Haplotype characterization of a stranded common minke whale calf (Balaenoptera acutorostrata lacépède, 1804): Is the mediterranean sea a potential calving or nursery ground for the species?

The stranding of a suckling calf of Common Minke Whale (Balaenoptera acutorostrata) on the coast near Salerno (Campania, Southern Italy) is reported. The molecular analysis of a partial sequence of the mitochondrial DNA control region shows that the animal bore a haplotype identical to haplotype Ba169 considered as typical of individuals from North Atlantic population. Historical data and our results suggest the possibility that the Mediterranean Sea might be a potential calving or nursery ground for this species

Sex chromosome diversification in the smooth snake Coronella austriaca (Reptilia, Serpentes)

The smooth snake Coronella austriaca is a widespread Palearctic colubrid species. The species has been the subject of several molecular and phylogeographic studies which highlighted the occurrence of distinct genetic lineages in different areas of the species distribution, but scarce cytogenetic data are currently available on the species. In this paper we present a molecular and karyological study performed with several banding, staining methods and NOR-FISH on samples of C. austriaca from different geographical areas (Italy and Greece) of the species distribution. The molecular and phylogenetic analysis unambiguously placed the studied samples in different clades with a clear geographical pattern. The karyotype of the two female samples studied was composed of 2n = 36 chromosomes with 16 macro- and 20 microchromosomes and a mix of plesiomorphic and derivate chromosome features. All macrochromosomes were biarmed with the exception of pair 5 that was telocentric. NORs were detected on a microchromosome pair. In both females, the pair 4 was heteromorphic (and completely heterochromatic after C-banding in the Italian female), representing the first report of a ZZ/ZW sex chromosome system with female heterogamety in C. austriaca. In addition, the W chromosome showed a different morphology between the two female studied (submetacentric and subtelocentric), highlighting the occurrence of a chromosomal diversification among distinct geographical areas of the species distribution and further supporting that the species contains different diverging evolutionary clades

First Insights on the Karyotype Diversification of the Endemic Malagasy Leaf-Toed Geckos (Squamata: Gekkonidae: Uroplatus)

We provide here the first karyotype description of eight Uroplatus species and a characterization of their chromosomal diversity. We performed a molecular taxonomic assessment of several Uroplatus samples using the mitochondrial 12S marker and a comparative cytogenetic analysis with standard karyotyping, silver staining (Ag-NOR) and sequential C-banding + Giemsa, +Chromomycin A3 (CMA3), +4',6-diamidino-2-phenylindole (DAPI). We found chromosomal variability in terms of chromosome number (2n = 34-38), heterochromatin composition and number and localization of loci or Nucleolar Organizer Regions (NORs) (alternatively on the 2nd, 6th, 10th or 16th pair). Chromosome morphology is almost constant, with karyotypes composed of acrocentric chromosomes, gradually decreasing in length. C-banding evidenced a general low content of heterochromatin, mostly localized on pericentromeric and telomeric regions. Centromeric bands varied among the species studied, resulting in CMA3 positive and DAPI negative or positive to both fluorochromes. We also provide evidence of a first putative heteromorphic sex chromosome system in the genus. In fact, in U. alluaudi the 10th pair was highly heteromorphic, with a metacentric, largely heterochromatic W chromosome, which was much bigger than the Z. We propose an evolutionary scenario of chromosome reduction from 2n = 38 to 2n = 34, by means of translocations of microchromosomes on larger chromosomes (often involving the NOR-bearing microchromosomes). Adding our data to those available from the literature, we show that similar processes characterized the evolutionary radiation of a larger gecko clade. Finally, we hypothesize that sex chromosome diversification occurred independently in different genera

Chromosome Diversity and Evolution of the Endemic Malagasy Velvet Geckos of the Genus Blaesodactylus (Reptilia, Gekkonidae)

: We performed a molecular and phylogenetic analysis and a comparative cytogenetic study with standard karyotyping, silver staining (Ag-NOR) and sequential C-banding + Giemsa, + fluorochromes on several Blaesodactylus samples. The phylogenetic inference retrieved two main clades, the first comprises B. victori, B. microtuberculatus and B. boivini, while the second includes B. sakalava, B. antongilensis and B. ambonihazo. The available samples of B. sakalava form two different clades (here named B. sakalava clade A and clade B), which probably deserve a taxonomic re-evaluation. We found a karyological variability in Blaesodactylus in terms of chromosome number (2n = 40-42), morphology, location of NORs, and heterochromatin distribution pattern. Blaesodactylus antongilensis and B. sakalava clade A and B showed a karyotype of 2n = 40 mostly telocentric chromosomes. Pairs 1 and 6 were metacentric in B. sakalava clade A and B, while pair 1 was composed of subtelocentric/submetacentric elements in B. antongilensis. In contrast, B. boivini displayed a karyotype with 2n = 42 only telocentric chromosomes. NORs were on the first chromosome pair in B. boivini, and on the second pair in B. antongilensis. Adding our data to those available from the literature on evolutionarily related species, we highlight that the chromosome diversification in the genus probably proceeded towards a progressive reduction in the chromosome number and the formation of metacentric elements

Evolutionary and Genomic Diversity of True Polyploidy in Tetrapods

: True polyploid organisms have more than two chromosome sets in their somatic and germline cells. Polyploidy is a major evolutionary force and has played a significant role in the early genomic evolution of plants, different invertebrate taxa, chordates, and teleosts. However, the contribution of polyploidy to the generation of new genomic, ecological, and species diversity in tetrapods has traditionally been underestimated. Indeed, polyploidy represents an important pathway of genomic evolution, occurring in most higher-taxa tetrapods and displaying a variety of different forms, genomic configurations, and biological implications. Herein, we report and discuss the available information on the different origins and evolutionary and ecological significance of true polyploidy in tetrapods. Among the main tetrapod lineages, modern amphibians have an unparalleled diversity of polyploids and, until recently, they were considered to be the only vertebrates with closely related diploid and polyploid bisexual species or populations. In reptiles, polyploidy was thought to be restricted to squamates and associated with parthenogenesis. In birds and mammals, true polyploidy has generally been considered absent (non-tolerated). These views are being changed due to an accumulation of new data, and the impact as well as the different evolutionary and ecological implications of polyploidy in tetrapods, deserve a broader evaluation

The Satellite DNA PcH-Sat, Isolated and Characterized in the Limpet Patella caerulea (Mollusca, Gastropoda), Suggests the Origin from a Nin-SINE Transposable Element

Satellite DNA (sat-DNA) was previously described as junk and selfish DNA in the cellular economy, without a clear functional role. However, during the last two decades, evidence has been accumulated about the roles of sat-DNA in different cellular functions and its probable involvement in tumorigenesis and adaptation to environmental changes. In molluscs, studies on sat-DNAs have been performed mainly on bivalve species, especially those of economic interest. Conversely, in Gastropoda (which includes about 80% of the currently described molluscs species), studies on sat-DNA have been largely neglected. In this study, we isolated and characterized a sat-DNA, here named PcH-sat, in the limpet Patella caerulea using the restriction enzyme method, particularly HaeIII. Monomeric units of PcH-sat are 179 bp long, AT-rich (58.7%), and with an identity among monomers ranging from 91.6 to 99.8%. Southern blot showed that PcH-sat is conserved in P. depressa and P. ulyssiponensis, while a smeared signal of hybridization was present in the other three investigated limpets (P. ferruginea, P. rustica and P. vulgata). Dot blot showed that PcH-sat represents about 10% of the genome of P. caerulea, 5% of that of P. depressa, and 0.3% of that of P. ulyssiponensis. FISH showed that PcH-sat was mainly localized on pericentromeric regions of chromosome pairs 2 and 4–7 of P. caerulea (2n = 18). A database search showed that PcH-sat contains a large segment (of 118 bp) showing high identity with a homologous trait of the Nin-SINE transposable element (TE) of the patellogastropod Lottia gigantea, supporting the hypothesis that TEs are involved in the rising and tandemization processes of sat-DNAs

Karyotype, chromosome structure, reproductive modalities of three Southern Eurasian populations of the common lacertid lizard, Zootoca vivipara (Jacquin, 1787)

According to a hypothesis of the evolution of viviparity the lacertid lizard Zootoca vivipara, rare relict oviparous populations of the species might occur in southern-eastern part of its distribution area. Such a hypothesis has been verified by comparing the karyotype, chromosome structure, and reproductive modality of three populations of south-eastern part of Russia, including Altai and neighbouring regions, where small territories remained isolated during the Pleistocene cooling and where Pleistocenic fossils of Z. vivipara have been found. The chromosomal study was carried out by conventional staining method and banding methods, namely C-banding and sequential staining of C-banding+ fluorochromes, CMA3 and DAPI. All studied females displayed viviparous reproductive modality and showed a karyotype of 2N = 35 acrocentric chromosomes, with a Z1Z2W sex chromosome system. Chromosome W was subtelocentric. No inter-population variability on karyotype and heterochromatin distribution and composition was observed. From the obtained data the three studied south-eastern Russian viviparous populations belong to the Russian viviparous form of Z. v. vivipara

A preliminary checklist of the species of non-marine Molluscs from the Alburni Mountains, Campania, Southern Italy (Mollusca Gastropoda Bivalvia)

An annotated checklist of the species of non-marine molluscs from the Alburni Mountains (Salerno Province, Campania, Southern Italy) is reported. The research was carried out from 2010 to 2013 inside a Site of Community Importance (SCI) and a Special Protection Area (SPA), of the Cilento, Vallo di Diano and Alburni National Park. The non-marine molluscs sampled on the field were compared with data available from the literature and malacological collections. Up to now, only 12 non-marine Mollusc species were known from the Alburni Mountains through bibliographical data. In all, the malacofauna of Alburni Mountains is composed by 83 non-marine Mollusc species (73 species of land snails, and 10 species of freshwater molluscs). The presence of nine species (six species of land snails and three species of freshwater snails) was confirmed by our field investigation, four species (3 species of land snails and 1 species of allochthonous freshwater snails) were recorded only by bibliographical data and were not yet found. Our analysis identifies 70 species of non-marine Molluscs (64 species of land snails, 6 species of freshwater molluscs) recorded on the basis of field data which were not previously recorded from the study area. At least 11 species are new records for the Campania Region. Extremely interesting is the record of Vertigo angustior Jeffreys, 1830 a species protected in European Union by the Annex II of the “Habitats Directive” and listed as “Vulnerable” at the European level. A Red List of Threatened Species is proposed and the species were classified with the code of I.U.C.N. (Version 2014.3). Five allochthonous species were surveyed for the first time in the study area: 3 land snails: Lucilla scintilla (Lowe, 1852), Lucilla singleyana (Pilsbry, 1829) and Paralaoma servilis (Shuttleworth, 1852), and 2 freshwater snails: Potamopyrgus antipodarum (J.E. Gray, 1843) and Ferrissia fragilis (Tryon, 1863). Four species are known exclusively from the literature: Vertigo (Vertigo) moulinsiana (Dupuy, 1849), Macrogastra (Pyrostoma) plicatula(Draparnaud, 1801), Cernuella virgata (Da Costa, 1778), and Haitia acuta (Draparnaud, 1805)

Chromosome analysis on Central and Southern Italy population of the common toad, Bufo bufo (Amphibia, Anura)

Amphibians constitute a very good model to explore the historical aspects of species distributions due to their low dispersal capacity and low individual vagility. Bufonidae are one of the most speciose family of Anura, including taxa, such as Bufo bufo, widespread in Eurasian regions. We performed a karyological study with standard and sequential C-banding + fluorochromes (Chromomycin A3 (CMA) and Diamidinophenylindole (DAPI) on several tadpoles from different populations of Central and Southern Italy. All the examined tadpoles exhibited the standard Bufokaryotype of 2n = 22 biarmed chromosomes, with the first six pairs larger than the other five (7 - 11) pairs and NOR associated heterochromatin distal on the long arms of the 6thchromosome pair, that was also the only chromosome CMA-positive region. C-banding evidenced centromeric heterochromatin, DAPI positive, on all the chromosomes in all the studied populations from Central Italy. The Southern Italy populations differed in additional paracentromeric C-bands on the short arms of chromosomes 1, 3 and 5. These results support the partition of Central populations of B. bufo from the Southern ones, as evidenced also from molecular phylogenetic studie