scholarly journals Geographic distribution of sex chromosome polymorphism in Anastrepha fraterculus sp. 1 from Argentina

BMC Genetics ◽  
2020 ◽  
Vol 21 (S2) ◽  
Author(s):  
María Cecilia Giardini ◽  
Mariela Nieves ◽  
Alejandra Carla Scannapieco ◽  
Claudia Alejandra Conte ◽  
Fabián Horacio Milla ◽  
...  
Keyword(s):  
Geographic Distribution ◽  
Buenos Aires ◽  
Sex Chromosome ◽  
Low Frequency ◽  
Mass Rearing ◽  
Chromosome Polymorphism ◽  
Wild Populations ◽  
Evolutionary Forces ◽  
Anastrepha Fraterculus ◽  
Entre Rios

Abstract Background Anastrepha fraterculus is recognized as a quarantine pest in several American countries. This fruit fly species is native to the American continent and distributed throughout tropical and subtropical regions. It has been reported as a complex of cryptic species, and at least eight morphotypes have been described. Only one entity of this complex, formerly named Anastrepha fraterculus sp. 1, is present in Argentina. Previous cytogenetic studies on this morphotype described the presence of sex chromosome variation identified by chromosomal size and staining patterns. In this work, we expanded the cytological study of this morphotype by analyzing laboratory strains and wild populations to provide information about the frequency and geographic distribution of these sex chromosome variants. We analyzed the mitotic metaphases of individuals from four laboratory strains and five wild populations from the main fruit-producing areas of Argentina, including the northwest (Tucumán and La Rioja), northeast (Entre Ríos and Misiones), and center (Buenos Aires) of the country. Results In wild samples, we observed a high frequency of X1X1 (0.94) and X1Y5 (0.93) karyomorphs, whereas X1X2 and X1Y6 were exclusively found at a low frequency in Buenos Aires (0.07 and 0.13, respectively), Entre Ríos (0.16 and 0.14, respectively) and Tucumán (0.03 and 0.04, respectively). X2X2 and X2Y5 karyomorphs were not found in wild populations but were detected at a low frequency in laboratory strains. In fact, karyomorph frequencies differed between wild populations and laboratory strains. No significant differences among A. fraterculus wild populations were evidenced in either karyotypic or chromosomal frequencies. However, a significant correlation was observed between Y5 chromosomal frequency and latitude. Conclusions We discuss the importance of cytogenetics to understand the possible route of invasion and dispersion of this pest in Argentina and the evolutionary forces acting under laboratory conditions, possibly driving changes in the chromosomal frequencies. Our findings provide deep and integral genetic knowledge of this species, which has become of relevance to the characterization and selection of valuable A. fraterculus sp. 1 strains for mass rearing production and SIT implementation.

Redescription, shell variability and geographic distribution of Plagiodontes dentatus (Wood, 1828) (Gastropoda: Orthalicidae: Odontostominae) from Uruguay and Argentina

Zootaxa ◽  
2003 ◽  
Vol 154 (1) ◽  
pp. 1 ◽  
Author(s):  
JULIA PIZÁ ◽  
NÉSTOR J. CAZZANIGA
Keyword(s):  
Multivariate Analysis ◽  
Statistical Analysis ◽  
Geographic Distribution ◽  
Type Species ◽  
Buenos Aires ◽  
Geographic Range ◽  
South American ◽  
Entre Rios ◽  
High Degree ◽  
Shell Sculpture

Plagiodontes dentatus (Wood, 1828) is the type species of a South American genus including eight named species that show a high degree of local endemism. Due to some misidentifications with P. multiplicatus (Doering, 1874) and P. daedaleus (Deshayes, 1851), P. dentatus has been cited as inhabiting two disjunct areas with quite different ecological conditions. In this paper the identity of this morphospecies is clarified through a study of shell sculpture and apertural teeth data, and a comparison with the smaller adult specimens (<25 mm long) of its closest species, P. patagonicus (d’Orbigny, 1835) and P. multiplicatus, i.e., the only shells to which P. dentatus could have been confounded. A statistical analysis of shell variability revealed that, beyond the qualitative diagnostic characters, there are significantly different shell proportions that also define P. dentatus. The distribution of P. dentatus over two disjunct areas is not supported, its confirmed geographic range being restricted to the Oriental Republic of Uruguay and the Argentine provinces of Entre Ríos and northeastern Buenos Aires. An intraspecific multivariate analysis upholds the opinion that any subspecific discrimination is unwarranted.

La esperanza-desesperanza y el manejo de la agresividad en estudiantes universitarios de Puerto Rico y de Argentina: un estudio transcultural

2001 ◽  
Vol 1 (2) ◽  
pp. 99-111
Author(s):  
Mario Pereyra ◽  
Jorge Bruno
Keyword(s):  
Puerto Rico ◽  
Buenos Aires ◽  
Entre Rios ◽  
Estudiantes Universitarios

Se investiga la esperanza-desesperanza y las respuestas ante el agravio, en tres muestras de estudiantes universitarios, de dos diferentes países —Puerto Rico (n = 103) y la Argentina (n = 226)—, y de diferentes contextos culturales (Centro y Norteamérica, Buenos Aires y Entre Ríos) a fin de comparar si la estructuración del tiempo y el manejo de la agresividad están mediatizados por la cultura o, como presupone la literatura, constituyen dimensiones intrínsecas de la personalidad.

scholarly journals Genetic analysis of medfly populations in an area of sterile insect technique applications

2021 ◽  
Author(s):  
Rubén Sancho ◽  
Ana Guillem-Amat ◽  
Elena López-Errasquín ◽  
Lucas Sánchez ◽  
Félix Ortego ◽  
...  
Keyword(s):  
Genetic Markers ◽  
Sterile Insect Technique ◽  
Ceratitis Capitata ◽  
Natural Populations ◽  
Low Frequency ◽  
Fruit Fly ◽  
Wild Populations ◽  
Genetic Sexing ◽  
Environmental Implications ◽  
Genetic Sexing Strains

AbstractThe sterile insect technique (SIT) is widely used in integrated pest management programs for the control of the Mediterranean fruit fly (medfly), Ceratitis capitata. The genetic interactions between the released individuals from the genetic sexing strains (GSS), used for SIT applications worldwide, and wild individuals have not been studied. Under the hypothesis that a number of Vienna GSS individuals released to the field might not be completely sterile and may produce viable offspring, we have analyzed medfly Spanish field populations to evaluate the presence of Vienna strain genetic markers. To this goal, we have used contrasted nuclear and mitochondrial genetic markers, and two novel sets of nuclear polymorphisms with the potential to be markers to discriminate between Vienna and wild individuals. Nuclear Vienna markers located on the 5th chromosome of Vienna males have been found in 2.2% (19 from 875) of the Spanish wild medfly females captured at the area where SIT is applied. In addition, a female-inherited mitochondrial Vienna marker has been found in two from the 19 females showing nuclear Vienna markers. The detection of several of these markers in single individuals represents evidence of the introgression of Vienna strain into natural populations. However, alternative explanations as their presence at low frequency in wild populations in the studied areas cannot be fully discarded. The undesired release of non-fully sterile irradiated GSS individuals into the field and their interactions with wild flies, and the potential environmental implications should be taken into account in the application of the SIT.

On the Maintenance of Sex Chromosome Polymorphism by Sex-Antagonistic Selection

2011 ◽  
Vol 178 (4) ◽  
pp. 515-524 ◽  
Author(s):  
Olivier Blaser ◽  
Samuel Neuenschwander ◽  
Nicolas Perrin
Keyword(s):  
Sex Chromosome ◽  
Chromosome Polymorphism ◽  
Antagonistic Selection ◽  
Maintenance Of Sex

scholarly journals Wolbachia infection in Argentinean populations of Anastrepha fraterculus sp1: preliminary evidence of sex ratio distortion by one of two strains

2019 ◽  
Author(s):  
CA Conte ◽  
DF Segura ◽  
FH Milla ◽  
AA Augustinos ◽  
JL Cladera ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Insect Pests ◽  
Wolbachia Infection ◽  
Larval Survival ◽  
Preliminary Evidence ◽  
Wild Populations ◽  
Crossing Experiments ◽  
Anastrepha Fraterculus ◽  
Male Killing ◽  
Filarial Nematodes

ABSTRACTBackgroundWolbachia, one of the most abundant taxa of intracellular Alphaproteobacteria, is widespread among arthropods and filarial nematodes. The presence of these maternally inherited bacteria is associated with modifications of host fitness, including a variety of reproductive abnormalities, such as cytoplasmic incompatibility, thelytokous parthenogenesis, host feminization and male-killing. Wolbachia has attracted much interest for its role in biological, ecological and evolutionary processes as well as for its potential use in novel and environmentally-friendly strategies for the control of insect pests and disease vectors including a major agricultural pest, the South American fruit fly, Anastrepha fraterculus Wiedemann (Diptera: Tephritidae).ResultsWe used wsp, 16S rRNA and a multilocus sequence typing (MLST) scheme including gatB, coxA, hcpA, fbpA, and ftsZ genes to detect and characterize the Wolbachia infection in laboratory strains and wild populations of A. fraterculus from Argentina. Wolbachia was found in all A. fraterculus individuals studied. Nucleotide sequences analysis of wsp gene allowed the identification of two Wolbachia nucleotide variants (named wAfraCast1_A and wAfraCast2_A). After the analysis of 76 individuals, a high prevalence of the wAfraCast2_A variant was found both, in laboratory (82%) and wild populations (95%). MLST analysis identified both Wolbachia genetic variants as sequence type 13. Phylogenetic analysis of concatenated MLST datasets clustered wAfraCast1/2_A in the supergroup A. Paired-crossing experiments among single infected laboratory strains showed a phenotype specifically associated to wAfraCast1_A that includes slight detrimental effects on larval survival, a female-biased sex ratio; suggesting the induction of male-killing phenomena, and a decreased proportion of females producing descendants that appears attributable to the lack of sperm in their spermathecae.ConclusionsWe detected and characterized at the molecular level two wsp gene sequence variants of Wolbachia both in laboratory and wild populations of A. fraterculus sp.1 from Argentina. Crossing experiments on singly-infected A. fraterculus strains showed evidence of a male killing-like mechanism potentially associated to the wAfraCast1_A - A. fraterculus interactions. Further mating experiments including antibiotic treatments and the analysis of early and late immature stages of descendants will contribute to our understanding of the phenotypes elicited by the Wolbachia variant wAfraCast1_A in A. fraterculus sp.1.

scholarly journals Tendencias del estudio Las prácticas de enseñanza de los docentes de educación secundaria

2021 ◽  
pp. 76-95
Author(s):  
Horacio Ademar Ferreyra ◽  
Ana Rua
Keyword(s):  
Buenos Aires ◽  
Entre Rios

Entre 2016 y 2018, los integrantes del Equipo de Investigación de Educación de Adolescentes y Jóvenes de la Facultad de Educación de la Universidad Católica de Córdoba (UCC), Unidad Asociada del Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), asumimos la tarea de concretar la investigación Las prácticas de enseñanza de los docentes de educación secundaria. Un estudio en las provincias de Córdoba, Buenos Aires y Entre Ríos, República Argentina. Completado el período de indagación, presentamos este artículo cuyos propósitos son los siguientes: -reseñar los veintidós documentos producidos agrupados en cuatro tipos que se corresponden con las etapas de desarrollo de la investigación: definiciones conceptuales y metodológicas, operativización de componentes, recolección y sistematización de evidencia empírica y comunicación de resultados; - plantear información de síntesis que pueda ser profundizada y rastreada en los distintos documentos;-presentar algunas de las tendencias que se han manifestado con más contundencia durante el estudio a partir del entrecruzamiento y triangulación de los datos obtenidos.

scholarly journals The ghost of climatic change in the geographic distribution of Tillandsia aeranthos (Bromeliaceae)

Rodriguésia ◽  
2020 ◽  
Vol 71 ◽  
Author(s):  
Elián Leandro Guerrero
Keyword(s):  
South America ◽  
Climatic Change ◽  
Geographic Distribution ◽  
Buenos Aires ◽  
New Records ◽  
Southern Limit ◽  
New Findings ◽  
Southward Shift ◽  
Possible Cause ◽  
Color Variants

Abstract The geographic distribution of Tillandsia aeranthos is updated with new records. Its southern limit is extended 200 kilometers in a zone previously studied by many botanists and naturalists, but also in poorly explored areas. For this reason, the possibility that the change in distribution is recent is postulated and discussed. The coincidence of this change with the southward shift in the isohyets and the decrease of winter frost frequency are highlighted as a possible cause of the advance to the south. In addition, two petal color variants of this species are first mentioned for Argentina. The new findings display that it is necessary to further explore some dry forests of eastern Buenos Aires and study the possible consequences of the climatic change in the biota of South America.

scholarly journals The evolution of the Y chromosome with X-Y recombination.

Genetics ◽  
1988 ◽  
Vol 119 (3) ◽  
pp. 711-720
Author(s):  
A G Clark
Keyword(s):  
Natural Selection ◽  
Y Chromosome ◽  
Meiotic Recombination ◽  
Population Genetic ◽  
Sex Chromosome ◽  
Genetic Model ◽  
Chromosome Polymorphism ◽  
Significant Finding ◽  
Special Cases ◽  
Theoretical Population

Abstract A theoretical population genetic model is developed to explore the consequences of X-Y recombination in the evolution of sex chromosome polymorphism. The model incorporates one sex-determining locus and one locus subject to natural selection. Both loci have two alleles, and the rate of classical meiotic recombination between the loci is r. The alleles at the sex-determining locus specify whether the chromosome is X or Y, and the alleles at the selected locus are arbitrarily labeled A and a. Natural selection is modeled as a process of differential viabilities. The system can be expressed in terms of three recurrence equations, one for the frequency of A on the X-bearing gametes produced by females, one for each of the frequency of A on the X- and Y-bearing gametes produced by males. Several special cases are examined, including X chromosome dominance and symmetric selection. Unusual equilibria are found with the two sexes having very different allele frequencies at the selected locus. A significant finding is that the allowance of recombination results in a much greater opportunity for polymorphism of the Y chromosome. Tighter linkage results in a greater likelihood for equilibria with a large difference between the sex chromosomes in allele frequency.

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