Detection of differentially methylated regions of irradiated fig tree selections

Fig tree (Ficus carica L.) breeding programs using conventional methods, such as directed crosses, to obtain new cultivars, are unworkable in many countries, including Brazil. Consequently, genetic breeding through mutagenesis has emerged as an important line of research that can improve this crop, and be a significant source of information about this species and assist in the implementation of propagation projects and appropriate management. The aim of this study was to verify the existence of epigenetic variability attributable to DNA methylation in irradiated fig selections when compared both to each other and to the main commercial cultivar, “Roxo-de-Valinhos”, which had previously used methylation-sensitive amplified polymorphism (MSAP) and DNA sequencing to detect the position of polymorphic regions, analyzable by bioinformatic tools. The sequencing of DNA, isolated from the differentially methylated sites, makes it possible to observe different patterns of methylation by sequencing the treated DNA with sodium bisulfite in the coding regions of regulatory genes active in the development, and fruit ripening stages. Furthermore, they have been found in the mitochondrial DNA of treatments which regulate the supply of energy in Adenosine triphosphate (ATP) form in plants. Closely related to their development, they justify the different phenotypes found in both fruit and plant growth that have suffered stress due to exposure to gamma radiation. Thus, future studies on gene expression in treatments have emerged as an extremely important strategy for understanding these complex regulatory systems, which may lead to the identification of genes of agricultural interest for the fig tree crop, and allow for manipulation and subsequent propagation of improved crops for commercial purposes

Expressão de genes relacionados à função mitocondrial em bovinos Nelore extremos para consumo alimentar residual

A pecuária de corte é uma atividade de grande importância social e econômica no Brasil e criar animais mais produtivos e eficientes é fundamental para aumentar a rentabilidade do sistema. Um dos componentes de maior custo envolvido na produção animal é a alimentação. Por isso, muitos índices já foram propostos com o intuito de melhorar a eficiência alimentar. Uma das características que têm sido estudadas, com objetivo de selecionar animais, é o consumo alimentar residual (CAR), que é estimado considerandose a diferença entre o consumo real e a quantidade de alimento que o animal deveria ingerir baseado no seu peso vivo médio, o que permite identificar e selecionar animais mais eficientes, sem que haja seleção para maior peso a idade adulta. A função mitocondrial tem sido apontada como sendo um fator de grande influência no CAR. Com isso, analisar genes envolvidos na função mitocondrial torna-se uma alternativa para identificar marcadores moleculares associados à maior eficiência alimentar. O co-ativador PGC1, pode induzir a biogênese mitocondrial, termogênese e respiração. A proteína TFAM (fator de transcrição mitocondrial A) está envolvida no processo de transcrição do DNA mitocondrial e é um fator-chave para a replicação do DNA mitocondrial. As proteínas desacopladoras (UCPs) localizam-se na membrana interna da mitocôndria, e dentre elas, estão a UCP2 e a UCP3, que atuam no controle da termogênese adaptativa e da produção de espécies reativas de oxigênio na mitocôndria. Nesse trabalho foram analisadas a expressão dos genes PGC1 , TFAM, UCP2 e UCP3 por meio da técnica de PCR quantitativa em tempo real, em tecidos hepático e muscular de dois grupos de bovinos Nelore com valores contrastantes de CAR, visando avaliar as relações destes genes com consumo alimentar residual...The beef cattle industry is an activity of significative social and economic importance in Brazil and to raise more efficient animals is fundamental to increase the system profitability . One of the most expensive components involved in animal production is the cost of food. Therefore, many indexes have been proposed to improve feed efficiency. One of the traits that have been studied in order to select animals is the residual feed intake (RFI), which is estimated considering the difference between the real consumption and the amount of food the animal should eat based on its live weight, which allows to identify and select more efficient animals, without selecting for higher adult weight. Mitochondrial function has been identified as an influential factor on RFI. Thus, to analyze genes involved in mitochondrial function becomes an alternative to identify molecular markers associated with higher feed efficiency. The co-activator PGC1 can induce mitochondrial biogenesis, thermogenesis and breathing. The protein TFAM (mitochondrial transcription factor A) is involved in mitochondrial DNA transcription and is a key factor for the replication of mitochondrial DNA. The uncoupling proteins (UCPs) are located in the inner mitochondrial membrane, and among them, are UCP2 and UCP3, which act in the control of adaptive thermogenesis and of the production of reactive oxygen species in the mitochondria. In this study the expression of genes PGC1 , TFAM, UCP2 and UCP3 by real-time quantitative PCR in liver and muscle tissues in two groups of Nellore cattle with contrasting values of RFI were analyzed, to evaluate the relationships of these genes with residual feed intake. In liver tissue, the TFAM and UCP2 genes were more expressed in negative RFI animals compared to positive RFI animals. The PGC1 gene expression had no significant difference... (Complete abstract click electronic access below

Expressão gênica diferencial em tecido muscular de bovinos Nelore divergentes para qualidade de carne

Mais de 80% da carne bovina brasileira é proveniente de animais de origem zebuína. Este produto é considerado de baixa maciez e reduzido teor de gordura entremeada quando comparado à carne de animais de raças taurinas. Investir na melhoria das características organolépticas como marmoreio e maciez da carne torna-se importante do ponto de vista econômico, pois tratam-se de atributos muito apreciados pelo consumidor. A maciez pode ser medida por meio de análises sensoriais, índice de fragmentação miofibrilar ou força de cisalhamento. Nesse último, um aparelho é utilizado para medir a força necessária para o cisalhamento de uma seção transversal de carne e, quanto maior a força dispensada, menor é a maciez apresentada pelo corte de carne. Outra característica relacionada à qualidade da carne é o marmoreio, que pode ser analisada por meio de escala de graduação visual denominada Quality Grade. No entanto, estas metodologias só podem ser utilizadas após o abate do animal. As técnicas de análise do transcriptoma, como o RNA-Seq, permitem a identificação de genes cuja expressão está relacionada com o controle de características quantitativas e podem ser alternativas na busca pelo melhoramento destes atributos. Com isso, o objetivo deste trabalho foi identificar genes diferencialmente expressos utilizando a técnica RNA-Seq, em tecido muscular de bovinos da raça Nelore, visando contribuir para o conhecimento dos fatores genéticos que estão relacionados com a qualidade da carne. Para isso, foi sequenciado o mRNA de 40 amostras divergentes para a maciez da carne (20 com carne dura e 20 com carne macia) e 40 amostras divergentes para marmoreio (20 com alto e 20 com baixo marmoreio). Essas amostras foram escolhidas com base na análise de força de cisalhamento e índice de marmorização realizadas em 132 e 80 amostras de músculo longissimus dorsi respectivamente, coletadas da meia carcaça esquerda de cada animal. As análises dos resultados obtidos pela técnica de RNA-Seq revelaram genes diferencialmente expressos relativos à maciez e marmoreio da carne em gado Nelore. Os genes referentes à maciez estão relacionados ao metabolismo de colágeno, à actina e miosina, ao transporte de cálcio, dentre outros. Por outro lado, nos resultados das análises de marmoreio, os genes que se mostraram diferencialmente expressos estão relacionados à ocitocina, ao transporte de oxigênio, ao crescimento e à síntese de lipídios e proteínas. Portanto, este estudo revelou a possibilidade de se utilizar alguns desses genes diferencialmente expressos como marcadores genéticos em bovinos Nelore para seleção precoce quanto à maciez e marmoreio da carne.More than 80% of Brazilian beef comes from zebu animals. The Zebu meat show reduced marbling and is considered harder when compared to Taurine meat. The improvement of the organoleptic traits like marbling and meat tenderness is important from an economic point of view, because these attributes are highly appreciated by the consumer. The meat tenderness can be measured by sensory analysis, myofibril fragmentation index or by shear force. This method use an apparatus which measure the force required to shear a cross section of meat. The higher the strength dispensed, lower is the tenderness showed by the cut of meat. Another trait related to meat quality is marbling, which can be analyzed by Quality Grade visual graduation scale. However, these methods can only be performed after the animal was killed. The transcriptome analysis techniques, as RNA-Seq, are able to identify genes whose expression are related to quantitative traits control and can be used as alternative to help the improvement of these traits. Thus, the aim of this study was to identify differentially expressed genes using RNA-Seq, in Nelore cattle muscular tissue, to contribute to the knowledge of the genetic factors that are related to meat quality. We sequenced the mRNA of 40 samples divergently ranked to meat tenderness (20 with hard meat and 20 with tender meat) and sequenced the mRNA of 40 samples divergently ranked to marbling (20 with high and 20 with low marbling). These samples were chosen based on shear force and marbling content analysis held at 132 and 80 longissimus dorsi muscle samples respectively, collected from each left half carcass. The analysis of the results obtained by RNA-Seq technique revealed differentially expressed genes related to meat tenderness and marbling in Nelore cattle. Regarding the meat tenderness, these genes are related to collagen metabolism, actin and myosin, the calcium transport, among others. Moreover, the marbling analysis results, revealed differentially expressed genes related to oxytocin, transport of oxygen, growth and lipids and proteins synthesis. Therefore, this study showed the possibility of using some of these differentially expressed genes as genetic markers in Nellore cattle for early selection to meat tenderness and marbling.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Differences in global gene expression in muscle tissue of Nellore cattle with divergent meat tenderness

Background: Meat tenderness is the consumer's most preferred sensory attribute. This trait is affected by a number of factors, including genotype, age, animal sex, and pre-and post-slaughter management. In view of the high percentage of Zebu genes in the Brazilian cattle population, mainly Nellore cattle, the improvement of meat tenderness is important since the increasing proportion of Zebu genes in the population reduces meat tenderness. However, the measurement of this trait is difficult once it can only be made after animal slaughtering. New technologies such as RNA-Seq have been used to increase our understanding of the genetic processes regulating quantitative traits phenotypes. The objective of this study was to identify differentially expressed genes related to meat tenderness, in Nellore cattle in order to elucidate the genetic factors associated with meat quality. Samples were collected 24 h postmortem and the meat was not aged. Results: We found 40 differentially expressed genes related to meat tenderness, 17 with known functions. Fourteen genes were up-regulated and 3 were down-regulated in the tender meat group. Genes related to ubiquitin metabolism, transport of molecules such as calcium and oxygen, acid-base balance, collagen production, actin, myosin, and fat were identified. The PCP4L1 (Purkinje cell protein 4 like 1) and BoLA-DQB (major histocompatibility complex, class II, DQ beta) genes were validated by qRT-PCR. The results showed relative expression values similar to those obtained by RNA-Seq, with the same direction of expression (i.e., the two techniques revealed higher expression of PCP4L1 in tender meat samples and of BoLA-DQB in tough meat samples). Conclusions: This study revealed the differential expression of genes and functions in Nellore cattle muscle tissue, which may contain potential biomarkers involved in meat tenderness.project "Genomic tools for the genetic improvement of traits of direct economic importance in Nelore cattle"; Sao Paulo Research Foundation - FAPESP [2009/16118-5, 2013/09190-7]Open access journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Genome-wide association study for stayability at different calvings in Nellore beef cattle

Abstract Backgrounding Stayability, which may be defined as the probability of a cow remaining in the herd until a reference age or at a specific number of calvings, is usually measured late in the animal’s life. Thus, if used as selection criteria, it will increase the generation interval and consequently might decrease the annual genetic gain. Measuring stayability at an earlier age could be a reasonable strategy to avoid this problem. In this sense, a better understanding of the genetic architecture of this trait at different ages and/or at different calvings is important. This study was conducted to identify possible regions with major effects on stayability measured considering different numbers of calvings in Nellore cattle as well as pathways that can be involved in its expression throughout the female’s productive life. Results The top 10 most important SNP windows explained, on average, 17.60% of the genetic additive variance for stayability, varying between 13.70% (at the eighth calving) and 21% (at the fifth calving). These SNP windows were located on 17 chromosomes (1, 2, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 18, 19, 20, 27, and 28), and they harbored a total of 176 annotated genes. The functional analyses of these genes, in general, indicate that the expression of stayability from the second to the sixth calving is mainly affected by genetic factors related to reproductive performance, and nervous and immune systems. At the seventh and eighth calvings, genes and pathways related to animal health, such as density bone and cancer, might be more relevant. Conclusion Our results indicate that part of the target genomic regions in selecting for stayability at earlier ages (from the 2th to the 6th calving) would be different than selecting for this trait at later ages (7th and 8th calvings). While the expression of stayability at earlier ages appeared to be more influenced by genetic factors linked to reproductive performance together with an overall health/immunity, at later ages genetic factors related to an overall animal health gain relevance. These results support that selecting for stayability at earlier ages (perhaps at the second calving) could be applied, having practical implications in breeding programs since it could drastically reduce the generation interval, accelerating the genetic progress

Whole-genome sequencing provides new insights into genetic mechanisms of tropical adaptation in Nellore (Bos primigenius indicus)

Abstract Most of the knowledge about genetic variants at the sequence level in cattle is for Bos primigenius taurus populations. Here, we presented a complete genomic characterization of 52 Nellore (Bos primigenius indicus) bulls, revealing specific zebu DNA variants with putative impact in tropical adaptation and productive traits. Single nucleotide polymorphisms (SNPs) and insertion/deletion (INDELs) mutations were identified using the newest bovine reference genome ARS_UCD1.2, and variant functional consequences were predicted using the Ensembl VEP software. A total of 35,753,707 SNPs and 4,492,636 INDELs were detected and annotated to their functional effects. We identified 400 genes that comprised both, a SNP and an INDEL, of high functional impact on proteins (i.e. variants that cause protein truncation, loss of function or triggering nonsense-mediated decay). Among these, we highlight the following genes: BoLA, associated with cattle immune response to infections and reproduction aspects; HSPA8, DNAJC27, and DNAJC28, involved with thermoregulatory protective mechanisms in mammals; and many olfactory signaling pathway related genes that are important genetic factors in the evolution of mammalian species. All these functional aspects are directly related to cattle adaptability to tropical environments

Expression of genes related to mitochondrial function in Nellore cattle divergently ranked on residual feed intake

Several measures have been proposed to investigate and improve feed efficiency in cattle. One of the most commonly used measure of feed efficiency is residual feed intake (RFI), which is estimated as the difference between actual feed intake and expected feed intake based on the animal's average live weight. This measure permits to identify and select the most efficient animals without selecting for higher mature weight. Mitochondrial function has been indicated as a major factor that influences RFI. The analysis of genes involved in mitochondrial function is therefore an alternative to identify molecular markers associated with higher feed efficiency. This study analyzed the expression of PGC1 alpha, TFAM, UCP2 and UCP3 genes by quantitative real-time PCR in liver and muscle tissues of two groups of Nellore cattle divergently ranked on RFI values in order to evaluate the relationship of these genes with RFI. In liver tissue, higher expression of TFAM and UCP2 genes was observed in the negative RFI group. Expression of PGC1 alpha gene did not differ significantly between the two groups, whereas UCP3 gene was not expressed in liver tissue. In muscle tissue, higher expression of TFAM gene was observed in the positive RFI group. Expression of PGC1 alpha, UCP2 and UCP3 genes did not differ significantly between the two groups. These results suggest the use of TFAM and UCP2 as possible candidate gene markers in breeding programs designed to increase the feed efficiency of Nellore cattle.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP