细叶马先蒿根系发育形态学研究

细叶马先蒿为玄参科多年生草本植物。年生产周期明显缩短。根系营养生长至花期为粗壮主根与纤细侧根并存,果期侧根几乎全部枯萎脱落,所存留根系皆呈乳白色。由胚根形成的初生主根根毛密集,初生木质部二原型。侧生分生组织只有形成层而无木栓形成层。根表皮细胞经解离后略呈不规则方形片状,横切面为平周长梭形,进行垂周分裂增加梭形根表皮细胞长度,以适应根的增粗生长。根表皮脱落时,外皮层以同样生长方式代替脱落的表皮。在年     

Trophic divergence of Lake Kivu cichlid fishes along a pelagic versus littoral habitat axis

Local adaptation to the littoral and pelagic zones in two cichlid haplochromine fish species from Lake Kivu was investigated using morphometrics. Cranial variation and inferred jaw mechanics in both sexes of the two species across the two habitat types were quantified and compared. Comparisons of littoral versus pelagic populations revealed habitat‐specific differences in the shape of the feeding apparatus. Also, kinematic transmission of the anterior jaw four‐bar linkage that promotes greater jaw protrusion was higher in the pelagic zone than in the littoral zone for both species. Inferred bite force was likewise higher in pelagic zone fish. There were also sex‐specific differences in craniofacial morphology as males exhibited longer heads than females in both habitats. As has been described for other cichlids in the East African Great Lakes, local adaptation to trophic resources in the littoral and pelagic habitats characterizes these two Lake Kivu cichlids. Similar studies involving other types of the Lake Kivu fishes are recommended to test the evidence of the observed trophic patterns and their genetic basis of divergences.     

Adaptations to Captivity in the Butterfly Pieris brassicae (L.) and the Implications for Ex situ Conservation

Captive breeding has been suggested as a method of conserving many threatened vertebrates, and is increasingly being proposed as a valuable conservation strategy for invertebrates. Potential genetic problems associated with ex situ conservation are widely recognized, but a further issue has received less attention: the possibility that populations will undergo adaptation to the captive environment, rendering them less well adapted to survival in the wild. We investigated six traits related to dispersal and reproduction in a culture of the large white butterfly Pieris brassicae (L.), that had been captive for c. 100–150 generations, and in recently wild stock reared simultaneously in a common environment. Individuals in the captive culture were heavier, with smaller wings and lower wing aspect ratios. Females from the captive culture laid many more eggs in cage experiments, and had higher ovary mass at the time of peak egg production. These differences are consistent with adaptation to captive conditions. Over time, similar evolutionary changes may affect invertebrates reared in ex situ conservation programmes, decreasing the likelihood that these species can be re-established in the wild. Although the timescale over which most vertebrates are likely to adapt to captivity is longer, and the traits involved will be different, invertebrates like P. brassicae may also provide a model of potential problems in long-term ex situ conservation programmes for both invertebrates and vertebrates. We suggest that measures to reduce or slow adaptation to captivity should be introduced alongside measures to reduce deleterious genetic effects in captive populations.     

The cranial morphology of the Botocudo Indians,Brazil

The Botocudo Indians were hunter‐gatherer groups that occupied the East‐Central regions of Brazil decimated during the colonial period in the country. During the 19th century, craniometric studies suggested that the Botocudo resembled more the Paleoamerican population of Lagoa Santa than typical Native Americans groups. These results suggest that the Botocudo Indians might represent a population that retained the biological characteristics of early groups of the continent, remaining largely isolated from groups that gave origin to the modern Native South American variation. Moreover, recently, some of the Botocudo remains have been shown to have mitochondrial and autosomal DNA lineages currently found in Polynesian populations. Here, we explore the morphological affinities of Botocudo skulls within a worldwide context. Distinct multivariate analyses based on 32 craniometric variables show that 1) the two individuals with Polynesian DNA sequences have morphological characteristics that fall within the Polynesian and Botocudo variation, making their assignation as Native American specimens problematic, and 2) there are high morphological affinities between Botocudo, Early Americans, and the Polynesian series of Easter Island, which support the early observations that the Botocudo can be seen as retaining the Paleoamerican morphology, particularly when the neurocranium is considered. Although these results do not elucidate the origin of the Polynesian DNA lineages among the Botocudo, they support the hypothesis that the Botocudo represent a case of late survival of ancient Paleoamerican populations, retaining the morphological characteristics of ancestral Late Pleistocene populations from Asia. Am J Phys Anthropol 157:202–216, 2015. © 2015 Wiley Periodicals, Inc.     

Digit ratios, secondary sexual characters and condition in barn swallows Hirundo rustica

The second and fourth digit length ratio (2D:4D) is sexuallydimorphic in many vertebrates. This ratio has been suggestedto provide an estimate of steroid levels encountered duringprenatal development, which may have organizational consequencesfor physiology and behavior of adults. However, recent studiesshowed that the relation between digit ratio and steroids seemsinconsistent and may vary among species and populations. Wetested the hypothesis that digit ratios would be correlatedwith the expression of secondary sexual characters, using thebarn swallow (Hirundo rustica) as a model system. This was doneby testing whether variation in 2D:4D ratio was correlated withtail length and features of song, which are important secondarysexual characters positively correlated with circulating steroidconcentration in adult birds. Furthermore, we examined the predictionthat male and female digit ratios would correlate with bodymass in an antagonistic way. There was no significant sexualdimorphism in digit ratio, which may be due to low levels ofsexual selection in this population. Adult right 2D:4D ratiowas negatively linked to tail length but not to male song output.Moreover, right 2D:4D ratio was negatively correlated with bodymass in male and positively in females. These results are consistentwith high digit ratios reflecting low levels of testosteronein this bird species.     

天然真菌与人工发酵制品对免疫系统的影响研究概况

整理分析有关真菌及其生物技术制品生物活性的研究文献,发现真菌类中药资源丰富、品种繁多、成分复杂、药理作用广泛。目前已被动物实验或临床研究证实具有显著生物活性的主要成分是多糖类、三萜类、核苷类以及多肽类等天然化合物。尤其是作为真菌细胞结构物质的高分子多糖体对机体免疫系统具有显著的影响。如在保护机体免疫器官、增加免疫器官重量,以及对单核吞噬细胞系统、T细胞、B细胞、红细胞、NK细胞、LAK细胞、补体系统、白细胞介素、干扰素、集落刺激因子、肿瘤坏死因子及一氧化碳等多项或单项免疫功能具有显著的增强或调节作用。在抗病毒与抗肿瘤免疫等方面显示出自身特点和优势。虽然也有一些真菌及其提取物被证明对机体免疫功能具有显著的、与药物剂量相关的抑制作用,但并未发现对机体免疫器官或免疫细胞有任何的毒副反应。作者拟将20年来有关真菌及其提取物对机体免疫系统的影响研究文献进行了整理,并按免疫功能分类进行了综述,对相关问题在文后还作了讨论,以期为真菌类药物在医学上进行深入的临床研究与应用提供思路。     

23种顶蒴藓类孢子形态的观察

报道了中国２３种顶蒴藓类孢子的形态特征。观察结果显示：孢子形状有两类,球形和卵球形。孢子直径可分为４组：１０μm以下、１１－２０μm、２１－３０μm和３１μm以上。萌发孔有３种类型：近极薄壁区、单裂缝和无萌发孔。外壁纹饰有４种：棒状、瘤状、疣状和鼓槌状。孢子颜色有６种：黄褐色、黑褐色、金黄色、草绿色和紫红色。藓类孢子体积不同物种间有差异,但球形和卵球形是基本类型。苔藓孢子的萌发孔有３种类型：三裂缝为类     

Characterization of the crustose red alga Peyssonnelia japonica (Rhodophyta,Gigartinales) and its taxonomic relationship with Peyssonnelia boudouresquei based on morphological and molecular data

The vegetative and reproductive morphology of the crustose red alga Peyssonnelia japonica (Segawa) Yoneshigue was re‐examined based on the holotype specimen and recent collections from various localities in Japan, including the type locality, and Hawaii. This species is characterized by the following features: thallus with appressed margins, perithallial filaments arising from the entire upper surface of each hypothallial cell (the Peyssonnelia rubra‐type), easily separable perithallial filaments in a gelatinous matrix, hypothallial filaments arranged in parallel rows, unicellular rhizoids, hypobasal calcification, gonimoblasts derived mainly from connecting filaments, and spermatangia produced in a series of whorls comprised of one to four paired spermatangia surrounding each central cell (the Peyssonnelia dubyi‐type). In addition to these features, the dimensions of the vegetative and reproductive structures of Peyssonnelia boudouresquei Yoneshigue described from Brazil were consistent with those of P. japonica. Molecular phylogenetic analyses using partial 26S rDNA, rbcL, and cox2‐3 spacer DNA sequences also supported the monophyly of P. japonica (from 16 localities in Japan and one locality in Hawaii) and P. boudouresquei (from two localities in Brazil). Therefore, P. boudouresquei may be a taxonomic synonym of P. japonica. However, considering the relatively high sequence divergences between the two taxa (2.1–2.5% in partial 26S rDNA, 5.9–6.7% in rbcL, and 5.8–6.7% in cox2‐3 spacer), and the relatively limited geographic sampling ranges, we reserve the taxonomic conclusion until further morphological and genetic data of the specimens from other geographic areas connecting Japan and Brazil become available.