scholarly journals Chromosome polymorphism in Ancistrus cuiabae Knaack, 1999 (Siluriformes: Loricariidae: Ancistrini)

2009 ◽  
Vol 7 (4) ◽  
pp. 595-600 ◽  
Author(s):  
Sandra Mariotto ◽  
Liano Centofante ◽  
Carlos S. Miyazawa ◽  
Luiz Antonio Carlos Bertollo ◽  
Orlando Moreira Filho

Cytogenetic and FISH analyses were performed in 30 Ancistrus cuiabae specimens from a bay near the town of Poconé, in the Pantanal of Mato Grosso, Brazil. The observed diploid number was 2n = 34 chromosomes for both sexes and three distinct katyotypic formulae were found, namely cytotype A (20m, 8sm, 6st, Fundamental Number/FN = 68; 6 males and 11 females), cytotype B (19m, 8sm, 6st, 1a, FN = 67; 8 males and 4 females) and cytotype C (18m, 8sm, 6st, 2a, FN = 66; a single male). NORs's analyses showed that these regions were located in distinct sites on the NOR-bearing chromosome pair, according to cytotypes. Thus, in cytotype A, NORs were located in the terminal region of the short arm of the second metacentric chromosome pair; in cytotype B, they were detected in the short arm of the metacentric chromosome and interstitially on the acrocentric chromosome and, in cytotype C, NORs were observed in the interstitial region of the acrocentric chromosome pair. C-positive heterochromatic bands were adjacent to the rDNA sites in the corresponding chromosomes. Thus, the chromosomal polymorphism of A. cuiabae was probably originated through a pericentric inversion in chromosome pair nº 2 involving the NOR sites, which represents a novelty in the Ancistrini tribe. The results also broaden the knowledge of the chromosomal evolution in Ancistrus, the most derived genus of the Ancistrini tribe.

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Dayane Petik dos Santos ◽  
Denise Felicetti ◽  
Lucas Baumgärtner ◽  
Vladimir Pavan Margarido ◽  
Daniel Rodrigues Blanco ◽  
...  

ABSTRACT Auchenipteridae is divided into subfamilies Centromochlinae and Auchenipterinae. Parauchenipterus is included in the latter and is subject of taxonomic discussions concerning its validation or synonymization with Trachelyopterus. Herein, three species from two hydrographic basins were cytogenetically analyzed: Parauchenipterus striatulus from Doce River and two sympatric species, P. galeatus and Trachelyopterus coriaceus, from the Araguaia River. Diploid number of 58 chromosomes was verified for all species, but P. striatulus has different karyotype formula from the others. The three species have heterochromatin located in terminal regions of almost all chromosomes and in pericentromeric region on acrocentric chromosomes. Simple NORs was verified on a subtelocentric chromosome for all species. 5S rDNA sites were detected in three submetacentric chromosome pairs in P. striatulus; in a metacentric chromosome pair and submetacentric pair in T. coriaceus; and in one metacentric chromosome pair in P. galeatus. The similarities found in the karyotypes of the three species suggest the existence of only one genus, Trachelyopterus; therefore, our data refutes the validation of Parauchenipterus. Moreover, the differences in 5S rDNA distribution in P. galeatus in comparison with other populations already studied, indicate the existence of a new taxonomic unit, which suggests a species complex in P. galeatus.


2013 ◽  
Vol 11 (2) ◽  
pp. 327-334 ◽  
Author(s):  
Roberto Laridondo Lui ◽  
Daniel Rodrigues Blanco ◽  
Juliana de Fatima Martinez ◽  
Vladimir Pavan Margarido ◽  
Paulo Cesar Venere ◽  
...  

Ageneiosus is the most widely distributed genus of the family Auchenipteridae among South American river basins. Although chromosome studies in the family are scarce, this genus has the largest number of analyzed species, with 2n = 54 to 56 chromosomes, differing from the rest of the family (2n = 58). This study aimed to analyze Ageneiosus inermis from the Araguaia River basin. The diploid number found was of 56 chromosomes. Heterochromatin was allocated in terminal region of most chromosomes, plus a pericentromeric heterochromatic block in pair 1, a pair distinguished by size in relation to other chromosomes pairs. AgNORs were detected in only one submetacentric chromosome pair, which was confirmed by FISH. 5S rDNA was present in only one metacentric chromosome pair. Hybridization with [TTAGGG]n sequence marked the telomeres of all chromosomes, in addition to an ITS in the proximal region of the short arm of pair 1. The repetitive [GATA]n sequence was dispersed, with preferential location in terminal region of the chromosomes. Ageneiosus has a genomic organization somewhat different when compared to other Auchenipteridae species. Evidences indicate that a chromosomal fusion originated the first metacentric chromosome pair in A. inermis, rearrangement which may be a basal event for the genus


1994 ◽  
Vol 72 (2) ◽  
pp. 364-367 ◽  
Author(s):  
Pawel Woznicki ◽  
Malgorzata Jankun

A population of Atlantic salmon from the River Dzwina was karyotyped using conventional staining and banding techniques. The chromosome number was 2n = 58, and the chromosome arm number (NF) was 74. Variation in the size of the long arm of the eighth chromosome pair was observed. The presence of constitutive heterochromatin on this arm was confirmed by C-banding. Silver banding revealed variability in the location of nucleolus organizer regions (NORs) on this arm. Four cytotypes and three phenotypes of the NOR-bearing chromosome were found. The polymorphism of the eighth metacentric pair of chromosomes observed in Atlantic salmon was probably due to deletion and paracentric inversion of the arm involved.


Genome ◽  
2000 ◽  
Vol 43 (2) ◽  
pp. 255-263 ◽  
Author(s):  
Lyn G Cook

Chromosome number reflects strong constraints on karyotype evolution, unescaped by the majority of animal taxa. Although there is commonly chromosomal polymorphism among closely related taxa, very large differences in chromosome number are rare. This study reports one of the most extensive chromosomal ranges yet reported for an animal genus. Apiomorpha Rübsaamen (Hemiptera: Coccoidea: Eriococcidae), an endemic Australian gall-inducing scale insect genus, exhibits an extraordinary 48-fold variation in chromosome number with diploid numbers ranging from 4 to about 192. Diploid complements of all other eriococcids examined to date range only from 6 to 28. Closely related species of Apiomorpha usually have very different karyotypes, to the extent that the variation within some species- groups is as great as that across the entire genus. There is extensive chromosomal variation among populations within 17 of the morphologically defined species of Apiomorpha indicating the existence of cryptic species-complexes. The extent and pattern of karyotypic variation suggests rapid chromosomal evolution via fissions and (or) fusions. It is hypothesized that chromosomal rearrangements in Apiomorpha species may be associated with these insects' tracking the radiation of their speciose host genus, Eucalyptus. Key words: Apiomorpha, cytogenetics, chromosomal evolution, holocentric.


Rodriguésia ◽  
2020 ◽  
Vol 71 ◽  
Author(s):  
Verónica Lucía Bugallo ◽  
María Florencia Realini ◽  
Gabriela Rosa Facciuto ◽  
Lidia Poggio

Abstract The genus Passiflora (Passifloraceae) has more than 500 species, nineteen are native to Argentina. By their austral distribution, these species were included in breeding programs to obtain ornamental varieties tolerant to low temperatures. The aim of this work was to know the cytogenetic characteristics of Passiflora genotypes present in a working collection, as an indispensable knowledge for the development of a breeding plan. Chromosomal preparations were performed and karyotypic characteristics, rDNA sites by FISH and affinity among subgenera by GISH were studied. Chromosome counts in fourteen Argentinean species confirmed the basic chromosome numbers previously published: x = 6 for subgenus Decaloba, x = 9 for subgenus Passiflora and x = 10 for Dysosmia. The karyotypic parameters (karyotype, haploid chromosome length and asymmetry indices) and genomic affinities among the subgenera, clarify most of the chromosomal evolution of the genus. The results obtained strongly suggest that the basic number x = 6 would be the original one and that x = 9 was originated by processes of polyploidy and descendent dysploidy. Since subgenus Passiflora possesses the largest genomes, it is postulated that evolutionary process leading to x = 9 was accompanied by unequal distribution of non-coding repetitive DNA, mainly transposable elements. These processes could explain the asymmetrical karyotypes of species of subgenus Passiflora.


2010 ◽  
Vol 1 (1) ◽  
pp. 25
Author(s):  
Dayane Aparecida dos Santos ◽  
Angela Kwiatkowski ◽  
Marcos Vieira da Silva ◽  
Dalany Menezes ◽  
Lucimar Peres de Moura Pontara

<p>Monitoring the microbiology of honey is necessary to ensure its final quality. The microbial contamination is a danger to public health, a major concern for the surveillance agency. The objective of this study was to evaluate the microbiological quality of honey produced in the cerrado region, Mato Grosso State. The apiary was installed in the town of Conquista D'Oeste city, a total of 30 boxes of honey covered with asbestos tile and exposed to the sun. The honey was collected in November of 2008. The physical and chemical analysis were carried out: moisture, total soluble solids (TSS) and pH. Microbiological analysis were: mesophilic bacteria facultative aerobic, yeast and mold, Staphylococcus, the most probable number (MPN) of coliforms at 35&ordm;C and 45&ordm;C, and the presence of Salmonella sp. The methods used followed the directions of the Normative Instruction no. 62, August 23, 2003 of Minist&eacute;rio da Agricultura, Pecu&aacute;ria e Abastecimento - MAPA. The pH value resulted in 3.80, SST at 81.5 and humidity at 17 %. Microbiological analysis showed no presence of Salmonella, Staphylococcus and yeast. The count of facultative aerobic bacteria was 5.0 x 101, the two groups of coliforms in NMP was &lt;3.0, and 3.0 x 101 mold. The samples of honey studied showed appropriate microbiological quality.</p><p>&nbsp;</p><p><span>DOI:&nbsp;</span><a href="http://dx.doi.org/10.14685/rebrapa.v4i1.102"><span>http://dx.doi.org/10.14685/rebrapa.v1i1.5</span></a><span>&nbsp;</span></p><p>&nbsp;</p>


Author(s):  
O. Yu. Yurkevich ◽  
T. E. Samatadze ◽  
I. Yu. Selyutina ◽  
S. I. Romashkina ◽  
S. A. Zoshchuk ◽  
...  

For the first time, chromosomal polymorphism in karyotypes of three species from the section Hedysarum (= syn. Gamotion) of the genus Hedysarum L. (Fabaceae) grown in Southern Siberia has been studied with the useof molecular cytogenetic markers. This comparative molecular cytogenetic analysis revealed high similarity in morphology of chromosomes in H. alpinum L., H. austrosibiricum B. Fedtsch. and H. theinum Krasnob. as well as in patterns ofdistribution of 45S and 5S rDNA loci in their karyotypes confirming their close relationships. Considerable intra-specificpolymorphism on 45S rDNA chromosome localization was detected in H. theinum. In karyotype of H. alpinum, unlikethe other two species, two chromosome pairs bearing 5S rDNA locus were observed which could be used as additionalspecies-specific markers.


2018 ◽  
Vol 12 (3) ◽  
pp. 285-298 ◽  
Author(s):  
Ivanny Coelho da Fonseca ◽  
Luan Aércio Melo Maciel ◽  
Frank Raynner Vasconcelos Ribeiro ◽  
Luís Reginaldo Ribeiro Rodrigues

The genus Pimelodus LaCépède, 1803 comprises 35 formally recognized species distributed along the major neotropical river basins. Despite conservatism in diploid number with 2n=56, an intense variation of chromosomal morphology (karyotypic formula) has been documented in Pimelodus species. In the present study, we analyzed karyotypes of 20 specimens, identified as Pimelodusblochii Valenciennes, 1840 and collected from the lower courses of the Tapajós, Amazonas and Trombetas Rivers. The karyotypes were characterized by Giemsa conventional staining, C-banding, silver staining (Ag-NOR) and fluorescent in situ hybridization (FISH) with 5S and 18S rDNA probes. The karyotypes showed 2n=56 chromosomes in fish from the Tapajós River. In contrast, fish from the Amazonas and Trombetas Rivers had 2n=58. The nucleolus organizing regions were labeled on the short arm of an acrocentric chromosome as demonstrated by silver staining and FISH. Signals for 18S and 5S rDNA were co-localized on one chromosome pair. Our results demonstrate karyotypic divergence between Tapajós and Amazonas-Trombetas populations of P.blochii, interpreted as supporting the existence of a species complex in this taxon.


1971 ◽  
Vol 13 (4) ◽  
pp. 793-800 ◽  
Author(s):  
K. L. Ying ◽  
H. Butler

Chromosome studies were performed on 11 lesser bush babies (Galago senegalensis) which were divided into three subspecies. Among these animals five different karyotypes were identified with the diploid numbers 36, 37 and 38. A fusion type of mechanism might have been involved in the chromosomal evolution of this species.


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