Reyna Lara-Martínez

• National Autonomous University of Mexico

Two genes encoding cytochrome c oxidase subunits, Cox2a and Cox2b, are present in the nuclear genomes of apicomplexan parasites and show sequence similarity to corresponding genes in chlorophycean algae. We explored the presence of COX2A and COX2B subunits in the cytochrome c oxidase of Toxoplasma gondii. Antibodies were raised against a synthetic...

Taenia solium infections continue being a health problem in undeveloped countries, and few effective control measures against this parasite are being applied. Antimicrobial peptides (AMPs) belong to the innate immune response and capable of destroying pathogens. We tested the ability of two AMPs, Temporin A (TA) and Iseganan IB-367 (IB-367) to dama...

Our group is interested in rRNA and ribosome biogenesis in the parasitic protozoan Trypanosoma cruzi. Epimastigotes represent an extracellular replicative stage of T. cruzi and can be cultured in axenic media. The growth curve of epimastigotes allows assessment of potential differences in the nucleoli of cells undergoing growth-rate transitions. To...

La estructura in situ del núcleo de la célula ha sido ampliamente estudiada con el microscopio de luz y con el microscopio electrónico. Recientemente se ha comenzado a utilizar el microscopio de fuerza atómica para este propósito. En este trabajo se presentan observaciones con el microscopio de fuerza atómica sobre la estructura del núcleo a partir...

Baculovirus is one of the most complex viruses found in nature. Proteomic analysis of budded viruses (BVs) indicates that they are formed by at least 50 different structural proteins. The function of most of these structural proteins and their specific localization in individual virions remain unknown. In the present study, we have conducted single...

Background Periodontitis is a chronic infectious disease, characterized by an exacerbated inflammatory response and a progressive loss of the supporting tissues of the teeth. Porphyromonas gingivalis is a key etiologic agent in periodontitis. Cystatin C is an antimicrobial salivary peptide that inhibits the growth of P. gingivalis . This study aime...

We analyzed size variation of Hemileia vastatrix coffee leaf rust urediniospores. Further, the morphological structure and vegetative hyphae of uredinia were examined. The study included isolates collected in 17 coffee cultivars grown at various altitudes (229 to 1,649 m) in 14 regions of four Mexican states. In 2015, 265 leaf samples with rust sym...

Social cheating is the exploitation of public goods that are costly metabolites, like exoproteases. Exoprotease exploitation in Pseudomonas aeruginosa has been studied in reference strains. Experimental evolution with reference strains during continuous growth in casein has demonstrated that non-exoprotease producers that are lasR mutants are selec...

Bacteria frequently store excess carbon in hydrophobic granules of polyhydroxybutyrate (PHB) that in some growth conditions can occupy most of the cytoplasmic space. Different types of proteins associate to the surface of the granules, mainly enzymes involved in the synthesis and utilization of the reserve polymer and a diverse group of proteins kn...

Biomonitoring is a valuable tool for assessing the presence and effects of air pollutants such as heavy metals (HM); due to their toxicity and stability, these compounds can affect human health and the balance of ecosystems. To assess its potential as a sentinel organism of HM pollution, the wild plant Gnaphalium lavandulifolium was exposed to four...

Pseudomonas aeruginosa is one of the most worrisome infectious bacteria due to its intrinsic and acquired resistance against several antibiotics and the recalcitrance of its infections; hence, the development of novel antimicrobials able to inhibit it is mandatory. In this work, silver nanoparticles obtained by green synthesis using a leaf extract...

Morphological and phylogenetic analyses were conducted with two white blister rust specimens from Amaranthus palmeri S. Watson collected in Sinaloa, Mexico. Secondary sporangia were similar to those of Wilsoniana bliti (Biv.) Thines and Wilsoniana amaranthi Y.J. Choi, Thines & H.D. Shin. The coarsely reticulate epispore of the oospores corresponded...

Introducción: Se reconoce la importancia ecológica de los anfibios y reptiles, vitales en el funcionamiento de los ecosistemas y con patrones de reproducción diversos. No existen muchos estudios en biología de la reproducción en especies cubanas. El objetivo es mostrar el impacto de los estudios histológicos y ultraestructurales de las gónadas de a...

The photoautotrophic poly(3-hydroxybutyrate) (PHB) production by cyanobacteria is an attractive option as it only requires CO2 and light. In this work, a new wild-type strain producing PHB, Synechococcus elongatus UAM–C/S03, was identified using a polyphasic approach. The strain was cultured in a photobioreactor operated under N-sufficiency conditi...

Enterococcus faecalis has been associated with root canal infections, while Streptococcus mutans has a central role in the etiology of dental caries. One of the main reasons of endodontic failure has been associated to the presence of E. faecalis and the formation of biofilms. S. mutans inhabits the oral cavity, specifically the dental plaque, whic...

El objetivo de este estudio fue hacer una descripción macro y microscópica de la morfología gonadal de Peltophryne empusa. Para realizarlo se recolectaron seis ejemplares (dos machos y cuatro hembras) de esta especie en las dos estaciones, seca y húmeda, del período 2018-2019 en la localidad de San Paúl, Artemisa, Cuba. Los ejemplares fueron aneste...

During sporulation Bacillus subtilis Mfd couples transcription to nucleotide excision repair (NER) to eliminate DNA distorting lesions. Here, we report a significant decline in sporulation following Mfd disruption, which was manifested in the absence of external DNA-damage suggesting that spontaneous lesions activate the function of Mfd for an effi...

Background and aims This is the first time that obesity and diabetes mellitus (DM) as protein conformational diseases (PCD) are reported in children and they are typically diagnosed too late, when β-cell damage is evident. Here we wanted to investigate the level of naturally-ocurring or real (not synthetic) oligomeric aggregates of the human islet...

The cell nucleus contains domains related to gene expression. The nucleolus is involved in pre-rRNA metabolism while inter-chromatin granules are involved in pre-mRNA metabolism. It was recently shown that no ultrastructural changes are detected in the nucleolar organization, but no data of the effect of transfection in speckles are known. The aim...

The formation of amyloid oligomers and fibrils of the human islet amyloid polypeptide (hIAPP) has been linked with β- cell failure and death which causes the onset, progression, and comorbidities of diabetes. We begin to unpack the aggregation-oligomerization-fibrillization process of these oligomers taken from sera of pediatric patients. The natur...

The study of mechanotransduction signals and cell response to mechanical properties requires designing culture substrates that possess some, or ideally all, of the following characteristics: (1) biological compatibility and adhesive properties, (2) stiffness control or tunability in a dynamic mode, (3) patternability at the microscale and (4) integ...

Introduction: It is known that the fetal growth and development are directly related with the nutritional state of the mother. Under health compromising conditions, as in the diabetes, it is suggested the use of supplements to decrease the risk of complications for the mother as well as for the product. One of the most recommended supplements is th...

p> Background: The possible intraspecific anatomical variation in inferior tracheophytes is not recorded. In this study, we describe the anatomical variation of the aerial stems of Selaginella pallescens and the pit membrane (PM). Hypothesis: There is significant structural variation of the aerial stem and PM in a single species in relation to its...

Light and electron microscopy have been used to study cell structure for many years, but atomic force microscopy is a more recent technique used to analyze cells, mainly due to the absence of techniques to prepare the samples. Isolated molecules or organelles, whole cells, and to a lesser extent in situ cell structure have been observed by differen...

Human islet amyloid peptide (hIAPP1-37) aggregation is an early step in Diabetes Mellitus. We aimed to evaluate a family of pharmaco-chaperones to act as modulators that provide dynamic interventions and the multi-target capacity (native state, cytotoxic oligomers, protofilaments and fibrils of hIAPP1-37) required to meet the treatment challenges o...

Protein folding is a process of self-assembly defined by the sequence of the amino acids of the protein involved. Additionally, proteins tend to unfold, misfold and aggregate due to both intrinsic and extrinsic causes. Human islet amyloid polypeptide (hIAPP) aggregation is an early step in diabetes mellitus. However, the aggregation of rat IAPP (rI...

The nucleolus is the major site of ribosome biogenesis in eukaryotes. Until recently, G. lamblia was considered the only eukaryote lacking nucleoli. Recently, light and electron microscopy cytochemical techniques have been used to demonstrate the presence of nucleoli in the interphase nucleus of G. lamblia. Here we review the work made during the l...

Serine/arginine proteins increased their activity during the alternative splicing in cell nucleus. The nuclear speckles, also known as interchromatin granule clusters, are enriched with SR splicing factors and are implicated in gene expression. Nuclear speckle formation is developmentally regulated; in certain cases phosphorylated SR proteins are a...

Nucleolar assembly is a cellular event that requires the synthesis and processing of ribosomal RNA, in addition to the participation of pre-nucleolar bodies (PNBs) at the end of mitosis. In mammals and plants, nucleolar biogenesis has been described in detail, but in unicellular eukaryotes it is a poorly understood process. In this study, we used l...

The nucleolus is a nuclear organelle involved in ribosome biogenesis. In most eukaryotes this structure disperses during prophase through anaphase and reorganizes at telophase by a process known as nucleologenesis. This process involves new transcription of ribosomal DNA at the nucleolar organizer region and the formation of prenucleolar bodies fus...

Harmful algal blooms are a threat to coastal ecosystems and human health. Among diatoms, several species of the genus Pseudo-nitzschia could represent a major concern because of their toxicity and cause of amnesic shellfish poisoning (asp). The objective of this research is to study the annual dynamics of Pseudo-nitzschia in the Veracruz Reef Syste...

The increasing prevalence of conformational diseases, including Alzheimer's disease, type 2 Diabetes Mellitus and Cancer, poses a global challenge at many different levels. It has devastating effects on the sufferers as well as a tremendous economic impact on families and the health system. In this work, we apply a cross-functional approach that co...

In this paper pits, secondary wall, and pit membrane of tracheary elements of two species of Cactaceae with contrasting wood were characterized and compared. Mature plants of Echinocactus grusonii (dimorphic wood) and Mammillaria compressa (non-fibrous wood) belonging to the tribe Cacteae were collected and prepared using different methods to study...

In this paper pits, secondary wall, and pit membrane of tracheary elements of two species of Cactaceae with contrasting wood were characterized and compared. Mature plants of Echinocactus grusonii (dimorphic wood) and Mammillaria compressa (non-fibrous wood) belonging to the tribe Cacteae were collected and prepared using different methods to study...

In this paper pits, secondary wall, and pit membrane of tracheary elements of two species of Cactaceae with contrasting wood were characterized and compared. Mature plants of Echinocactus grusonii (dimorphic wood) and Mammillaria compressa (non-fibrous wood) belonging to the tribe Cacteae were collected and prepared using different methods to study...

Introduction: Type 2 diabetes mellitus is a conformational disease (CD), characterised by deposition (fibrils and cytotoxic oligomers) of the human islet amyloid peptide (hIAPP). CDs have devastating effects on the sufferers and their caregivers, as well as a tremendous economic impact on families and the health system. Novel molecule candidates ta...

Ectothermic vertebrates may have a pigment of unknown function, although in some cases melanomacrophage centers with apparent phagocytic function have been described; however, it is not common to find pigmented gonads in Anuran amphibians. The main objective of this paper is to report and analyze the presence of pigment in the testes of frogs (thre...

The genus Eleutherodactylus in Cuba has 52 species of frogs that breed on land and have direct development. The description of the reproductive system, especially the morphology of their gonads, provides data on their adaptive radiation. Our objectives are to describe the morphology of the ovaries of six species of Eleutherodactylus: E. goini, E. p...

Hemidactylus mabouia [Moreau de Jonnès, 1818], conocido comúnmente como geco tropical casero, es una especie originaria de África, quese ha extendido por las Américas. Sus hábitos alimentarios demuestran que estos lagartos pueden ser usados como controladores biológicos de insectos y sus colores los hacen atractivos como mascotas. Se conoce muy poc...

Bufo longinasus is classified as endangered in the IUCN Red List of Threatened Species. There is very little knowledge about this species as well as the possibility of the existence of subspecies, so the results of this research may help to clarify systematic aspects. The main goal of the study is to describe the male gonad of Bufo longinasus by Tr...

Morphology and ultrastructure of the male gonad of the endemic toad to Cuba, Bufo fustiger was described. Eight adults were collected in the area of La Chorrera in Pinar del Rio province. They were transferred to the laboratory and treated properly. Gonads were processed to be observed by light microscopy and transmission electron microscopy (ТЕМ)....

ln eukaryotes, mRNA is produced as a primary transcript or pre-mRNA which matures in a three step process: 1st) addition of the 7 meG group to end 5'; 2nd) end 3' polyadenylation; 3rd) splicing. For these steps to take place, several factors are required. The cellular organization of such factors corresponds to a distribution called speckled patter...

The in situ structure of the cell has been extensively studied by light and electron microscopy. Recently, atomic force microscopy has been also used to this aim. In this study, atomic force microscopy observations on the nuclear structure are presented from semi-thin sections of material prepared for standard methods of electron microscopy. In the...

Bufo taladai, the Cuban Spotted Toad, is endemic, one of the four larges toads from Cuba and listed in the IUCN Red List of Threatened Species as Vulnerable because its area of occupancy is being lost. [1]. It's a nocturnal toad and also a member of the B. peltocephalus group with which it can hybridize [2]. This species is found in Central and Eas...

Eleutherodactylidae family is the most diverse among Cuban amphibians, including 52 species all in the genus Eleutherodactylus [1]. These frogs are between 20 and 50 mm snout-vent length and unlike many temperate zone species, breed on land and undergo a direct development. Hence, studies on its reproduction are of great importance to understand th...

El núcleo celular es altamente dinámico y organizado en dominios que corresponden al sustrato morfológico de diversos procesos moleculares relacionados con la expresión génica. Tal es el caso del proceso de splicing, encargado de la eliminación de intrones y unión de exones [1]. Este proceso requiere de aproximadamente 70 factores de splicing no sn...

Resumen La presencia de genes segmentados en eucariontes trae consigo la producción de un transcrito primario o pre-mRNA que tiene que ser procesado para salir al citoplasma en forma de mRNA y ser traducido a proteína por el ribosoma. Los pasos principales de procesamiento son 1) la metilación del extremo 5', 2) la poliadenilación del extremo 3' y...