Search results for "Amphibia"

Differenze sessuali nell'utilizzo spazio-temporale del territorio in una popolazione di Bufo viridis in Sicilia

2006

Entwicklungsmechanische Untersuchungen an Amphibien

1925

Izvilkums no: ''Biologischen Zentralblatt", 45. Bd., 2. Heft, Februar 1925.

Microscopical anatomy of the involution of the branchial bars of amphibia [Abinieku žaunu kātu involūcijas mikroskopiskā anatomija]

1936

Teksts angļu valodā, kopsavilkums latviešu valodā.

LACTATE-DEHYDROGENASE ISOENZYMES IN NERVOUS TISSUE. II. A COMPARATIVE ANALYSIS IN VERTEBRATES.

1963

The amphibian globin gene repertoire as revealed by the <i>Xenopus </i>genome

2006

The draft genome sequence of the Western clawed frog <i>Xenopus (Silurana) tropicalis</i> facilitates the identification, expression analysis and phylogenetic classification of the amphibian globin gene repertoire. Frog and mammalian neuroglobin display about 67% protein sequence identity, with the expected predominant expression in frog brain and eye. Frog and mammalian cytoglobins share about 69% of their amino acids, but the frog protein lacks the mammalian-type extension at the C-terminus. Like in mammals, <i>X. tropicalis</i> cytoglobin is expressed in many organs including neural tissue. Neuroglobin and cytoglobin genomic regions are syntenically conserved in a…

Distortion of symmetrical introgression in a hybrid zone: evidence for locus-specific selection and uni-directional range expansion

2006

The fate of species integrity upon natural hybridization depends on the interaction between selection and dispersal. The relative significance of these processes may be studied in the initial phase of contact before selection and gene flow reach equilibrium. Here we study a hybrid zone of two salamander species, Lyciasalamandra antalyana and Lyciasalamandra billae, at the initial phase of hybridization. We quantify the degree and mode of introgression using nuclear and mtDNA markers. The hybrid zone can be characterized as an abrupt transition zone, the central hybrid zone being only c. 400 m, but introgressed genes were traced up to 3 km. Introgression was traced in both sexes but gene flo…

To be or not to be heavier: The role of dermal bones in the buoyancy of the Late Triassic temnospondyl amphibian Metoposaurus krasiejowensis.

2022

Stereospondyli are a clade of large aquatic temnospondyls known to have evolved a large dermal pectoral girdle. Among the Stereospondyli, metoposaurids in particular possess large interclavicles and clavicles relative to the rest of the postcranial skel-eton. Because of the large size of these dermal bones, it was first proposed that they served as ballast during hydrostatic buoyancy control which assisted metoposaurids to live a bottom-dwelling mode of life. However, a large bone need not necessarily be heavy, for which determining the bone compactness becomes crucial for under-standing any such adaptation in these dermal bones. Previous studies on the evolu-tion of bone adaptations to aqu…

Species complexes and phylogenetic lineages of Hoferellus (Myxozoa, Cnidaria) including revision of the genus: A problematic case for taxonomy

2015

Background Myxozoans are metazoan parasites whose traditional spore morphology-based taxonomy conflicts DNA based phylogenies. Freshwater species of the genus Hoferellus are parasites of the excretory system, with several members infecting food and ornamental fish species, as well as amphibians. This study aims to increase our understanding of their molecular diversity and development, aspects about which little is known, and to generate a molecular diagnostic tool to discriminate between different pathogenic and non-pathogenic Hoferellus spp. Methods SSU and ITS rDNA phylogeny, along with morphological descriptions using light and electron microscopy were used to identify and characterize …

Genes coding for intermediate filament proteins closely related to the hagfish "thread keratins (TK)" alpha and gamma also exist in lamprey, teleosts…

2005

The "thread keratins (TK)" alpha and gamma so far have been considered highly specialized intermediate filament (IF) proteins restricted to hagfish. From lamprey, we now have sequenced five novel IF proteins closely related to TKalpha and TKgamma, respectively. Moreover, we have detected corresponding sequences in EST and genomic databases of teleosts and amphibians. The structure of the TKalpha genes and the positions of their deduced amino acid sequences in a phylogenetic tree clearly support their classification as type II keratins. The genes encoding TKgamma show a structure typical for type III IF proteins, whereas their positions in phylogenetic trees favor a close relationship to the…

Exploring the potential of life-history key innovation: brook breeding in the radiation of the Malagasy treefrog genus Boophis

2002

The treefrog genus Boophis is one of the most species-rich endemic amphibian groups of Madagascar. It consists of species specialized to breeding in brooks (48 species) and ponds (10 species). We reconstructed the phylogeny of Boophis using 16S ribosomal DNA sequences (558 bp) from 27 species. Brook-breeders were monophyletic and probably derived from an ancestral pond-breeding lineage. Pond-breeders were paraphyletic. The disparity in diversification among pond-breeders and brook-breeders was notable among endemic Malagasy frogs, although it was not significant when considering Boophis alone. Sibling species which have different advertisement calls but are virtually indistinguishable by mo…