毛茛属刺果毛茛化学成分研究

从刺果毛茛Ranunculus muricatus Linn.全草乙醇提取物分离得到17个化合物,通过MS、NMR等方法鉴定为:小毛茛内酯(1)、阿魏酸(2)、对羟基香豆酸(3)、原儿茶酸(4)、咖啡酰基(5)、丹参素(6)、丹参素甲酯(7)、山萘酚-3-O-β-D-槐糖-7-O-β-D-葡萄糖苷(8)、槲皮素-3-O-(2’’’-E-咖啡酰基)-α-L-阿拉伯糖-(1→2)-β-D-葡萄糖-7-O-β-D-葡萄糖苷(9)、山萘酚-3-O-β-D-葡萄糖-7-O-β-D-葡萄糖苷(10)、槲皮素-7-O-β-D-葡萄糖苷(11)、槲皮素-3-O-(2’’’-E-咖啡酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(12)、山萘酚-3-O-(2’’’-E-咖啡酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(13)、槲皮素-3-O-(2’’’-E-阿魏酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(14)、山萘酚-3-O-(2’’’-E-对羟基香豆酰基)-β-D-槐糖-7-O-β-D-葡萄糖苷(15)、芹菜素-8-C-α-L-阿拉伯糖-6-C-β-D-葡萄糖苷(16)、芹菜素-6-C-β-D-葡萄糖-8-C-β-D-葡萄糖苷(17)。除化合物4外,其他化合物均为首次从刺果毛茛中分离得到。     

Maternal influences on offspring phenotypes and sex ratios in a multi‐clutching lizard with environmental sex determination

Maternal and environmental factors are important sources of phenotypic variation because both factors influence offspring traits in ways that impact offspring and maternal fitness. The present study explored the effects of maternal factors (maternal body size, egg size, yolk‐steroid allocation, and oviposition‐site choice) and seasonally‐variable environmental factors on offspring phenotypes and sex ratios in a multi‐clutching lizard with environmental sex determination (Amphibolurus muricatus). Maternal identity had strong effects on offspring morphology, but the nature of maternal effects differed among successive clutches produced by females throughout the reproductive season (i.e. maternal identity by environment interactions). The among‐female and among‐clutch variation in offspring traits (including sex ratios) was not mediated through maternal body size, egg size, or variation in yolk steroid hormones. This lack of nongenetic maternal effects suggests that phenotypic variation may be generated by gene by environment interactions. These results demonstrate a significant genetic component to variation in offspring phenotypes, including sex ratios, even in species with environmental sex determination. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 256–266.     

The adaptive significance of temperature-dependent sex determination: experimental tests with a short-lived lizard

Abstract Why is the sex of many reptiles determined by the temperatures that these animals experience during embryogenesis, rather than by their genes? The Charnov‐Bull model suggests that temperature‐dependent sex determination (TSD) can enhance maternal fitness relative to genotypic sex determination (GSD) if offspring traits affect fitness differently for sons versus daughters and nest temperatures either determine or predict those offspring traits. Although potential pathways for such effects have attracted much speculation, empirical tests largely have been precluded by logistical constraints (i.e., long life spans and late maturation of most TSD reptiles). We experimentally tested four differential fitness models within the Charnov‐Bull framework, using a short‐lived, early‐maturing Australian lizard (Amphibolurus muricatus) with TSD. Eggs from wild‐caught females were incubated at a range of thermal regimes, and the resultant hatchlings raised in large outdoor enclosures. We applied an aromatase inhibitor to half the eggs to override thermal effects on sex determination, thus decoupling sex and incubation temperature. Based on relationships between incubation temperatures, hatching dates, morphology, growth, and survival of hatchlings in their first season, we were able to reject three of the four differential fitness models. First, matching offspring sex to egg size was not plausible because the relationship between egg (offspring) size and fitness was similar in the two sexes. Second, sex differences in optimal incubation temperatures were not evident, because (1) although incubation temperature influenced offspring phenotypes and growth, it did so in similar ways in sons versus daughters, and (2) the relationship between phenotypic traits and fitness was similar in the two sexes, at least during preadult life. We were unable to reject a fourth model, in which TSD enhances offspring fitness by generating seasonal shifts in offspring sex ratio: that is, TSD allows overproduction of daughters (the sex likely to benefit most from early hatching) early in the nesting season. In keeping with this model, hatching early in the season massively enhanced body size at the beginning of the first winter, albeit with a significant decline in probability of survival. Thus, the timing of hatching is likely to influence reproductive success in this short‐lived, early maturing species; and this effect may well differ between the sexes.     

Considerations in video playback design: using optic flow analysis to examine motion characteristics of live and computer-generated animation sequences

The increasing use of the video playback technique in behavioural ecology reveals a growing need to ensure better control of the visual stimuli that focal animals experience. Technological advances now allow researchers to develop computer-generated animations instead of using video sequences of live-acting demonstrators. However, care must be taken to match the motion characteristics (speed and velocity) of the animation to the original video source. Here, we presented a tool based on the use of an optic flow analysis program to measure the resemblance of motion characteristics of computer-generated animations compared to videos of live-acting animals. We examined three distinct displays (tail-flick (TF), push-up body rock (PUBR), and slow arm wave (SAW)) exhibited by animations of Jacky dragons (Amphibolurus muricatus) that were compared to the original video sequences of live lizards. We found no significant differences between the motion characteristics of videos and animations across all three displays. Our results showed that our animations are similar the speed and velocity features of each display. Researchers need to ensure that similar motion characteristics in animation and video stimuli are represented, and this feature is a critical component in the future success of the video playback technique.     

国产毛茛属三种植物的核型研究

对国产三种毛茛属 (Ranunclus)植物进行了核型研究 ,其中昆明毛茛 (RanunculuskunmingensisW .T .Wang)染色体数目 2n=1 4及核型 2n =1 4 =6m +4sm +4st为首次报道 ;匍枝毛茛 (R .repenceL .)核型公式为 2n =4x =3 2 =8m +1 2sm +1 0st+2t,它是由两个不同的染色体组组成 ;刺果毛茛 (R .muricatusL .)核型公式为 2n=8x=64=1 0m +2 2sm +2 8st+4t,它也是由两个不同的染色体组组成     

Ovotestes suggest cryptic genetic influence in a reptile model for temperature-dependent sex determination

Sex determination and differentiation in reptiles is complex. Temperature-dependent sex determination (TSD), genetic sex determination (GSD) and the interaction of both environmental and genetic cues (sex reversal) can drive the development of sexual phenotypes. The jacky dragon (Amphibolurus muricatus) is an attractive model species for the study of gene–environment interactions because it displays a form of Type II TSD, where female-biased sex ratios are observed at extreme incubation temperatures and approximately 50 : 50 sex ratios occur at intermediate temperatures. This response to temperature has been proposed to occur due to underlying sex determining loci, the influence of which is overridden at extreme temperatures. Thus, sex reversal at extreme temperatures is predicted to produce the female-biased sex ratios observed in A. muricatus. The occurrence of ovotestes during development is a cellular marker of temperature sex reversal in a closely related species Pogona vitticeps. Here, we present the first developmental data for A. muricatus, and show that ovotestes occur at frequencies consistent with a mode of sex determination that is intermediate between GSD and TSD. This is the first evidence suggestive of underlying unidentified sex determining loci in a species that has long been used as a model for TSD.