehydrogenase-dependent CEF) and pgr5 (proton gradient regulation, proposed to have reduced efficiency of antimycin-A-sensitive-CEF regulation) to moderate heat stress. Light-adapted leaves were switched from 23 to 40°C in 2 min. Gas exchange, chlorophyll fluorescence, the electrochromic shift (ECS), and P700 were measured. Photosynthesis of crr2 and pgr5 was more sensitive to heat and had less ability to recover than the genetic background gl. The proton conductance in light was increased by heat and it was twice as much in pgr5, which had much smaller light-induced proton motive force. We confirmed that P700 becomes more reduced at high temperature and show that, in contrast, the proportion of PSII open centers (with Q _A oxidized) increases. The two mutants had much slower P700⁺ reduction rate during and after heat than gl. The proportion of light absorbed by PSI versus PSII was increased in gl and crr2 during and after heat treatment, but not in pgr5. We propose that heat alters the redox balance away from PSII and toward PSI and that the regulation of CEF helps photosynthesis tolerate heat stress.