| 1. |
- Auer-Grumbach, Michaela, et al.
(författare)
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Rare Variants in MME, Encoding Metalloprotease Neprilysin, Are Linked to Late-Onset Autosomal-Dominant Axonal Polyneuropathies
- 2016
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297 .- 1537-6605. ; 99:3, s. 607-623
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Tidskriftsartikel (refereegranskat)abstract
- Axonal polyneuropathies are a frequent cause of progressive disability in the elderly. Common etiologies comprise diabetes mellitus, paraproteinaemia, and inflammatory disorders, but often the underlying causes remain elusive. Late-onset axonal Charcot-Marie-Tooth neuropathy (CMT2) is an autosomal-dominantly inherited condition that manifests in the second half of life and is genetically largely unexplained. We assumed age-dependent penetrance of mutations in a so far unknown gene causing late-onset CMT2. We screened 51 index case subjects with late-onset CMT2 for mutations by whole-exome (WES) and Sanger sequencing and subsequently queried WES repositories for further case subjects carrying mutations in the identified candidate gene. We studied nerve pathology and tissue levels and function of the abnormal protein in order to explore consequences of the mutations. Altogether, we observed heterozygous rare loss-of-function and missense mutations in MME encoding the metalloprotease neprilysin in 19 index case subjects diagnosed with axonal polyneuropathies or neurodegenerative conditions involving the peripheral nervous system. MME mutations segregated in an autosomal-dominant fashion with age-related incomplete penetrance and some affected individuals were isolated case subjects. We also found that MME mutations resulted in strongly decreased tissue availability of neprilysin and impaired enzymatic activity. Although neprilysin is known to degrade beta-amyloid, we observed no increased amyloid deposition or increased incidence of dementia in individuals with MME mutations. Detection of MME mutations is expected to increase the diagnostic yield in late-onset polyneuropathies, and it will be tempting to explore whether substances that can elevate neprilysin activity could be a rational option for treatment.
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| 2. |
- Zauli, Agnese, et al.
(författare)
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Antennal fine morphology of the threatened beetle Osmoderma eremita (Coleoptera: Scarabaeidae), revealed by scanning electron microscopy.
- 2016
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Ingår i: Microscopy Research and Technique. - : Wiley. - 1059-910X. ; 79, s. 178-191
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to characterize the antennal morphology of Osmoderma eremita, a threatened scarab beetle inhabiting tree hollows. O. eremita males produce a sex pheromone, (R)-(+)-γ-decalactone, responsible mainly for the attraction of females but also other males. Gross and fine morphology of microstructures including sensilla, microsculpture and pores were analyzed using Scanning Electron Microscopy. The antenna of O. eremita showed the typical lamellicorn shape of scarab beetles, with a basal scape, a pedicel, a funicle composed of five antennomeres and a club composed of three lamellae. Six different subtypes of sensilla chaetica (Ch.1 - 6), Böhm sensilla (Bo), one subtype of sensilla basiconica (Ba.1), two subtypes of sensilla coeloconica (Co.1 - 2), two subtypes of sensilla placodea (Pl.1 - 2), pores and peculiar folds were described. The two sexes did not show any significant differences in the occurrence and number of the sensilla placodea, known to be responsible for the pheromone reception. Instead, some sexual differences were found on the occurrence and topology of three different microstructures: (1) one subtype of sensillum chaeticum (Ch.2) occurring on the pedicel only in males; (2) a characteristic pore occurring on the funicle only in males; (3) a peculiar fold occurring on different antennomeres of the funicle in the two sexes, on the fourth in males and on the fifth in females. A comparison between sensilla of O. eremita and those of other Scarabaeoidea is provided. Microsc. Res. Tech., 2016. © 2016 Wiley Periodicals, Inc.
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| 3. |
- Zauli, Agnese, et al.
(författare)
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Assessing the taxonomic status of Osmoderma cristinae (Coleoptera : Scarabaeidae), endemic to Sicily, by genetic, morphological and pheromonal analyses
- 2016
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Ingår i: Journal of Zoological Systematics and Evolutionary Research. - : Hindawi Limited. - 0947-5745 .- 1439-0469. ; 54:3, s. 506-514
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Tidskriftsartikel (refereegranskat)abstract
- Resolving complexes of closely related and cryptic insect species can be challenging, especially when dealing with rare and protected taxa that are difficult to collect for genetic and morphological analyses. Until recently, populations of the genus Osmoderma (Scarabaeidae), widespread in Europe, were treated as a single species O. eremita (Scopoli, 1763) in spite of observed geographic variation in morphology. A previous survey using sequence data from the mtDNA cytochrome C oxidase I gene (COI) revealed the occurrence of at least two distinct lineages within this species complex: O. eremita in the west and O. barnabita Motschulsky, 1845, in the east. Interestingly, beetles confined to Sicily have been described as a distinct species, O. cristinae Sparacio, 1994, based on morphological traits. Only few Sicilian specimens were included in the former genetic analysis, and the results led to a still questionable taxonomic rank for these populations. To explore the robustness of the previous taxonomic arrangement for O. cristinae, a combination of genetic, morphological and pheromonal analyses was used. A 617-bp fragment of the COI gene, aligned with O. cristinae and O. eremita sequences already available in GenBank, showed a clear genetic divergence between the two species (interspecific mean distance = 6.6%). Moreover, results from AFLP markers sustained the distinction of the two species. In addition, geometric morphometric analyses of the shape of male genitalia revealed a clear differentiation between the two species. Via scent analysis and field trapping, we demonstrated the production of the sex pheromone (R)-(+)-γ-decalactone by males of O. cristinae, the attraction by conspecific individuals (mostly females) to this compound, and a lack of antagonistic effect of (S)-(-)-γ-decalactone. The fact that O. eremita and O. eremita use the same compound for mate finding suggests that this sex pheromone has not undergone a differentiation and probably the allopatry of these two species compensates for the absence of a mechanism to avoid cross-attraction. Our genetic and morphological data support the divergence of the two species and confirm the species status for O. cristinae, while sex pheromones are confirmed to be invariant among different species of the genus Osmoderma.
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| 4. |
- Zauli, Agnese, et al.
(författare)
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Scanning electron microscopy analysis of the antennal sensilla in therare saproxylic beetle Elater ferrugineus (Coleoptera: Elateridae)
- 2016
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Ingår i: Italian Journal of Zoology. - : Informa UK Limited. - 1125-0003 .- 1748-5851. ; 83:3, s. 338-350
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Tidskriftsartikel (refereegranskat)abstract
- This work provides the first morphological analysis (both at gross and fine level) of the antennal structures in the genusElater (Coleoptera, Elateridae). The typology, number and distribution patterns of the antennal sensilla in the rare saproxylicElater ferrugineus (both male and female) were studied using scanning electron microscopy (SEM). The serrate antennae ofE. ferrugineus consisted of a scape, a pedicel, and nine flattened flagellomeres. Overall, 10 types of sensilla were identifiedaccording to their morphological features: one type of sensilla chaetica (Ch), one type of Böhm sensilla (Bo), three types ofsensilla trichodea (Tr.1–3), two types of sensilla basiconica (Ba.1–2), one type of sensilla styloconica (St), one type ofgrooved peg sensilla (Gp) and one type of sensilla campaniformia (Ca). A marked sexual dimorphism was found at bothgross and fine scale. The male antenna was bigger (8.6 mm) than the female one (7.0 mm) and carried one type of sensillatrichodea (Tr.2) absent in female antennae possibly responsible for reception of the female-emitted sex pheromone. Thefemale antenna carried a higher number of sensilla (~ 9800) than the male one did (~7,000), with more abundant sensillachaetica (Ch) and basiconica (Ba.1 and Ba.2).
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