The Karyotype of Salvator merianae (Squamata, Teiidae): Analyses by Classical and Molecular Cytogenetic Techniques

2020 ◽  
Vol 160 (2) ◽  
pp. 94-99 ◽  
Author(s):  
Marcelo J. da Silva ◽  
Ana P. de Araújo Vieira ◽  
Flávia M. Galvão Cipriano ◽  
Maria R. dos Santos Cândido ◽  
Edivaldo H.C. de Oliveira ◽  
...  

In this study, we analyzed the karyotype of Salvator merianae (Teiidae) from the Brazilian semiarid region using different cytogenetic markers. Chromosomes were examined by classical (Giemsa and AgNOR staining) and molecular (FISH with ribosomal, telomeric, and microsatellite probes) cytogenetic approaches. S. merianae showed a diploid chromosome number of 2n = 38 (10 biarmed macrochromosomes + 28 microchromosomes). No sex-linked chromosome heteromorphisms were observed. Clusters of 18S/28S rDNA were localized in the terminal region of the long arm of pair 2. In addition to the typical telomeric signals, (TTAGGG)n repeats were detected in the pericentromeric region of some macrochromosome pairs, which might indicate the occurrence of chromosomal rearrangements via chromosome fusions. Hybridization signals of the microsatellite probes (GA)n, (GAA)n, and (GAG)n were uniformly distributed across all chromosomes, while (CA)n, (CAA)n, and (CAC)n produced brighter signals in the telomeric and pericentromeric regions of specific chromosome pairs. The comparison with previous studies demonstrates that, despite the wide distribution of S. merianae, the macrostructure organization of the karyotype remained unchanged, showing stability in diploid number and chromosome morphology.

2021 ◽  
Vol 43 (3) ◽  
pp. 237-249 ◽  
Author(s):  
Thanh Dat Ta ◽  
Nomar Espinosa Waminal ◽  
Thi Hong Nguyen ◽  
Remnyl Joyce Pellerin ◽  
Hyun Hee Kim

Abstract Background DNA tandem repeats (TRs) are often abundant and occupy discrete regions in eukaryotic genomes. These TRs often cause or generate chromosomal rearrangements, which, in turn, drive chromosome evolution and speciation. Tracing the chromosomal distribution of TRs could therefore provide insights into the chromosome dynamics and speciation among closely related taxa. The basic chromosome number in the genus Senna is 2n = 28, but dysploid species like Senna tora have also been observed. Objective To understand the dynamics of these TRs and their impact on S. tora dysploidization. Methods We performed a comparative fluorescence in situ hybridization (FISH) analysis among nine closely related Senna species and compared the chromosomal distribution of these repeats from a cytotaxonomic perspective by using the ITS1-5.8S-ITS2 sequence to infer phylogenetic relationships. Results Of the nine S. tora TRs, two did not show any FISH signal whereas seven TRs showed similar and contrasting patterns to other Senna species. StoTR01_86, which was localized in the pericentromeric regions in all S. tora, but not at the nucleolar organizer region (NOR) site, was colocalized at the NOR site in all species except in S. siamea. StoTR02_7_tel was mostly localized at chromosome termini, but some species had an interstitial telomeric repeat in a few chromosomes. StoTR05_180 was distributed in the subtelomeric region in most species and was highly amplified in the pericentromeric region in some species. StoTR06_159 was either absent or colocalized in the NOR site in some species, and StoIGS_463, which was localized at the NOR site in S. tora, was either absent or localized at the subtelomeric or pericentromeric regions in other species. Conclusions These data suggest that TRs play important roles in S. tora dysploidy and suggest the involvement of 45S rDNA intergenic spacers in “carrying” repeats during genome reshuffling.


Author(s):  
Uemeson José dos Santos ◽  
Everardo Valadares de Sá Barretto Sampaio ◽  
Eunice Maia de Andrade ◽  
Alexandre de Siqueira Pinto ◽  
Bruno de Oliveira Dias ◽  
...  

2021 ◽  
pp. 1-12
Author(s):  
José Almir Cirilo ◽  
Alfredo Ribeiro Neto ◽  
Nyadja Menezes Rodrigues Ramos ◽  
Carla Fernanda Fortunato ◽  
Júlia Daniele Silva de Souza ◽  
...  

2018 ◽  
Vol 30 (0) ◽  
Author(s):  
Josiane Souza Santos ◽  
Nadson Ressyé Simões ◽  
Sérgio Luiz Sonoda

Abstract Aim: The objective of this study was to investigate the spatial and temporal variation of microcrustacean assemblages of a reservoir in the Brazilian semiarid region. Methods Physical and chemical water variables and samples of microcrustaceans were collected at eight sites of the reservoir between July 2013 and November 2014, in a total of seven campaigns. For this study, the reservoir was categorized in two compartments: lateral and central. Results Limnological variables showed significant temporal variation (PERMANOVA, Pseudo-F = 19.51, p = 0.001). Higher turbidity values and suspended solids were observed in the rainiest months, while during the dry months, we measured higher values of transparency, dissolved oxygen, and chlorophyll-a. It was not found significant spatial variation of limnological variables (PERMANOVA, Pseudo-F = 0.96; p = 0.394). During the study period, ten species were recorded: four Cladocera (Ceriodaphnia cornuta, Daphnia gessneri, Diaphanosoma birgei and Diaphanosoma spinulosum ) three Copepoda Calanoida (Argyrodiaptomus azevedoi, Notodiaptomus cearensis and Notodiaptomus iheringi) and three Copepoda Cyclopoida (Macrocyclops albidus, Thermocyclops minutus and Thermocyclops decipiens). The microcrustacean assemblages showed significant temporal variation (PERMANOVA, Pseudo-F = 4.34; p = 0.001) as well as significant spatial variation (PERMANOVA, Pseudo-F = 9.46; p = 0.001). The highest values of abundance and richness were observed in the lateral compartment, this result is mainly related to the presence of aquatic macrophytes in this region, because the analysis of partial RDA indicated that limnological variables explained only 11% of this variation (Pseudo-F = 2.08, p = 0.001). Conclusions The results suggest that the seasonality of the semiarid is an important factor in the temporal dynamics of the limnological variables, while the aquatic macrophytes play an important role in the spatial distribution of the microcrustacean assembly.


2014 ◽  
Author(s):  
Sergio Rosim ◽  
João Ricardo de Freitas Oliveira ◽  
Jussara de Oliveira Ortiz ◽  
Miguel Zanic Cuellar ◽  
Alexandre Copertino Jardim

2021 ◽  
Vol 26 (2) ◽  
Author(s):  
Luan Pedro-Silva ◽  
Thaynara Sousa Silva ◽  
José Iranildo Miranda De Melo

2021 ◽  
Vol 7 (7) ◽  
pp. 69081-69099
Author(s):  
Tatiane Aparecida Queiroz ◽  
Francisca Patrícia Barreto De Carvalho ◽  
Alfredo Marcelo Grigio ◽  
Weslley Misael Bezerra Damasio ◽  
Lara Candice Costa de Morais Leonez ◽  
...  

Author(s):  
Diego de M. Bento ◽  
Marconi Souza-Silva ◽  
Alexandre Vasconcellos ◽  
Bruno C. Bellini ◽  
Xavier Prous ◽  
...  

Author(s):  
Laylson da Silva Borges ◽  
Geandro Carvalho Castro ◽  
João Lopes Anastácio Filho ◽  
Isak Samir de Sousa Lima ◽  
Flávio Carvalho de Aquino ◽  
...  

2019 ◽  
Vol 11 (4) ◽  
pp. 536
Author(s):  
Jucirema Ferreira da Silva ◽  
Jeane Cruz Portela ◽  
Nildo da Silva Dias ◽  
Cezar Augusto Medeiros Rebouças ◽  
Francisco Ernesto Sobrinho ◽  
...  

The ethnopedological approach to soil characterization presents great challenges, since the understanding of the systems occurs through the knowledge acquired by the man in his coexistence with agroecosystems. The aim of the present research was to characterize the agricultural soils through morphological, physical and chemical analysis, using ethnopedological studies in the ‘Santa Agostinha’ Settlement Project, Caraúbas-RN, Brazil. Five areas were defined for study in the soil/landscape relation: i) area with cashew cultivation; ii) area of pasture; iii) area of crops in consortium; iv) agroforestry; and v) preserved forest, used as the reference. Participatory workshops, exchanges and classifications (from the locals and formal) were carried out with the analysis of the morphological, physical and chemical attributes of the studied soils in the layers of 0.00-0.10, 0.10-0.20 and 0.20-0.30 m. The results of the ethicist classification, based on the attributes evaluation were: Quartzarenic latosol NEOSOL (cashew area); Regolitic euthrofic NEOSOL (pasture area); Ortic quartzarenic fragiudult NEOSOL (intercropping area); typical quartzarenic ortic NEOSOL (agroforestry area and typical hydromorphic quartzarenic NEOSOL that presented a close relation with the emicist classification (from the local people). The observation of the different soil types in the landscape, due to the stratification of the environments, allowed the growers to identify characteristics associated with soil potentials and restrictions and, consequently, the correct management to be adopted. The experiences of local growers in the participatory workshops provided an exchange of popular and scientific knowledge, as well as new perspectives of coexistence with the semiarid.


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