Effects of Waking Time and Breakfast Intake Prior to Evaluation of Psychomotor Performance in the Early Morning

Many studies conducted in the field of chronobiology report diurnal fluctuation in cognitive and physical performance that occurs in phase with the body temperature circadian rhythm. Waking time and whether or not breakfast is consumed are currently considered to influence the diurnal fluctuation in data collected in the morning at 06∶00 h and evening at 18∶00 h. Nineteen male subjects participated in four test sessions to examine if wake‐up time (04∶00 h or 05∶00 h) and eating or not eating breakfast influence psychomotor performance capacity at 06∶00 h. All four sessions were separated by ≥36 h and were completed in a counterbalanced order. Each test session comprised sign cancellation, Epworth Sleepiness Scale, simple reaction time, and manual dexterity tests. Most of the results indicate that psychomotor performance when evaluated at 06∶00 h under each of the four different study situations (two waking times and two breakfast conditions) is not statistically significantly different. Consequently, previous results that documented diurnal fluctuations in morning and evening performance capacities, with test sessions at 06∶00 h, are confirmed. Being less efficient in the early morning than in the afternoon potentially exposes people to elevated risk of accident and injury at this time of the day. Prior waking time and/or consumption of a light meal, plus other countermeasures mentioned in the literature, are insufficient to prevent this risk.     

Cloning and characterisation of novel cystatins from elapid snake venom glands

Snake venoms contain a complex mixture of polypeptides that modulate prey homeostatic mechanisms through highly specific and targeted interactions. In this study we have identified and characterised cystatin-like cysteine-protease inhibitors from elapid snake venoms for the first time. Novel cystatin sequences were cloned from 12 of 13 elapid snake venom glands and the protein was detected, albeit at very low levels, in a total of 22 venoms. One highly conserved isoform, which displayed close sequence identity with family 2 cystatins, was detected in each elapid snake. Crude Austrelaps superbus (Australian lowland copperhead) snake venom inhibited papain, and a recombinant form of A. superbus cystatin inhibited cathepsin L ≅ papain > cathepsin B, with no inhibition observed for calpain or legumain. While snake venom cystatins have truncated N-termini, sequence alignment and structural modelling suggested that the evolutionarily conserved Gly-11 of family 2 cystatins, essential for cysteine protease inhibition, is conserved in snake venom cystatins as Gly-3. This was confirmed by mutagenesis at the Gly-3 site, which increased the dissociation constant for papain by 10⁴-fold. These data demonstrate that elapid snake venom cystatins are novel members of the type 2 family. The widespread, low level expression of type 2 cystatins in snake venom, as well as the presence of only one highly conserved isoform in each species, imply essential housekeeping or regulatory roles for these proteins.     

爬行动物温度依赖性性别决定研究进展

综述了近年来爬行类温度依赖性性别决定的最新进展。回顾了爬行类TSD的特点,并从性激素方面和分子水平上探讨了TSD的可能机制。     

A novel prothrombin activator from the venom of Micropechis ikaheka: isolation and characterization

A novel prothrombin activator, Mikarin, has been isolated from Micropechis ikaheka venom. It is a single polypeptide chain metalloproteinase with the apparent molecular weight of 47kDa. Mikarin exhibits Ca(2+)-independent prothrombin activation, but no effects on other blood coagulation factors, such as factor X and fibrinogen. Mikarin is the first member of group I prothrombin activators from elapid venom. Like other high-molecular-weight snake venom proteinases, it has three structural domains, metalloproteinase and disintegrin-like and Cys-rich domains, and belongs to the P-III class of snake venom metalloproteinases. The N-terminal of Mikarin exhibits 76% sequence identity with Cobrin, a metalloproteinase identified from Naja naja venom, but very lower identities were found when compared with those from viperid and crotalid venom. In addition, the presence of disintegrin-like and Cys-rich domains in snake venom metalloproteinases with diverse biological activities suggests that these domains may be important for their function.     

上海大金山岛的两栖爬行动物

大金山岛位于杭州湾东北角,是上海市最高和最大的基岩岛.该岛人为干扰较少,保留着上海地区珍贵的动植物资源原始本底.2017年5月至2018年10月,在两栖爬行动物的繁殖季节对大金山岛进行了6次全面调查.结果显示,大金山岛是上海市爬行动物多样性最丰富的地区.     

Ultrastructure of epidermal sensory receptors in Amphibolurus barbatus (Lacertilis: Agamidae)

Summary The histological and ultrastructural organisation of the epidermal sensory organs in Amphibolurus barbatus has been described with respect to their position and possible functions. The sensory organs, located at the scale's edge, are most numerous in scales of the dorsal surface of the head. Most other scales of the body surface have two receptors located laterally to the spine or keel of the scale. In the imbricate scales of the ventral body region, the receptors lie just beneath the reinforced scale lip. Scanning electron microscopy has revealed the surface of the organ to be a crater lacking any surface projections. These sensory organs have a dermal papilla consisting of a nerve plexus and loose connective tissue. The nerve fibres arising from the plexus, pass to the epidermal columnar cells, where some form nerve terminals at the base of the cells, while others pass between them to form nerve terminals embedded in a superficial layer of cuboidal cells. The superficial terminals are held against the overlying keratin by masses of tonofilaments. The keratin is thickened to form a collar around the periphery of the organ but is only about 0.5 m thick immediately above it. Mechanical deformation of the scale's spine or reinforced scale lip may initiate stimulation of the nerve terminals described.     

Do lizards and snakes really differ in their ability to take large prey? A study of relative prey mass and feeding tactics in lizards

Adaptations of snakes to overpower and ingest relatively large prey have attracted considerable research, whereas lizards generally are regarded as unable to subdue or ingest such large prey items. Our data challenge this assumption. On morphological grounds, most lizards lack the highly kinetic skulls that facilitate prey ingestion in macrostomate snakes, but (1) are capable of reducing large items into ingestible-sized pieces, and (2) have much larger heads relative to body length than do snakes. Thus, maximum ingestible prey size might be as high in some lizards as in snakes. Also, the willingness of lizards to tackle very large prey items may have been underestimated. Captive hatchling scincid lizards (Bassiana duperreyi) offered crickets of a range of relative prey masses (RPMs) attacked (and sometimes consumed parts of) crickets as large as or larger than their own body mass. RPM affected foraging responses: larger crickets were less likely to be attacked (especially on the abdomen), more likely to be avoided, and less likely to provide significant nutritional benefit to the predator. Nonetheless, lizards successfully attacked and consumed most crickets ≤35% of the predator’s own body mass, representing RPM as high as for most prey taken by snakes. Thus, although lizards lack the impressive cranial kinesis or prey-subduction adaptations of snakes, at least some lizards are capable of overpowering and ingesting prey items as large as those consumed by snakes of similar body sizes.     

湖南省永州都庞岭自然保护区爬行动物群落结构的调查研究

本文报道了湖南永州都庞岭自然保护区的４１ 种爬行动物, 它们隶属２ 目,１２ 科, 其中龟鳖目３ 科（平胸龟科、龟科、鳖科） ３ 种; 有鳞目中的蜥蜴亚目５ 科（鬣蜥科、壁虎科、石龙子科、蜥蜴科、双足蜥科） ８ 种;蛇亚目４ 科（闪鳞蛇科、游蛇科、眼镜蛇科、蝰科） ３０ 种。保护区内的爬行动物有１２－２％ 属广布动物, ８７－８％ 属东洋界种类。     

Invader danger: lizards faced with novel predators exhibit an altered behavioral response to stress

Animals respond to stressors by producing glucocorticoid stress hormones, such as corticosterone (CORT). CORT acts too slowly to trigger immediate behavioral responses to a threat, but can change longer-term behavior, facilitating an individual's survival to subsequent threats. To be adaptive, the nature of an animal's behavior following elevated CORT levels should be matched to the predominant threats that they face. Seeking refuge following a stressful encounter could be beneficial if the predominant predator is a visual hunter, but may prove detrimental when the predominant predator is able to enter these refuge sites. As a result, an individual's behavior when their CORT levels are high may differ among populations of a single species. Invasive species impose novel pressures on native populations, which may select for a shift in their behavior when CORT levels are high. We tested whether the presence of predatory invasive fire ants (Solenopsis invicta) at a site affects the behavioral response of native eastern fence lizards (Sceloporus undulatus) to elevated CORT levels. Lizards from an uninvaded site were more likely to hide when their CORT levels were experimentally elevated; a response that likely provides a survival advantage for lizards faced with native predatory threats (e.g. birds and snakes). Lizards from a fire ant invaded site showed the opposite response; spending more time moving and up on the basking log when their CORT levels were elevated. Use of the basking log likely reflects a refuge-seeking behavior, rather than thermoregulatory activity, as selected body temperatures were not affected by CORT. Fleeing off the ground may prove more effective than hiding for lizards that regularly encounter small, terrestrially-foraging fire ant predators. This study suggests that invasive species may alter the relationship between the physiological and behavioral stress response of native species.     

昆明市宠物市场爬行动物贸易调查

目的了解昆明市宠物市场上销售爬行动物的种类、数量、来源、价格及市场管理情况,为爬行类资源的保护和管理提供基础资料。方法采用观察和访谈相结合方式进行调查。结果昆明市6个宠物市场爬行动物类共有35种,其中蛇类14种,隶属3科12属;蜥蜴类6种,隶属4科5属;龟类15种,隶属6科12属。国外物种15种,占市场种类的42.9%;国内物种20种,占57.1%。依据《中国物种红色名录》(2004),1种为极危,4种为濒危,2种为易危;属于CITES(2013)附录Ⅱ有5种,附录Ⅲ有3种;属于国家重点保护的有2种。结论昆明市宠物市场爬行动物贸易缺乏相应的法制法规进行监督管理,应尽早制定规章制度加强对市场的管理,使市场更加规范有序。     

Structural data concerning reptilian (tortoise) egg lysozyme

Summary A first series of structural studies allowed a reptilian egg-white lysozyme isolated fromTrionyx gangeticus to be classified among the c (chicken) type lysozymes     

鳄蜥捕食蜥蜴和蛇的现象

鳄蜥(Shinisaurus crocodilurus)主要捕食部分昆虫、蜘蛛、蚯蚓、小型蛙类和小鱼等,但尚未见报道鳄蜥捕食其他相对较大的动物。本文报道了鳄蜥捕食变色树蜥(Calotesversicolor)和翠青蛇(Cyclophiopsmajor)的现象,以全事件记录法观察分析了鳄蜥猎捕这两种爬行动物的行为过程。这次新发现说明鳄蜥食谱较广,具有捕食蜥蜴等个体偏大动物的能力。因此,我们建议在饲养繁育中投喂更多类型的食物以避免营养不良。     

中华鳖孵化一周胚胎的肾脏/尿生殖嵴混合组织的cDNA文库构建与特征

为克隆到与胚胎发育有关的新基因,以孵化一周的中华鳖(Trionyxsinensis)胚胎的肾脏及尿生殖嵴混合组织为原始材料,采用SMART和长距离PCR技术,构建了一个中华鳖cDNA表达文库。分析结果表明,该未扩增的cDNA文库大约含有4.134×105个克隆。任意挑取了192个克隆,提取质粒后用SfiⅠ酶切鉴定表明没有插入片段的克隆为9个,插入了cDNA片段的克隆为183个,插入的cDNA片段大小范围为0.4-3.8kb。其中,插入片段在0.4-1.0kb之间的克隆为19个,在1.1-2.0kb之间的克隆为53个,在2.1-3.0kb之间的克隆为92个,大于3.1kb的克隆为19个。另外,任意挑选45个克隆,提取质粒后,从5′端进行测序,Blast分析表明,除了21个序列在GenBank中找不到同源序列外,其余24个序列在GenBank中均被证实有各自相应的同源序列,这些序列代表6种类型的基因核糖体蛋白基因、代谢酶基因、组织特异性表达的基因、转录因子基因、受体蛋白基因及其它基因。该发育阶段特异性cDNA文库可以进一步用于中华鳖胚胎发育过程中相关基因的鉴定分离、结构功能分析、以及表达调控机制等研究。     

Adenohypophysial cell-types in the pituitary gland of the soft-shelled turtle,Trionyx sinensis

Summary By using various staining techniques, two acidophilic and three basophilic cell-types have been distinguished in the pars distalis of Trionyx sinensis. Seasonal fluctuations in their cytoplasmic granulation, cell and nuclear size have been compared with seasonal patterns of activity in the gonads, adrenals and thyroid. On the basis of the results, specific functions have been ascribed to each cell-type. Basophils 1 activity closely parallels the seasonal thyroid cycle. Basophils 2 are probably FSH-secreting gonadotropes and their activity correlates with the seasonal cycle of spermatogenesis in the seminiferous tubules. The functional activity of the testicular interstitial cells correlates with the secretory pattern of the basophils 3. That these are LH-secreting cells is also suggested by the epididymidal cycle, which indicates a high level of androgen secretion coincident with the rapid degranulation of these cells, at a time of no spermatogenetic activity. Adrenal activity shows no relationship with the basophils 3 cycle, and chromophobic cells may be the locus of ACTH secretion. Acidophils 2 remain stable throughout the year and are probably somatotropes, but acidophils 1 increase their activity in autumn and are likely to be lactotropes.     

The photoreceptors and visual pigments of the garter snake (Thamnophis sirtalis): a microspectrophotometric, scanning electron microscopic and immunocytochemical study

Scanning electron microscopy, immunocytochemistry, and single cell microspectrophotometry were employed to characterize the photoreceptors and visual pigments in the retina of the garter snake, Thamnophis sirtalis. The photoreceptor population was found to be comprised entirely of cones, of which four distinct types were identified. About 45.5% of the photoreceptors are double cones consisting of a large principal member joined near the outer segment with a much smaller accessory member. About 40% of the photoreceptors are large single cones, and about 14.5% are small single cones forming two subtypes. The outer segments of the large single cones and both the principal and accessory members of the doubles contain the same visual pigment, one with peak absorbance near 554 nm. The small single cones contain either a visual pigment with peak absorbance near 482 nm or one with peak absorbance near 360 nm. Two classes of small single cones could be distinguished also by immunocytochemistry and scanning electron microscopy. The small single cones with the 360-nm pigment provide the garter snake with selective sensitivity to light in the near ultraviolet region of the spectrum. This ultraviolet sensitivity might be important in localization of pheromone trails. Accepted: 10 March 1997     

Heat,sight and scent:multiple cues influence foraging site selection by an ambush-foraging snake Hoplocephalus bungaroides(Elapidae)

Most mobile organisms respond to multiple cues when selecting habitat types,and laboratory experiments that manipulate only single cues may fail to reveal the true complexity of habitat-selection behaviour.In south-eastern Australia,broad-headed snakes Hoplocephalus bungaroides(Elapidae)lie in wait under sun-warmed rocks to ambush velvet geckos Oedura leseuerii(Gekkonidae).Previous laboratory work has shown that both the geckos and the snakes actively select hotter rather than colder rocks,and that the snak...