Search results for "Otus"

Stepes strupastu galvas smadzeņu morfometriskā mainība guentheri grupā (Arvicolinae, Sumeriomys apakšģints)

2019

Šī darba mērķis ir galvas smadzeņu diverģences izpēte pēc to lieluma un ģeometriskās formas trim strupastu “guentheri” grupas taksoniem ar lineārās un ģeometriskās morfometrijas metožu izmantošanu. Iegūtie dati rāda, ka dzimuma faktors neietekmē izpētīto taksonu smadzeņu lineāros parametrus un formu, kas liecina par dzimuma atlases vāju iedarbību uz morfoloģisko pielāgojumu veidošanos un smadzeņu uzbūves mainību. Tiek atrastas būtiskas atšķirības strupastu galvas smadzeņu absolūtā un relatīvā masā (cefalizācijas indekss): vismazākā tā tiek atzīmēta M. guentheri, lielāka M. hartingi, bet savā starpā M. h. hartingi un M. h. lydius populācijas ievērojami diverģē. Visi lineārie mērījumi trim ta…

Acquisition of thermotolerance in sea urchin embryos correlates with the synthesis and age of the heat shock proteins.

1986

Preheating at 31 degrees C induces thermotolerance in Paracentrotus lividus embryos, which therefore become able to withstand 1-h treatment at the otherwise lethal temperature of 35 degrees C, and to develop normally. The acquisition of thermotolerance is positively correlated with the amount of heat shock proteins produced during the 31 degrees C treatment. Evidence is provided that the heat shock proteins, although present in the embryo for long periods after synthesis, lose their effect on thermotolerance within 3 h of the cessation of synthesis.

Amplification, contraction and genomic spread of a satellite DNA family (E180) in Medicago (Fabaceae) and allied genera

2011

†Background and Aims Satellite DNA is a genomic component present in virtually all eukaryotic organisms. The turnover of highly repetitive satellite DNA is an important element in genome organization and evolution in plants. Here we assess the presence and physical distribution of the repetitive DNA E180 family in Medicago and allied genera. Our goals were to gain insight into the karyotype evolution of Medicago using satellite DNA markers, and to evaluate the taxonomic and phylogenetic signal of a satellite DNA family in a genus hypothesized to have a complex evolutionary history. †Methods Seventy accessions from Medicago, Trigonella, Melilotus and Trifolium were analysed by PCR to assess …

DNA sequence and pattern of expression of the sea urchin (Paracentrotus lividus) alpha-tubulin genes.

1989

To study the molecular aspects of the regulation of transcription of a multigene family, we have isolated and sequenced cDNA and genomic clones coding for the alpha-tubulin of the sea urchin Paracentrotus lividus. Two cDNA clones, P alpha 10 and P alpha 4, contain respectively the coding information for 391 C-terminal and for 338 N-terminal amino acids of the 452 residues that constitute the complete protein. They show silent nucleotide substitutions only, suggesting that P alpha 10 and P alpha 4 represent the cloned copies of two allelic gene transcripts, which encode for two alpha-tubulin isoforms with identical amino acid sequence in the region of the overlap. The comparison of the predi…

The role of swarming sites for maintaining gene flow in the brown long-eared bat (Plecotus auritus)

2004

Bat-swarming sites where thousands of individuals meet in late summer were recently proposed as 'hot spots' for gene flow among populations. If, due to female philopatry, nursery colonies are genetically differentiated, and if males and females of different colonies meet at swarming sites, then we would expect lower differentiation of maternally inherited genetic markers among swarming sites and higher genetic diversity within. To test these predictions, we compared genetic variance from three swarming sites to 14 nursery colonies. We analysed biparentally (five nuclear and one sex-linked microsatellite loci) and maternally (mitochondrial D-loop, 550 bp) inherited molecular markers. Three m…

2007

The lack of obvious morphological differences between species impedes the identification of species in many groups of organisms. Meanwhile, DNA-based approaches are increasingly used to survey biological diversity. In this study we show that sequencing the mitochondrial protein-coding gene NADH dehydrogenase, subunit 1 (nd1) from 534 bats of the Western Palaearctic region corroborates the promise of DNA barcodes in two major respects. First, species described with classical taxonomic tools can be genetically identified with only a few exceptions. Second, substantial sequence divergence suggests an unexpected high number of undiscovered species.

Polymorphisms in the intergenic region of the sea urchin Paracentrotus lividus ribosomal DNA

1990

Abstract Blot-hybridizations of the sea urchin Paracentrotus lividus genomic DNA with ribosomal DNA (rDNA) probes revealed individual variations in the length and in the sequence of the non-transcribed spacer (NTS) region. The number of rDNA repeat subclasses distinguishable within any individual sea urchin is usually limited (1 to 3) with respect to the widest polymorphism of the population as a whole. The heterogeneity in sequence is revealed by the presence or the absence of specific restriction sites in the spacer region. The data obtained by the intensity of the polymorphic bands indicate that different mechanisms bring about these two types of polymorphism. Preliminary data also indic…

Karyotype analysis of the sea urchinParacentrotus lividus (Echinodermata): evidence for a heteromorphic chromosome sex mechanism

1996

A consistent diploid number of 2n = 36 was determined for the sea urchinParacentrotus lividus from the Gulf of Palermo by analysis of mitotic chromosomes of both early developing embryos and male gonads. The haploid numbern = 18 was determined by counts of spermatocyte bivalents at diakinesis. A heteromorphic chromosome sex mechanism of the XY type is likely present in this species. This is indicated by the occurrence of a chromosomal pair, pair No. 2, which is heteromorphic in both morphology and size in about 50% of the mitotic figures (metaphases and anaphases) of einbryos. In addition, heteromorphism of the same pair of chromosomes occurred during spermatogonial metaphases in the five m…

First record of brown long-eared bat Plecotus auritus (Chiroptera: Vespertilionidae) for Sicily island (Italy)

2015

The knowledge of the bat fauna of Sicily (Southern Italy) is scarce, fragmentary or sometimes even confusing. A recent review mentioned 20 species for the region, but it is likely that the checklist of bats of Sicily is still far from being exhaustive. To help fill this gap, in the past few years specific studies were carried out on the distribution of bat species in Sicily, especially in the woodlands of the Nebrodi Mountains. In the municipality of Caronia (Messina province) has captured a young female brown long-eared bat Plecotus auritus (Linneaus, 1758). The capture of P. auritus in Sicily represents the first record of brown long-eared bat Plecotus auritus for Sicily island, an intere…

Caratteri ecologici e biogeografici dei pleuroti delle ombrellifere in Sicilia

2011

Biogeographia vol. XXX - 2011 (Pubblicato il 23 dicembre 2011) La Biogeografla della Sicilia Caratteri ecologici e biogeografici dei pleuroti delle ombrellifere in Sicilia GIUSEPPE VENTURELLA Dzpartimmto a'i Biologia Amoientale e Biooliz/ersita, Unioersita ilegli Stuoli di Palermo, via Arc/Jirafi 38, I—90I23 Palermo (Italy) Key words: Pleurotm, Apiaceae, Sicily. SUMMARY In this brief note the ecological and bio-geographical features of Pleurotu: species growing on Apiaceae species are pointed out. These fungi are closely related to the host plants and well distinguished on the basis of their mor- phological, ecological, distributive and genetic features. INTRODUZIONE I caratteri morfologi…