Search results for "OTU"

Centrosome structure is very similar in eupyrene and apyrene spermatocytes ofEphestia kuehniella(Pyralidae, Lepidoptera, Insecta)

1997

Summary The higher Lepidoptera produce two types of sperm, eupyrene and apyrene. Eupyrene spermatozoa are fertile, while apyrene spermatozoa are anucleate and, therefore, sterile. Meiosis differs between the two developmental lines. One of the most obvious differences is the aberrant organization of the apyrene spindles. They possess fewer microtubules than eupyrene spindles and chromosome segregation is irregular. To determine whether micotubule nucleation is impaired in the aprene spindles, the present fine structure study concentrated on the centrosomes in both spermatocyte types. In addition, the presence of gamma-tubulin, a newly discovered tubulin isoform which is prevalent in centros…

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…

Abnormal mitotic spindle assembly and cytokinesis induced by D-Limonene in cultured mammalian cells

2013

D-Limonene is found widely in citrus and many other plant species; it is a major constituent of many essential oils and is used as a solvent for commercial purposes. With the discovery of its chemotherapeutic properties against cancer, it is important to investigate the biological effects of the exposure to D-Limonene and elucidate its, as yet unknown, mechanism of action. We reported here that D-Limonene is toxic in V79 Chinese hamster cells in a dose-dependent manner. Moreover, to determine the cellular target of D-Limonene, we performed morphological observations and immunocytochemical analysis and we showed that this drug has a direct effect on dividing cells preventing assembly of mito…

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…

Aerobic fitness, but not physical activity, is associated with grey matter volume in adolescents.

2019

Higher levels of aerobic fitness and physical activity are linked to beneficial effects on brain health, especially in older adults. The generalizability of these earlier results to young individuals is not straightforward, because physiological responses (such as cardiovascular responses) to exercise may depend on age. Earlier studies have mostly focused on the effects of either physical activity or aerobic fitness on the brain. Yet, while physical activity indicates the amount of activity, aerobic fitness is an adaptive state or attribute that an individual has or achieves. Here, by measuring both physical activity and aerobic fitness in the same study, we aimed to differentiate the assoc…

Historical remarks, orginal description and last advances on Pleurotus nebrodensis

2013

Giuseppe Inzenga, the scientist who first described Pleurotus nebrodensis, was one of the major mycologists of the second half of the 19th century. This chapter describes the main biographical aspects of the life of Inzenga and its contribution to science with particular reference to mycology. The chapter also includes notes on the social and academic context of the mid-1800s, which led Inzenga to the original description of P. nebrodensis, the analysis of the critical aspects of nomenclature and the logical path that led us to the recent designation of a P. nebrodensis epitype. An updated description of the taxon and the discovery of the loci classici of P. nebrodensis collections is also …

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…

Female Preference and Adverse Developmental Effects of Glyphosate-Based Herbicides on Ecologically Relevant Traits in Japanese Quails

2019

Controversial glyphosate-based herbicides (GBHs) are the most frequently used herbicides globally. An increasing number of studies have identified GBH residues in soil, water, and even human food that may expose nontarget organisms including wildlife, livestock, and humans to health risks. After a heated debate, the European Union allowed the use of GBHs to continue until 2022, after which their risks will be re-evaluated. Thus, decision makers urgently need scientific evidence on GBH residues and their possible effects on ecosystems. An important, yet neglected, aspect is to assess whether animals show preference or avoidance for GBH-contaminated food, as it can influence the likelihood of…