RESUMEN

OBJECTIVES: This study explored novel biomarkers that can affect the diagnosis and treatment in Alzheimer's Disease (AD) related to mitochondrial metabolism. METHODS: The authors obtained the brain tissue datasets for AD from the Gene Expression Omnibus (GEO) and downloaded the mitochondrial metabolism-related genes set from MitoCarta 3.0 for analysis. Differentially Expressed Genes (DEGs) were screened using the "limma" R package, and the biological functions and pathways were investigated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The LASSO algorithm was used to identify the candidate center genes and validated in the GSE97760 dataset. PMAIP1 with the highest diagnostic value was selected and its effect on the occurrence of AD by biological experiments. RESULTS: A sum of 364 DEGs and 50 hub genes were ascertained. GO and KEGG enrichment analysis demonstrated that DEGs were preponderantly associated with cell metabolism and apoptosis. Five genes most associated with AD as candidate central genes by LASSO algorithm analysis. Then, the expression level and specificity of candidate central genes were verified by GSE97760 dataset, which confirmed that PMAIP1 had a high diagnostic value. Finally, the regulatory effects of PMAIP1 on apoptosis and mitochondrial function were detected by siRNA, flow cytometry and Western blot. siRNA-PMAIP1 can alleviate mitochondrial dysfunction and inhibit cell apoptosis. CONCLUSION: This study identified biomarkers related to mitochondrial metabolism in AD and provided a theoretical basis for the diagnosis of AD. PMAIP1 was a potential candidate gene that may affect mitochondrial function in Hippocampal neuronal cells, and its mechanism deserves further study.

Asunto(s)

Enfermedad de Alzheimer , Biología Computacional , Humanos , Algoritmos , Enfermedad de Alzheimer/genética , Apoptosis/genética , Biomarcadores/análisis , Biomarcadores/metabolismo , Perfilación de la Expresión Génica/métodos , Ontología de Genes , Genes Mitocondriales/genética , Mitocondrias/genética , Mitocondrias/metabolismo , Proteínas Mitocondriales/genética

RESUMEN

Physiological and haplogroup studies performed to understand high-altitude adaptation in humans are limited to individual genes and polymorphic sites. Due to stochastic evolutionary forces, the frequency of a polymorphism is affected by changes in the frequency of a near-by polymorphism on the same DNA sample making them connected in terms of evolution. Here, first, we provide a method to model these mitochondrial polymorphisms as "co-mutation networks" for three high-altitude populations, Tibetan, Ethiopian and Andean. Then, by transforming these co-mutation networks into weighted and undirected gene-gene interaction (GGI) networks, we were able to identify functionally enriched genetic interactions of CYB and CO3 genes in Tibetan and Andean populations, while NADH dehydrogenase genes in the Ethiopian population playing a significant role in high altitude adaptation. These co-mutation based genetic networks provide insights into the role of different set of genes in high-altitude adaptation in human sub-populations.

Asunto(s)

Adaptación Fisiológica/genética , Altitud , Epistasis Genética/genética , Genes Mitocondriales/genética , Genes Mitocondriales/fisiología , Mitocondrias/genética , Mitocondrias/fisiología , Etiopía , Humanos , Polimorfismo Genético , América del Sur , Tibet

RESUMEN

Analysis of the mtDNA variation in Apis mellifera L. has allowed distinguishing subspecies and evolutionary lineages by means of different molecular methods; from RFLP, to PCR-RFLP and direct sequencing. Likewise, geometric morphometrics (GM) has been used to distinguish Africanized honey bees with a high degree of consistency with studies using molecular information. High-resolution fusion analysis (HRM) allows one to quickly identify sequence polymorphisms by comparing DNA melting curves in short amplicons generated by real-time PCR (qPCR). The objective of this work was to implement the HRM technique in the diagnosis of Africanization of colonies of A. mellifera from Argentina, using GM as a validation method. DNA was extracted from 60 A. mellifera colonies for mitotype identification. Samples were initially analyzed by HRM, through qPCRs of two regions (485 bp/385 bp) of the mitochondrial cytochrome b gene (cytb). This technique was then optimizing to amplify a smaller PCR product (207 bp) for the HRM diagnosis for the Africanization of colonies. Of the 60 colony samples analyzed, 41 were classified as colonies of European origin whereas 19 revealed African origin. All the samples classified by HRM were correctly validated by GM, demonstrating that this technique could be implemented for a rapid identification of African mitotypes in Apis mellifera samples.

Asunto(s)

Abejas/clasificación , Abejas/genética , ADN Mitocondrial/genética , Filogenia , Animales , Citocromos b/genética , Evolución Molecular , Genes Mitocondriales/genética , Desnaturalización de Ácido Nucleico , Reproducibilidad de los Resultados

RESUMEN

Baryancistrus xanthellus (Loricariidae) is an endemic fish species from the Xingu River basin with its life history in the shallow rapid waters flowing over bedrock substrates. In order to investigate the genetic diversity and demographic history of B. xanthellus we analyzed sequence data for one mitochondrial gene (Cyt b) and introns 1 and 5 of nuclear genes Prolactin (Prl) and Ribosomal Protein L3 (RPL3). The analyses contain 358 specimens of B. xanthellus from 39 localities distributed throughout its range. The number of genetically diverged groups was estimated using Bayesian inference on Cyt b haplotypes. Haplotype networks, AMOVA and pairwise fixation index was used to evaluate population structure and gene flow. Historical demography was inferred through neutrality tests and the Extended Bayesian Skyline Plot (EBSP) method. Five longitudinally distributed Cyt b haplogroups for B. xanthellus were identified in the Xingu River and its major tributaries, the Bacajá and Iriri. The demographic analysis suggests that rapids habitats have expanded in the Iriri and Lower Xingu rivers since 200 ka (thousand years) ago. This expansion is possibly related to an increase in water discharge as a consequence of higher rainfall across eastern Amazonia. Conversely, this climate shift also would have promoted zones of sediment trapping and reduction of rocky habitats in the Xingu River channel upstream of the Iriri River mouth. Populations of B. xanthellus showed strong genetic structure along the free-flowing river channels of the Xingu and its major tributaries, the Bacajá and Iriri. The recent impoundment of the Middle Xingu channel for the Belo Monte hydroelectric dam may isolate populations at the downstream limit of the species distribution. Therefore, future conservation plans must consider the genetic diversity of B. xanthellus throughout its range.

Asunto(s)

Bagres/genética , Variación Genética/genética , Filogeografía , Proteína Ribosomal L3/genética , Animales , Brasil , Flujo Génico/genética , Genes Mitocondriales/genética , Haplotipos

RESUMEN

The evolution of the Hexapoda mitochondrial genome has been the focus of several genetic and evolutionary studies over the last decades. However, they have concentrated on certain taxonomic orders of economic or health importance. The recent increase of mitochondrial genomes sequencing of diverse taxonomic orders generates an important opportunity to clarify the evolution of this group of organisms. However, there is no comparative study that investigates the evolution of the Hexapoda mitochondrial genome. In order to verify the level of rearrangement and the mitochondrial genome evolution, we performed a comparative genomic analysis of the Hexapoda mitochondrial genome available in the NCBI database. Using a combination of bioinformatics methods to carefully examine the mitochondrial gene rearrangements in 1198 Hexapoda species belonging to 32 taxonomic orders, we determined that there is a great variation in the rate of rearrangement by gene and by taxonomic order. A higher rate of genetic reassortment is observed in Phthiraptera, Thysanoptera, Protura, and Hymenoptera; compared to other taxonomic orders. Twenty-four events of convergence in the genetic order between different taxonomic orders were determined, most of them not previously reported; which proves the great evolutionary dynamics within Hexapoda.

Asunto(s)

Genes Mitocondriales/genética , Genoma Mitocondrial/genética , Insectos/genética , Animales , Bases de Datos Genéticas , Evolución Molecular , Orden Génico/genética , Reordenamiento Génico/genética , Insectos/clasificación , Mitocondrias/clasificación , Mitocondrias/genética , Filogenia , Análisis de Secuencia de ADN/métodos

RESUMEN

Central Mexico is characterized by a complex topography that is the result of historic and contemporary tectonic and climatic factors. These events have influenced the evolutionary history of numerous freshwater fishes in the region. Nonetheless, recent studies have shown that life-history traits and ecological characteristics of species may influence dispersal capabilities and the degree of genetic connectivity. Goodea (Cyprinodontiformes: Goodeidae) is one of the most widely distributed and environmentally tolerant genera of goodeids. In this study, the authors analysed variation in the mitochondrial cytochrome b gene to evaluate the phylogeographic relationships, genetic structure, genetic diversity and demographic history of Goodea from across its distribution range. They found low genetic differentiation and identified shared haplotypes among several regions. Geographic segregation was found in samples southwest and northeast of the Lower Lerma region, with some internal isolated groups showing phylogeographic differentiation and unique haplotypes. The AMOVA best explained genetic structure when grouped by haplogroups rather than when grouped by recognized biogeographic regions. Several regions showed null genetic diversity, raising the possibility of dispersal mediated by humans. Finally, Bayesian Skyline Plot analysis showed a population expansion for the Southwest haplogroup, except for the Armería population and sub-group II of the Northeast haplogroup. All this suggests a recent colonization of Goodea atripinnis throughout some of the biogeographic regions currently inhabited by this species.

Asunto(s)

Evolución Biológica , Ciprinodontiformes/clasificación , Ciprinodontiformes/genética , Variación Genética , Distribución Animal , Animales , Teorema de Bayes , Citocromos b/genética , Agua Dulce , Genes Mitocondriales/genética , Flujo Genético , Genética de Población , Haplotipos , México , Filogeografía

RESUMEN

Evolutionary reconstructions of scleractinian corals have a discrepant proportion of zooxanthellate reef-building species in relation to their azooxanthellate deep-sea counterparts. In particular, the earliest diverging "Basal" lineage remains poorly studied compared to "Robust" and "Complex" corals. The lack of data from corals other than reef-building species impairs a broader understanding of scleractinian evolution. Here, based on complete mitogenomes, the early onset of azooxanthellate corals is explored focusing on one of the most morphologically distinct families, Micrabaciidae. Sequenced on both Illumina and Sanger platforms, mitogenomes of four micrabaciids range from 19,048 to 19,542 bp and have gene content and order similar to the majority of scleractinians. Phylogenies containing all mitochondrial genes confirm the monophyly of Micrabaciidae as a sister group to the rest of Scleractinia. This topology not only corroborates the hypothesis of a solitary and azooxanthellate ancestor for the order, but also agrees with the unique skeletal microstructure previously found in the family. Moreover, the early-diverging position of micrabaciids followed by gardineriids reinforces the previously observed macromorphological similarities between micrabaciids and Corallimorpharia as well as its microstructural differences with Gardineriidae. The fact that both families share features with family Kilbuchophylliidae ultimately points towards a Middle Ordovician origin for Scleractinia.

Asunto(s)

Antozoos/genética , Genoma Mitocondrial/genética , Animales , Evolución Biológica , Arrecifes de Coral , Genes Mitocondriales/genética , Filogenia

RESUMEN

Limia islai, a new species of livebearing fish, is described from Lake Miragoane in south-western Haiti on Hispaniola. The new species has a conspicuous barred pattern consisting of several (4-12) black bars along the body, ray 4p serrae of the gonopodium in males with 10 segments and origin of dorsal fin in females slightly behind the origin of the anal fin. Although the new species colour pattern is similar to that of the humpbacked limia Limia nigrofasciata Regan 1913, L. islai sp. nov. has exclusive morphological features, such as slender body, lack of hump anterior to dorsal fin in males and presence of specific features in the gonopodial suspensory, which allow an unambiguous diagnosis from L. nigrofasciata. L. islai further differs from L. nigrofasciata in reproductive behaviour since L. islai males rely on sneak copulations and gonopodial thrusting, whereas L. nigrofasciata display an elaborate courtship behaviour. The new species is also genetically distinct in both nuclear (Rh, Myh6) and mitochondrial (12S, ND2, D-loop, Cytb) genes from other species in the genus showing reciprocal monophyly. The description of this new Limia species from Lake Miragoane confirms this lake as an important centre of endemism for the genus, with a total of eight endemic species described so far.

Asunto(s)

Ciprinodontiformes/clasificación , Aletas de Animales/anatomía & histología , Animales , Ciprinodontiformes/anatomía & histología , Ciprinodontiformes/genética , Femenino , Proteínas de Peces/genética , Genes Mitocondriales/genética , Haití , Lagos , Masculino , Pigmentación , Conducta Sexual Animal , Especificidad de la Especie

RESUMEN

A new species of Moniliformis Travassos, 1915 (Acanthocephala: Moniliformidae) is described from the hairy-tailed bolo mouse, Necromys lasiurus Lund, 1840 (Cricetidae: Sigmondontinae), captured in the Brazilian Cerrado, in Uberlândia, state of Minas Gerais, Brazil. The specimens were studied by light and scanning electron microscopy. Molecular phylogenies were inferred from partial nuclear large subunit ribosomal RNA gene sequences and partial mitochondrial cytochrome c oxidase subunit I gene. The new species is distinguished from other moniliformid species by the number of rows and number of hooks per row, size of the proboscis, size of the eggs, host species and geographical distribution. Molecular phylogenies and genetic distances analyses demonstrated that Moniliformis necromysi sp. n. forms a well-supported monophyletic group with sequences of other species of Moniliformis and is distinguished from them, which agrees with the morphological characteristics, allocating the new species to this genus and to the family Moniliformidae Van Cleave, 1924. This is the first moniliformid acanthocephalan described from a wild rodent in Brazil.

Asunto(s)

Moniliformis/clasificación , Moniliformis/ultraestructura , Sigmodontinae/parasitología , Animales , Brasil , Femenino , Genes Mitocondriales/genética , Masculino , Microscopía Electrónica de Rastreo , Filogenia , ARN Ribosómico/genética

RESUMEN

Cystic echinococcosis is a disease that affects both humans and animals, caused by cryptic species complex belonging to the platyhelminth Echinococcus granulosus sensu lato (s.l.). This disease is distributed worldwide, with E. granulosus sensu stricto (s.s.) being the most widespread of the species. High genetic variability has been demonstrated within E. granulosus s.s. studying single cyst per infected animal identifying a number of different haplotypes. However, few studies have addressed the genetic diversity of this parasite within a single intermediate host with multiple Echinococcus cysts. To date, it remains unknown if specific haplotypes of E. granulosus s.s. produce differences in biological features of the cyst. Here, we use the full length of the mitochondrial gene cox1 to determine E. granulosus s.s. haplotypes in samples from both cattle and sheep which harboured more than one cyst in different areas in Chile, where this parasite is endemic. We found 16 different haplotypes in 66 echinococcal cysts from 10 animals, and both cattle and sheep can harbour up to five different haplotypes of E. granulosus s.s. in the same animal. Regarding cyst fertility, five animals had both fertile and infertile Echinococcus cysts in both single and multiple haplotype infections. There was no association between haplotype and cyst fertility, size, or adventitial layer characteristics. Sampling and sequencing every Echinococcus cyst found in the intermediate host reveals a high molecular variability. We speculate that multiple haplotype infections could also suggest that intermediate hosts come from hyperendemic areas.

Asunto(s)

Enfermedades de los Bovinos/parasitología , Equinococosis/veterinaria , Echinococcus granulosus/clasificación , Enfermedades de las Ovejas/parasitología , Animales , Bovinos , Chile , Ciclooxigenasa 1/genética , Equinococosis/parasitología , Echinococcus granulosus/genética , Echinococcus granulosus/aislamiento & purificación , Fertilidad , Genes Mitocondriales/genética , Variación Genética/genética , Genotipo , Haplotipos , Humanos , Ovinos/genética

RESUMEN

We sequenced mitochondrial COI and COII genes (1,377 base pairs) of 166 woolly monkeys (Lagothrix) to determine the phylogenetic relationships of tschudii in reference to the other taxa within the genus Lagothrix, to provide the first genetic diversity level estimates for tschudii, and to reconstruct the historical demographic evolution of this taxon. The sample set included, for the first time, 10 individuals of the elusive tschudii taxon sensu Groves from southern Peru and northern Bolivia. Our phylogenetic analyses showed that these 10 exemplars formed a statistically significant and differentiated (molecularly and morphologically) monophyletic clade relative to other traditional subspecies of Lagothrix lagothricha. Therefore, tschudii should be recognized as a fifth subspecies: Lagothrix lagothricha tschudii. The temporal divergence of the ancestors of tschudii and L. l. cana was estimated to have occurred around 1.8 million years ago (MYA). Additionally, mitochondrial diversification within tschudii started no later than 0.96 MYA (Bayesian Inference) or 0.88 MYA (Median Joining -Network), respectively. In contrast to the phylogenetic trees, the FSTstatistic and the gene flow estimates showed L. l. lugens to be the least differentiated taxon of L. lagothricha from L. l. tschudii. Based on genetic distances, L. l. tschudii had the smallest average genetic distance from the other subspecies of L. lagothricha.It was also the taxon within L. lagothricha that had the smallest genetic distance from L. flavicauda. It should be related to L. l. tschudii as the first original taxon in L. lagothricha. Furthermore, the Andean mountains were extremely important in the original diversification of the Lagothrix genus and in the original diversification of L. lagothricha. Although L. l. tschudii has the smallest geographical range of all the taxa of L. lagothricha, its genetic diversity is even higher than in other taxa with wider geographical ranges, such as L. l. lagothricha and L. l. cana. L. l. tschudii showed a very slight demographic increase during the Pleistocene with a decrease of females in the last 10,000 Y, similar to that found for L. l. lugens in a previous study.

Asunto(s)

Atelinae/genética , Complejo IV de Transporte de Electrones/análisis , Genes Mitocondriales/genética , Variación Genética , Filogenia , Animales , Bolivia , Perú , Filogeografía

RESUMEN

Pediculus humanus is an obligate and highly intimate bloodsucking insect parasite of humans that has two ecotypes, head louse and body louse. This study analyzed genetic diversity at three mitochondrial genes (cytochrome b [cytb], cytochrome oxidase subunit 1 [cox1] and 12S ribosomal RNA [12S]) in 98 head lice collected from an isolated Native American population from the Wayampi community in Trois-Sauts, French Guiana. These results are integrated with all prior data of P. humanus (1402 cytb, 743 cox1 and 344 12S) from other parts of the world. The phylogenetic analysis revealed six highly divergent and well-supported monophyletic clades. Five clades corresponded to the previously recognized mitochondrial clades A, D, B, C and E, while the sixth (clade F) was novel, as it exhibited 5.4%, 3.7% and 3.6% divergence at cytb, cox1 and 12S, respectively, from its nearest neighbor clade B. Interestingly, the clade F has only been recovered in a few lice sequences from Mexico and Argentina, while it was the most common lineage in the Amazonian lice, which hints its association with the Native American region. Furthermore, Pediculus mjobergi, a New World monkeys' louse, which is thought to be transmitted to monkeys from the first humans that had reached the American continent thousands of years ago, also belonged to this clade, suggesting that this louse may not be a separate species but an evolutionary lineage of P. humanus. The discovery of new Amazonian clade F with the recovery of additional haplotypes within each of the five clades demonstrates that the levels of genetic diversity in P. humanus are higher than previously thought.

Asunto(s)

Genes Mitocondriales/genética , Pediculus/clasificación , Animales , Variación Genética , Humanos , Pediculus/genética , Pediculus/ultraestructura , Filogenia , Filogeografía , América del Sur

RESUMEN

Adults of the genus Austrodiplostomum are parasites in cormorants of the New World, whereas metacercariae are parasites from eye globe and brain of freshwater and brackish water fishes. In this study, specimens of Austrodiplostomum mordax from South America (type-species) were analyzed together with other specimens of Austrodiplostomum spp. collected from several locations across Middle America and North America. Partial DNA sequences of the mitochondrial gene cytochrome c oxidase subunit I ( COI), the internal transcribed spacers ( ITS1, ITS2, and 5.8S gene), and the D2-D3, domains of the large subunit ( LSU) of nuclear ribosomal DNA, were generated for both developmental stages and compared with available sequences of Austrodiplostomum spp. Phylogenetic analyses inferred with each molecular marker using maximum likelihood and Bayesian inference revealed the existence of 4 lineages representing 2 described species, A. mordax and Austrodiplostomum compactum (syn. Austrodiplostomum ostrowskiae) and 2 undescribed species of Austrodiplostomum recognized in previous studies. The COI haplotype network inferred with 172 sequences detected 28 haplotypes divided into 4 clusters, separating each other by 33 and 40 substitutions and with a genetic divergence ranging from 9 to 12%. The largest group included specimens identified as A. compactum plus those identified as A. ostrowskiae, supporting the synonymy of both species. As a result, we conclude that A. compactum is widely distributed across the Americas, in locations of the United States, Mexico, El Salvador, Honduras, Costa Rica, Venezuela, Peru, and Brazil. The other 2 undescribed species of the genus Austrodiplostomum were previously recorded in the United States and now are reported in Mexico. These 2 species cannot be described because adult forms have not been found in their definitive hosts. Finally, the species A. mordax has been found only in some lakes from Argentina, and it was validated in this study through molecular analyses.

Asunto(s)

Enfermedades de las Aves/parasitología , Complejo IV de Transporte de Electrones/genética , Enfermedades de los Peces/parasitología , Genes Mitocondriales/genética , Trematodos/clasificación , Animales , Secuencia de Bases , Teorema de Bayes , Aves , Encéfalo/parasitología , América Central , ADN Intergénico/química , ADN Ribosómico/química , Peces , Agua Dulce , Haplotipos , Funciones de Verosimilitud , Metacercarias/clasificación , Metacercarias/genética , América del Norte , Filogenia , ARN Ribosómico 5.8S/genética , Aguas Salinas , América del Sur , Trematodos/genética , Cuerpo Vítreo/parasitología

RESUMEN

Lutzomyia longipalpis es el principal v ector de una importante enfermedad desatendida en América. La diversidad genética de este vector se estimó en la población colectada en dos áreas geográficas separadas por hasta 37 km. Analizamos la secuencia CB3­PDR / N1N­PDR de 22 individuos obte­ niendo un parámetro de: h = 0.43 y π = 0.0017 (Bona), h = 0.89, π = 0.004 (El Limón) con una dife­ renciación genética de kst = 0.03; p> 0.05 entre ellos. Ocho haplotipos fueron detectados, de los cuales fue compartido. Se detectó una diferenciación significativa entre las poblaciones Panamá­ Colombia (kst = 0.98), Panamá­Costa Rica (kst = 0.98) y Panamá­Brasil (kst = 0.72) bajo el modelo de aislamiento. Las inferencias genéticas de esta población pueden complementar la información de la capacidad de dispersión y brindar pistas importantes para comprender la ecología de Lutzom­yia longipalpisen Panamá.

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Lutzomyia longipalpis is the main vector of an important neglected disease in America. The genetic div ers ity of this vector was estimated in the population collected in two geographical areas separated by up to 37 km. We analyzed the sequence CB3­PDR / N1N­PDR of 22 individuals obtaining a parameter of: h = 0.43 and π = 0.0017 (Bona), h = 0.89, π = 0.004 (The Lemon) with a genetic differentiation of kst = 0.03; p> 0.05 between them. Eight haplotypes were detected, of which it was shared. A significant differentiation was detected between the Panama­Colombia (ks t = 0.98), Panama­Costa Rica (kst = 0.98) and Panama­Brazil (kst = 0.72) populations under the isolation model. The genetic inferences of this population can complement the dispersion information and provide important clues to understand the ecology of Lutzomyia longipalpis in Panama.

Asunto(s)

Psychodidae/patogenicidad , Leishmaniasis/epidemiología , Genes Mitocondriales/genética , Complejo IV de Transporte de Electrones/genética

RESUMEN

Due to the fact that mitochondrial defects and oxidative stress have been related with obesity and breast cancer is more aggressive in women with obesity, we investigated if postmenopausal Mexican-Mestizo women with breast cancer presented somatic mutations in the sequence of the ATP6 and/or ND3 genes. Twenty one postmenopausal Mexican-Mestizo women with breast cancer who underwent mastectomy or breast conserving surgery were studied. Height and weight were used to calculate body mass index. DNA from tumor tissue samples and blood leukocytes was amplified by polymerase chain reaction and sequenced the ATP6 and ND3 mitochondrial genes. Ages ranged from 46 to 82. According to World Health Organization criteria among the 21 women, 7 had a normal BMI, 7 were overweight and 7 had obesity. In regard to the molecular study, after sequencing the coding region of ATP6 and ND3 genes of the DNA obtained from both leukocytes and tumor tissue, we did not find somatic mutations. All of the changes that we found in both genes were polymorphisms: in ATP6, we identified in ten patients 3 non-synonymous nucleotide changes and in ND3 we observed that six patients presented polymorphisms, three of them were synonymous and two non-synonymous. To our knowledge, this constitutes the first report where the complete sequence of the ATP6 and ND3 genes has been analyzed in postmenopausal Mexican-Mestizo women with breast cancer and diverse BMI. Our results differ with those reported in Caucasian and Asian populations, possibly due to ethnic differences.

Asunto(s)

Neoplasias de la Mama/genética , Carcinoma Ductal de Mama/genética , Complejo I de Transporte de Electrón/genética , ATPasas de Translocación de Protón Mitocondriales/genética , Anciano , Anciano de 80 o más Años , Índice de Masa Corporal , Neoplasias de la Mama/complicaciones , Carcinoma Ductal de Mama/complicaciones , Análisis Mutacional de ADN , Femenino , Genes Mitocondriales/genética , Humanos , México , Persona de Mediana Edad , Obesidad/complicaciones , Sobrepeso/complicaciones , Posmenopausia

RESUMEN

We analyzed 156 specimens of diverse howler monkey taxa (Alouatta; Atelidae, Primates) for different mitochondrial genes (5,567 base pairs), with special emphasis on A. palliata and related taxa. Our results showed no relevant differences among individuals of different putative taxa, A. p. palliata, A. p. aequatorialis, A. coibensis coibensis, and A. c. trabeata. We found no spatial differences in genetic structure of A. p. palliata throughout Costa Rica, Nicaragua, and Honduras. A. p. mexicana (genetic distance: 1.6-2.1%) was the most differentiated taxon within A. palliata. Therefore, we postulate the existence of only 2 clearly defined subspecies within A. palliata (A. p. palliata and A. p. mexicana). A. palliata and A. pigra (traditionally considered a subspecies of A. palliata) are 2 clearly differentiated species as was demonstrated by Cortés-Ortiz and colleagues in 2003, with a temporal split between the 2 species around 3.6-3.7 million years ago (MYA). Our results with the Median Joining Network procedure showed that the ancestors of the cis-Andean Alouatta gave rise to the ancestors of the trans-Andean Alouatta around 6.0-6.9 MYA. As Cortés-Ortiz et al. showed, A. sara and A. macconnelli are differentiable species from A. seniculus, although the first 2 taxa were traditionally considered subspecies of A. seniculus. Our findings agree with the possibility that the ancestor of A. sara gave rise to the ancestor of A. pigra in northern South America. In turn, the ancestor of A. pigra originated the ancestor of A. palliata. Two of our results strongly support the hypothesis that the South American A. palliata (the putative A. p. aequatorialis) was the original population of this species; it has high genetic diversity and no evidence of population expansion. The Central America A. palliata is the derived population. It has low genetic diversity and there is clear evidence of population expansion. However, A. palliata and A. pigra probably migrated into Central America by 2 different routes: the Isthmus of Panama (A. palliata) and Caribbean island arch (A. pigra). Finally, the red howler monkeys from the island of Trinidad in the Caribbean Sea were not A. macconnelli (= A. s. stramineus) as Groves maintained in his influential 2001 publication on primate taxonomy. This taxon is more related to A. s. seniculus, although it formed a monophyletic clade. Future molecular and karyotypic studies will show if the Trinidad red howler monkeys should be considered as an extension of the Venezuelan taxon, A. arctoidea, as a subspecies of A. seniculus(A. s. seniculus), or, in the case of extensive chromosomal rearrangements, even a new species.

Asunto(s)

Alouatta/genética , Genes Mitocondriales/genética , Filogenia , Alouatta/clasificación , Distribución Animal , Animales , América Central , Femenino , Variación Genética , Filogeografía , América del Sur

RESUMEN

The genetic relationships of native or introduced Plagioscion squamosissimus in five Brazilian Neotropical basins were evaluated using the mitochondrial atpase6/8 genes. Results revealed that the population of the Tocantins River basin is more basal than the native populations of the Amazon and Parnaíba River basins. Moreover, the populations of P. squamosissimus that were introduced in the São Francisco and upper Paraná River basins originated from the population of the Parnaíba River.

Asunto(s)

Peces/clasificación , Peces/genética , Genes Mitocondriales/genética , ATPasas de Translocación de Protón Mitocondriales/genética , Animales , Secuencia de Bases , Brasil , ADN Mitocondrial/química , ADN Mitocondrial/aislamiento & purificación , Variación Genética , Haplotipos , Especies Introducidas , Funciones de Verosimilitud , Filogenia , Dinámica Poblacional , Ríos

RESUMEN

Functional gene transfers from the mitochondrion to the nucleus are ongoing in angiosperms and have occurred repeatedly for all 15 ribosomal protein genes, but it is not clear why some of these genes are transferred more often than others nor what the balance is between DNA- and RNA-mediated transfers. Although direct insertion of mitochondrial DNA into the nucleus occurs frequently in angiosperms, case studies of functional mitochondrial gene transfer have implicated an RNA-mediated mechanism that eliminates introns and RNA editing sites, which would otherwise impede proper expression of mitochondrial genes in the nucleus. To elucidate the mechanisms that facilitate functional gene transfers and the evolutionary dynamics of the coexisting nuclear and mitochondrial gene copies that are established during these transfers, we have analyzed rpl5 genes from 90 grasses (Poaceae) and related monocots. Multiple lines of evidence indicate that rpl5 has been functionally transferred to the nucleus at least three separate times in the grass family and that at least seven species have intact and transcribed (but not necessarily functional) copies in both the mitochondrion and nucleus. In two grasses, likely functional nuclear copies of rpl5 have been subject to recent gene conversion events via secondarily transferred mitochondrial copies in what we believe are the first described cases of mitochondrial-to-nuclear gene conversion. We show that rpl5 underwent a retroprocessing event within the mitochondrial genome early in the evolution of the grass family, which we argue predisposed the gene towards successful, DNA-mediated functional transfer by generating a "pre-edited" sequence.

Asunto(s)

ADN Mitocondrial/genética , Mitocondrias/genética , Poaceae/genética , Secuencia de Aminoácidos/genética , Núcleo Celular/genética , Evolución Molecular , Conversión Génica/genética , Genes Mitocondriales/genética , Genes de Plantas , Genoma Mitocondrial , Magnoliopsida/genética , Filogenia , Proteínas de Plantas/genética , Seudogenes/genética , Edición de ARN , Proteínas Ribosómicas/genética , Homología de Secuencia de Aminoácido

RESUMEN

A new species of Ituglanis associated to the grasslands of the Pampa biome is described from the rio Uruguai basin, southern Brazil. The new species is distinguished from its congeners by the low number of ribs and by a unique color pattern composed of an outer layer with scattered round black blotches equivalent in size to the eye circumference over a reddish brown background on the lateral surface of the body. We provide the genetic sequences of the mitochondrial gene Cytochrome c Oxydase subunit I (COI) for three of the paratypes and discuss aspects about the recent discovery of the new species.(AU)

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Uma nova espécie de Ituglanis, associada aos campos do bioma Pampa, é descrita para a bacia do rio Uruguai no sul do Brasil. A nova espécie distingue-se de todos seus congêneres pelo pequeno número de costelas e por um padrão de coloração único que consiste de manchas pretas arredondadas de tamanho equivalente à circunferência do olho sobre um fundo marrom avermelhado na superfície lateral do corpo. Sequências genéticas do gene mitocondrial Citocromo Oxidase subunidade I (COI) para três dos parátipos são fornecidas, e aspectos sobre a recente descoberta da nova espécie são discutidos.(AU)

Asunto(s)

Animales , Bagres/clasificación , Genes Mitocondriales/genética

RESUMEN

A new species of Ituglanis associated to the grasslands of the Pampa biome is described from the rio Uruguai basin, southern Brazil. The new species is distinguished from its congeners by the low number of ribs and by a unique color pattern composed of an outer layer with scattered round black blotches equivalent in size to the eye circumference over a reddish brown background on the lateral surface of the body. We provide the genetic sequences of the mitochondrial gene Cytochrome c Oxydase subunit I (COI) for three of the paratypes and discuss aspects about the recent discovery of the new species.(AU)

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Uma nova espécie de Ituglanis, associada aos campos do bioma Pampa, é descrita para a bacia do rio Uruguai no sul do Brasil. A nova espécie distingue-se de todos seus congêneres pelo pequeno número de costelas e por um padrão de coloração único que consiste de manchas pretas arredondadas de tamanho equivalente à circunferência do olho sobre um fundo marrom avermelhado na superfície lateral do corpo. Sequências genéticas do gene mitocondrial Citocromo Oxidase subunidade I (COI) para três dos parátipos são fornecidas, e aspectos sobre a recente descoberta da nova espécie são discutidos.(AU)

Asunto(s)

Animales , Bagres/clasificación , Genes Mitocondriales/genética