196,335 research outputs found
Pubblicazioni di Daria Bertolani Marchetti.
No full textElenco delle pubblicazioni della Prof. Daria Bertolani Marchetti per la giornata della sua commemorazione a Formigine, 18 Maggio 199
DNA barcoding and integrative taxonomy of Macrobiotus hufelandi C.A.S. Schultze 1834, the first tardigrade species to be described, and some related species
No full textWithin the framework of a DNA barcoding project on tardigrade species, a study was carried out on Macrobiotus hufelandi C.A.S. Schultze 1834, the first formally described tardigrade species. We used samples collected from the type locality and additional material from other European sites containing species of the “M. hufelandi group”. The study was performed by integrating morphological, karyological and molecular (mt-DNA cox1) information and comparing these data with morphological data from the type material. Several species from this group were found in the type locality of M. hufelandi (near Freiburg, Black Forest, Germany) and these were all barcoded. One was M. hufelandi, the other two were: Macrobiotus sandrae Bertolani & Rebecchi 1993 (originally described from the same locality), and Macrobiotus vladimiri Bertolani, Biserov, Rebecchi & Cesari in press (type locality Andalo, Italy), all with interspecific genetic distances of more than 19%. A fourth cryptic species, which had the same morphology as M. hufelandi but a genetic distance of 6.7%, was not described as a new taxon but named M. cf. hufelandi sp.1 for this study. Macrobiotus sandrae and M. vladimiri were also present (and barcoded) in Italy (Alps). Additional individuals (animals and eggs) were also found, and barcoded, in Italy (Apennines) and Switzerland that belonged to the haplogroup Macrobiotus cf. hufelandi sp. 1. These data together with other recent studies on tardigrade DNA barcoding represent a starting point for further studies on tardigrade biogeography, phylogeography and diversity
Chromosome c-banding and Ag-NOR pattern in tardigrades
No full textThe first data on tardigrade chromosomes were derived from histological sections (Henneke 1911; von Wenck 1914). Specific studies were performed in the early seventies on animals stained in toto with acetic lactic orcein and squashed (Figs. 3-4; Bertolani 1971, 1975, 1982). Besides the definition of the chromosome number of several species (often n = 5 or n = 6), the main results were the identification of the polyploidy (triploidy and tetraploidy) and the definition of the cytology in the oocyte maturation of the parthenogenetic animals. Chromosomes always appeared small, without an evident centromere and similar to each other in the same plate and among the species. Oocyte chromosomes were clearly larger than those of the spermatocytes and of the mitotic divisions. More recently, Giemsa staining was applied to the eutardigrade Xerobiotus pseudohufelandi, in which diploid, triploid and tetraploid cytotypes were identified (Rebecchi, 1991). Triploidy and tetraploidy in tardigrades had been confirmed on the basis of the DNA content (Bertolani et al. 1987, 1994). Giemsa staining provides good details of the chromosome shape and confirms that M. richtersi is characterized by a chromosome set made up of very similar elements. Sex chromosomes are not recognizable.The kind of chromosome arrangement along the spindle fibers and the presence of a heterochromatic region on a telomere, evidenced by C-banding, allow us to conclude that all chromosomes of M. richtersi are acrocentric.There is only one NOR, localized on one extremity of one chromosome pair. It is evident in the oocyte prophases. In the oocyte metaphases the NOR could correspond to the most intense terminal dots that often characterize one of the six bivalents. As in other animals, the NOR coincides or is just adjacent the C-band site. The silver-positive regions located on one of the telomeres of all the other chromosomes of M. richtersi should correspond to the kynetochore, whereas the fainter regions located on the other telomere of all five bivalents resemble the “telochore” evidenced in the grasshoppers (Suja and Rufas 1994)
An example of problems associated with DNA barcoding in tardigrades: a novel method for obtaining voucher specimens
No full textWe have in recent papers revealed that an integrative taxonomy approach helps to solve taxonomic problems in tardigrades. However, whole tardigrades are required for DNA work, which leaves no hologenophore voucher specimens with adult morphology. Using a novel methodology for the Tardigrada, we introduce the practice of collecting high quality maximum magnification light microscopy images of recently thawed animals to act as hologenophore voucher specimens of animals later used for DNA barcode sequencing. Within the framework of a DNA barcoding project on tardigrades, we collected a moss sample from the type locality of Macrobiotus terminalis Bertolani & Rebecchi, 1993 (Castelsantangelo, Central Apennines, Italy), a species of the “Macrobiotus hufelandi group”. Within the moss sample we found several animals and eggs with a morphology that corresponded to the original description of M. terminalis, while others were attributable to Macrobiotus macrocalix Bertolani & Rebecchi, 1993. In this study, molecular (cox1 mtDNA) analyses demonstrated no intraspecific variability in M. terminalis from the type locality but very large interspecific differences when compared with M. macrocalix and GenBank data for other species within the M. “hufelandi group”. There was also a large difference between our M. terminalis sequences and the GenBank data of a specimen attributed to the same species. The GenBank sequence originated from a population in the Northern Apennines, whose morphology appeared to be like that of the specimens of the locus typicus. This confirmed the importance in utilising material from the type locality for linking molecular data to the species’ morphological characters. Our paper underlines the importance of an integrative taxonomy in species diagnoses and demonstrates a scenario where morphological observations alone are not always sufficient. Lastly, this work adds reliable information to the sequence reference library that provides a useful building block for further studies on similar and related tardigrade taxa
FIGURE 1. Macrobiotus augusti Murray, 1907 in Designation of Pseudobiotus kathmanae Nelson, Marley & Bertolani, 1999 as the type species for the genus Pseudobiotus Nelson, 1980 (Tardigrada)
No full textFIGURE 1. Macrobiotus augusti Murray, 1907, as illustrated in the original description. [25a) M. augusti, sp. n., 25b) M. augusti egg, 25c) M. augusti pharynx of young in the egg, 25d) M. augusti claws. Reproduced by permission of the Royal Society of Edinburgh from Transactions of the Royal Society of Edinburgh, volume 45 (1907), pp. 641–668.]Published as part of <i>Marley, Nigel J., Bertolani, Roberto & Nelson, Diane R., 2008, Designation of Pseudobiotus kathmanae Nelson, Marley & Bertolani, 1999 as the type species for the genus Pseudobiotus Nelson, 1980 (Tardigrada), pp. 41-47 in Zootaxa 1940 (1)</i> on page 43, DOI: 10.11646/zootaxa.1940.1.4, <a href="http://zenodo.org/record/10092898">http://zenodo.org/record/10092898</a>
Mineralogical characterization of sericite-chlorite clays from Davoli (Calabria, south Italy): a proposal for ceramic products
No full textThe mineralogical, physical and chemical characteristics of a clay deposit near Davoli are discussed and related to minerogenesis. The material is composed of a chlorite-sericite clayey fraction plus quartz and sodium feldspar. X-ray diffraction, thermal analysis, microprobe analysis and firing tests in gradient kilns were used to detect about the properties and a possible use of this clay as a ceramic raw material. High temperature products such as mullite and spinel were revealed by X-ray powder diffraction (XRPD) technique. -Author
Taxonomy and biogeography of tardigrades using an integrated approach: new results on species of the Macrobiotus hufelandi group
No full textThis study reconsiders a tardigrade population previously studied and tentatively attributed to Macrobiotus cf. terminalis by Bertolani, Rebecchi (1993) with a new approach by joining molecular and indispensible traditional methods, light microscopy, and scanning electron microscopy. Differences in adult animals and, above all, egg shell morphology, and the peculiar cox1 sequence indicate that this population clearly belongs to a new species, M. vladimiri sp. n., which is here described. The results provide an example of how modern taxonomic and biogeographical research can be carried out on this animal phylum and in general on the animals belonging to the so-called meiofauna,in which morphological characters are often very few. This is the first tardigrade species to be described and barcoded contemporarily
Contributo alla cariologia dei Tardigradi. Osservazioni su Macrobiotus hufelandii.
No full textThe chromosome number in Macrobiotus hufelandi is 2n = 12 and n = 6 as in two other species of Macrobiotus (M. richtersi from Pisa and M. harmsworthi). The results differ from previous data which have stated 2n = 14 in M. hufelandi females. It is supposed that at least two sibling species are included in M. hufelandi
Macrobiotus azzunae Marnissi & Cesari & Rebecchi & Bertolani 2021, sp. nov.
No full textMacrobiotus azzunae sp. nov. urn:lsid:zoobank.org:act: 933CCC06-F69D-49E2-AF4F-0C042D8F5C99 Figs 1–4, 5A, C, 7 Etymology The new species is dedicated in honor of Atf Azzouna, professor in the Faculty of Mathematical, Physical and Natural Sciences of Tunis and supervisor of the PhD thesis of Jamila Ben Marnissi. Type material Holotype TUNISIA • spec. of unidentified sex; North-West Tunisia, Kroumiri Mountains, Ain Soltan forest, Jendouba; 36º31′21.788″ N, 8º19′57.741″ E; 893 m a.s.l.; Apr. 2017; Marnissi leg.; moss on trunk of Quercus canariensis; UNIMORE, slide code C4218–S32. Paratypes TUNISIA • 17 specs, sex unidentified; same collection data as for holotype; UNIMORE, slide codes C4218–S2 to C4218–S7, C4218–S9, C4218–S17, C4218–S30, C4218–S31, C4218–S33 to C4218– S35 • 3 eggs; same collection data as for holotype; UNIMORE, slide codes C4218–S10, C4218–S11, C4218–S25. Type depositories The holotype (slide: C 4218– S 32), 17 paratypes (slides C 4218– S 2 to C 4218– S 7, C 4218– S 17, C 4128– S 30, C 4218– S 31, C 4218– S 33 to C 4218- S 35), 3 eggs (slides: C 4218– S 10/11/25) and two vouchers (slides SP 04 and SP 07, corresponding to specimens C 4218 V 4 and C 4218 V 7, respectively) mounted in Faure-Berlese fluid, are deposited in the Bertolani collection at the Department of Life Science, UNIMORE, Modena, Italy. Type locality NW Tunisia, Kroumrie mountains, Ain Soltan forest, Jendouba, 36º31′21.788″ N, 8º19′57.741″ E. Altitude 893 m a.s.l. Description Adult specimens Body white, transparent after mounting in Faure-Berlese, from 162.2 to 410.3 µm in length (Fig. 2A, Table 3; structures measured only in the animals more than 200 µm in length). Eye spots present, even after mounting. Cuticle smooth but with small round or oval pores, 1–1.5 µm in diameter (Fig. 2B), better visible after fixation in Carnoy and orcein staining (Fig. 3C), scattered randomly on the entire cuticle, including the dorsal surface of all legs. With SEM, pores look oval or in the shape of a seed (Fig. 3A, D) with the largest diameter of 0.7–0.8 µm. Weak cuticular granulation also present on the lateral surface of all legs and specially on legs IV (Fig. 2B, arrow). Only with SEM is it possible to define the shape of the granulation on the legs, which looks as a regular disposition of star-shaped protuberances (about 0.3 µm; Fig. 3F). Six buccal sensory lobes around the mouth, well recognizable with SEM. Mouth antero-ventral; buccal-pharyngeal apparatus of the Macrobiotus type (sensu Pilato & Binda 2010), with ventral lamina and ten small peribuccal lamellae (in the holotype, after mounting, separated from the mouth). Buccal armature, corresponding to oral cavity armature, OCA, according to Michalczyk & Kaczmarek (2003), without an anterior band of teeth visible, corresponding to the first band of teeth according to Michalczyk & Kaczmarek (2003), and to the anterior band of the buccal ring according to Guidetti et al. (2012); posterior band of teeth poorly visible, corresponding to second band of teeth, according to Michalczyk & Kaczmarek (2003), followed by three dorsal and three ventral crests, corresponding to third band of teeth according to Michalczyk & Kaczmarek (2003); the dorsal crests (Fig. 2D) are distinct transverse ridges, whereas the ventral crests (Fig. 2E) appear as two separate lateral transverse ridges and a roundish median tooth. The posterior band of teeth and the transverse ridges are part of the buccal tube, according to Guidetti et al. (2012). Buccal tube narrow; pharyngeal bulb spherical with triangular apophyses, two rod-shaped macroplacoids, relatively short, the first longer than the second and evidently but not deeply narrowed at its middle (Fig. 2C), the second with a not particularly evident subterminal constriction. Microplacoid present. Slender claws of the hufelandi type (sensu Pilato & Binda 2010); the external claw longer than the internal one and the posterior longer than the anterior. Primary branches of each claw with distinct accessory points (Fig. 2F), a common tract of medium length (about a third of the total claw length) and an evident stalk connecting the claw to the lunule. Lunules under all claws, smooth, larger on the hind legs (Figs 2G, 3E). Cuticular bars under claws absent. The population is dioecious (gonochoristic). Males were recognized using orcein staining, which revealed that the testis is filled with spermatozoa with a coiled head (Fig. 3G) and spermatids. No morphological secondary sexual dimorphism, such as gibbosities on legs IV in males, was identified. Eggs Eggs are laid freely, and are white, spherical or slightly oval. One egg containing a fully developed embryo showed the shape of the buccal-pharyngeal apparatus (Fig. 4A). Processes of the eggshell are in the shape of inverted goblets (Fig. 4B) with conical trunks and well-defined distal discs as large as the process bases (for measurements see Table 4). Distal discs concave, with a median small protuberance and, using PhC, with border often smooth, or sometimes slightly jagged, or slightly ragged (Fig. 4C), but never clearly jagged, serrated or dentate. Surface among processes of the hufelandi type (sensu Kaczmarek & Michalczyk 2017a), i.e., covered by a very thin grid (Fig. 4D). Meshes around the process bases slightly larger and with slightly thicker wires compared with interbasal meshes. Mesh diameter around 0.5 µm. Comparisons Macrobiotus azzunae sp. nov. has eggs with processes as inverted goblets and a reticulate eggshell between the processes. Consequently, a comparison must be done with the Macrobiotus species listed by Kaczmarek & Michalczyk (2017a) with hufelandi type eggshells, excluding the species with processes that are not like inverted goblets, and adding the species with hufelandi type chorion eggs described after that publication. The species with hufelandi type chorion eggs that do not have processes as inverted goblets are Macrobiotus acadianus (Meyer & Domingue, 2011), M. dariae Pilato & Bertolani, 2004, M. lissostomus Durante Pasa & Maucci, 1979, M. santoroi Pilato & D’Urso, 1976, and M. scoticus Stec, Morek, Gąsiorek, Blagden & Michalczyk, 2017. Moreover, M. azzunae sp. nov. has egg processes with distal discs with a smooth or slightly jagged border, therefore it differs from all the species that have clearly indented, serrated or clearly jagged distal discs, such as: Macrobiotus canaricus Stec, Krzywański & Michalczyk, 2018, M. crustulus Stec, Dudziak & Michalczyk, 2020, M. hannae Nowak & Stec, 2018 (whose egg surface is more cribriform than reticulate), M. hibiscus de Barros, 1942, M. horningi Kaczmarek & Michalczyk, 2017b (which also has very high processes), M. hufelandi C.A.S. Schultze, 1834, M. humilis Binda & Pilato, 2001, M. iharosi Pilato, Binda & Catanzaro 1991, M. joannae Pilato & Binda, 1983, M. julianae (Meyer, 2012), M. kamilae Coughlan & Stec, 2019, M. modestus Pilato & Lisi, 2009, M. noonragi s Coughlan & Stec, 2019, M. papei Stec, Kristensen & Michalczyk, 2018 (with particularly long filaments starting from the distal disc), M. paulinae Stec, Smolak, Kaczmarek & Michalczyk, 2015, M. polypiformis Roszkowska, Ostrowska, Stec, Janko & Kaczmarek, 2017 (even with cog-teeth extended to form a long, thin, hair-like and flexible filament), M. punctillus Pilato, Binda & Azzaro, 1990, M. sapiens Binda & Pilato, 1984, M. sottilei Pilato, Kiosya, Lisi & Sabella, 2012. For the shape of the egg Macrobiotus azzunae sp. nov. differs from M. rawsoni Horning, Schuster & Grigarick, 1978 because this species has only one strip of meshes around each egg process (see Kaczmarek & Michalczyk 2017b); it differs from M. serratus Bertolani, Guidi & Rebecchi, 1996 because in this species the egg surface is porous more than reticulated, with pores small and spaced from each other, and its egg processes have a large, often square, distal disc; it differs from M. seychellensis Biserov, 1994 because the distal disc of the egg processes of this species, even though not dentate, has long and very developed lobes. The remaining nine species of the hufelandi group should be compared singularly. Macrobiotus almadai Fontoura, Pilato & Lisi, 2008 Macrobiotus azzunae sp. nov. differs from M. almadai in having a posterior band of teeth in the buccal cavity visible with LM (not visible in M. almadai), and distal disc with a jagged margin instead of very small teeth as in M. almadai. Macrobiotus canaricus Stec, Krzywański & Michalczyk, 2018 With LM the margin of the distal disc of M. azzunae sp. nov., never dentate in this species, looks similar to that of M. canaricus, but the SEM images of the eggs of the latter species evidence the presence of an almost dentate disc. Moreover, the peribasal meshes of the eggshell are larger than interbasal ones in the new species while they do not differ from the interbasal ones in M. canaricus; regarding the animals there are differences in the buccal armature: in M. azzunae sp. nov. the posterior band of teeth is visible with LM (even though poorly) and the three dorsal crests are distinct transverse ridges, while in M. canaricus the posterior band of teeth is visible only with SEM and with LM the dorsal teeth form a transversal ridge weakly divided into three teeth. Macrobiotus madegassus Maucci, 1993 The new species differs from M. madegassus by the presence of the eye spots (absent in M. madegassus), pores on the cuticle (absent in M. madegassus), presence in the buccal armature of posterior band of teeth, even though weak (fully absent in M. madegassus), buccal tube much larger (pt of the holotypes 15.9 vs 7), insertion of the stylet supports on the buccal tube much more posterior (pt of the holotypes 76.1 vs 68), first and second macroplacoid longer (pt of the holotypes 25.5 and 18.1 vs 21.3 and 12.0), lunules on the hind legs without kerning (crenate in M. madegassus), eggshell processes with distal disc as large as the base (similar range 3.2–5.2 for both measurements) with respect to that of M. madegassus (disc vs base: 4.3–5.4 vs 2.3–2.6). Macrobiotus martini Bartels , Pilato, Lisi & Nelson, 2009 The cuticular pores in M. azzunae sp. nov. are much smaller than those of M. martini; the distal disc of the egg processes in M. azzunae sp. nov. has a diameter similar to that of the process base, while in M. martini the distal disc is much narrower than the base. Macrobiotus nebrodensis Pilato, Sabella, D’Urso & Lisi, 2017 Macrobiotus azzunae sp. nov. differs from M. nebrodensis by the absence of the cuticular bar near the lunules on the first three pairs of legs (a faint bar is present in M. nebrodensis). The egg processes of M. azzuane sp. nov. are in higher number on the circumference (29–33) with respect to those of M. nebrodensis (18). In the latter species there are some egg processes very high (up to 20.6 µm), while in the new species process height and shape are more uniform. The difference in the eggshell between meshes around the process base and the others is much less evident in M. azzunae sp. nov. than in M. nebrodensis. Macrobiotus personatus Biserov, 1990 The new species differs from M. personatus by the posterior band of the buccal armature less evident, the presence of a clear constriction in the first macroplacoid (Fig. 5A), in the paratype of M. personatus examined by us barely identifiable (Fig. 6A) and, according to Biserov (1990) usually absent in the type material of that species. The pores on the cuticle of M. azzunae sp. nov. are small, approximately 1 µm in diameter, while in M. personatus they are strongly elliptic and about 3 µm in length (Fig. 6B). Lunules on leg IV are always smooth in M. azzunae sp. nov., sometimes indented in M personatus. With respect to the eggs of M. personatus (Fig. 6C–D), the egg processes of M. azzunae sp. nov. (Figs 4C–D, 5C) are clearly shorter, 5.4 ± 0.6 vs 9.5 ± 0.5 (range 4.2–6.4 vs 9–10.5) and with a narrower base and distal disc (both 3.2–5.2 vs 7–10.5 and 7–9 respectively). Males are present in the new species, while in M. personatus only females were found (Biserov 1990), suggesting parthenogenesis in that species. Macrobiotus sandrae Bertolani & Rebecchi, 1993 The new species differs from M. sandrae for the eggshell shape, with thinner wires of the reticulum and meshes around the processes larger than the inter-process meshes in M. azzunae sp. nov. (Fig. 5C), all meshes similar in size in M. sandrae (Fig. 5D). Figure 5C–D also show a difference in the process base diameter, narrower in M. azzunae sp. nov. With regard to the animals, M. azzunae sp. nov. differs from M. sandrae by a constriction of the first macroplacoid much more pronounced (Fig. 5A; it is hardly visible in M. sandrae; Fig. 5B). Moreover, in animals of similar size the posterior band of the buccal armature is just less evident in the new species, and lunules on the hind legs are without hint of teeth (but teeth, present in the holotype of M. sandrae, are often difficult to identify in other specimens of that species). Macrobiotus terminalis Bertolani & Rebecchi, 1993 Macrobiotus azzunae sp. nov. differs from M. terminalis for the absence of granulation on the cuticle (noted only in the redescription of M. terminalis; see Cesari et al. 2011), for the absence of teeth on the lunules, especially evident on the hind legs of M. terminalis, and for the presence of males, absent in M. terminalis (see redescription by Cesari et al. 2011). Macrobiotus vladimiri Bertolani, Biserov, Rebecchi & Cesari, 2011 With respect to M. vladimiri, animals of M. azzunae sp. nov. reach a shorter length (up to 410.3 µm vs 515.1 µm), in M. azzunae sp. nov. the posterior band of teeth of the buccal armature is less evident and the lunules on the hind legs are not indented. In M. azzunae sp. nov. the egg diameter without processes (64.7–80.6 µm) is less than that of the eggs of M. vladimiri (89.9–92.0 µm); the processes are shorter (4.2–6.4 µm in the new species vs 6.5–8 µm in M. vladimiri). In the new species the base process diameter is narrower (3.2–5.2 µm) than in M. vladimiri (5.1–7.3 µm), the distal disc is weakly or not jagged (clearly jagged in M. terminalis). In M. azzunae sp. nov. males are present, while they are absent in M. vladimiri. Genetic distances The ranges of uncorrected genetic p-distances between M. azzunae sp. nov. and the other species of the M. hufelandi group (Supp. file 7, Supp. file 8, Supp. file 9, Supp. file 10), are as follows: 18S 0.1–5.6%, with the most similar being M. sandrae from Germany (present paper) 28S 0.1%, with the only available M. vladimiri from Spain (FJ435751 –5) ITS-2 7.7–32.2%, with the most similar being Macrobiotus vladimiri (MN888347) from Finland COI 6.3–25.6%, with the most similar being Macrobiotus sandrae (HQ876574, HQ876577, HQ876578, HQ876579, HQ876581) from Germany The COI dataset is the most complete and informative for species delimitation investigation. Both phylogenetic reconstructions on the COI dataset resulted in the same topology, and thus the ML tree was utilized for the PTP analysis (Fig. 7, left), which shows 14 putative species clusters: M. crustulus, M.hannae, M. cf. recens, M.canaricus, M.hufelandi, M. cf. hufelandi sp.1, M. terminalis, M. cf. terminalis, M. wandae, M. macrocalix, M. cf. macrocalix, M. vladimiri, M. sandrae and M. azzunae sp. nov. This subdivision is further validated by both the ABGD and the haplotype network analysis (Fig. 7, centre and right). Present molecular data therefore confirms the validity of the erection of M. azzunae sp. nov.Published as part of Marnissi, Jamila Ben, Cesari, Michele, Rebecchi, Lorena & Bertolani, Roberto, 2021, Integrative description of a new Tunisian tardigrade species, Macrobiotus azzunae sp. nov. (Eutardigrada, Macrobiotidae, hufelandi group), pp. 122-146 in European Journal of Taxonomy 758 (1) on pages 126-138, DOI: 10.5852/ejt.2021.758.1429, http://zenodo.org/record/508810
Osservazioni cariologiche su alcuni Macrobiotus (Tardigrada).
No full textThe chromosome morphology and number in somatic and germinal cells were studied in some species of Macrobiotus. Most of these species ((M. areolatus, M. coronifer, M. harmsworthi, M. hufelandi, and the bisexual biotype of M. richtersi) have 2n = 12 chromosomes, but in two freswater species with similar morphology (M. dispar and M. pullari) 2n = 10 chromosomes are found. The chromosome number in males and females of M. areolatus and M. richtersi is the same. In the ripening oocytes and in the first blastomeres the metaphasic chromosomes show a peculiar large size. No idiograms were made because the chromosomes are too small, similar and without detectable centromeres
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