Age-related Variation in Snake Venom: Evidence from Two Snakes (Naja atra and Deinagkistrodon acutus) in Southeastern China

In this study we explored electrophoretic profiles, enzymatic activities and immunoreactivity of neonate and adult venoms from two snakes （Naja atra and Deinagkistrodon acutus） coexisting in southeastern China. Age-related variation in electrophoretic profiles was found in both species and proteolytic and fibrinogenolytic activity was higher in neonate than adult venoms. Neonate D. acutus venom had higher 5＇ nucleotidase, PLA2, hyaluronidase and gelatinolytie activity, but lower esterolytic activity, than adult venom. Neonate and adult D. acutus venoms showed identical phosphomonoesterase, LAO and fibrinolytic activities. Neonate N. atra venom had higher phosphomonoesterase and LAO activity, but lower 5＇ nucleotidase, PLA2, hyaluronidase and Ache activities than adult venom. Neonate and adult N. atra venoms showed similar gelatinolytic activity. Further, age-dependent immunoreactivity was found in both species, and cross-reactions between homologous venoms and antiserums were closely related to venom composition. We speculate that age-related variation in venom characteristics is possibly driven by evolutionary forces associated with ontogenetic shifts in dietary habits, competition and predation pressure.

Maternal Thermal Effects on Female Reproduction and Hatchling Phenotype in the Chinese Skink(Plestiodon chinensis)

We maintained gravid Chinese skinks(Plestiodon chinensis) at three constant temperatures(25, 28 and 31 °C) during gestation, and randomly assigned eggs from each female to one of the same three temperatures for incubation to determine maternal thermal effects on female reproduction and hatchling phenotype. Maternal temperature affected egg-laying date, hatching success and hatchling linear size(snout-vent length, SVL) but not clutch size, egg size, egg component, and embryonic stage at laying. More specifically, females at higher temperatures laid eggs earlier than did those at low temperatures, eggs laid at 31 °C were less likely to hatch than those laid at 25 °C or 28 °C, and hatchlings from eggs laid at 31 °C were smaller in SVL. Our finding that maternal temperature(pre-ovipositional thermal condition) rather than incubation temperature(post-ovipositional thermal condition) affected hatching success indicated that embryos at early stages were more vulnerable to temperature than those at late stages. Our data provide an inference that moderate maternal temperatures enhance reproductive fitness in P. chinensis.

Identifying Intraspecific Variation in Venom Yield of Chinese Cobra(Naja atra) from Ten Populations in China's Mainland

Detailed information on venom yield is helpful in preparing antivenoms and treating snakebites, but such information is lacking for many species of venomous snakes. The Chinese cobra(Naja atra) is a large sized, venomous snake commonly found in southeastern China, where it causes a heavy burden of snakebites. To examine the effects of various factors(morphology, sex, age, season, and geographical origin) on the venom yield in this snake, we collected venom samples of 446 individuals(426 adults and 20 neonates) from 10 populations of N. atra over an eightyear period. We used two variables, lyophilized venom mass(venom yield) and solid content of venom(% solids), to quantify the venom yield. We used linear regression analysis to check if venom yield was related to morphological factors, one-way ANOVA and one-way ANCOVA to detect the sexual, ontogenetic, and geographic variation in venom yield, and repeated-measures ANOVA to examine seasonal shifts in venom yield. Our results indicate that venom yield of N. atra is positively related to the morphological traits examined, with male snakes expelling more venom than females. Venom yield in N. atra was age-related, with elder snakes always expelling more venom than younger ones. Geographic variation in venom yield was also observed, while seasonal variation was not. The solid content of venom was lower in males than in females, but this was not related to morphology, season, age, or geography. Our findings suggest that venom yield in N. atra is influenced by multiple factors, as well as by the interactions among these factors.

Application and Analysis of Wavelet Transform in Image Edge Detection

For the image processing technology, technicians have been looking for a convenient and simple detection method for a long time, especially for the innovation research on image edge detection technology. Because there are a lot of original information at the edge during image processing, thus, we can get the real image data in terms of the data acquisition. The usage of edge is often in the case of some irregular geometric objects, and we determine the contour of the image by combining with signal transmitted data. At the present stage, there are different algorithms in image edge detection, however, different types of algorithms have divergent disadvantages so It is diffi cult to detect the image changes in a reasonable range. We try to use wavelet transformation in image edge detection, making full use of the wave with the high resolution characteristics, and combining multiple images, in order to improve the accuracy of image edge detection.

Thermal preference, thermal tolerance and the thermal dependence of digestive performance in two Phrynocephalus lizards （Agamidae）, with a review of species studied

We reported data on thermal preference, thermal tolerance and the thermal dependence of digestive performance for two Phrynocephalus lizards （P. frontalis and P. versicolor）, and compared data among lizards so far studied worldwide. Mean values for selected body temperature （Tsel） and critical thermal maximum （CTMax） were greater in P versicolor, whereas mean values for critical thermal minimum （CTMin） did not differ between the two species. The two lizards differed in food intake, but not in food passage time, apparent digestive coefficient （ADC） and assimilation efficiency （AE）, across the experimental tem- peratures. Four general conclusions can be drawn from published data. Firstly, thermal preference and thermal tolerance differ among lizards differing in distribution, temporal activity pattern and habitat use. Lizards in thermally more variable regions are better able to tolerate low and high temperatures. Diurnal lizards generally select higher body temperatures than nocturnal lizards, and lizards using habitats with direct sun exposure generally selected higher body temperatures and are better able to tolerate high temperatures. Secondly, CTMax is positively correlated with Tsel. Lizards more likely exposed to extremely high temperatures while active select higher body temperatures than those using shaded habitats. Thirdly, the effects of body temperature on food intake, food passage time, ADC and AE differ among lizards, but it seems to be common among lizards that ADC and AE are less thermally sensitive than food intake and food passage time. Lastly, ADC is dependent on the type of food ingested, with insectivorous lizards digesting food more efficiently than herbivorous lizards

Tail loss affects fecundity but not offspring traits in the Chinese skink Eumeces chinensis

We used the Chinese skink Eumeces chinensis as a model animal to study the effects of tail loss on reproductive in- vestment and offspring traits. A total of 147 wild-captured adult females were divided into four groups according to their tail con- ditions. Tail breaks occurred most frequently in the proximal portion of the tail and least frequently in the distal portion, with the middle portion in between. This finding suggests that tail breaks occurring in nature often entails substantial energetic costs in E. chinensis where the tail is a major site of energy storage. The proportion of females that laid eggs was higher in females with in- tact or completely regenerated tails than in those with broken tails. Following whole-tail autotomy, the clutch size was reduced by 17%, and the clutch mass was reduced by 14%. Females undergoing substantial tail autotomy reduced reproductive investment, and they did so by reducing the number but not the size of eggs produced. None of the egg and hatchling traits was affected by tail loss. Comparing our data with those reported for other oviparous and viviparous skinks allows us to draw two general conclu- sions： one is that fecundity （clutch or litter size） is affected by tail loss in all species so far studied, whereas offspring size is af- fected by tail loss in some species, but not in others; the other is that the reduction in fecundity following tail loss is more evident in species lacking abdominal fat bodies

基于花青素代谢培育蓝色花卉的研究进展

花色是植物吸引昆虫传播花粉的主要因素,对于植物在自然界的生存必不可少,也是观赏植物最重要的性状之一。在蓬勃发展的花卉产业中,色彩各异花卉的培育,可以弥补自然花色的匮乏,但是令人垂涎的蓝色花比较难培育。花色的多样性主要是由花青素及其衍生物的种类和含量等因素决定的,飞燕草色素的合成是形成蓝色花的关键因素,许多植物体内缺少合成飞燕草色素的结构基因。近年来,利用基因工程技术培育蓝色花的研究也时有报道。文中以常见的观赏植物为例,基于花青素代谢调控,从影响飞燕草色素合成的关键因素和不同分子改良途径培育蓝色花等几个方面对植物花朵呈色的机制进行了综述,并展示不同分子育种策略可能在其他领域的应用,为其他植物或经济作物的色泽改良如彩色棉蓝色纤维的培育等提供参考和技术支持。