Reproductive biology of the fire-bellied toads, Bombina bombina and B. variegata (Anura: Discoglossidae): egg size, clutch size and larval period length differences

Clutch size, egg size, larval size and duration of larval period were estimated for samples of Bombina bombina and B. variegata from several populations. Bombina variegata lays fewer eggs per batch (mean 17.4) than B. bombina (mean 32.5). The volume of B. variegata eggs is 2.4 times greater and the dry weight 2.3 times greater than that of B. bombina. As a consequence, the volume of B. variegata hatchlings and their dry weight are respectively 1.9 times and 2.5 times greater than that of B. bombina. Analysis of variance showed that variation of egg size in B. variegata is significantly greater than in B. bombina. When reared under laboratory conditions freshly metamorphosed individuals of both species showed no difference in body size or weight. Although growth rates are equal, tadpoles of B. variegata reached metamorphosis 14 days earlier than B. bombina tadpoles because of differences in size of hatchlings. Differences in reproductive parameters found for the two European Bombina species can be interpreted as adaptations to contrasting environments in which they breed.     

Hybridization between the fire-bellied toads Bombina bombina and Bombina variegata in the karst regions of Slovakia and Hungary: morphological and allozyme evidence

Geographic variability and genetic interactions in the contact zone between the fire-bellied toads, Bombina bombina and B. variegata, were studied using analysis of morphological and genetic variation in sixteen samples from the Slovak Karst and Aggtelek Karst regions. Genotype frequencies at four marker loci (Ldh-1, Mdh-1, Adk, Hem) demonstrate the existence of a hybrid zone with highly variable population structures. While some samples appear to represent panmictic hybrid populations, other samples are very heterogeneous. Pure individuals of both species occurred together with hybrids at one site. Habitat segregation among genetically differentiated demes probably causes this heterogeneity of population structures. Increased frequencies of the allele Ldh-1^M, which is present in low proportion in B. bombina south of the contact zone, were found in some hybrid populations.     

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.     

Early embryogenesis in discoglossoid frogs: a study of heterochrony at different taxonomic levels

We studied the timing of the early development of the cranial neural crest, neural tube differentiation, somite formation and body elongation in the closely related frog species Discoglossus montalenti , Discoglossus galganoi , Discoglossus pictus , Bombina orientalis , Bombina variegata and Bombina maxima . Despite their different egg and embryo sizes, event pairing shows that there are only very few heterochronies among the three Bombina species and the three Discoglossus species in early developmental events. Instead, differences become apparent at the genus level (interpreted as phylogenetic signal). For example, the separation into a mandibular and a hyoid portion of cranial neural crest could be seen earlier in the Discoglossus than in the Bombina species when compared with the development of the neural tube. The development of the cranial neural crest streams also shifts (relatively) forward in time when compared with body elongation and somite formation in the Discoglossus species in contrast to the Bombina species. Comparisons with other species show that attempts to correlate heterochronies in early development with life history changes should take into account the possibility of a rather high evolvability, i.e. a high probability of convergence in the timing of these early events.     

Advertisement calls of the midwife toads Alytes (Amphibia, Anura, Discoglossidae) in continental Spain

The advertisement calls of six Spanish populations of midwife toads (genus Alytes ) are described presenting characteristic audiospectrograms and oscillograms of the calls. Numerical data concerning the spectral and temporal features of the calls in relation to caller size (SVL) and temperature are also compared. The regression temperature vs. call duration groups the different populations according to the extant recognized phylogeny of the genus. Based on this character, the montane population of A. obstetricans from Penalara (Madrid) appears to be more closely related to the Pyrenean populations of A. o. almogavarii than to the more western populations of A. o. boscai in Central Spain, which are closer geographically.

Zusammenfassung

Paarungsrufe der Geburtshelferköten Alytes (Amphibia, Anura, Discoglossidae) aus zentralspanischen Populationen
Die Paarungsrufe von sechs Geburtshelferkröten aus sechs spanischen Populationen werden hinsichtlich ihrer charakteristischen Tonfrequenz-Spektrogramme und Oszillogramme beschrieben.
Die numerischen Daten der spektralen und zeitlichen Eigenheiten der Rufmerkmale wurden mit der Größe der Männchen (SVL) und der Temperatur verglichen. Die Regression zwischen Temperatur und Dauer des Rufes ordnet die verschiedenen Populationen in der gleichen Weise ein, wie sie schon aus der allgemein anerkannten Phylogenetik der Gattung bekannt ist. Aufgrund dieser Untersuchungen, kann davon ausgegangen werden, daß die Gebirgspopulation A. obstetricans von Pealara (Madrid) enger mit der Pyrenäen-Population A. o. almogavarii verwandt ist als mit der westlichen Population A. o. boscai in Zentralspanien, obwohl sie zu jener geographisch näher liegt.     

Advertisement calls of the midwife toads Alytes (Amphibia, Anura, Discoglossidae) in continental Spain

The advertisement calls of six Spanish populations of midwife toads (genus Alytes) are described presenting characteristic audiospectrograms and oscillograms of the calls. Numerical data concerning the spectral and temporal features of the calls in relation to caller size (SVL) and temperature are also compared. The regression temperature vs. call duration groups the different populations according to the extant recognized phylogeny of the genus. Based on this character, the montane population of A. obstetricans from Penalara (Madrid) appears to be more closely related to the Pyrenean populations of A. o. almogavarü than to the more western populations of A. oboscai in Central Spain, which are closer geographically.     

PKs的生物学功能

PKs是最近发现的多功能分泌蛋白,由PK1和PK2组成.在不同的系统中,它们通过两个高度同源G-蛋白偶联受体发挥各种生物学功能.它们与神经和血管的形成以及免疫应答的调节有关,并且对生殖系统的正常生理和促性腺激素释放激素系统的发育都有很大的影响.     

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.     

Ultrastructure of the taste disc in the red-bellied toad Bombina orientalis (Discoglossidae,Salientia)

The taste disc of the red-bellied toad Bombina orientalis (Discoglossidae) has been investigated by light and electron microscopy and compared with that of Rana pipiens (Ranidae). Unlike the frog, B. orientalis possesses a disc-shaped tongue that cannot be ejected for capture of prey. The taste discs are located on the top of fungiform papillae. They are smaller than those in Ranidae, and are not surrounded by a ring of ciliated cells. Ultrastructurally, five types of cells can be identified (mucus cells, wing cells, sensory cells, and both Merkel cell-like basal cells and undifferentiated basal cells). Mucus cells are the main secretory cells of the taste disc and occupy most of the surface area. Their basal processes do not synapse on nerve fibers. Wing cells have sheet-like apical processes and envelop the mucus cells. They contain lysosomes and multivesicular bodies. Two types of sensory cells reach the surface of the taste disc; apically, they are distinguished by either a brush-like arrangement of microvilli or a rod-like protrusion. They are invaginated into lateral folds of mucus cells and wing cells. In contrast to the situation in R. pipiens, sensory cells of B. orientalis do not contain dark secretory granules in the perinuclear region. Synaptic connections occur between sensory cells (presynaptic sites) and nerve fibers. Merkel cell-like basal cells do not synapse onto sensory cells, but synapse-like connections exist between Merkel cell-like basal cells (presynaptic site) and nerve fibers.     

Precopulatory behaviour and the evolutionary relationships of Discoglossidae

The phylogenetic relationships among primitive anurans remain controversial, even when several morphological and molecular approaches have been used in an attempt to resolve them. Nevertheless, very little effort has been made to study these relationships with behavioural data. We studied the relation between some precopulatory behaviour characters (male call characteristics and call recognition by females) and the different proposed phylogenies among the anuran genera Alytes, Discoglossus and Bombina . Different acoustic variables were analysed from male calls of different species of these genera; Alytes cisternasii females were used in recognition tests with calls from those species. A phenetic tree generated from male call characteristics grouped Bombina with Discoglossu s and separated these two genera from Alytes, although the tree generated from female response data did not show such a clear result. A. cisternasii females are mostly using some features that are absent in Alytes calls in order to recognize male calls. The two characters, mapped onto the three alternative phylogenetic proposals, did not resolve the trichotomy among the three genera, but suggested that the studied behavioural characters have a clear phylogenetic load.     

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.     

Subspecific divergence in a loud call of the ruffed lemur (Varecia variegata)

A loud call of the ruffed lemur (Varecia variegata) was analyzed for subspecific and gender differences according to four variables: pulse rate, median pulse duration, median high frequency, and median low frequency. These vocalizations of black-and-white and red ruffed lemurs and one hybrid ruffed lemur were recorded at the Duke University Primate Center (Durham, NC). Significant differences were found between subspecies but not between the sexes. Quantitative differences in this loud call of ruffed lemur subspecies indicate that these prosimians exhibit subspeciation trends similar to anthropoid primates for which comparable data exist. Preliminary data are presented that support the hypothesis that the vocalization functions as a terrestrial predator alarm call.