Development of activation-tagged gain-of-functional mutants in indica rice line (BPT 5204) for sheath blight resistance.

BACKGROUND: The development of sheath blight (ShB) resistance varieties has been a challenge for scientists for long time in rice. Activation tagging is an efficient gain-of-function mutation approach to create novel phenotypes and to identify their underlying genes. In this study, a mutant population was developed employing activation tagging in the recalcitrant indica rice (Oryza sativa L.) cv. BPT 5204 (Samba Mahsuri) through activation tagging. METHODS AND RESULTS: In this study, we have generated more than 1000 activation tagged lines in indica rice, from these mutant population 38 (GFP- RFP+) stable Ds plants were generated through germinal transposition at T2 generation based on molecular analysis and seeds selected on hygromycin (50 mg/L) containing medium segregation analyses confirmed that the transgene inherited as mendelian segregation ratio of 3:1 (3 resistant: 1 susceptible). Of them, five stable activation tagged Ds lines (M-Ds-1, M-Ds-2, M-Ds-3, M-Ds-4 and M-Ds-5) were selected based on phenotypic observation through screening for sheath blight (ShB) resistance caused by fungal pathogen Rhizoctonia solani (R. solani),. Among them, M-Ds-3 and M-Ds-5 lines showed significant resistance for ShB over other tagged lines and wild type (WT) plants. Furthermore, analysed for launch pad insertion through TAIL-PCR results and mapped on corresponding rice chromosomes. Flanking sequence and gene expression analysis revealed that the upregulation of glycoside hydrolase-OsGH or similar to Class III chitinase homologue (LOC_Os08g40680) in M-Ds-3 and a hypothetical protein gene (LOC_Os01g55000) in M-Ds-5 are potential candidate genes for sheath blight resistance in rice. CONCLUSION: In the present study, we developed Ac-Ds based ShB resistance gain-of-functional mutants through activation tagging in rice. These activation tagged mutant lines can be excellent sources for the development of ShB resistant cultivars in rice.

Efecto del Programa de Ejercicios de Otago en la fragilidad de personas entre 65 y 80 años / Effect of the Otago Exercise Programme on the frailty of people between 65 and 80 years old

Objetivo: Evaluar el efecto del Programa de Ejercicios de Otago en la fragilidad de personas entre 65 y 80 años no institucionalizadas y estudiar factores asociados a la fragilidad. Método: Estudio pre-post test (basal y tras 12 meses) sin grupo control en personas de entre 65-80 años (que viven en la comunidad y con deambulación independiente) tras formarles en el Programa de Ejercicios de Otago en 5 sesiones: semanas 1, 2, 4 y 8, y una sesión de refuerzo a los 6 meses. Los pacientes se seleccionaron en 3 áreas de salud (n=200). La fragilidad se evaluó con la escala FRAIL. Resultados: Las personas que comenzaron el estudio fueron 198 y terminaron el seguimiento de 12 meses 161. La edad promedio de la muestra fue de 72,28 años; predominio del sexo femenino: 64,65%; nivel de estudios bajo 76,50%; personas viviendo solas 24,50%; sobrepeso en el 42% y obesidad grado i en el 32,32%. Se observan diferencias significativas con p=0,023 en el nivel de fragilidad entre el momento basal y a los 12 meses. El análisis exploratorio permitió identificar diferencias significativas antes y después de la intervención por sexo (ser mujer) (p=0,018) y condición de vivir solo (p=0,0468). Conclusiones: El Programa de Ejercicios de Otago presenta resultados positivos en la fragilidad en personas de 65 a 80 años y puede ayudar a mantener la funcionalidad y evitar su deterioro.(AU)

Aim: To evaluate the effect of the Otago Exercise Programme on the frailty of non-institutionalized people between 65 and 80 years of age and study factors associated with frailty. Method: Pre-post test study (baseline and after 12 months) without control group in people aged 65-80 years (living in the community and with independent ambulation) after being trained in the Otago Exercise Programme in 5 sessions: weeks 1, 2, 4 and 8, and a reinforcement session at 6 months. Patients were recruited from 3 health areas (n=200). Frailty was assessed with the FRAIL scale. Results: There were 198 people who started the study and 161 completed the 12-month follow-up. The average age of the sample was 72.28 years; predominance of female sex: 64.65%; low educational level 76.50%; people living alone 24.50%; overweight in 42%, and grade i obesity in 32.32%. Significant differences were observed with a P=.023 in the level of frailty between baseline and 12 months. The exploratory analysis identified significant differences before and after the intervention by sex (being a woman) (P=.018) and condition of living alone (P=.0468). Conclusions: The Otago Exercise Programme shows positive results in frailty in people 65 to 80 years of age and can help maintain function and prevent deterioration.(AU)

Effect of the Otago Exercise Programme on the frailty of people between 65 and 80 years old.

AIM: To evaluate the effect of the Otago Exercise Programme on the frailty of non-institutionalized people between 65 and 80 years of age and study factors associated with frailty. METHOD: Pre-post test study (baseline and after 12 months) without control group in people aged 65-80 years (living in the community and with independent ambulation) after being trained in the Otago Exercise Programme in 5 sessions: weeks 1, 2, 4 and 8, and a reinforcement session at 6 months. Patients were recruited from 3 health areas (n = 200). Frailty was assessed with the FRAIL scale. RESULTS: There were 198 people who started the study and 161 completed the 12-month follow-up. The average age of the sample was 72.28 years; predominance of female sex 64.65%; low educational level 76.50%; people living alone 24.50%; overweight in 42%, and grade I obesity in 32.32%. Significant differences were observed with a P = .023 in the level of frailty between baseline and 12 months. The exploratory analysis identified significant differences before and after the intervention by sex (being a woman) (P = .018) and condition of living alone (P = .0468). CONCLUSIONS: The Otago Exercise Programme prevents positive results in frailty in people 65 to 80 years of age and can help maintain function and prevent deterioration.

Design, Synthesis, and Pharmacological Evaluation of First-in-Class Multitarget N-Acylhydrazone Derivatives as Selective HDAC6/8 and PI3Kα Inhibitors.

Targeting histone deacetylases (HDACs) and phosphatidylinositol 3-kinases (PI3Ks) is a very promising approach for cancer treatment. This manuscript describes the design, synthesis, in vitro pharmacological profile, and molecular modeling of a novel class of N-acylhydrazone (NAH) derivatives that act as HDAC6/8 and PI3Kα dual inhibitors. The surprising selectivity for PI3Kα may be related to differences in the conformation in the active site. Cellular studies showed that these compounds act in HDAC6 inhibition and the PI3/K/AKT/mTOR pathway. The compounds that are selective for inhibition of HDAC6/8 and inhibit PI3Kα show potential for the treatment of cancer.

The Use of Conformational Restriction in Medicinal Chemistry.

During the early preclinical phase, from hit identification and optimization to a lead compound, several medicinal chemistry strategies can be used to improve potency and/or selectivity. The conformational restriction is one of these approaches. It consists of introducing some specific structural constraints in a lead candidate to reduce the overall number of possible conformations in order to favor the adoption of a bioactive conformation and, as a consequence, molecular recognition by the target receptor. In this work, we focused on the application of the conformational restriction strategy in the last five years for the optimization of hits and/or leads of several important classes of therapeutic targets in the drug discovery field. Thus, we recognize the importance of several kinase inhibitors to the current landscape of drug development for cancer therapy and the use of G-protein Coupled Receptor (GPCR) modulators. Several other targets are also highlighted, such as the class of epigenetic drugs. Therefore, the possibility of exploiting conformational restriction as a tool to increase the potency and selectivity and promote changes in the intrinsic activity of some ligands intended to act on many different targets makes this strategy of structural modification valuable for the discovery of novel drug candidates.

Elevada frequência de Aeromonas spp. e genes de virulência em cultivos de tilápia-do-nilo (Oreochromis niloticus) em tanques-rede, na região semiárida de Pernambuco, Brasil / High frequency of Aeromonas spp. and virulence genes in Nile Tilapia farms (Oreochromis niloticus) in semi-arid regions of Pernambuco, Brazil

Objetivou-se avaliar a ocorrência de Aeromonas spp. em peixes e amostras de água na região semiárida de Pernambuco e avaliar a frequência de aerolissina (aerA), enterotoxina citotóxica (act), enterotoxina citotônica (alt) e serina protease (ahp) nesses isolados. Foram analisados 70 peixes vivos e oito mortos com sinais clínicos de aeromoniose e 16 amostras de água. Aeromonas spp. foram identificadas por análises microbiológicas (provas bioquímicas) e molecular, usando-se primers específicos para a região 16S rRNA, e a distribuição dos quatro fatores de virulência (aerA, alt, act e ahp) foi investigada por ensaio de PCR. Cento e cinquenta e cinco (84,7%) isolados foram confirmados como Aeromonas spp. na análise molecular. Os genes de virulência mais frequentes foram act (53,55%) e aerA (51,61%). De acordo com o tipo de amostra, observou-se maior frequência do gene aerA (87,5% P=0,0474) em isolados de peixes mortos e a menor frequência do gene act (47,73% P=0,0002) em peixes vivos. Este estudo demonstrou a presença de aeromoniose no cultivo de tilápias em tanques-rede, nos municípios de Jatobá e Petrolândia, na região semiárida de Pernambuco. A detecção de aerA, act e alt pode ser utilizada na tipagem de virulência de Aeromonas spp.(AU)

The purpose of this study was to evaluate the occurrence of Aeromonas spp. from fishes and tilapia net-cage farm water in semi-arid regions of Pernambuco and to evaluate the frequency of the aerolysin (aerA), cytotoxic enterotoxin (act), cytotonic enterotoxin (alt) and serine protease (ahp) genes in Aeromonas isolates. 70 live and eight dead fish with aeromoniosis clinical signs and 16 water samples were analyzed. Aeromonas spp. isolated were identified by microbiological (biochemical evidence) and molecular analysis using specific primers for 16SrRNA region, while the distribution of four virulence factors, including aerA, alt, act and ahp, was investigated by PCR assay. One hundred fifty-five (84.7%) isolates were confirmed as Aeromonas spp. by molecular analysis. The most frequent virulence genes in isolates were act (53.55%) and aerA (51,61%). According to the kind of sample, the higher frequency of aerA gene (87.5% P= 0.0474) was observed in isolates from dead fish and the lowest frequency of act gene (47.73% P= 0.0002) from live fish. This study found the presence of aeromoniosis on tilapia farming in net-cages on Jatobá and Petrolândia counties in the semiarid Pernambuco region. The detection of aerA, act and alt can be used for virulence typing of Aeromonas spp. isolates.(AU)

Design, Synthesis, Experimental and Theoretical Characterization of a New Multitarget 2-Thienyl-N-Acylhydrazone Derivative.

Pulmonary arterial hypertension (PAH) is a chronic cardiovascular disease that displays inflammatory components, which contributes to the difficulty of adequate treatment with the available therapeutic arsenal. In this context, the N-acylhydrazone derivative LASSBio-1359 was previously described as a multitarget drug candidate able to revert the events associated with the progression of PAH in animal models. However, in spite of having a dual profile as PDE4 inhibitor and adenosine A2A receptor agonist, LASSBio-1359 does not present balanced potencies in the modulation of these two targets, which difficult its therapeutic use. In this paper, we describe the design concept of LASSBio-1835, a novel structural analogue of LASSBio-1359, planned by exploiting ring bioisosterism. Using X-ray powder diffraction, calorimetric techniques, and molecular modeling, we clearly indicate the presence of a preferred synperiplanar conformation at the amide function, which is fixed by an intramolecular 1,5-N∙∙∙S σ-hole intramolecular interaction. Moreover, the evaluation of LASSBio-1835 (4) as a PDE4 inhibitor and as an A2A agonist confirms it presents a more balanced dual profile, being considered a promising prototype for the treatment of PAH.

Cytotoxic activity of Secondary Metabolites from Marine-derived Fungus Neosartorya siamensis in Human Cancer Cells.

Compounds isolated from the marine sea fan-derived fungus Neosartorya siamensis (KUFA 0017), namely, 2,4-dihydroxy-3-methylacetophenon (1), chevalone C (2), nortryptoquivaline (4), tryptoquivaline H (6), tryptoquivaline F (7), fiscalin A (8), epi-fiscalin A (9), epi-neofiscalin A (11) and epi-fiscalin C (13) were tested for anti-proliferative activity by MTT assay, DNA damage induction by comet assay, and induction of cell death by nuclear condensation assay on colon HCT116, liver HepG2 and melanoma A375 cancer cell lines. Compounds 2, 4, 8, 9, 11 and 13 presented IC50 values ranging from 24 to 153 µM in the selected cell lines. Cell death was induced in HCT116 by compounds 2, 4 and 8. In HepG2, compounds 4, 8, 9 and 11 were able to induce significant cell death. This induction of cell death is possibly not related to genotoxicity because none of the compounds induced significant DNA damage. These results suggest that selected compounds present an interesting anti-proliferative activity and cell death induction, consequently showing potential (specifically epi-fiscalin C) as future leads for chemotherapeutic agents. Further studies on mechanisms of action should ensue. Copyright © 2016 John Wiley & Sons, Ltd.

Silencing of CYP6 and APN Genes Affects the Growth and Development of Rice Yellow Stem Borer, Scirpophaga incertulas.

RNAi is a powerful tool to target the insect genes involved in host-pest interactions. Key insect genes are the choice for silencing to achieve pest derived resistance where resistance genes are not available in gene pool of host plant. In this study, an attempt was made to determine the effect of dsRNA designed from two genes Cytochrome P450 derivative (CYP6) and Aminopeptidase N (APN) of rice yellow stem borer (YSB) on growth and development of insect. The bioassays involved injection of chemically synthesized 5' FAM labeled 21-nt dsRNA into rice cut stems and allowing the larvae to feed on these stems which resulted in increased mortality and observed growth and development changes in larval length and weight compared with its untreated control at 12-15 days after treatment. These results were further supported by observing the reduction in transcripts expression of these genes in treated larvae. Fluorescence detection in treated larvae also proved that dsRNA was readily taken by larvae when fed on dsRNA treated stems. These results from the present study clearly show that YSB larvae fed on dsRNA designed from Cytochrome P450 and Aminopeptidase N has detrimental effect on larval growth and development. These genes can be deployed to develop YSB resistance in rice using RNAi approach.

Effects of phenylalanine on reproductive performance and teratogenesis in mice.

We evaluated the effects of phenylalanine on reproductive performance and teratogenesis in mice, as well as we assessed its protective effect in mice treated with an acute dose of cyclophosphamide. Animals were divided into 6 experimental groups (females N = 15/group, males N = 5/group): G1, the negative control group, phosphate-buffered saline; G2, the positive control group, 35 mg cyclophosphamide/kg body weight (b.w.); G3 and G4 received phenylalanine at doses of 150 and 300 mg/ kg b.w., respectively; G5 and G6 received phenylalanine at doses of 150 and 300 mg/kg b.w. co-administered with cyclophosphamide at a dose of 35 mg/kg b.w., respectively. Pregnant mice received phenylalanine from 8-12 days of pregnancy and cyclophosphamide on the 10th day of treatment or the respective vehicles. In animals treated with cyclophosphamide, offspring fetal weight significantly decreased. The G5 and G6 groups, which received cyclophosphamide co-administered with phenylalanine, showed a smaller reduction in weight. Based on this analysis, the offspring from groups G2, G5, and G6 showed low weight due to pregnancy age. Moreover, at the doses used, phenylalanine did not interfere with embryo-fetal development. However, further studies are necessary to increase the understanding of the effects of phenylalanine on mouse reproductive performance and teratogenesis.

Electromyographic analysis of masseter and temporal muscles, bite force, masticatory efficiency in medicated individuals with schizophrenia and mood disorders compared with healthy controls.

This study aimed to comparatively analyse the electromyographic activity of the masseter and temporal muscles at rest and during mandible postural clinical conditions (right and left laterality, protrusion and maximum voluntary contraction), right and left maximum molar bite forces and the masticatory efficiency of individuals with schizophrenia or mood disorders - all medicated (medicated groups) compared with control group (healthy volunteers) via electromyography. Individuals were distributed into three groups: Group I (Schizophrenia - 20 individuals), Group II (mood disorders - 20 individuals) and Group III (Control - 40 individuals). Basically, the results were only statistically significant for the clinical mandible conditions and bite force. The most unsatisfactory results were observed in the medicated groups in relation to the control group. The group with mood disorders obtained the most unsatisfactory results compared with the group with schizophrenia. It was suggested by these observations that the association of mood disorders and schizophrenia with medication has negatively affected the stomatognathic system in relation to controls when the electromyography and bite force were used for the analysis.

Is impaired sleep quality responsible for a nondipping pattern even in normotensive individuals?

OBJECTIVE: We aimed to evaluate the relationship between sleep quality and a dipping-nondipping pattern in normotensive individuals. MATERIALS AND METHODS: Our study was carried out on 100 normotensive individuals; 50 of these individuals had a dipping pattern and 50 had a nondipping pattern, and were chosen from among patients in whom ambulatory blood pressure monitoring was applied before for any reason. All study participants underwent the Pittsburgh Sleep Quality Index survey to evaluate sleep disturbances. RESULTS: The overall scores and all the components of the Pittsburgh Sleep Quality Index scores were significantly higher in the nondipper normotensive group compared with the dipper normotensive group. CONCLUSION: In conclusion, the nondipping blood pressure pattern appears to be associated with poor sleep quality not only in hypertensive patients but also in normotensive healthy individuals. When evaluating patients with poor sleep quality, the possibility that they may have a nondipping pattern even if they are normotensive should be kept in mind.

Contagem de células somáticas, composição e contagem bacteriana total do leite de propriedades leiteiras nos municípios de Miranda do Norte, Itapecurú­Mirim e Santa Rita, Maranhão / Somatic cell counts, composition and total bacterial counts of milk from dairy farms in the cities of Miranda do Norte, Itapecurú-Mirim and Santa Rita, Maranhão State, Brazil

Objetivou-se com este estudo avaliar a contagem de células somáticas (CCS), composição e contagem bacteriana total (CBT) sobre a qualidade do leite produzido em propriedades leiteiras de Miranda do Norte, Itapecurú-Mirim e Santa Rita, Estado do Maranhão. Verificou-se no período A que a média de CCS foi de 2.236.700 células/mL, 3,87 % de gordura, 3,19% de proteína, 4,36% de lactose, 12,25% de EST, 8,55% de ESD (%) e CBT de 677,90 UFC/mL, e no período B a média de CCS foi de 2.629.950 células/mL, 3,87% de gordura, 3,27% de proteína, 4,45% de lactose, 13,19% de EST, 8,74% de ESD e CBT de 8421,35 UFC/mL. Quanto à sazonalidade, as médias de CCS e CBT foram mais elevadas no período B do que no período A.

The aim of this study was to evaluate somatic cell counts (SCC), composition and total bacterial counts (TBC) of milk from dairy farms in Miranda do Norte, Itapecurú-Mirim and Santa Rita, all located in Brazilian Maranhão state. In the A period, it were verified means of 2,236,700 somatic cells/mL; 3.87% fat; 3.19% protein; 4.36% lactose; 12.25% (TS); 8.55% non-fat solids (NFS) and 677.90 clonies forming unit (CFU)/mL. In the winter period means were 2,629,950 cells/mL; 3.87% fat; 3.27% protein; 4.45% lactose; 13.19% TS; 8.74% NFS and 8,421,35 CFU/mL. Regarding sazonality, both SCC and TBC means were higher during the period B than during the period A.

A quantum chemical and chemometrical study of indolo[2,1-b]quinazoline and their analogues with cytotoxic activity against breast cancer cells.

Some indolo[2,1-b]quinalozine (tryptanthrin) analogues present cytotoxic activity against human breast cancer cells. In this work, chemometric methods were applied in the search for building discriminant models between active and inactive analogues, based on the correlations among their in vitro cytotoxic activities and their electronic and geometric molecular descriptors. From 88 descriptors calculated with density functional theory with the exchange correlation functional B3LYP and the basis set 6-31G* (Gaussian 03), 29 were pre-selected based on their Fisher weights, and finally five descriptors (partial charge on atom 15, bond orders between atoms 12-13, 17-25 and 18-26, and energy difference between frontier molecular orbitals) were selected for principal component analysis. This analysis was able to discriminate 12 inactive from 22 active analogues by using only one principal component, accounting for 49% of the total variance and allowing us to better understand the influence of these electronic descriptors in the cytotoxic activity. In addition, a supervised partial least-squares discriminant model was build and successfully used to discriminate tryptanthrin analogues. The model was validated through an independent test set and considered robust to overfitting.

Introduction of bacterial blight resistance into Triguna, a high yielding, mid-early duration rice variety.

Bacterial blight (BB) is a serious disease of rice in India. We have used molecular marker-assisted selection in a backcross breeding program to introgress three genes (Xa21, xa13, and xa5) for BB resistance into Triguna, a mid-early duration, high yielding rice variety that is susceptible to BB. At each generation in the backcross program, molecular markers were used to select plants possessing these resistance genes and to select plants that have maximum contribution from the Triguna genome. A selected BC3F1 plant was selfed to generate homozygous BC(3)F(2) plants with different combinations of BB resistance genes. Plants containing the two-gene combination, Xa21 and xa13, were found to exhibit excellent resistance against BB. Single plant selections for superior agronomic characteristics were performed on the progeny of these plants, from BC(3)F(3) generation onwards. The selected plants were subjected to yield trials at the BC(3)F(8) generation and were found to have a significant yield advantage over Triguna. The newly developed lines are being entered into national multi-location field trials. This work represents a successful example of the application of molecular marker-assisted selection for BB resistance breeding in rice.

In silico analysis of microsatellites in organellar genomes of major cereals for understanding their phylogenetic relationships.

Microsatellites are abundant across prokaryotic and eukaryotic genomes. However, comparative analysis of microsatellites in the organellar genomes of plants and their utility in understanding phylogeny has not been reported. The purpose of this study was to understand the organization of microsatellites in the coding and non-coding regions of organellar genomes of major cereals viz., rice, wheat, maize and sorghum. About 5.8-14.3% of mitochondrial and 30.5-43.2% of chloroplast microsatellites were observed in the coding regions. About 83.8-86.8% of known mitochondrial genes had at least one microsatellite while this value ranged from 78.6-82.9% among the chloroplast genomes. Dinucleotide repeats were the most abundant in the coding and non-coding regions of the mitochondrial genome while mononucleotides were predominant in chloroplast genomes. Maize harbored more repeats in the mitochondrial genome, which could be due to the larger size of genome. A phylogenetic analysis based on mitochondrial and chloroplast genomic microsatellites revealed that rice and sorghum were closer to each other, while wheat was the farthest and this corroborated with the earlier reported phylogenies based on nuclear genome co-linearity and chloroplast gene-based analysis.

Simple sequence repeats in organellar genomes of rice: frequency and distribution in genic and intergenic regions.

MOTIVATION: Simple sequence repeats (SSRs) are abundant across genomes. However, the significance of SSRs in organellar genomes of rice has not been completely understood. The availability of organellar genome sequences allows us to understand the organization of SSRs in their genic and intergenic regions. RESULTS: We have analyzed SSRs in mitochondrial and chloroplast genomes of rice. We identified 2528 SSRs in the mitochondrial genome and average 870 SSRs in the chloroplast genomes. About 8.7% of the mitochondrial and 27.5% of the chloroplast SSRs were observed in the genic region. Dinucleotides were the most abundant repeats in genic and intergenic regions of the mitochondrial genome while mononucleotides were predominant in the chloroplast genomes. The rps and nad gene clusters of mitochondria had the maximum repeats, while the rpo and ndh gene clusters of chloroplast had the maximum repeats. We identified SSRs in both organellar genomes and validated in different cultivars and species.

Biocompatibilidade e comportamento de compósitos de hidroxiapatita em falha óssea na ulna de coelhos / Biocompatibility and behavior of hydroxyapatite on bone defect on rabbit's ulna

Avaliaram-se os compósitos de hidroxiapatita sintética e carbono (HAC) e hidroxiapatita sintética, carbono e fosfato biácido de sódio (HACF), ambos na forma sólida, como substituto ósseo em 36 coelhos adultos. Após protocolos anestésico e cirúrgico habituais, retirou-se um fragmento de aproximadamente 2cm de comprimento no terço médio da ulna esquerda. Os animais do grupo 1 receberam, em cada falha provocada, blocos de HAC e HACF, e os do grupo 2 somente HAC. Os do grupo 3 não receberam tratamento. Os animais foram submetidos a avaliações clínicas e radiológicas nos dias 8, 15, 30, 60, 120 e 180 de pós-operatório. Nas mesmas datas, dois animais de cada grupo foram sacrificados e deles colheu-se material para histologia. Observou-se evolução normal da regeneração óssea em todos os animais, sendo mais precoce nos dos grupos que receberam os compósitos. O uso de HAC e HACF na ulna de coelho mostrou-se um método eficiente, não apresentando sinais de infecção e nem evidência de rejeição.

Cytogenetics of the Brazilian whiptail lizard Cnemidophorus littoralis (Teiidae) from a restinga area (Barra de Maricá) in Southeastern Brazil.

Chromosomes of Cnemidophorus littoralis, a new species of teiid lizard recently described, were studied. The animals are from a restinga area in Barra de Maricá, RJ. The karyotype presents a diploid number of 2n = 46 chromosomes and a chromosomal sex determination mechanism of the type XX:XY. Nucleolar organizer regions, Ag-NORs, are at the sixth pair of chromosomes; there is variability of size and number of the Ag-stained nucleoli on the 50 interphase nuclei for each specimen analyzed. These nucleoli are related to NOR patterns that also demonstrated variability in size and number. This paper presents the first description of the karyotype of Cnemidophorus littoralis and of a chromosomal sex determination mechanism of the XX:XY type in the genus Cnemidophorus from Southeastern Brazil.

Cytogenetics of the Brazilian whiptail lizard Cnemidophorus littoralis (Teiidae) from a restinga area (Barra de Maricá) in Southeastern Brazil

Estudamos os cromossomos de Cnemidophorus littoralis, uma nova espécie de lagarto recentemente descrita, pertencente à família Teiidae. Os animais são oriundos de uma população de restinga na Barra de Maricá, RJ. O cariótipo apresenta número diplóide 2n = 46 cromossomos, com mecanismo cromossômico de determinação do sexo do tipo XX:XY. As regiões organizadoras do nucléolo, Ag-RONs, estão no sexto par de cromossomos. Analisamos 50 núcleos interfásicos corados pela prata para cada exemplar e observamos variação quanto ao número e ao tamanho de nucléolos; estes estão relacionados aos padrões RONs, que também apresentaram variação quanto ao tamanho e ao número. Este trabalho também descreve pela primeira vez a presença de um mecanismo de determinação cromossômica do sexo para o gênero Cnemidophorus do Sudeste do Brasil.