Chromosomal evolution in Gekkonidae. I. Chromosome painting between Gekko and Hemidactylus species reveals phylogenetic relationships within the group

Geckos are a large group of lizards characterized by a rich variety of species, different modes of sex determination and diverse karyotypes. In spite of many unresolved questions on lizards' phylogeny and taxonomy, the karyotypes of most geckos have been studied by conventional cytogenetic methods only. We used flow-sorted chromosome-specific painting probes of Japanese gecko (Gekko japonicus), Mediterranean house gecko (Hemidactylus turcicus) and flat-tailed house gecko (Hemidactylus platyurus) to reveal homologous regions and to study karyotype evolution in seven gecko species (Gekko gecko, G. japonicus, G. ulikovskii, G. vittatus, Hemidactylus frenatus, H. platyurus and H. turcicus). Generally, the karyotypes of geckos were found to be conserved, but we revealed some characteristic rearrangements including both fissions and fusions in Hemidactylus. The karyotype of H. platyurus contained a heteromorphic pair in all female individuals, where one of the homologues had a terminal DAPI-negative and C-positive heterochromatic block that might indicate a putative sex chromosome. Among two male individuals studied, only one carried such a polymorphism, and the second one had none, suggesting a possible ZZ/ZW sex determination in some populations of this species. We found that all Gekko species have retained the putative ancestral karyotype, whilst the fission of the largest ancestral chromosome occurred in the ancestor of modern Hemidactylus species. Three common fissions occurred in the ancestor of Mediterranean house and flat-tailed house geckos, suggesting their sister group relationships. PCR-assisted mapping on flow-sorted chromosome libraries with conserved DMRT1 gene primers in G. japonicus indicates the localization of DMRT1 gene on chromosome 6.

Color alteration of the paint used for iris painting in ocular prostheses

The purpose of this study was to assess color alteration of the paints used for iris painting in artificial eyes. Five disks of heat cured acrylic resin were confectioned by microwave energy for each paint analyzed, in a total of 40 specimens. Each specimen consisted of a colorless acrylic resin disk and another of equal size, of scleral white colored acrylic resin, with the painting interposed between the two disks. The specimens were submitted to an accelerated aging process in a chamber under ultraviolet radiation for 1,008 hours. To assess color variation, a reflective spectrophotometer was used. The results were statistically analyzed by ANOVA and the Tukey test (p < 0.05). All the paints underwent chromatic alteration. The oil paint presented the highest resistance to accelerated aging.

Investigation of Partamona helleri (Apidae, Meliponini) B chromosome origin. An approach by microdissection and whole chromosome painting

The stingless bee Partamona helleri in southeast Brazil shows the regular chromosome number 2n = 34 and a variable number of up to four minute B1 or B2 chromosomes. Previous cytogenetic analyses have indicated morphological similarities between the B1 chromosome and chromosome segments in the regular karyotype. In this study, microdissection and chromosome painting were employed along with C banding, NOR banding, and base-specific fluorochrome staining to investigate the origin of the B1 chromosome in P. helleri. B1-generated probe hybridized exclusively to B1 chromosomes. This result suggests an independent origin from the regular karyotype or, alternatively, that the B chromosome may have suffered substantial genetic alterations along its independent evolution. The absence of higher dosages of these small B chromosomes in this population of P. helleri may be related to the existence of either a genetic or cytogenetic constraint in the establishment of such high numbered karyotypes. © 2012 INRA, DIB and Springer-Verlag, France.

Chromosome painting of Z and W sex chromosomes in Characidium (Characiformes, Crenuchidae)

Some species of the genus Characidium have heteromorphic ZZ/ZW sex chromosomes with a totally heterochromatic W chromosome. Methods for chromosome microdissection associated with chromosome painting have become important tools for cytogenetic studies in Neotropical fish. In Characidium cf. fasciatum, the Z chromosome contains a pericentromeric heterochromatin block, whereas the W chromosome is completely heterochromatic. Therefore, a probe was produced from the W chromosome through microdissection and degenerate oligonucleotide-primed polymerase chain reaction amplification. FISH was performed using the W probe on the chromosomes of specimens of this species. This revealed expressive marks in the pericentromeric region of the Z chromosome as well as a completely painted W chromosome. When applying the same probe on chromosome preparations of C. cf. gomesi and Characidium sp., a pattern similar to C. cf. fasciatum was found, while C. cf. zebra, C. cf. lagosantense and Crenuchus spilurus species showed no hybridization signals. Structural changes in the chromosomes of an ancestral sexual system in the group that includes the species C. cf. gomesi, C. cf. fasciatum and Characidium sp., could have contributed to the process of speciation and could represent a causal mechanism of chromosomal diversification in this group. The heterochromatinization process possibly began in homomorphic and homologous chromosomes of an ancestral form, and this process could have given rise to the current patterns found in the species with sex chromosome heteromorphism. © 2013 Springer Science+Business Media Dordrecht.

Comparative analysis of sex chromosomes in Leporinus species (Teleostei, Characiformes) using chromosome painting

Background: The Leporinus genus, belonging to the Anostomidae family, is an interesting model for studies of sex chromosome evolution in fish, particularly because of the presence of heteromorphic sex chromosomes only in some species of the genus. In this study we used W chromosome-derived probes in a series of cross species chromosome painting experiments to try to understand events of sex chromosome evolution in this family.Results: W chromosome painting probes from Leporinus elongatus, L. macrocephalus and L. obtusidens were hybridized to each others chromosomes. The results showed signals along their W chromosomes and the use of L. elongatus W probe against L. macrocephalus and L. obtusidens also showed signals over the Z chromosome. No signals were observed when the later aforementioned probe was used in hybridization procedures against other four Anostomidae species without sex chromosomes.Conclusions: Our results demonstrate a common origin of sex chromosomes in L. elongatus, L. macrocephalus and L. obtusidens but suggest that the L. elongatus chromosome system is at a different evolutionary stage. The absence of signals in the species without differentiated sex chromosomes does not exclude the possibility of cryptic sex chromosomes, but they must contain other Leporinus W sequences than those described here. © 2013 Parise-Maltempi et al.; licensee BioMed Central Ltd.

A figura feminina na obra de Antônio da Fonseca Soares

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reacondicionamiento y reparación de contenedores: preparación y pintura de superficies = Refurbishment and repair of containers: surface preparation and painting

Incluye Bibliografía

Delimiting the Origin of a B Chromosome by FISH Mapping, Chromosome Painting and DNA Sequence Analysis in Astyanax paranae (Teleostei, Characiformes)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Similarity of heterochromatic regions in the stingless bees (Hymenoptera: Meliponini) revealed by chromosome painting

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Possible interspecific origin of the B chromosome of Hypsiboas albopunctatus (Spix, 1824) (Anura, Hylidae), revealed by microdissection, chromosome painting, and reverse hybridisation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chromosome painting in three-toed sloths: a cytogenetic signature and ancestral karyotype for Xenarthra

Background: Xenarthra (sloths, armadillos and anteaters) represent one of four currently recognized Eutherian mammal supraorders. Some phylogenomic studies point to the possibility of Xenarthra being at the base of the Eutherian tree, together or not with the supraorder Afrotheria. We performed painting with human autosomes and X-chromosome specific probes on metaphases of two three-toed sloths: Bradypus torquatus and B. variegatus. These species represent the fourth of the five extant Xenarthra families to be studied with this approach. Results: Eleven human chromosomes were conserved as one block in both B. torquatus and B. variegatus: (HSA 5, 6, 9, 11, 13, 14, 15, 17, 18, 20, 21 and the X chromosome). B. torquatus, three additional human chromosomes were conserved intact (HSA 1, 3 and 4). The remaining human chromosomes were represented by two or three segments on each sloth. Seven associations between human chromosomes were detected in the karyotypes of both B. torquatus and B. variegatus: HSA 3/21, 4/8, 7/10, 7/16, 12/22, 14/15 and 17/19. The ancestral Eutherian association 16/19 was not detected in the Bradypus species. Conclusions: Our results together with previous reports enabled us to propose a hypothetical ancestral Xenarthran karyotype with 48 chromosomes that would differ from the proposed ancestral Eutherian karyotype by the presence of the association HSA 7/10 and by the split of HSA 8 into three blocks, instead of the two found in the Eutherian ancestor. These same chromosome features point to the monophyly of Xenarthra, making this the second supraorder of placental mammals to have a chromosome signature supporting its monophyly.

Variable patterns of Y chromosome homology in Akodontini rodents (Sigmodontinae): a phylogenetic signal revealed by chromosome painting

The Akodontini is the second most speciose tribe of sigmodontine rodents, one of the most diverse groups of neotropical mammals. Molecular phylogenetic analyses are discordant regarding the interrelationships of genera, with low support for some clades. However, two clades are concordant, one (clade A) with Akodon sensu strictu (excluding Akodon serrensis), "Akodon" serrensis, Bibimys, Deltamys, Juscelinomys, Necromys, Oxymycterus, Podoxymys, Thalpomys and Thaptomys, and another (clade B) with Blarinomys, Brucepattersonius, Kunsia, Lenoxus and Scapteromys. Here, we present chromosome painting using Akodon paranaensis (APA) Y paint, after suppression of simple repetitive sequences, on ten Akodontini genera. Partial Y chromosome homology, in addition to the homology already reported on the Akodon genus, was detected on the Y chromosomes of "A." serrensis, Thaptomys, Deltamys, Necromys and Thalpomys and on Y and X chromosomes in Oxymycterus. In Blarinomys, Brucepattersonius, Scapteromys and Kunsia, no APA Y signal was observed using different hybridization conditions; APA X paint gave positive signals only on the X chromosome in all genera. The Y chromosome homology was variable in size and positioning among the species studied as follow: (1) whole acrocentric Y chromosome in Akodon and "A." serrensis, (2) Yp and pericentromeric region in submetacentric Y of Necromys and Thaptomys, (3) pericentromeric region in acrocentric Y of Deltamys, (4) distal Yq in the acrocentric Y chromosome of Thalpomys and (5) proximal Yq in the acrocentric Y and Xp in the basal clade A genus Oxymycterus. The results suggest that the homology involves pairing (pseudoautosomal) and additional regions that have undergone rearrangement during divergence. The widespread Y homology represents a phylogenetic signal in Akodontini that provides additional evidence supporting the monophyly of clade A. The findings also raise questions about the evolution of the pseudoautosomal region observed in Oxymycterus. The Y chromosomes of these closely related species seem to have undergone dynamic rearrangements, including restructuring and reduction of homologous segments. Furthermore, the changes observed may indicate progressive attrition of the Y chromosome in more distantly related species.

Influence of artificial accelerated ageing on the colour stability of paints used for ocular prosthesis iris painting

Objectives: To evaluate the colour stability of paints used for ocular prosthesis iris painting submitted for accelerated artificial ageing (AAA). Materials and methods: Forty specimens of acrylic resin for sclera (16 x 2 mm) were made and separated into eight groups (n = 10) according to the type of paint (gouache, GP; oil, OP; acrylic AP; and composite resin for characterisation, CR) and the colours used (blue/brown). After drying (72 h), a new layer of colourless acrylic resin was applied and the initial colour readout was performed (Spectrophotometer PCB 6807). New colour readouts were performed after AAA, and Delta E was calculated. Results: Statistical analysis (two-way ANOVA-Bonferroni, p < 0.05) demonstrated that the brown colour showed lower Delta E means in comparison with the blue colour, with statistically significant difference for AP only. Blue colour showed no statistically significant difference with regard to the type of paint used. Brown AP showed lower Delta E than the other groups, with significant difference for OP and GP. GP showed greater alteration in Delta E for the brown colour, being statistically similar only to OP. Conclusions: Only the AP group for brown pigment shows clinically acceptable values for colour stability after AAA.

The Effect of Preservative Interventions on the Chemical- Physical and Structural Characteristics of Panel Painting

This work studies the impact of two traditional Romanian treatments, Red Petroleum and Propolis, in terms of real efficiency and consequence on the wooden artifacts. The application of these solutions is still a widely adopted and popular technique in preservative conservation but the impact of these solutions is not well known. It is important to know the effect of treatments on chemical-physical and structural characteristics of the artifacts, not only for understanding the influence on present conditions but also for foreseeing the future behavior. These treatments with Romanian traditional products are compared with a commercial antifungal product, Biotin R, which is utilized as reference to control the effectiveness of Red Petroleum and Propolis. Red Petroleum and Propolis are not active against mould while Biotin R is very active. Mould attack is mostly concentrated in the painted layer, where the tempera, containing glue and egg, enhance nutrition availability for moulds. Biotin R, even if is not a real insecticide but a fungicide, was the most active product against insect attack of the three products, followed by Red Petroleum, Propolis and untreated reference. As for colour, it did not change so much after the application of Red Petroleum and Biotin R and the colour difference was almost not perceptible. On the contrary, Propolis affected the colour a lot. During the exposure at different RH, the colour changes significantly at 100% RH at equilibrium and this is mainly due to the mould attack. Red Petroleum penetrates deeply into wood, while Propolis does not penetrate and remains only on the surface. However, Red Petroleum does not interact chemically with wood substance and it is easy volatilized in oven-dry condition. On the contrary Propolis interacts chemically with wood substance and hardly volatilized, even in oven-dry condition and consequently Propolis remains where it penetrated, mostly on the surface. Treatment by immersion has impact on wood physical parameters while treatment by brushing does not have significant impact. Especially Red Petroleum has an apparent impact on moisture content (MC) due to the penetration of solution, while Propolis does not penetrate so much and remains only on surface therefore Propolis does not have so much impact as Red Petroleum. However, if the weight of the solution penetrated in wood is eliminated, there is not significant difference in MC between treated and untreated samples. Considering physical parameters, dimensional stability is an important parameter. The variation of wood moisture content causes shrinkages/swelling of the wood that polychrome layer can only partially follow. The dimension of wooden supports varied under different moisture conditioning; the painted layer cannot completely follow this deformation, and consequently a degradation and deterioration caused by detachment, occurs. That detachment affects the polychrome stratification of the panel painting and eventually the connections between the different layer compositions of the panel painting.