中国东方铃蟾(Bombina orientalis)皮肤中C_(-12-b)肽的分离与鉴定

东方铃蟾鲜皮的甲醇提取液,可引起大鼠离体平滑肌的收缩。此液经碱性氧化铝柱层析分离,其80%乙醇洗脱的 C 组分显示生物活性。C 组分再经葡聚糖凝胶 G-15柱分离,其活性较强的早期洗脱组分 C_(_12),可被糜蛋白酶水解灭活,但其活性并不被5-HT 拮抗剂赛庚啶[2×10~(-6)mol/L]完全拮抗。继用反相高效液相色谱(RP-HPLC)分析,见分离出的 C_(_12_h)峰与铃蟾肽~*(Bombesin,BBS)的出峰时间相同,且具相同的氨基酸组成。上述实验结果提示,C_(_12_h)肽可能就是铃蟾肽。     

Immune-complex-trapping cells in the spleen of the oriental fire-bellied toad,Bombina orientalis

Summary The spleen of the oriental fire-bellied toad, Bombina orientalis, consists of well-developed white pulp, separated from the lymphocytic marginal zone by the connective tissue boundary layer. Injection of peroxidase-conjugated rabbit anti-peroxidase revealed that these immune complexes were localized on the surface of acid-phosphatase-positive and non-specific-esterasepositive cells in the white pulp. The majority of immunecomplex-trapping cells were present around the blood vessels. Cell processes of some of these cells penetrated into the wall of blood vessels. The significance of the present findings is discussed with respect to the evolution of immune-complex-trapping cells in the spleen.     

Maternal effects on offspring growth and development depend on environmental quality in the frogBombina orientalis

Summary Differences in maternal investment and initial offspring size can have important consequences for offspring growth and development. To examine the effects of initial size variability in the frogBombina orientalis, we reared larvae (N=360) in one of two treatments representing different levels of environmental quality. We used snout-vent length at the feeding stage (stage 25, Gosner 1960) as a measure of maternal investment. In a “low quality” treatment, larvae were reared with two conspecific tadpoles and food was limited, whereas in a “high quality” treatment, larvae were reared individually and were fed ad libitum. Among tadpoles reared in the low quality treatment, individuals that were initially small had smaller body sizes through metamorphosis and longer larval periods than individuals that were initially large. Among tadpoles reared in the high quality treatment, initial size had only a weak influence on later larval size, and did not significantly affect metamorphic size of the duration of the larval period. This interaction between maternal investment and rearing conditions suggests that production of initially small offspring could be advantageous if these offspring develop in relatively benign environments, but disadvantageous if environments are more severe. These findings are discussed in light of previous studies that have demonstrated such interactions in organisms with complex life cycles.     

Eight new microsatellite loci for the critically endangered fire‐bellied toad Bombina bombina and their cross‐species applicability among anurans

We describe eight new microsatellite loci for the critically endangered fire‐bellied toad, Bombina bombina. Seven of them are polymorphic with two to seven alleles per locus, an expected heterozygosity between 0.41 and 0.8, and an observed heterozygosity between 0.27 and 0.7. The yield of new loci was relatively low, presumably due to mildly repetitive sequence motifs in microsatellite flanking regions. As typical for anurans, cross‐species amplification was limited (here, to congeners Bombina orientalis and Bombina variegata). Combining these new loci with those already available provides a reasonable number of loci for population studies and pedigree analysis in Bombina.     

Demographic responses to weather fluctuations are context dependent in a long‐lived amphibian

Weather fluctuations have been demonstrated to affect demographic traits in many species. In long‐lived organisms, their impact on adult survival might be buffered by the evolution of traits that reduce variation in interannual adult survival. For example, skipping breeding is an effective behavioral mechanism that may limit yearly variation in adult survival when harsh weather conditions occur; however, this in turn would likely lead to strong variation in recruitment. Yet, only a few studies to date have examined the impact of weather variation on survival, recruitment and breeding probability simultaneously in different populations of the same species. To fill this gap, we studied the impact of spring temperatures and spring rainfall on survival, on reproductive skipping behavior and on recruitment in five populations of a long‐lived amphibian, the yellow‐bellied toad (Bombina variegata). Based on capture–recapture data, our findings demonstrate that survival depends on interactions between age, population and weather variation. Varying weather conditions in the spring result in strong variation in the survival of immature toads, whereas they have little effect on adult toads. Breeding probability depends on both the individual's previous reproductive status and on the weather conditions during the current breeding season, leading to high interannual variation in recruitment. Crucially, we found that the impact of weather variation on demographic traits is largely context dependent and may thus differ sharply between populations. Our results suggest that studies predicting the impact of climate change on population dynamics should be taken with caution when the relationship between climate and demographic traits is established using only one population or few populations. We therefore highly recommend further research that includes surveys replicated in a substantial number of populations to account for context‐dependent variation in demographic processes.     

Bombinins, antimicrobial peptides from Bombina species

The skin secretions of Bombina species contain peptides and small proteins with interesting biological properties. These include bombesin, thyrotropin releasing hormone, BSTI and Bv8. In this review, the biosynthesis and antimicrobial activity of two groups of peptides, bombinins and bombinins H, are described. To date, these have only been found in Bombina skin. They are derived from common precursors containing one or two bombinin copies at the amino and a single bombinin H at the carboxyl end. Bombinins are active against Gram-positive and Gram-negative bacteria and fungi but virtually inactive in haemolysis assays. Conversely, bombinins H have lower bactericidal activities but lyse erythrocytes. In the skin secretions, bombinins H are present in two sizes with either 20 or 17 amino acids. Moreover, they occur as epimers with either an l- or a d-amino acid at position 2. An enzyme catalyzing this inversion of chirality of an amino acid in peptide linkage has been isolated from Bombina skin secretions. In different tests, also with different stages of the life cycle of Leishmania parasites, the d-forms were found to be more active. Biophysical studies have yielded some insight into the different behaviours of the epimers in model membranes.     

Life history tactics shape amphibians’ demographic responses to the North Atlantic Oscillation

Over the last three decades, climate abnormalities have been reported to be involved in biodiversity decline by affecting population dynamics. A growing number of studies have shown that the North Atlantic Oscillation (NAO) influences the demographic parameters of a wide range of plant and animal taxa in different ways. Life history theory could help to understand these different demographic responses to the NAO. Indeed, theory states that the impact of weather variation on a species’ demographic traits should depend on its position along the fast–slow continuum. In particular, it is expected that NAO would have a higher impact on recruitment than on adult survival in slow species, while the opposite pattern is expected occur in fast species. To test these predictions, we used long‐term capture–recapture datasets (more than 15,000 individuals marked from 1965 to 2015) on different surveyed populations of three amphibian species in Western Europe: Triturus cristatus, Bombina variegata, and Salamandra salamandra. Despite substantial intraspecific variation, our study revealed that these three species differ in their position on a slow–fast gradient of pace of life. Our results also suggest that the differences in life history tactics influence amphibian responses to NAO fluctuations: Adult survival was most affected by the NAO in the species with the fastest pace of life (T. cristatus), whereas recruitment was most impacted in species with a slower pace of life (B. variegata and S. salamandra). In the context of climate change, our findings suggest that the capacity of organisms to deal with future changes in NAO values could be closely linked to their position on the fast–slow continuum.     

大蹼铃蟾与昭觉林蛙的肌肉系统比较

本文从肌肉系统对大蹼铃蟾和昭觉林蛙进行了观察比较,结果表明这两种无尾两栖类的从存在一定差异。大蹼铃蟾的肌肉结合紧密程度不如昭觉林蛙,且肌肉分节现象较昭觉林蛙了后,以形态－功能－适应三位一体的分析原理为依据,就２个种存在的形态差异,从功能与适应的意义和生物进化地角度两个方面进行了分析和探讨。     

东方铃蟾消化道组织学的初步研究

采用组织学方法对东方铃蟾的消化道进行了研究。结果表明:肠分为十二指肠、空肠和大肠。消化道管壁由粘膜层、粘膜下层、肌层和浆膜层构成。食道、胃和肠均为单层柱状上皮。胃和十二指肠的粘膜皱褶最丰富。食道腺为复泡状腺,胃腺属于单管状腺,肠的各段无多细胞腺体,但空肠和大肠有丰富的杯状细胞。肌层均为平滑肌,内层环肌较厚,外侧纵肌较薄,其中大肠的外侧纵肌最发达。