scholarly journals Cytogenetic markers as a tool for characterization of hybrids of Astyanax Baird & Girard, 1854 and Hyphessobrycon Eigenmann, 1907

2020 ◽  
Vol 14 (2) ◽  
pp. 231-242
Author(s):  
Caio Augusto Gomes Goes ◽  
Sandro Natal Daniel ◽  
Lucas Henrique Piva ◽  
George Shigueki Yasui ◽  
Roberto Ferreira Artoni ◽  
...  

Astyanax Baird et Girard, 1854, is one of the largest genera in the family Characidae and comprises 177 valid species. This genus has been the focus of cytogenetic studies primarily owing to the presence of B chromosomes and high karyotypic diversity among different populations. The intense genetic variability in Astyanax is one of the factors responsible for the occurrence of species complexes, which are groups (1) with certain difficulties in establishing common genetic pools or (2) belonging to different cryptic species. To evaluate cytogenetic marker inheritance and the possibility of the identification of these hybrids, this study aimed to describe cytogenetic hybrids from three strains of species of the genera Astyanax and Hyphessobrycon Eigenmann, 1908. A. lacustris Lütken, 1875, A. schubarti Britski, 1964, A. fasciatus Cuvier, 1819, and H. anisitsi Eigenmann, 1907 were used to generate three hybrid lineages. The diploid number, heterochromatin sites, and ribosomal genes (18S and 5S rDNA) of the parental strains and the hybrids were analyzed. The results indicated that the three hybrid lineages had cytogenetic markers of both parents, presenting Mendelian inheritance. However, differences in distribution of heterochromatic blocks were observed between the hybrids and the parent strains. Our results allowed the identification of the hybrid strains based on the cytogenetic markers applied, reinforcing the efficiency of cytogenetic markers as tools for identification and indicating that such events may increase the karyotypic diversity in the genera Astyanax and Hyphessobrycon.

2020 ◽  
Vol 14 (4) ◽  
pp. 639-643
Author(s):  
Caio Augusto Gomes Goes ◽  
Sandro Natal Daniel ◽  
Lucas Henrique Piva ◽  
George Shigueki Yasui ◽  
Roberto Ferreira Artoni ◽  
...  

Astyanax Baird et Girard, 1854, is one of the largest genera in the family Characidae and comprises 177 valid species. This genus has been the focus of cytogenetic studies primarily owing to the presence of B chromosomes and high karyotypic diversity among different populations. The intense genetic variability in Astyanax is one of the factors responsible for the occurrence of species complexes, which are groups (1) with certain difficulties in establishing common genetic pools or (2) belonging to different cryptic species. To evaluate cytogenetic marker inheritance and the possibility of the identification of these hybrids, this study aimed to describe cytogenetic hybrids from three strains of species of the genera Astyanax and Hyphessobrycon Eigenmann, 1908. A. lacustris Lütken, 1875, A. schubarti Britski, 1964, A. fasciatus Cuvier, 1819, and H. anisitsi Eigenmann, 1907 were used to generate three hybrid lineages. The diploid number, heterochromatin sites, and ribosomal genes (18S and 5S rDNA) of the parental strains and the hybrids were analyzed. The results indicated that the three hybrid lineages had cytogenetic markers of both parents, presenting Mendelian inheritance. However, differences in distribution of heterochromatic blocks were observed between the hybrids and the parent strains. Our results allowed the identification of the hybrid strains based on the cytogenetic markers applied, reinforcing the efficiency of cytogenetic markers as tools for identification and indicating that such events may increase the karyotypic diversity in the genera Astyanax and Hyphessobrycon.


Author(s):  
Horia R. Galea ◽  
Davide Maggioni

This study reports on 25 species of hydroids occurring in the collections gathered during KANACONO and KANADEEP expeditions carried out in the SE of New Caledonia in 2016, and off the western coast of the island in 2017, respectively. Of these, 19 have not been dealt with in earlier reports on these collections. Two new genera and four new species are described, viz, Actinopluma mirifica Galea gen. et sp. nov., provisionally assigned to the family Kirchenpaueriidae Stechow, 1921, Schizoplumularia helicoidalis sp. nov., belonging to the Plumulariidae McCrady, 1859, and Corhiza patula Galea sp. nov. and Thamnopteros uniserius Galea gen. et sp. nov., both placed in the family Halopterididae Millard, 1962. The gonotheca and the medusoid gonophore of Plumularia contraria Ansín Agís et al., 2014 are described for the first time, allowing a genus transfer to Dentitheca Stechow, 1919, as D. contraria comb. nov. Plumularia conjuncta Billard, 1913, known earlier from a minute portion of colony, is redescribed based on a complete, though infertile, specimen. Similarly, complete specimens corresponding to the hydroid previously referred to as Antennella megatheca Ansín Agís et al., 2009 are documented, allowing a provisional reallocation to Corhiza Millard, 1962 and a description of its so far unknown gonothecae. Fertile material assignable to the poorly-known Monostaechas fisheri Nutting, 1905 allows the recognition of this hydroid as a valid species, distinct from M. quadridens (McCrady, 1859). Most taxa are illustrated to validate the reliability of their identifications. Finally, phylogenetic reconstructions of the families Aglaopheniidae, Plumulariidae, and Halopterididae, based on the 16S rRNA, allowed a first genetic characterization of some of the species dealt with in this work.


2018 ◽  
Vol 16 (2) ◽  
Author(s):  
Simone C. Girardi ◽  
Carla S. Pavanelli ◽  
Vladimir P. Margarido

ABSTRACT Pimelodidae harbors several species and is widely distributed throughout the Neotropical region. Pimelodus is the genus with the largest number of species, however it is a polyphyletic group. Cytogenetic analyzes of the valid species still covers less than half of them. Herein, seven Pimelodus species from three Brazilian hydrographic systems were analyzed through basic (Giemsa, AgNORs and C banding) and molecular (5S and 18S rDNA-FISH) cytogenetic methods. All species had 2n=56 chromosomes with different karyotype formulas observed among the species. AgNORs were corresponding to 18S rDNA and localized on long arm of one chromosome pair in all species. Heterochromatin distribution follows the pattern commonly verified in the family and allows to identify each one of the studied species. 5S rDNA marker was interspecifically variable in number and position of cistrons. Pimelodus ortmanni had B chromosomes varying intra and inter-individually. We performed a discussion on our own and available cytogenetic data for Pimelodidae, and the associating of them with available phylogeny enable us identifying features that distinguish subgroups within Pimelodidae, such as NORs location (terminal/long arm for species belonging to “Iheringichthys-Parapimelodus” and “Pimelodus maculatus” subclades) and location of 5S rDNA sites (pericentromeric/interstitial/ long arm for species belonging to Pimelodus group).


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chuan Ma ◽  
Yeying Wang ◽  
Licui Zhang ◽  
Jianke Li

AbstractThe Trigonidiidae, a family of crickets, comprises 981 valid species with only one mitochondrial genome (mitogenome) sequenced to date. To explore mitogenome features of Trigonidiidae, six mitogenomes from its two subfamilies (Nemobiinae and Trigonidiinae) were determined. Two types of gene rearrangements involving a trnN-trnS1-trnE inversion and a trnV shuffling were shared by Trigonidiidae. A long intergenic spacer was observed between trnQ and trnM in Trigonidiinae (210−369 bp) and Nemobiinae (80–216 bp), which was capable of forming extensive stem-loop secondary structures in Trigonidiinae but not in Nemobiinae. The anticodon of trnS1 was TCT in Trigonidiinae, rather than GCT in Nemobiinae and other related subfamilies. There was no overlap between nad4 and nad4l in Dianemobius, as opposed to a conserved 7-bp overlap commonly found in insects. Furthermore, combined comparative analysis and transcript verification revealed that nad1 transcripts ended with a U, corresponding to the T immediately preceding a conserved motif GAGAC in the superfamily Grylloidea, plus poly-A tails. The resultant UAA served as a stop codon for species lacking full stop codons upstream of the motif. Our findings gain novel understanding of mitogenome structural diversity and provide insight into accurate mitogenome annotation.


2018 ◽  
Vol 63 (3) ◽  
pp. 495-503 ◽  
Author(s):  
Letícia P. Vidal ◽  
Douglas McIntosh ◽  
José L. Luque

Abstract During a parasitological survey of Astyanax altiparanae captured in the Mogi Guaçú river, Pirassununga, state of São Paulo, Brazil, a new species of myxozoa was observed infecting the kidney of 30 of 42 specimens. Plasmodia of the new myxozoa, referred to herein as Unicauda whippsi n. sp. were spherical and varied from 450 to 1000 μm in length. The mature spore was elongated and measured 11 ± 1.2 (10–12) μm long by 5.4 ± 0.6 (4.7–7.2) μm wide. Polar capsules of unequal length with the filament coiled 7–9 times and a unique caudal process characteristic of the genus Unicauda, were recorded. Phylogenetic analysis demonstrated that U. whippsi n. sp. clustered with members of the genus Unicauda and Myxobolus, confirming it’s placement within the family Myxobolidae. This is the first record of a species of Unicauda infecting characiform fish, as well as the first registered occurrence of species of this genus in South America.


2010 ◽  
Vol 8 (2) ◽  
pp. 361-368 ◽  
Author(s):  
Daniel Rodrigues Blanco ◽  
Roberto Laridondo Lui ◽  
Luiz Antonio Carlos Bertollo ◽  
Vladimir Pavan Margarido ◽  
Orlando Moreira Filho

Three populations of the group Hoplias malabaricus from the hydrographic basins of the São Francisco, Araguaia/Tocantins and Xingu Rivers in Brazil were analyzed using classic cytogenetic methods (Giemsa staining, C-banding and Ag-NORs) and molecular methods (fluorescent in situ hybridization with 18S rDNA, 5S rDNA and 5SHindIII satellite DNA probes). The chromosome markers allowed the characterization of these populations as belonging to karyomorph A and the detection of inter-population divergences. These differences likely stem from different evolutionary histories resulting from geographic isolation between populations associated to the dispersive mode of these organisms, reinforcing genetic diversity in the group Hoplias malabaricus.


2018 ◽  
Vol 12 (2) ◽  
pp. 145-162 ◽  
Author(s):  
Clóvis C. Motta-Neto ◽  
André Marques ◽  
Gideão W.W.F. Costa ◽  
Marcelo B. Cioffi ◽  
Luiz A.C. Bertollo ◽  
...  

Representatives of the order Labriformes show karyotypes of extreme conservatism together with others with high chromosomal diversification. However, the cytological characterization of epigenetic modifications remains unknown for the majority of the species. In the family Labridae, the most abundant fishes on tropical reefs, the genomes of the genus Bodianus Bloch, 1790 have been characterized by the occurrence of a peculiar chromosomal region, here denominated BOD. This region is exceptionally decondensed, heterochromatic, argentophilic, GC-neutral and, in contrast to classical secondary constrictions, shows no signals of hybridization with 18S rDNA probes. In order to characterize the BOD region, the methylation pattern, the distribution of Alu and Tol2 retrotransposons and of 18S and 5S rDNA sites, respectively, were analyzed by Fluorescence In Situ Hybridization (FISH) on metaphase chromosomes of two Bodianus species, B.insularis Gomon & Lubbock, 1980 and B.pulchellus (Poey, 1860). Immunolocalization of the 5-methylcytosine revealed hypermethylated chromosomal regions, dispersed along the entire length of the chromosomes of both species, while the BOD regions exhibited a hypomethylated pattern. Hypomethylation of the BOD region is associated with the precise co-location of Tol2 and Alu elements, suggesting their active participation in the regulatory epigenetic process. This evidence underscores a probable differential methylation action during the cell cycle, as well as the role of Tol2/Alu elements in functional processes of fish genomes.


1979 ◽  
Author(s):  
M Ribieto ◽  
J Elion ◽  
D Labie ◽  
F Josso

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion. Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Val-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin l (Pl) and the appearance of abnormal intermediates migrating faster than Pl.


2014 ◽  
Vol 25 (3-4) ◽  
pp. 77-83
Author(s):  
S. L. Grabovska ◽  
L. O. Kolodochka

This article deals with the results of study of species content and basic peculiarities of beaked mites-Phytoseiidae in plant associations of one of the regional centers of Ukraine. The species composition and distribution of mites-Phytoseiidae (Parasitiformes, Phytoseiidae) in plantations of Brovary town of Kyiv region were determined. Fourteen species of 8 genera of phytoseiid mites were found. Index of their existing and relative biotope connection of each registered species to vegetation types and plant species were computed. The study was conducted according to the results of material treatment on the territory of the mentioned city from 25 species of plants (16 species of hardy-shrub and 9 of herbaceous vegetations). The studies of distribution of plant-living mites-Phytoseiidae were conducted separately for hardy-shrub and herbaceous plants). The collection of faunistic material was executed during the vegetation of periods of 2011 and 2013. Within the city the collection of the material was conducted with hardy-shrub plants and herbaceous type of vegetation along the streets, in parks and squares of Brovary city of Kyiv region, district center, one of the satellite-cities of Kiev, the capital of Ukraine. The study of species complexes characteristics of mites was conducted with usage of data calculated on the basis of frequency index (Is), degree of relative habitat confinedness (F) (Pesenko, 1982) and domination index Paliy-Kovnatski (Di) (Shitikov, 2003). Only on one species of plant (F=1) 6 species of mites-Phytoseiidae were found – T.сotoneastri on blue spruce, T. laurae – on common spruce, T. aceri – on ash-leaved maple, P. incognitus – on dog-rose, P. soleiger – on mulberry-tree, A. caudiglans – on sea-buckthorn. These species can be related to stenoecic. The mentioned species are stenotopic only in relation to the sample of plants from the plant associations of Brovary, as in other regions these species of mites can populate the other species of plants. The rest 8 species, being registered on two or more types of plants, are related to euryoecic. Among them there is a group of 6 species with “positive tendencies to population of plants”, owning the indicators of habitat confinedness 0<F<1: A. andersoni (0,92–0,96), A. rademacheri (0,85–0,96), N. herbarius (0,92–0,96), T. tiliarum (0,66–0,77), A. pirianykae (0,73–0,99), A. clavata (0,82–0,98). The rest species, E. finlandicus и K. aberrans, have the expanded range of indicators in relation to habitat confinedness (-0,71<F<0,55 и -0,16<F<0,88), that specifies on their ability to populate the big quality of species. E. finlandicus has the negative indicator of relative habitat confinedness in relation to the plants of herbaceous morphotype that serves confirmation of the ecological peculiarity of the species detected earlier. The data of relative habitat confinedness of mites to certain species of plants shows availability of stenoecic (T.сotoneastri, T. laurae, T. aceri, P. incognitus, P. soleiger, A. caudiglans) and euryoecic species (A. andersoni, A. rademacheri, N. herbarius, E. finlandicus, K. aberrans, T. tiliarum, A. pirianykae, A. clavata). 


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