Diversity and Karyotypic Evolution in the Genus Neacomys (Rodentia, Sigmodontinae)

2015 ◽  
Vol 146 (4) ◽  
pp. 296-305 ◽  
Author(s):  
Willam O. da Silva ◽  
Julio C. Pieczarka ◽  
Rogério V. Rossi ◽  
Horacio Schneider ◽  
Iracilda Sampaio ◽  
...  
Keyword(s):  
Molecular Phylogeny ◽  
Diploid Number ◽  
Constitutive Heterochromatin ◽  
Chromosomal Evolution ◽  
The Other ◽  
Karyotypic Evolution ◽  
Drastic Reduction ◽  
Ancestral Species ◽  
Pericentric Inversions ◽  
Amazonian Region

Neacomys (Sigmodontinae) comprises 8 species mainly found in the Amazonian region. We describe 5 new karyotypes from Brazilian Amazonia: 2 cytotypes for N. paracou (2n = 56/FNa = 62-66), 1 for N. dubosti (2n = 64/FNa = 68), and 2 for Neacomys sp. (2n = 58/FNa = 64-70), with differences in the 18S rDNA. Telomeric probes did not show ITS. We provide a phylogeny using Cytb, and the analysis suggests that 2n = 56 with a high FNa is ancestral for the genus, as found in N. paracou, being retained by the ancestral forms of the other species, with an increase in 2n occurring independently in N. spinosus and N. dubosti. Alternatively, an increase in 2n may have occurred in the ancestral taxon of the other species, followed by independent 2n-reduction events in Neacomys sp. and in the ancestral species of N. tenuipes, N. guianae, N. musseri, and N. minutus. Finally, a drastic reduction event in the diploid number occurred in the ancestral species of N. musseri and N. minutus which exhibit the lowest 2n of the genus. The karyotypic variations found in both intra- and interspecific samples, associated with the molecular phylogeny, suggest a chromosomal evolution with amplification/deletion of constitutive heterochromatin and rearrangements including fusions, fissions, and pericentric inversions.

Comparative study of G- and C-banded chromosomes of five species of Microtidae: a chromosomal evolution analysis

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 540-546 ◽  
Author(s):  
M. Burgos ◽  
R. Jiménez ◽  
R. Díaz de la Guardia
Keyword(s):  
Comparative Study ◽  
Chromosomal Evolution ◽  
Karyotypic Evolution ◽  
Banding Patterns ◽  
Robertsonian Translocations ◽  
Interspecific Differences ◽  
Evolution Analysis ◽  
Pericentric Inversions

G-banded karyotypes were compared in the following species of Microtidae: Microtus nivalis, M. cabrerae, M. arvalis, and Arvicola sapidus. Previous observations on A. sapidus and A. terrestris were also incorporated in this study. The results show that Robertsonian translocations and pericentric inversions are common mechanisms involved in the karyotypic evolution of this group. Interspecific differences on the G-banding patterns were also analysed, and an attempt was made to establish a presumptive phylogenetic tree.Key words: chromosomal evolution, Microtidae, G-bands, C-bands.

Karyotype evolution in Curimatidae (Teleostei, Characiformes) from the Amazon region. II. Centric fissions in the genus Potamorhina

Genome ◽  
1993 ◽  
Vol 36 (2) ◽  
pp. 372-376 ◽  
Author(s):  
Eliana Feldberg ◽  
J. I. R. Porto ◽  
C. M. Nakayama ◽  
L. A. C. Bertollo
Keyword(s):  
Diploid Number ◽  
Constitutive Heterochromatin ◽  
Karyotype Evolution ◽  
Organizer Region ◽  
Nucleolar Organizer Region ◽  
Nucleolar Organizer ◽  
Karyotypic Evolution ◽  
M 10 ◽  
Amazon Fish ◽  
Region Ii

Using cytogenetic analysis following Giemsa staining, nucleolar organizer region (NOR) staining, and C-banding, three distinct karyotypes in three species of curimatids belonging to the fish genus Potamorhina were identified: 2n = 54/44 M + 10 SM (P. pristigaster), 2n = 56/52 M + 2 SM + 2 ST (P. latior), and 2n = 102/2 M + 2 SM + 98 A (P. altamazonica). A 2n = 54 was considered to be the ancestral diploid number and the different karyotypes were probably the result of centric fissions. Both the NOR pattern and constitutive heterochromatin pattern are species specific.Key words: centric fissions, karyotypic evolution, Amazon fish, Curimatidae.

scholarly journals Sequential Steps of Chromosomal Differentiation in Atlantic Surgeonfishes: Evolutionary Inferences

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Paulo Roberto Antunes de Mello Affonso ◽  
Maria Aparecida Fernandes ◽  
Josivanda Santos Almeida ◽  
Wagner Franco Molina
Keyword(s):  
Molecular Phylogeny ◽  
Nucleolar Organizer ◽  
Chromosomal Evolution ◽  
Nucleolar Organizer Regions ◽  
Similar Distribution ◽  
Noncoding Sequences ◽  
Pericentric Inversions ◽  
Chromosomal Differentiation ◽  
Chromosomal Data

Surgeonfishes are a species-rich group and a major biomass on coral reefs. Three species are commonly found throughout South Atlantic,Acanthurus bahianus,A. chirurgus, andA. coeruleus. In this paper, we present the first cytogenetic data of these species, revealing a sequential chromosomal diversification.A. coeruleuswas characterized by a relatively conserved karyotype evolved by pericentric inversions of some pairs (2n=48, 2sm + 4st + 42a). In contrast, the karyotypes ofA. bahianus(2n=36) andA. chirurgus(2n=34) were highly differentiated by the presence of six large metacentric pairs inA. bahianus(12m + 2sm + 4st + 18a) andA. chirurgus(12m + 2sm + 4st +1 6a) probably derived by chromosomal fusions that corroborate their closer relationship. A discerniblein tandemfusion represents an autapomorphic character toA. chirurgus. In spite of macrostructure variation, single nucleolar organizer regions (NORs) on short arms of a subtelocentric pair and similar distribution of C-bands were observed in the three species. Overlapping of chromosomal data with molecular phylogeny indicated pericentric inversions which took place nearly at 19 Ma while centric fusions are as recent as 5 Ma. A physical mapping of coding and noncoding sequences inAcanthuruscould clarify the role of additional rearrangements during their chromosomal evolution.

scholarly journals Diversification of the Balloon bushcrickets (Orthoptera, Hexacentrinae, Aerotegmina) in the East African mountains

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beata Grzywacz ◽  
Elżbieta Warchałowska-Śliwa ◽  
Maciej Kociński ◽  
Klaus-Gerhard Heller ◽  
Claudia Hemp
Keyword(s):  
Molecular Phylogeny ◽  
Large Scale ◽  
Diploid Number ◽  
Karyotype Analysis ◽  
Spatial Separation ◽  
Eastern Arc Mountains ◽  
East African ◽  
Habitat Islands ◽  
Extinction Event ◽  
Underlying Processes

AbstractEast African mountains constitute a network of isolated habitat islands among dry savannah and are thus ideal for studying species diversification processes. This study elucidated the phylogenetic and phylogeographic relationships of all bushcricket species comprising the genus Aerotegmina. Our analysis indicated that large-scale climatic and topographic processes in Africa are likely to have driven speciation in this group, and revealed the cytogenetic traits of the species. Molecular phylogeny supported the monophyly of Aerotegmina and showed that the genus probably originated in the old Eastern Arc Mountains of Tanzania and Kenya. Two lineages were distinguished: small- and large-sized species with geographically distinct habitats. The underlying processes are thought to be eight dispersals, ten vicariance events, and one extinction event linked to repeated fragmentation of the African rainforest. Those processes, in conjunction with habitat change, probably also led to the spatial separation of the species into a northern clade with a diploid number of chromosomes 2n = 32 + X0 or 2n = 30 + neo-XY and a southern clade with a reduced number of chromosomes (2n = 28 + X0 or 24 + neo-X1X2Y). Karyotype analysis suggests that Aerotegmina is currently in the process of speciation.

scholarly journals Chromosomal painting of the sandpiper (Actitis macularius) detects several fissions for the Scolopacidae family (Charadriiformes)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Melquizedec Luiz Silva Pinheiro ◽  
Cleusa Yoshiko Nagamachi ◽  
Talita Fernanda Augusto Ribas ◽  
Cristovam Guerreiro Diniz ◽  
Patricia Caroline Mary O´Brien ◽  
...  
Keyword(s):  
Chromosome Painting ◽  
Diploid Number ◽  
Chromosomal Evolution ◽  
Long Distance ◽  
Chromosomal Painting ◽  
Cytogenetic Studies ◽  
Burhinus Oedicnemus ◽  
Clear Idea ◽  
First Time

Abstract Background The Scolopacidae family (Suborder Scolopaci, Charadriiformes) is composed of sandpipers and snipes; these birds are long-distance migrants that show great diversity in their behavior and habitat use. Cytogenetic studies in the Scolopacidae family show the highest diploid numbers for order Charadriiformes. This work analyzes for the first time the karyotype of Actitis macularius by classic cytogenetics and chromosome painting. Results The species has a diploid number of 92, composed mostly of telocentric pairs. This high 2n is greater than the proposed 80 for the avian ancestral putative karyotype (a common feature among Scolopaci), suggesting that fission rearrangements have formed smaller macrochromosomes and microchromosomes. Fluorescence in situ hybridization using Burhinus oedicnemus whole chromosome probes confirmed the fissions in pairs 1, 2, 3, 4 and 6 of macrochromosomes. Conclusion Comparative analysis with other species of Charadriiformes studied by chromosome painting together with the molecular phylogenies for the order allowed us to raise hypotheses about the chromosomal evolution in suborder Scolopaci. From this, we can establish a clear idea of how chromosomal evolution occurred in this suborder.

CHROMOSOMES AND DNA OF MICROTUS II. CONFIRMATION OF DELETION OF CONSTITUTIVE HETEROCHROMATIN IN M. AGRESTIS CELLS IN VITRO

1977 ◽  
Vol 19 (3) ◽  
pp. 537-541 ◽  
Author(s):  
J. E. K. Cooper
Keyword(s):  
Somatic Cell ◽  
Cell Line ◽  
Cell Lines ◽  
X Chromosome ◽  
Sex Chromosomes ◽  
Constitutive Heterochromatin ◽  
The Other ◽  
Microtus Agrestis ◽  
C Banding

The distribution of constitutive heterochromatin has been examined by C-banding in two somatic cell lines, grown in vitro, from a female Microtus agrestis. One line retains one intact X chromosome together with the short arm of the other X chromosome, while the other cell line retains only the short arm of one X chromosome. Thus, each cell line has lost substantial amounts of heterochromatin from the sex chromosomes, but this material has been deleted from the cells, and not translocated to other chromosomes. Nonetheless, both cell lines continue to propagate well in vitro.

scholarly journals The status of the Hungarian Merino sheep breed compared to the other merino breeds

2016 ◽  
pp. 151-156
Author(s):  
Mária Szabó ◽  
Szilvia Kusza ◽  
István Csízi ◽  
István Monori
Keyword(s):  
Gene Pool ◽  
Genetic Resource ◽  
Sheep Breed ◽  
The Other ◽  
Drastic Reduction ◽  
Merino Sheep ◽  
Sheep Breeds ◽  
The World ◽  
The Status ◽  
Over Time

Merino and Merino-derived sheep breeds have been widely known and distributed across the world, both as purebred and admixed populations. They represent a diverse genetic resource which over time has been used as the basis for the development of new breeds. In spite of this, their gene-pool potential is still unexplored. The Merino sheep represent the most important sheep resource of the Hungarian husbandry. It has the largest amount of individuals between both of the stock and commercial flocks. But in Europe the Merino stocks went through a drastic reduction in number. Thus these breeds became endangered in several countries as well as in Hungary. In this study we would like to present the recent status of different Merino breeds of the world to ground our further phylogenetic research with the Hungarian Merino breed.

scholarly journals Comparative cytogenetics of two species of Dermanura (Chiroptera, Phyllostomidae) in Midwestern Brazil

2021 ◽  
Vol 15 (2) ◽  
pp. 89-99
Author(s):  
Ricardo Firmino de Sousa ◽  
Paulo Cesar Venere ◽  
Karina de Cassia Faria
Keyword(s):  
Diploid Number ◽  
Constitutive Heterochromatin ◽  
Sex Chromosome ◽  
Type System ◽  
Pericentromeric Region ◽  
Morphological Characters ◽  
Comparative Cytogenetics ◽  
Taxonomic Implications ◽  
Sex Chromosome System ◽  
First Time

Dermanura Gervais, 1856 is represented by small frugivorous bats of the Stenodermatinae subfamily. The taxonomy of this group presents controversies and has been subject to changes, especially since the morphological characters evaluated have left gaps that are difficult to fill regarding good species characterization. Previous studies performed in Dermanura cinerea Gervais, 1856 found that the karyotype of this species has a diploid number of chromosomes equal to 30 and 56 autosomal arms. The objective of the present study was to describe, for the first time, the karyotypes of the species Dermanura anderseni (Osgood, 1916) and Dermanura gnoma (Handley, 1987) based on classical cytogenetic markers. For both species, the diploid number found was 2n = 30 and NFa = 56. Two pairs of chromosomes showed markings of the nucleolus organizing regions (AgNORs) in the species D. anderseni and only one pair in D. gnoma, differing from what has already been described for D. cinerea. The two species analyzed here also showed differences in the sex chromosome system, with D. gnoma showing a neo-XY type system while in D. anderseni the classic XY sexual system was observed. In both species, visualization of the constitutive heterochromatin occurred in the pericentromeric region of all chromosomes, as well as in the short arms of the subtelocentric chromosomes. The present work represents an important expansion of karyotypic information for the subfamily Stenodermatinae, bringing chromosomal features that are possible to use in the taxonomic implications of the group.

scholarly journals Taxonomic revision of the genus Zygorhizidium: Zygorhizidiales and Zygophlyctidales ord. nov. (Chytridiomycetes, Chytridiomycota)

2020 ◽  
Vol 5 (1) ◽  
pp. 17-38 ◽  
Author(s):  
K. Seto ◽  
S. Van Den Wyngaert ◽  
Y. Degawa ◽  
M. Kagami
Keyword(s):  
Molecular Phylogeny ◽  
Host Specificity ◽  
Type Species ◽  
Taxonomic Revision ◽  
The Other ◽  
Ultrastructural Observation ◽  
Resting Spore ◽  
Distinct Genus ◽  
Current Classification

During the last decade, the classification system of chytrids has dramatically changed based on zoospore ultrastructure and molecular phylogeny. In contrast to well-studied saprotrophic chytrids, most parasitic chytrids have thus far been only morphologically described by light microscopy, hence they hold great potential for filling some of the existing gaps in the current classification of chytrids. The genus Zygorhizidium is characterized by an operculate zoosporangium and a resting spore formed as a result of sexual reproduction in which a male thallus and female thallus fuse via a conjugation tube. All described species of Zygorhizidium are parasites of algae and their taxonomic positions remain to be resolved. Here, we examined morphology, zoospore ultrastructure, host specificity, and molecular phylogeny of seven cultures of Zygorhizidium spp. Based on thallus morphology and host specificity, one culture was identified as Z. willei parasitic on zygnematophycean green algae, whereas the others were identified as parasites of diatoms, Z. asterionellae on Asterionella, Z. melosirae on Aulacoseira, and Z. planktonicum on Ulnaria (formerly Synedra). According to phylogenetic analysis, Zygorhizidium was separated into two distinct order-level novel lineages; one lineage was composed singly of Z. willei, which is the type species of the genus, and the other included the three species of diatom parasites. Zoospore ultrastructural observation revealed that the two lineages can be distinguished from each other and both possess unique characters among the known orders within the Chytridiomycetes. Based on these results, we accommodate the three diatom parasites, Z. asterionellae, Z. melosirae, and Z. planktonicum in the distinct genus Zygophlyctis, and propose two new orders: Zygorhizidiales and Zygophlyctidales.

scholarly journals Debating phylogenetic relationships of the scleractinian Psammocora: molecular and morphological evidences

2007 ◽  
Vol 76 (1) ◽  
pp. 35-54 ◽  
Author(s):  
Francesca Benzoni ◽  
Fabrizio Stefani ◽  
Jaroslaw Stolarski ◽  
Michel Pichon ◽  
Guillaume Mitta ◽  
...  
Keyword(s):  
Molecular Phylogeny ◽  
Phylogenetic Relationships ◽  
Molecular Data ◽  
Genetic Distances ◽  
The Other ◽  
Congeneric Species ◽  
Genetic Affinity ◽  
Phylogenetic Structure ◽  
Skeletal Structures ◽  
The Family

The phylogenetic relationships of the scleractinian genus Psammocora with the other genera traditionally included in the family Siderastreidae and some Fungiidae are assessed based on combined skeletal and molecular data. P. explanulata differs from the other examined congeneric species (P. contigua, P. digitata, P. nierstraszi , P. profundacella, P. superficialis, and P. stellata) in possessing interstomatous septa between adult corallites, costae, and in having continuous buttress-like structures joining septal faces (i.e., fulturae) which typically occur in fungiids. These characters are shared with Coscinaraea wellsi but not with the remainder of the examined siderastreids (the congeneric C. columna, and Anomastraea irregularis, Horastrea indica, Pseudosiderastrea tayamai, Siderastrea savignyana) whose septa are interconnected by typical synapticulae. Most of the examined species form septa with distinct transverse groups of centers of calcification, a biomineralization pattern typical of the Robusta clade. The observations on skeletal structures corroborate the results of the ITS2 and 5.8S molecular phylogeny. C. wellsi and P. explanulata are phylogenetically very close to each other and show closer genetic affinity with the examined Fungiidae (Halomitra pileus, Herpolitha limax, Fungia paumotensis, and Podabacia crustacea) than with the other species in the genera Psammocora and Coscinaraea, or with any other siderastreid. Our results show that neither Psammocora nor Coscinaraea are monophyletic genera. The high genetic distances between the species of Siderastreidae, especially between Pseudosiderastrea tayamai and Siderastrea savignyana on one side and the other genera on the other, suggest a deep divergence in the phylogenetic structure of the family.

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