RESUMO
During asymmetric cell division, cell polarity is coordinated with the cell cycle to allow proper inheritance of cell fate determinants and the generation of cellular diversity. In the Caenorhabditis elegans zygote, polarity is governed by evolutionarily conserved Partitioning-defective (PAR) proteins that segregate to opposing cortical domains to specify asymmetric cell fates. Timely establishment of PAR domains requires a cell cycle kinase, Aurora A (AIR-1 in C. elegans). Aurora A depletion by RNAi causes a spectrum of phenotypes including reversed polarity, excess posterior domains and no posterior domain. How depletion of a single kinase can cause seemingly opposite phenotypes remains obscure. Using an auxin-inducible degradation system and drug treatments, we found that AIR-1 regulates polarity differently at different times of the cell cycle. During meiosis I, AIR-1 acts to prevent later formation of bipolar domains, whereas in meiosis II, AIR-1 is necessary to recruit PAR-2 onto the membrane. Together, these data clarify the origin of multiple polarization phenotypes in RNAi experiments and reveal multiple roles of AIR-1 in coordinating PAR protein localization with cell cycle progression.
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Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Zigoto/metabolismo , Ciclo Celular/genética , Polaridade Celular/genética , Embrião não Mamífero/metabolismoRESUMO
Rieske dioxygenases have a long history of being utilized as green chemical tools in the organic synthesis of high-value compounds, due to their capacity to perform the cis-dihydroxylation of a wide variety of aromatic substrates. The practical utility of these enzymes has been hampered however by steric and electronic constraints on their substrate scopes, resulting in limited reactivity with certain substrate classes. Herein, we report the engineering of a widely used member of the Rieske dioxygenase class of enzymes, toluene dioxygenase (TDO), to produce improved variants with greatly increased activity for the cis-dihydroxylation of benzoates. Through rational mutagenesis and screening, TDO variants with substantially improved activity over the wild-type enzyme were identified. Homology modeling, docking studies, molecular dynamics simulations, and substrate tunnel analysis were applied in an effort to elucidate how the identified mutations resulted in improved activity for this polar substrate class. These analyses revealed modification of the substrate tunnel as the likely cause of the improved activity observed with the best-performing enzyme variants.
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Oxigenases , Oxigenases/genética , Oxigenases/metabolismo , Oxigenases/química , Engenharia de Proteínas/métodos , Hidroxilação , Especificidade por Substrato , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Complexo III da Cadeia de Transporte de Elétrons/genética , Complexo III da Cadeia de Transporte de Elétrons/químicaRESUMO
Carotid Blowout Syndrome (CBS) is a critical and often fatal complication associated with head and neck malignancies. CBS is characterized by three stages: threatened, impending, and acute rupture/hemorrhage. The condition is notably linked with a history of radiotherapy for head and neck cancers, with an incidence of approximately 3-4% among those who have received such treatment. Historically, surgical management of CBS has involved open surgical ligation. However, advancements in endovascular techniques, including endovascular destructive procedures (e.g., coil embolization) and reconstructive procedures (e.g., carotid artery stenting), have become increasingly prevalent. This report presents two cases where a self-expandable PTFE-coated nitinol stent with a heparin coating (Viabahn; Gore and Associates) was utilized in the treatment of CBS.
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OBJECTIVE: To report gross anatomical gastrointestinal measurements and compare enterotomy leak pressures between fresh and cooled feline cadavers. STUDY DESIGN: Ex vivo, randomized study. ANIMALS: Fresh feline cadavers (n = 20). METHODS: Jejunal segments (8 cm) were harvested on the same day as euthanasia. From each cadaver, one segment was randomly assigned to control (C), fresh enterotomy (FE), and cooled enterotomy (CE) groups. Enterotomy construction and leak testing were performed within 12 h of euthanasia for the C and FE groups and after 17-29 h of cooling for the CE group. Initial leak pressure (ILP) and maximum intraluminal pressure (MIP) were compared. Gastrointestinal wall thickness and intraluminal diameter were measured on harvested applicable gastrointestinal divisions at up to three time points: day 1 fresh, day 2 cooled, and day 3 cooled. RESULTS: The mean (± SD) ILPs for the C, FE, and CE constructs were 600 (± 0.0), 200.3 (± 114.7), and 131.3 (± 92.6) mmHg, respectively. The C ILP was higher (p < .001) than the FE and CE ILP. The ILP (p = .11) and the MIP (p = .21) did not differ between the FE and CE constructs. Wall thickness (measured in mm) did not differ between duodenum day 1 fresh and day 2 cooled groups (p = .18) or between any jejunum day groups (p = .86). The intraluminal diameters (mean ± SD) for the duodenum, jejunum, and ileum were 5.7 (± 0.7), 5.8 (± 0.8), and 7.2 (± 2.2) mm, respectively. CONCLUSION: No difference was appreciated between FE and CE ILP and MIP. Wall thickness measurements did not differ between days for duodenum or jejunum. CLINICAL RELEVANCE: Cadaveric feline intestine cooled for up to 29 h may be used for determining intestinal leak pressures.
Assuntos
Cadáver , Pressão , Animais , Gatos/cirurgia , Temperatura Baixa , Jejuno/cirurgia , Jejuno/anatomia & histologia , Intestinos/cirurgia , Intestinos/anatomia & histologiaRESUMO
Many of the world's agriculturally important plant and animal populations consist of hybrids of subspecies. Cattle in tropical and sub-tropical regions for example, originate from two subspecies, Bos taurus indicus (Bos indicus) and Bos taurus taurus (Bos taurus). Methods to derive the underlying genetic architecture for these two subspecies are essential to develop accurate genomic predictions in these hybrid populations. We propose a novel method to achieve this. First, we use haplotypes to assign SNP alleles to ancestral subspecies of origin in a multi-breed and multi-subspecies population. Then we use a BayesR framework to allow SNP alleles originating from the different subspecies differing effects. Applying this method in a composite population of B. indicus and B. taurus hybrids, our results show that there are underlying genomic differences between the two subspecies, and these effects are not identified in multi-breed genomic evaluations that do not account for subspecies of origin effects. The method slightly improved the accuracy of genomic prediction. More significantly, by allocating SNP alleles to ancestral subspecies of origin, we were able to identify four SNP with high posterior probabilities of inclusion that have not been previously associated with cattle fertility and were close to genes associated with fertility in other species. These results show that haplotypes can be used to trace subspecies of origin through the genome of this hybrid population and, in conjunction with our novel Bayesian analysis, subspecies SNP allele allocation can be used to increase the accuracy of QTL association mapping in genetically diverse populations.
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Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Animais , Bovinos/genética , Teorema de Bayes , Mapeamento Cromossômico , HaplótiposRESUMO
OBJECTIVE: To compare effects of transcranial direct current stimulation (tDCS) and transcranial random noise stimulation with a direct-current offset (tRNS + DC-offset) on working memory (WM) performance and task-related electroencephalography (EEG) in individuals with Major Depressive Disorder (MDD). METHODS: Using a sham-controlled, parallel-groups design, 49 participants with MDD received either anodal tDCS (N = 16), high-frequency tRNS + DC-offset (N = 16), or sham stimulation (N = 17) to the left dorsolateral prefrontal cortex (DLPFC) for 20-minutes. The Sternberg WM task was completed with concurrent EEG recording before and at 5- and 25-minutes post-stimulation. Event-related synchronisation/desynchronisation (ERS/ERD) was calculated for theta, upper alpha, and gamma oscillations during WM encoding and maintenance. RESULTS: tDCS significantly increased parieto-occipital upper alpha ERS/ERD during WM maintenance, observed on EEG recorded 5- and 25-minutes post-stimulation. tRNS + DC-offset did not significantly alter WM-related oscillatory activity when compared to sham stimulation. Neither tDCS nor tRNS + DC-offset improved WM performance to a significantly greater degree than sham stimulation. CONCLUSIONS: Although tDCS induced persistent effects on WM-related oscillatory activity, neither tDCS nor tRNS + DC-offset enhanced WM performance in MDD. SIGNIFICANCE: This reflects the first sham-controlled comparison of tDCS and tRNS + DC-offset in MDD. These findings directly contrast with evidence of tRNS-induced enhancements in WM in healthy individuals.
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Transtorno Depressivo Maior , Estimulação Transcraniana por Corrente Contínua , Humanos , Transtorno Depressivo Maior/terapia , Eletroencefalografia , Memória de Curto Prazo/fisiologia , Córtex Pré-Frontal/fisiologiaRESUMO
BACKGROUND: Cytoplasmic and nuclear maturation of oocytes, as well as interaction with the surrounding cumulus cells, are important features relevant to the acquisition of developmental competence. METHODS: Here, we utilized Brilliant cresyl blue (BCB) to distinguish cattle oocytes with low activity of the enzyme Glucose-6-Phosphate Dehydrogenase, and thus separated fully grown (BCB positive) oocytes from those in the growing phase (BCB negative). We then analyzed the developmental potential of these oocytes, mitochondrial DNA (mtDNA) copy number in single oocytes, and investigated the transcriptome of single oocytes and their surrounding cumulus cells of BCB positive versus BCB negative oocytes. RESULTS: The BCB positive oocytes were twice as likely to produce a blastocyst in vitro compared to BCB- oocytes (P < 0.01). We determined that BCB negative oocytes have 1.3-fold more mtDNA copies than BCB positive oocytes (P = 0.004). There was no differential transcript abundance of genes expressed in oocytes, however, 172 genes were identified in cumulus cells with differential transcript abundance (FDR < 0.05) based on the BCB staining of their oocyte. Co-expression analysis between oocytes and their surrounding cumulus cells revealed a subset of genes whose co-expression in BCB positive oocytes (n = 75) and their surrounding cumulus cells (n = 108) compose a unique profile of the cumulus-oocyte complex. CONCLUSIONS: If oocytes transition from BCB negative to BCB positive, there is a greater likelihood of producing a blastocyst, and a reduction of mtDNA copies, but there is no systematic variation of transcript abundance. Cumulus cells present changes in transcript abundance, which reflects in a dynamic co-expression between the oocyte and cumulus cells.
Assuntos
Células do Cúmulo , Oócitos , Animais , Blastocisto , Bovinos , Citoplasma , DNA Mitocondrial/genética , FemininoRESUMO
From the time oocytes leave quiescence, there are constant microenvironmental influences contributing to development, thus acquiring developmental competence is not a simple, linear phenomenon. During folliculogenesis, oocytes experience many morphological and cytological changes that contribute toward the acquisition of developmental competence, a process defined by an oocyte's ability to progress through folliculogenesis, be fertilized, undergo cleavage, and develop into an embryo. Many factors, such as ovarian follicle size, cow age, and the morphology of the cumulus-oocyte complex, have been extensively investigated to understand this process. In parallel to aiding in the understanding of oocyte biology, these features have been used to characterize an oocyte's ability to achieve competence. In addition, oocytes undergo intense gene transcription and protein translation to accumulate the maternal stores. When the oocyte is fully grown, most genes are transcriptionally inactive, and the chromatin is densely compacted. More recently, RNA profiling has been used to further define the transcriptional parameters that are associated with oocyte development. Here, focusing on cattle, we provide an overview of the experimental models commonly used to understand the underlying biology related to oocyte developmental competence. We compiled public data and showed that cattle oocytes can express over 15 000 protein-coding genes, suggesting a complex transcriptome landscape. Surprisingly, less than 2% of the expressed genes have been linked to developmental competence. The identification of the gene products that contribute to oocyte development, and understanding their biological function, are a vital component of our quest toward defining oocyte developmental competence at the molecular level.
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Oócitos/metabolismo , Oogênese/fisiologia , Folículo Ovariano/metabolismo , RNA/metabolismo , Animais , Bovinos , Células do Cúmulo/metabolismo , FemininoRESUMO
BACKGROUND: In tropically-adapted beef heifers, application of genomic prediction for age at puberty has been limited due to low prediction accuracies. Our aim was to investigate novel methods of pre-selecting whole-genome sequence (WGS) variants and alternative analysis methodologies; including genomic best linear unbiased prediction (GBLUP) with multiple genomic relationship matrices (MGRM) and Bayesian (BayesR) analyses, to determine if prediction accuracy for age at puberty can be improved. METHODS: Genotypes and phenotypes were obtained from two research herds. In total, 868 Brahman and 960 Tropical Composite heifers were recorded in the first population and 3695 Brahman, Santa Gertrudis and Droughtmaster heifers were recorded in the second population. Genotypes were imputed to 23 million whole-genome sequence variants. Eight strategies were used to pre-select variants from genome-wide association study (GWAS) results using conditional or joint (COJO) analyses. Pre-selected variants were included in three models, GBLUP with a single genomic relationship matrix (SGRM), GBLUP MGRM and BayesR. Five-way cross-validation was used to test the effect of marker panel density (6 K, 50 K and 800 K), analysis model, and inclusion of pre-selected WGS variants on prediction accuracy. RESULTS: In all tested scenarios, prediction accuracies for age at puberty were highest in BayesR analyses. The addition of pre-selected WGS variants had little effect on the accuracy of prediction when BayesR was used. The inclusion of WGS variants that were pre-selected using a meta-analysis with COJO analyses by chromosome, fitted in a MGRM model, had the highest prediction accuracies in the GBLUP analyses, regardless of marker density. When the low-density (6 K) panel was used, the prediction accuracy of GBLUP was equal (0.42) to that with the high-density panel when only six additional sequence variants (identified using meta-analysis COJO by chromosome) were included. CONCLUSIONS: While BayesR consistently outperforms other methods in terms of prediction accuracies, reasonable improvements in accuracy can be achieved when using GBLUP and low-density panels with the inclusion of a relatively small number of highly relevant WGS variants.
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Bovinos/genética , Genômica/métodos , Maturidade Sexual/genética , Animais , Teorema de Bayes , Cruzamento , Feminino , Genoma/genética , Estudo de Associação Genômica Ampla , Genótipo , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Maturidade Sexual/fisiologia , Sequenciamento Completo do Genoma/métodosRESUMO
During development, the embryo transitions from a metabolism favoring glycolysis to a metabolism favoring mitochondrial respiration. How metabolic shifts regulate developmental processes, or how developmental processes regulate metabolic shifts, remains unclear. To test the requirement of mitochondrial function in developing endoderm-derived tissues, we genetically inactivated the mitochondrial transcription factor, Tfam, using the Shh-Cre driver. Tfam mutants did not survive postnatally, exhibiting defects in lung development. In the developing intestine, TFAM-loss was tolerated until late fetal development, during which the process of villus elongation was compromised. While progenitor cell populations appeared unperturbed, markers of enterocyte maturation were diminished and villi were blunted. Loss of TFAM was also tested in the adult intestinal epithelium, where enterocyte maturation was similarly dependent upon the mitochondrial transcription factor. While progenitor cells in the transit amplifying zone of the adult intestine remained proliferative, intestinal stem cell renewal was dependent upon TFAM, as indicated by molecular profiling and intestinal organoid formation assays. Taken together, these studies point to critical roles for the mitochondrial regulator TFAM for multiple aspects of intestinal development and maturation, and highlight the importance of mitochondrial regulators in tissue development and homeostasis.
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Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/fisiologia , Proteínas de Grupo de Alta Mobilidade/metabolismo , Proteínas de Grupo de Alta Mobilidade/fisiologia , Mucosa Intestinal/metabolismo , Animais , Técnicas de Cultura de Células/métodos , Autorrenovação Celular/fisiologia , Proteínas de Ligação a DNA/genética , Feto/metabolismo , Regulação da Expressão Gênica/genética , Glicólise/genética , Glicólise/fisiologia , Proteínas de Grupo de Alta Mobilidade/genética , Mucosa Intestinal/embriologia , Mucosa Intestinal/crescimento & desenvolvimento , Camundongos , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Organogênese/genética , Organogênese/fisiologia , Organoides/metabolismo , Células-Tronco/metabolismo , Fatores de Transcrição/metabolismoRESUMO
The prevalence of Haldane's rule suggests that sex chromosomes commonly have a key role in reproductive barriers and speciation. However, the majority of research on Haldane's rule has been conducted in species with conventional sex determination systems (XY and ZW) and exceptions to the rule have been understudied. Here we test the role of X-linked incompatibilities in a rare exception to Haldane's rule for female sterility in field cricket sister species (Teleogryllus oceanicus and T. commodus). Both have an XO sex determination system. Using three generations of crosses, we introgressed X chromosomes from each species onto different, mixed genomic backgrounds to test predictions about the fertility and viability of each cross type. We predicted that females with two different species X chromosomes would suffer reduced fertility and viability compared with females with two parental X chromosomes. However, we found no strong support for such X-linked incompatibilities. Our results preclude X-X incompatibilities and instead support an interchromosomal epistatic basis to hybrid female sterility. We discuss the broader implications of these findings, principally whether deviations from Haldane's rule might be more prevalent in species without dimorphic sex chromosomes.
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Gryllidae/genética , Hibridização Genética , Infertilidade/genética , Cromossomo X/genética , Animais , Austrália , Cruzamentos Genéticos , Feminino , Fertilidade , Gryllidae/fisiologia , Modelos Lineares , Modelos GenéticosRESUMO
A major advance in modern evolutionary biology is the ability to start linking phenotypic evolution in the wild with genomic changes that underlie that evolution. We capitalized on a rapidly evolving Hawaiian population of crickets (Teleogryllus oceanicus) to test hypotheses about the genomic consequences of a recent Mendelian mutation of large effect which disrupts the development of sound-producing structures on male forewings. The resulting silent phenotype, flatwing, persists because of natural selection imposed by an acoustically orienting parasitoid, but it interferes with mate attraction. We examined gene expression differences in developing wing buds of wild-type and flatwing male crickets using RNA-seq and quantitative proteomics. Most differentially expressed (DE) transcripts were down-regulated in flatwing males (625 up vs. 1716 down), whereas up- and down-regulated proteins were equally represented (30 up and 34 down). Differences between morphs were clearly not restricted to a single pathway, and we recovered annotations associated with a broad array of functions that would not be predicted a priori. Using a candidate gene detection test based on homology, we identified 30% of putative Drosophila wing development genes in the cricket transcriptome, but only 10% were DE. In addition to wing-related annotations, endocrine pathways and several biological processes such as reproduction, immunity and locomotion were DE in the mutant crickets at both biological levels. Our results illuminate the breadth of genetic pathways that are potentially affected in the early stages of adaptation.
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Variação Genética , Gryllidae/genética , Fenótipo , RNA Mensageiro , Asas de Animais/crescimento & desenvolvimento , Animais , Havaí , Locomoção , Masculino , ProteômicaRESUMO
Social influences on mate choice are predicted to influence evolutionary divergence of closely related taxa, because of the key role mate choice plays in reproductive isolation. However, it is unclear whether females choosing between heterospecific and conspecific male signals use previously experienced social information in the same manner or to the same extent that they do when discriminating among conspecific mates only. We tested this using two field cricket sister species (Teleogryllus oceanicus and Teleogryllus commodus), in which considerable information is known about the role of male calling song in premating isolation, in addition to the influence of acoustic experience on the development of reproductive traits. We manipulated the acoustic experience of replicate populations of both species and found, unexpectedly, that experience of male calling song during rearing did not change how accurate females were in choosing a conspecific over a heterospecific male song during playback trials. However, females with acoustic experience were considerably less responsive to male song compared with naïve females. Our results suggest that variation in the acoustic environment affects mate choice in both species, but that it may have a limited impact on premating isolation. The fact that social flexibility during interspecific mate discrimination does not appear to operate identically to that which occurs during conspecific mate discrimination highlights the importance of considering the context in which animals exercise socially flexible mating behaviours. We suggest an explanation for why social flexibility might be context dependent and discuss the consequences of such flexibility for the evolution of reproductive isolation.
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Gryllidae , Isolamento Reprodutivo , Meio Social , Vocalização Animal , Animais , Feminino , MasculinoRESUMO
Stem cells often rely on signals from a niche, which in many tissues adopts a precise morphology. What remains elusive is how niches are formed and how morphology impacts function. To address this, we leverage the Drosophila gonadal niche, which affords genetic tractability and live-imaging. We have previously shown mechanisms dictating niche cell migration to their appropriate position within the gonad and the resultant consequences on niche function. Here, we show that once positioned, niche cells robustly polarize filamentous actin (F-actin) and non-muscle myosin II (MyoII) toward neighboring germ cells. Actomyosin tension along the niche periphery generates a highly reproducible smoothened contour. Without contractility, niches are misshapen and exhibit defects in their ability to regulate germline stem cell behavior. We additionally show that germ cells aid in polarizing MyoII within niche cells and that extrinsic input is required for niche morphogenesis and function. Our work reveals a feedback mechanism where stem cells shape the niche that guides their behavior.
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Actomiosina , Drosophila melanogaster , Nicho de Células-Tronco , Células-Tronco , Animais , Actomiosina/metabolismo , Nicho de Células-Tronco/fisiologia , Células-Tronco/fisiologia , Células-Tronco/metabolismo , Células-Tronco/citologia , Drosophila melanogaster/fisiologia , Miosina Tipo II/metabolismo , Células Germinativas/fisiologia , Células Germinativas/metabolismo , Masculino , Movimento Celular , Drosophila/fisiologia , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genéticaRESUMO
Stem cells often rely on signals from a niche, which in many tissues adopts a precise morphology. What remains elusive is how niches are formed, and how morphology impacts function. To address this, we leverage the Drosophila gonadal niche, which affords genetic tractability and live-imaging. We have previously shown mechanisms dictating niche cell migration to their appropriate position within the gonad, and the resultant consequences on niche function. Here, we show that once positioned, niche cells robustly polarize filamentous actin (F-actin) and Non-muscle Myosin II (MyoII) towards neighboring germ cells. Actomyosin tension along the niche periphery generates a highly reproducible smoothened contour. Without contractility, niches are misshapen and exhibit defects in their ability to regulate germline stem cell behavior. We additionally show that germ cells aid in polarizing MyoII within niche cells, and that extrinsic input is required for niche morphogenesis and function. Our work reveals a feedback mechanism where stem cells shape the niche that guides their behavior.
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BACKGROUND: Breastfeeding shares a complex, occasionally contradictory relationship with maternal mental health. Both positive and negative mood impacts have been noted in relation to breastfeeding initiation as well as cessation. Though popular magazines and online forums discuss the onset of psychiatric symptoms following weaning, there is limited medical literature detailing this relationship. METHODS: We describe the case of a patient who developed psychiatric symptoms shortly after weaning, including acute-onset insomnia and worsening anxiety. A literature review of psychiatric symptom development following breastfeeding cessation was conducted using the search engines PubMed, PsycINFO (EBSCOhost), and Embase. Search terms included controlled vocabulary, keywords (within title and abstract fields), synonyms, and related concepts for: postpartum period, postpartum depression, postpartum anxiety, breastfeeding cessation, breastfeeding weaning, lactation, dysphoric milk ejection reflex, and insomnia. Relevant case reports were reviewed and compared to this case. Information including the patient's age, psychiatric symptoms, past psychiatric history, medical work-up, treatment, and outcome was extracted from each article. RESULTS: Nine patients who developed psychiatric symptoms following breastfeeding cessation were identified in six case reports. Three patients experienced recurrent symptoms in multiple pregnancies. This led to documentation of 13 discrete post-weaning syndromes. All cases involved either first-time parents, those new to breastfeeding, or those experiencing symptoms during multiple weaning periods. Table 1 synthesizes data from article review. As with our case, 11 clinical cases describe sleep changes (primarily insomnia) and 4 discuss anxiety symptoms. Treatment varied based upon symptoms experienced, with no consistently effective treatments identified across cases. CONCLUSIONS: This case of unspecified insomnia and anxiety disorders following abrupt weaning adds to the limited literature in the field and suggests that physiologic and psychologic factors associated with breastfeeding cessation may play a role in the development or worsening of postpartum mood disorders. Intensive psychiatric treatment resulted in resolution of the patient's symptoms. The relationship between weaning and psychiatric disorders is evident in the lay press but is underrepresented in medical literature. Additional research is needed to better understand this relationship so that physicians can counsel, diagnose, and treat patients more effectively.
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Supplemental methionine (Met) is widely used within the swine industry; however, data are limited regarding the effect of Met sources on carcass cutability and meat quality. The objective was to determine the effects of L-Met (LM, 99%), DL-Met (DLM, 99%), or calcium salt of DL-Met hydroxyl analog (MHA, 84%) in finishing pig diets on carcass characteristics and meat quality. At 9 weeks of age, pigs (Nâ =â 240) were allocated to 60 single-sex pens for a four-phase finishing trial that lasted 104 d. Pigs were fed a common grower diet until day 56 where pens were randomly allotted to one of the three experimental diets. For the remaining 7 wk of the finisher phase, pigs (BWâ =â 79.9â ±â 0.80 kg) were fed diets containing LM, DLM, or MHA, with the supplemental Met source providing 25% of standardized ileal digestible (SID) Metâ +â cysteine (Cys) requirement based on 65% bioefficacy for MHA in comparison with LM or DLM. One pig per pen was slaughtered at the study conclusion (on day 104), and the left sides of carcasses were fabricated into subprimal cuts to determine carcass-cutting yields. Loin quality including proximate composition and shear force were measured. Hot carcass weight was not different (Pâ =â 0.34) between treatments (LM 104.5 kg; DLM 103.0 kg; MHA 101.5 kg), moreover, loin eye area was not different (Pâ =â 0.98) between treatments (LM 52.65 cm²; DLM 52.49 cm²; MHA 52.81 cm²). Boneless carcass-cutting yield was not different (Pâ =â 0.56) between treatments (LM 54.97 kg; DLM 54.82 kg; MHA 54.52 kg). Loin pH was not different (Pâ =â 0.24) between treatments (LM 5.45; DLM 5.48; MHA 5.45). However, drip loss tended to be reduced (Pâ =â 0.11) by the DLM treatment (5.58%) compared with LM (7.03%) and MHA (6.68%) treatments. Shear force was not different (Pâ =â 0.85) between treatments (LM 3.03 kg; DLM 3.06 kg; MHA 3.10 kg). However, cook loss tended to be reduced (Pâ =â 0.06) by the DLM treatment (16.20%) compared with LM (18.18%) and MHA (18.50%) treatments. These data suggest that only minimal differences in carcass cutability and meat quality can be attributed to Met source in finishing pig diets when using 65% bioefficacy for MHA relative to L-Met or DL-Met.
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The objective of this research was to determine the effects of mid-gestational maternal inflammation on performance, carcass characteristics, and meat quality of offspring. Pregnant gilts were administered either lipopolysaccharide (LPS; nâ =â 7) or saline (CON, nâ =â 7) from days 70 to 84 of gestation. Gilts assigned to the LPS treatment were administered an intravenous injection of reconstituted LPS every other day with a beginning dose of 10 µg LPS/kg body weight and subsequent doses increasing by 12%, while CON gilts received intravenous injections of comparable volumes of saline. Gilts farrowed naturally, and at day 66 of age, a total of 59 pigs, both barrows and gilts began a 3-phase feeding regimen designed to meet or exceed nutrient requirements for growing-finishing pigs. Pigs were weighed on days 0, 35, 70, and 105 of the finishing trial to determine average daily gain, average daily feed intake, and gain-to-feed ratio (G:F). On day 106, pigs were slaughtered under the supervision of the U.S. Department of Agriculture Food Safety Inspection Service. Ending live weight, hot carcass weight, and dressing percentage were determined. The left side of carcasses was weighed and fabricated to determine carcass cutting yields. The semitendinosus was collected for histological samples. Fresh belly characteristics and loin quality were measured. Two chops were collected for Warner-Bratzler shear force and proximate analysis. No differences (Pâ ≥â 0.13) between LPS and CON pigs were observed for growth performance in phases 1, 2, 3, or overall (days 0 to 105) performance with the exception of overall G:F reduced in CON pigs compared with LPS pigs (Pâ =â 0.03). There was a tendency for carcass yield to be reduced (Pâ =â 0.06; 0.82% units) in LPS pigs compared with CON pigs. Additionally, longissimus muscle area tended to be reduced (Pâ =â 0.10) 2.27 cm2 in LPS compared with CON pigs. Loin chop quality traits including instrumental color, subjective color, marbling, firmness, pH, and drip loss were not different (Pâ ≥â 0.09) between LPS and CON pigs. Fresh belly characteristics were not different (Pâ ≥â 0.22) between LPS and CON pigs. There were no differences in primal and subprimal weights, except that LPS pigs tended to have a reduction (Pâ ≥â 0.07) in tenderloin and Canadian back weights compared with CON pigs. Furthermore, LPS pigs had no differences (Pâ ≥â 0.25) in muscle fiber composition or size; however, LPS pigs tended (Pâ =â 0.10) to have a 13% reduction in estimated muscle fibers number compared with CON pigs. In summary, mid-gestational inflammation did not result in reduced meat quality, growth performance, or carcass yields of offspring.
Gestation is a crucial time for communicating the outside environment to the fetus. Any influence on the fetus during gestation may have lifelong effects on the offspring. Most muscle fiber formation occurs in the beginning of the third trimester of gestation. Therefore, maternal inflammation during this period may be detrimental to fetal muscle development, which can ultimately stunt growth potential and influence carcass characteristics and meat quality. A majority of previous research that investigates maternal inflammation as a result of innate immune activation focuses on neuropsychiatric disorders in the offspring, offering little relevance to animal agriculture. The influence of maternal infection on long-term growth performance, carcass characteristics, and meat quality has received little attention. Therefore, the objective of this study was to elucidate the impact of maternal inflammation on offspring growth, efficiency, carcass characteristics, and pork quality. The gestational challenge resulted in pigs that tended to have fewer total muscle fibers. However, gestational inflammation did not have an impact on overall growth performance, carcass characteristics, or pork quality of the offspring.
Assuntos
Inflamação , Lipopolissacarídeos , Carne , Animais , Feminino , Gravidez , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/administração & dosagem , Suínos/crescimento & desenvolvimento , Suínos/fisiologia , Inflamação/veterinária , Inflamação/induzido quimicamente , Carne/análise , Carne/normas , Masculino , Composição Corporal/efeitos dos fármacos , Doenças dos SuínosRESUMO
Most genetic variants associated with fertility in mammals fall in non-coding regions of the genome and it is unclear how these variants affect fertility. Here we use genome-wide association summary statistics for Heifer puberty (pubertal or not at 600 days) from 27,707 Bos indicus, Bos taurus and crossbred cattle; multi-trait GWAS signals from 2119 indicine cattle for four fertility traits, including days to calving, age at first calving, pregnancy status, and foetus age in weeks (assessed by rectal palpation of the foetus); and expression quantitative trait locus for whole blood from 489 indicine cattle, to identify 87 putatively functional genes affecting cattle fertility. Our analysis reveals a significant overlap between the set of cattle and previously reported human fertility-related genes, impling the existence of a shared pool of genes that regulate fertility in mammals. These findings are crucial for developing approaches to improve fertility in cattle and potentially other mammals.