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Featured researches published by Alejandro Varela-Romero.


Rivers of North America | 2005

23 – Rivers of Mexico

Paul F. Hudson; Dean A. Hendrickson; Arthur C. Benke; Alejandro Varela-Romero; Rocío Rodiles-Hernández; W. L. Minckley

This chapter discusses the physical and biological features of five major Mexican rivers—the Rio Panuco, Usumacinta–Grijalva rivers, Rio Candelaria, the Yaqui, and the Rio Conchos. Five additional rivers—the Chihuahuan Deserts Rio Salado; the Rio Tamesi, which joins the Rio Panuco near its mouth; the Rio Fuerte, which flows through some of the continents largest canyons in the Sierra Madre Occidental to the Gulf of California south of the Yaqui and Mayo rivers; the Ayuquila–Armeria river system, which empties into the Pacific Ocean; and the Rio Lacanja, a small mountainous tributary of the Usumacinta—are also briefly reviewed. The history of human impacts on Mexicos rivers includes many groups of prehistoric inhabitants. Mexicos major rivers are highly exploited. Construction of dams, primarily for crop irrigation in otherwise desert environments, is one of the major factors. Water pollution from discharge of domestic wastes, high salinity, and nutrients from irrigation returns, mining, and industrial wastes is widespread throughout Mexico. With the increase in population and associated land-use change and generally limited resources available for conservation of natural resources the scenario of the rivers are becoming much worse.


Reviews in Fish Biology and Fisheries | 2008

Mitochondrial haplotype variation in wild trout populations (Teleostei: Salmonidae) from northwestern Mexico

Faustino Camarena-Rosales; Gorgonio Ruiz-Campos; Jorge de la Rosa-Vélez; Richard L. Mayden; Dean A. Hendrickson; Alejandro Varela-Romero; Francisco León

The variation and composition of Mexican wild trout mitochondrial DNA haplotypes throughout northwestern Mexico was determined by means of polymerase chain reaction–restriction fragment polymorphism analysis (PCR–RFLP), of one region of mitochondrial DNA between cytochrome b and the D-loop. This analysis was based on 261 specimens taken in 12 basins and four hatcheries from northwestern Mexico. From 23 haplotypes, 15 wild trout haplotypes were identified and classified in four groups: (1) one restricted to Nelson’s trout (Oncorhynchus mykiss nelsoni), (2) four restricted to Río Mayo and RíoYaqui trout (O. mykiss sspp.), (3) six to Mexican golden trout (O. chrysogaster) with two subgroups, and (4) one exclusive to Río Piaxtla trout. Distributions of native haplotypes broadly overlap the distribution of non-native hatchery rainbow trout reflecting the historical management of introductions of exotic rainbow trout and the artificial transference of these trout among basins.


Comparative Biochemistry and Physiology Part D: Genomics and Proteomics | 2009

The complete mitochondrial genomes of the yellowleg shrimp Farfantepenaeus californiensis and the blue shrimp Litopenaeus stylirostris (Crustacea: Decapoda).

Alma B. Peregrino-Uriarte; Alejandro Varela-Romero; Adriana Muhlia-Almazán; Iván Anduro-Corona; Sarahí Vega-Heredia; Luis Enrique Gutierrez-Millan; Jorge de la Rosa-Vélez; Gloria Yepiz-Plascencia

Mitochondria play key roles in many cellular processes. Description of penaeid shrimp genes, including mitochondrial genomes are fairly recent and some are focusing on commercially important shrimp as the Pacific shrimp Litopenaeus vannamei that is being used for aquaculture not only in America, but also in Asia. Much less is known about other Pacific shrimp such as the yellowleg shrimp Farfantepenaeus californiensis and the blue shrimp Litopenaeus stylirostris. We report the complete mitogenomes from these last two Pacific shrimp species. Long DNA fragments were obtained by PCR and then used to get internal fragments for sequencing. The complete F. californiensis and L. stylirostris mtDNAs are 15,975 and 15,988 bp long, containing the 37 common sequences and a control region of 990 and 999 bp, respectively. The gene order is identical to that of the tiger shrimp Penaeus monodon. Secondary structures for the 22 tRNAs are proposed and phylogenetic relationships for selected complete crustacean mitogenomes are included. Phylogenomic relationships among five shrimp show strong statistical support for the monophyly of the genus across the analysis. Litopenaeus species define a clade, with close relationship to Farfantepenaeus, and both clade with the sister group of Penaeus and Fenneropenaeus.


Southwestern Naturalist | 2011

Status of the Yaqui Catfish (Ictalurus pricei) in the United States and Northwestern Mexico

Alejandro Varela-Romero; Dean A. Hendrickson; Gloria Yepiz-Plascencia; James E. Brooks; David A. Neely

Abstract To appraise conservation status of the Yaqui catfish Ictalurus pricei, we reviewed literature and unpublished records on a captive stock, examined voucher specimens at museums, re-sampled historical localities in the Yaqui, Mayo, and Fuerte river basins, and we surveyed rivers further south. A total of 72 specimens of native Ictalurus was collected in the Yaqui, Fuerte, Sinaloa, Culiacán, and San Lorenzo river basins. No native Ictalurus was collected in the Mayo Basin. Distribution of the Yaqui catfish appears restricted to the Yaqui, Mayo and Fuerte river basins, all of which now harbor nonnative blue (I. furcatus) and channel (I. punctatus) catfishes. The nonnative black bullhead (Ameiurus melas) is now known from the Yaqui Basin and the flathead catfish (Pylodictis olivaris) has been recorded anecdotally in the Yaqui Basin. Threats to the Yaqui catfish have increased in recent years and hybridization with the channel catfish now appears widespread. We conclude that the Yaqui catfish should be considered endangered throughout its range and that status of native populations of Ictalurus in the United States and Mexico should be reviewed and management intensified.


Southwestern Naturalist | 2014

Analysis of the Ictalurus pricei complex (Teleostei: Ictaluridae) in northwest Mexico based on mitochondrial DNA

Melissa Castañeda-Rivera; José Manuel Grijalva-Chon; Luis Enrique Gutierrez-Millan; Gorgonio Ruiz-Campos; Alejandro Varela-Romero

Abstract The genus Ictalurus is represented in northwest Mexico by a taxonomically problematic group of populations informally treated as the Ictalurus pricei complex. Several morphological characters separate the undescribed catfish populations (Sinaloa catfish) in the Culiacan River and San Lorenzo River basins from the Yaqui catfish (Ictalurus pricei), the only catfish species described from the region. In this paper, a phylogenetic analysis of cytochrome oxidase subunit 1 supports the monophyly of the I. pricei complex (Yaqui and Sinaloa catfishes). The complex appears closely related to Ictalurus lupus, another species from the American Southwest.


Mitochondrial DNA | 2016

Complete mitochondrial genome of Ictalurus pricei (Teleostei: Ictaluridae) and evidence of a cryptic Ictalurus species in Northwest Mexico.

Carlos A. Ballesteros-Córdova; Melissa Castañeda-Rivera; José Manuel Grijalva-Chon; Reyna A. Castillo-Gámez; Luis Enrique Gutierrez-Millan; Faustino Camarena-Rosales; Gorgonio Ruiz-Campos; Alejandro Varela-Romero

Abstract The nominal Yaqui catfish, Ictalurus pricei, is a species of Ictaluridae (Siluriformes) often recorded from Northwest Mexico. Southern distribution members of the I. pricei complex in Northwest Mexico include at least one undescribed species that differs from Yaqui catfish in morphological features, herein called “Sinaloa Catfish”. Sequencing of four geographical mitogenome haplotypes of Yaqui catfish and Sinaloa catfish showed geographical haplotypes of I. pricei within a clade of specific identity, close to Sinaloa catfish haplotypes. Our molecular phylogeny represents a working hypothesis supporting information on the evolutionary relationships of the Ictalurus species from Western Mexico and Western USA.


Revista Mexicana de Fitopatología, Mexican Journal of Phytopathology | 2018

Análisis filogenético multilocus del complejo fúngico asociado a pudrición radicular de sandía en Sonora, México

María Eugenia Rentería-Martínez; Miguel Ángel Guerra-Camacho; Andrés Ochoa-Meza; Sergio Francisco Moreno-Salazar; Alejandro Varela-Romero; Luis Enrique Gutierrez-Millan; Amparo del Carmen Meza-Moller

The state of Sonora is one of the main producers of watermelons in Mexico. Each year, agricultural producers deal with phytosanitary issues like soilborne pathogens. In this study the presence of phytopathogenic fungi associated to watermelon root rot was analyzed in the main production regions of Sonora. Morphological analysis revealed three genera: Fusarium (73%), Ceratobasidium (20%) and Rhizoctonia (6%). Through a multilocus phylogenetic analysis (ITS1, TEF and RPB2 for Fusarium ; ITS1 and RPB2 for Rhizoctonia and Ceratobasidium ), the following species were identified: Fusarium falciforme, F. brachygibbosum and F. oxysporum . In addition to this, two anastomosic groups for Ceratobasidium sp. (AG-F y AG-A) and two for Rhizoctonia spp. (AG-4 y AG-6) were identified. Pathogenicity assays showed that the representative isolates from these five different species caused root rot wounds and wilting in watermelon plantlets 21 days post inoculation. In this study, F. falciforme is reported for the first time and anastomosic groups for Rhizoctonia and Ceratobasidium are defined as causal agents of watermelon root rot in the region.


Indian Journal of Human Genetics | 2011

G-C heterozygosis in mutS homolog2 as a risk factor to hereditary nonpolyposis colon cancer in the absence of a family medical history.

Jorge Alfonso Arvayo-Zatarain; José Manuel Grijalva-Chon; Reina Castro-Longoria; Alejandro Varela-Romero

To detect the presence of point mutations in a small section of the mutS homolog2 (MSH2) gene in both healthy and affected persons treated at the General Hospital of the State of Sonora, a 353 base pair section of the MSH2 gene was amplified and sequenced from six persons affected by hereditary nonpolyposis colorectal cancer and from 19 healthy persons. The affected persons did not show the mutations reported in the scientific literature; however, six healthy persons were heterozygote and mutant-allele carriers. The heterozygote condition implies that carriers are candidates for the development of colorectal cancer. However, it is important to know the family medical history when investigating hereditary mutations.


Reviews in Fish Biology and Fisheries | 2002

Distribution, habitat and conservation status of desert pupfish (Cyprinodon macularius) in the Lower Colorado River Basin, Mexico

Alejandro Varela-Romero; Gorgonio Ruiz-Campos; Luz María Yépiz-Velázquez; Jorge Alaniz-Garcia


Reviews in Fish Biology and Fisheries | 2003

Morphometric variation of wild trout populations from northwestern Mexico (Pisces: Salmonidae)

Gorgonio Ruiz-Campos; Faustino Camarena-Rosales; Alejandro Varela-Romero; Sergio Sánchez-González; Jorge de la Rosa-Vélez

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Gorgonio Ruiz-Campos

Autonomous University of Baja California

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Faustino Camarena-Rosales

Autonomous University of Baja California

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Asunción Andreu-Soler

Autonomous University of Baja California

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Jorge de la Rosa-Vélez

Autonomous University of Baja California

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Josefina Ramos-Paredes

Autonomous University of Baja California

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Adriana Muhlia-Almazán

Spanish National Research Council

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Fernando Mendoza-Cano

Spanish National Research Council

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