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Conventional avian genome editing is mediated by isolation, culture, and genome editing of primordial germ cells (PGCs); screening and propagating the genome-edited PGCs; and transplantation of the PGCs into recipient embryos. The PGC-mediated procedures, however, are technically difficult, and therefore, the conventional method has previously been utilized only in chickens. Here, we generated germline mosaic founder chicken and duck lines without the PGC-mediated procedures by injecting an adenovirus containing the CRISPR-Cas9 system into avian blastoderms. Genome-edited chicken and duck offspring produced from the founders carried different insertion or deletion mutations without mutations in the potential off-target sites. Our data demonstrate successful applications of the adenovirus-mediated method for production of genome-edited chicken and duck lines.
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Galinhas , Edição de Genes , Animais , Edição de Genes/métodos , Galinhas/genética , Patos/genética , Sistemas CRISPR-Cas , Adenoviridae/genética , Células GerminativasRESUMO
OBJECTIVE: This study explores subjective and objective driving style similarity to identify how similarity can be used to develop driver-compatible vehicle automation. BACKGROUND: Similarity in the ways that interaction partners perform tasks can be measured subjectively, through questionnaires, or objectively by characterizing each agent's actions. Although subjective measures have advantages in prediction, objective measures are more useful when operationalizing interventions based on these measures. Showing how objective and subjective similarity are related is therefore prudent for aligning future machine performance with human preferences. METHODS: A driving simulator study was conducted with stop-and-go scenarios. Participants experienced conservative, moderate, and aggressive automated driving styles and rated the similarity between their own driving style and that of the automation. Objective similarity between the manual and automated driving speed profiles was calculated using three distance measures: dynamic time warping, Euclidean distance, and time alignment measure. Linear mixed effects models were used to examine how different components of the stopping profile and the three objective similarity measures predicted subjective similarity. RESULTS: Objective similarity using Euclidean distance best predicted subjective similarity. However, this was only observed for participants' approach to the intersection and not their departure. CONCLUSION: Developing driving styles that drivers perceive to be similar to their own is an important step toward driver-compatible automation. In determining what constitutes similarity, it is important to (a) use measures that reflect the driver's perception of similarity, and (b) understand what elements of the driving style govern subjective similarity.
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Condução de Veículo , Humanos , Inquéritos e Questionários , Automação , Acidentes de TrânsitoRESUMO
Zygotes at the 1-cell stage have been genetically modified by microinjecting the CRISPR/Cas9 components for the generation of targeted gene knockout in mammals. In the avian species, genetic modification of the zygote is difficult because its unique reproductive system limits the accessibility of the zygote at the 1-cell stage. To date, only a few CRISPR/Cas9-mediated gene knockouts have been reported using the chicken as a model among avian species, which requires 3 major processes: isolation and culture of primordial germ cells (PGCs), modification of the genome of PGCs in vitro, and injection of the PGCs into the extraembryonic blood vessel at the early embryonic stages when endogenous PGCs migrate through circulation to the genital ridge. In the present study, the adenoviral CRISPR/Cas9 vector was directly injected into the quail blastoderm in newly laid eggs. The resulting chimeras generated offspring with targeted mutations in the melanophilin (MLPH) gene, which is involved in melanosome transportation and feather pigmentation. MLPH homozygous mutant quail exhibited gray plumage, whereas MLPH heterozygous mutants and wild-type quail exhibited dark brown plumage. In addition, the adenoviral vector was not integrated into the genome of knockout quail, and no mutations were detected in potential off-target regions. This method of generating genome-edited poultry is expected to accelerate avian research and has potential applications for developing superior genetic lines for poultry production in the industry.
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Blastoderma , Proteína 9 Associada à CRISPR , Sistemas CRISPR-Cas , Coturnix/genética , Edição de Genes/métodos , Técnicas de Silenciamento de Genes/métodos , Adenoviridae/genética , Animais , Quimera/genética , Coturnix/embriologia , Plumas/anatomia & histologia , Feminino , MasculinoRESUMO
Developing materials with remote controllability of macroscale ligand presentation can mimic extracellular matrix (ECM) remodeling to regulate cellular adhesion in vivo. Herein, we designed charged mobile nanoligands with superparamagnetic nanomaterials amine-functionalized and conjugated with polyethylene glycol linker and negatively charged RGD ligand. We coupled negatively a charged nanoligand to a positively charged substrate by optimizing electrostatic interactions to allow reversible planar movement. We demonstrate the imaging of both macroscale and in situ nanoscale nanoligand movement by magnetically attracting charged nanoligand to manipulate macroscale ligand density. We show that in situ magnetic control of attracting charged nanoligand facilitates stem cell adhesion, both in vitro and in vivo, with reversible control. Furthermore, we unravel that in situ magnetic attraction of charged nanoligand stimulates mechanosensing-mediated differentiation of stem cells. This remote controllability of ECM-mimicking reversible ligand variations is promising for regulating diverse reparative cellular processes in vivo.
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Adesão Celular , Fenômenos Magnéticos , Oligopeptídeos , Células-Tronco , Diferenciação Celular , Matriz ExtracelularRESUMO
Advances in genome-editing technologies and sequencing of animal genomes enable researchers to generate genome-edited (GE) livestock as valuable animal models that benefit biological researches and biomedical and agricultural industries. As birds are an important species in biology and agriculture, their genome editing has gained significant interest and is mainly performed by using a primordial germ cell (PGC)-mediated method because pronuclear injection is not practical in the avian species. In this method, PGCs can be isolated, cultured, genetically edited in vitro, and injected into a recipient embryo to produce GE offspring. Recently, a couple of GE quail have been generated by using the newly developed adenovirus-mediated method. Without technically required in vitro procedures of the PGC-mediated method, direct injection of adenovirus into the avian blastoderm in the freshly laid eggs resulted in the production of germ-line chimera and GE offspring. As more approaches are available in avian genome editing, avian research in various fields will progress rapidly. In this review, we describe the development of avian genome editing and scientific and industrial applications of GE avian species.
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Biotecnologia/métodos , Galinhas/genética , Edição de Genes/métodos , Genoma , Adenoviridae/genética , Agricultura , Criação de Animais Domésticos/tendências , Animais , Animais Geneticamente Modificados , Sistemas CRISPR-Cas , Células Germinativas/citologia , Modelos Animais , Oócitos/citologia , Ovulação , Aves Domésticas , CodornizRESUMO
Mutation in myostatin (MSTN), a negative regulator of muscle growth in skeletal muscle, resulted in increased muscle mass in mammals and fishes. However, MSTN mutation in avian species has not been reported. The objective of this study was to generate MSTN mutation in quail and investigate the effect of MSTN mutation in avian muscle growth. Recently, a new targeted gene knockout approach for the avian species has been developed using an adenoviral CRISPR/Cas9 system. By injecting the recombinant adenovirus containing CRISPR/Cas9 into the quail blastoderm, potential germline chimeras were generated and offspring with three base-pair deletion in the targeted region of the MSTN gene was identified. This non-frameshift mutation in MSTN resulted in deletion of cysteine 42 in the MSTN propeptide region and homozygous mutant quail showed significantly increased body weight and muscle mass with muscle hyperplasia compared to heterozygous mutant and wild-type quail. In addition, decreased fat pad weight and increased heart weight were observed in MSTN mutant quail in an age- and sex-dependent manner, respectively. Taken together, these data indicate anti-myogenic function of MSTN in the avian species and the importance of cysteine 42 in regulating MSTN function.
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Proteínas Aviárias/genética , Coturnix/genética , Cisteína/genética , Músculo Esquelético/metabolismo , Mutação , Miostatina/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Sistemas CRISPR-Cas , Feminino , Técnicas de Inativação de Genes , Hiperplasia , Masculino , Desenvolvimento Muscular/genética , Músculo Esquelético/patologia , Deleção de Sequência , Homologia de Sequência de AminoácidosRESUMO
Sexual dimorphism is phenotypic differences between males and females in the same species. In general, males in most animals are larger than females at the same age, however, in quail, females have a larger body size with greater muscle mass than males. To understand what characteristics in muscle growth play roles in reversed sexual dimorphism in quail, the weights and the characteristics of the pectoralis major and gastrocnemius muscles (PM and GM, respectively) of male and female quail were compared in the current study. The data showed that 15-wk-old female quail have significantly heavier bodies, and PM and GM weights compared to male quail (1.27-folds, 1.29-folds, and 1.16-folds, respectively). To compare muscle characteristics such as hypertrophy (increased size) and hyperplasia (increased cell number), the PM and GM were stained using hematoxylin and eosin, and then histological characteristics such as total cross-sectional area (CSA), number and size of myofibers, and muscle bundle of the muscles were measured and analyzed. In both PM and GM, there were no differences in total numbers of myofibers and muscle bundles as well as the average numbers of myofibers per bundle between sexes. However, the sizes of myofiber and the bundle were significantly increased in female compared to male (1.33-folds and 1.28-folds in PM, and both 1.23-folds in GM, respectively). The findings of the current study suggest that muscle hypertrophy in female quail, not hyperplasia, can be attributed to the sexual dimorphism in quail size.
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Galinhas , Caracteres Sexuais , Feminino , Masculino , Animais , Tamanho Corporal , Hipertrofia/veterinária , Músculos Peitorais , CodornizRESUMO
As an anti-myogenic factor, the myostatin (MSTN) gene was mainly considered as a genetic marker to improve meat production. Moreover, an additional effect of the MSTN mutation on reducing fat deposition in various farm animals suggested a potential application of the MSTN gene on regulating fat deposition in poultry species. Although increase in muscle mass resulted from muscle hyperplasia in the MSTN mutant quail, cellular mechanism behind the decrease in fat deposition was not investigated in the quail model. In the current study, to investigate sexual dimorphic association between fat deposition and Mstn mutation in quail, leg and abdominal fat pads from 4-month-old male and female quail were histologically analyzed. Interestingly, abdominal and leg fat pad weights were significantly decreased by the MSTN mutation only in female quail, but not in male quail, showing sexual dimorphism in regulating fat deposition by the MSTN mutation in quail. Histological analysis also revealed that fat cell sizes of leg and abdominal fats were significantly reduced only in female groups aligning with the decreased fat pad weights. Sexual dimorphic effect of the MSTN mutation on fat cell hypotrophy and reduced fat pad weights in quail provided an important scientific finding to be considered on the usage of the MSTN gene as a genetic marker to reduce fat deposition in poultry species.
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Tecido Adiposo , Coturnix , Mutação , Miostatina , Animais , Miostatina/genética , Miostatina/metabolismo , Feminino , Masculino , Coturnix/genética , Coturnix/fisiologia , Tecido Adiposo/metabolismo , Caracteres Sexuais , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismoRESUMO
The myostatin (MSTN) gene is considered a potential genetic marker to improve economically important traits in livestock, since the discovery of its function using the MSTN knockout mice. The anti-myogenic function of the MSTN gene was further demonstrated in farm animal species with natural or induced mutations. In poultry species, myogenesis in cell culture was regulated by modulation of the MSTN gene. Also, different expression levels of the MSTN gene in poultry models with different muscle mass have been reported, indicating the conserved myogenic function of the MSTN gene between mammalian and avian species. Recent advances of CRISPR/Cas9-mediated genome editing techniques have led to development of genome-edited poultry species targeting the MSTN gene to clearly demonstrate its anti-myogenic function and further investigate other potential functions in poultry species. This review summarizes research conducted to understand the function of the MSTN gene in various poultry models from cells to whole organisms. Furthermore, the genome-edited poultry models targeting the MSTN gene are reviewed to integrate diverse effects of the MSTN gene on different traits of poultry species.
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Limited studies using animal models with a few natural mutations in melanophilin (Mlph) provided partial functions of Mlph in melanosome trafficking. To investigate cellular functions of Mlph, especially ZnF motif of Mlph, we analyzed all three Mlph knockout (KO) quail lines, one and two base pair (bp) deletions as models for total KO, and three bp deletion causing deletion of one Cysteine (C84del) in the ZnF motif. All quail lines had diluted feather pigmentation with impaired dendritogenesis and melanosome transport in melanocytes. In vitro studies revealed capability of binding of the ZnF motif to PIP3, and impairment of PI3P binding and mislocalization of MLPH proteins with ZnF motif mutations. The shortened melanocyte dendrites by the C84del mutation were rescued by introducing WT Mlph in vitro. These results revealed the diluted feather pigmentation by Mlph mutations resulted from congregation of melanosomes in the cell bodies with impairment of the dendritogenesis and the transport of melanosomes to the cell periphery.
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Plumas , Melanócitos , Melanossomas , Pigmentação , Animais , Plumas/metabolismo , Melanócitos/metabolismo , Pigmentação/genética , Melanossomas/metabolismo , Codorniz , Mutação , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismoRESUMO
The simplified molecular-input line-entry system (SMILES) has been utilized in a variety of artificial intelligence analyses owing to its capability of representing chemical structures using line notation. However, its ease of representation is limited, which has led to the proposal of BigSMILES as an alternative method suitable for the representation of macromolecules. Nevertheless, research on BigSMILES remains limited due to its preprocessing requirements. Thus, this study proposes a conversion workflow of BigSMILES, focusing on its automated generation from SMILES representations of homopolymers. BigSMILES representations for 4,927,181 records are provided, thereby enabling its immediate use for various research and development applications. Our study presents detailed descriptions on a validation process to ensure the accuracy, interchangeability, and robustness of the conversion. Additionally, a systematic overview of utilized codes and functions that emphasizes their relevance in the context of BigSMILES generation are produced. This advancement is anticipated to significantly aid researchers and facilitate further studies in BigSMILES representation, including potential applications in deep learning and further extension to complex structures such as copolymers.
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Mineralized eggshell is a unique and protective structure in an avian egg. Among different eggshell layers, the cuticle layer is an outermost layer and plays a critical role in protection against bacterial infection. Although the importance of nanosphere in the cuticle layer on the antimicrobial function has been widely accepted, the detailed nanostructure of the cuticle layer in the major poultry species has not been investigated. In the current study, eggs from Japanese quail, commercial layer chickens, mixed breed turkeys, and White Pekin ducks were collected. To investigate the nanostructure throughout the cuticle layer, images of the cross-sectional cuticle layer were taken using a scanning electron microscope (SEM). Unlike the cuticle layer in ducks showing deformed bunched nanospheres, clearly separated nanospheres were present throughout the cuticle layer in quail, chickens, and turkeys. The average size of the nanosphere was the biggest in turkeys and similar between quail and chickens. Most importantly, the size of nanospheres was increased as they ascended from the bottom of the cuticle layer in quail, showing a positive correlation between the size and distance of the nanospheres. However, different sizes of nanospheres were randomly distributed throughout the cuticle layer in chickens and turkeys, showing a weak correlation in chickens and no correlation in turkeys between the size and distance of nanospheres. These new findings in different nanostructures of the cuticle layers in quail, chickens, turkeys, and ducks will serve as a new foundation to better relate their structures with functions.
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Nanosferas , Aves Domésticas , Animais , Galinhas , Casca de Ovo/química , Coturnix , Estudos Transversais , Óvulo , Patos , PerusRESUMO
Poultry species is an important animal model in both avian research and the poultry industry. To advance our understanding of genetic factors and benefit both fields, a gene of interest can be genetically edited, and consequential phenotypic changes can be investigated. Injection of adenovirus containing the CRISPR/Cas9 system into avian blastoderm induced genome editing in blastodermal cells randomly, including primordial germ cells, which results in generation of whole-body knockout in the offspring of the virus-injected quail. However, to observe phenotypic and functional changes in whole-body, homozygous knockout of genes using this genome editing technology requires at least 2 generations of breeding of chimeric, and heterozygotes birds. In the current study, we developed a strategy to investigate the gene function in 1-generation by inducing regional genome editing around the injection sites with CRISPR/Cas9 adenovirus. The adenoviral CRISPR/Cas9 vector targeting the melanophilin (Mlph) gene, regulating feather pigmentation, was injected into 2 different regions of embryos, the cervical flexure of quail embryos at HH stage 13 to 15 and the tip of the upper limb bud of embryos at HH stage 22 to 24, to induce genome editing in those regions. Indel mutations in the target loci of the Mlph gene were detected by extracting genomic DNA from the embryonic tissues, and consequential phenotypes, feather color changes, were analyzed at 1 mo after hatch. Injection of the adenovirus into the cervical flexure and the tip of the upper limb bud of embryos resulted in 8 to 21% efficiency of indel mutation in the embryonic cells of the injected regions. In the posthatch quail, gray feathers were shown on their upper back and primary wing feathers, corresponding to the injection sites at embryos. Successful validation of this strategy for inducing genome editing in parts of tissues within 1-generation will accelerate studies on genetic functions with advantages of less time and cost, facilitating avian research and providing foundations for future application for the poultry industry.
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In avian species, positive relationships between egg weight (EW) and body weight (BW) have been reported. However, the correlation between the body growth rate and different weights of eggs from genetically mutated avian species was not studied yet. Myostatin (Mstn), an anti-myogenic factor, mutant quail were recently developed, and it was reported that EW produced from Mstn homozygous mutant quail (HO) was heavier compared to those from wild-type quail (WT). In the current study, distributions of pre-incubated EW and associations between EW and BW were compared between the Mstn mutant and WT quail lines. Average egg weight for the HO group was significantly heavier than the WT (P < 0.001) and the number of eggs having heavier EW (over 11 g) was higher in the HO compared to the WT (P < 0.01). BWs at wk (W) 0, 4, and 6 after hatch were also significantly greater in the HO (P < 0.001 in all groups). In addition, linear regression analyses revealed positive relationships between EW and BW from W0 to W6, regardless of sexes and genotypes. Furthermore, Mstn mutant quail were a heavier BW compared to the WT quail originated from eggs with similar weights. These data indicate that increased BW by Mstn mutation is contributed by increased EW and/or growth promoting activity of Mstn mutation independent of increasing egg sizes. These findings provide Mstn as a desirable genetic factor for selection of poultry breeds with superior growth. In addition, the knowledge gained from this study could inspire similar proof-of-concept studies involving standard and commercial lines of poultry.
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Miostatina , Codorniz , Animais , Codorniz/genética , Miostatina/genética , Galinhas/genética , Óvulo , MutaçãoRESUMO
Drivers have spare visual capacity in driving, and often this capacity is used for engaging in secondary in-car tasks. Previous research has suggested that the spare visual capacity could be estimated with the occlusion method. However, the relationship between drivers' occlusion times and in-car glance duration preferences has not been sufficiently investigated for granting occlusion times the role of an estimate of spare visual capacity. We conducted a driving simulator experiment (N = 30) and investigated if there is an association between drivers' occlusion times and in-car glance durations in a given driving scenario. Furthermore, we explored which factors and variables could explain the strength of the association. The findings suggest an association between occlusion time preferences and in-car glance durations in visually and cognitively low demanding unstructured tasks but that this association is lost if the in-car task is more demanding. The findings might be explained by the inability to utilize peripheral vision for lane-keeping when conducting in-car tasks and/or by in-car task structures that override drivers' preferences for the in-car glance durations. It seems that the occlusion technique could be utilized as an estimate of drivers' spare visual capacity in research - but with caution. It is strongly recommended to use occlusion times in combination with driving performance metrics. There is less spare visual capacity if this capacity is used for secondary tasks that interfere with the driver's ability to utilize peripheral vision for driving or preferences for the in-car glance durations. However, we suggest that the occlusion method can be a valid method to control for inter-individual differences in in-car glance duration preferences when investigating the visual distraction potential of, for instance, in-vehicle infotainment systems.
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Atenção , Condução de Veículo , Humanos , Automóveis , Acidentes de Trânsito/prevenção & controle , IndividualidadeRESUMO
In the modern layer industry, improvement of bone quality is one of the prior tasks to solve from economic and welfare standpoints. In addition to nutritional and environmental factors, genetic factors have been considered major factors regulating bone quality in layers but are yet to be fully investigated due to limitations on available animal models. Initially, the myostatin (MSTN) gene was genetically edited in quail to investigate the effect of MSTN mutation on economic traits in meat producing poultry species. In the current study, the function of the MSTN gene on regulation of bone quality in layers was investigated using MSTN mutant female quail as an animal model. Tibia bones were collected from wild-type (WT) and MSTN mutant female quail at 5 wk old and 4 mo old, representing prelaying and actively laying stages, respectively. Left tibia bones were analyzed by microcomputed tomography scanning to evaluate the architectural characteristics, while bone breaking strength (BBS) was measured using right tibia bones. At 5 wk of age, MSTN mutant female quail showed higher BBS and values on parameters related to bone quality such as bone mineral contents (BMC), bone mineral density (BMD), bone volume (BV), and/or trabecular bone thickness in whole diaphysis, whole metaphysis, and metaphyseal trabecular bone, compared to WT female quail. Although BBS and BMD became similar between the 2 groups at 4 mo of age, higher TV and TS in whole metaphysis and higher BMC and TV in whole diaphysis of MSTN mutant group compared to those of WT group suggested that the improved tibia bone quality by MSTN mutation before sexual maturation lasted to a certain degree even after sexual maturation. The use of the MSTN mutant female model provided new insights into genetic regulation on female quail bone quality depending on physiological changes.
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Coturnix , Tíbia , Animais , Feminino , Coturnix/genética , Tíbia/fisiologia , Microtomografia por Raio-X , Miostatina/genética , Maturidade Sexual , Galinhas , Densidade Óssea , Codorniz , MutaçãoRESUMO
The regulation of adipose deposition in broiler chickens is an important factor for production efficiency to poultry producers and health concerns to customers. Although vitamin A and its metabolite [all-trans retinoic acid (atRA)] have been used for studies on adipogenesis in mammals and avian, effects of embryonic atRA on adipose development in embryonic (E) and posthatch (D) ages in broiler chickens have not been studied yet. Different concentrations of atRA (0 M-2 µM) were injected in broiler eggs at E10, and adipose tissues were sampled at E16. Percentages of adipose tissues in chicken embryos were significantly increased in the group injected with 500 nM of atRA compared to the 0 M group (P < 0.05). In addition, the adipocyte cross-sectional area (CSA) was significantly greater by in ovo injection of 500 nM atRA compared to the injection of 0 M (P < 0.01). Moreover, in ovo atRA-injected embryos were hatched and BWs were measured at D0, D7, and D14. BWs were not different from those of the 0 M group. Percentages of adipose tissues and CSA of the in ovo atRA-injected group (500 nM) were not different from those of the 0 M group at D14. Taken together, the current study clearly showed that in ovo injection of atRA promoted adipose deposition with hypertrophy during embryonic development, but its effects were not maintained in early posthatch age in broiler chickens, implying that embryonic atRA has an important role in the regulation of adipose development in chicken embryos.
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Galinhas , Óvulo , Embrião de Galinha , Animais , Galinhas/fisiologia , Tretinoína , Hipertrofia/veterinária , Adipócitos , MamíferosRESUMO
The aim of this study was to compare the carcass, meat quality, and histochemical characteristics of pectoralis major (PM) muscle between wild type (WT) and myostatin (Mstn) homozygous mutant (HO) quail lines. The HO quail line exhibited significantly heavier body weight (HO vs. WT, 115.7 g vs. 106.2 g, approximately 110%) and PM muscle weight (HO vs. WT, 18.0 g vs. 15.2 g, approximately 120%) compared to the WT (p < 0.001). However, the two groups had similar traits (pH, redness, yellowness, and drip loss) for meat quality, although slightly higher lightness and cooking loss were observed in the mutant quail (103% and 141%, respectively, p < 0.05). For histochemical traits of PM muscle, Mstn mutant quail exhibited lower type IIA and higher type IIB percentage in the deep region than WT quail (p < 0.05), indicating a fiber conversion from the type IIA to IIB. However, the two quail lines had comparable histochemical traits in the superficial region (p > 0.05). These data suggest that Mstn mutation greatly increases muscle mass without significantly affecting meat quality.
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Meat-type (broiler) and egg-type (layer) chickens were bred by intensive selection over the years, resulting in more numbers and larger sizes of myofibers. Although the characteristics are important parameters in muscle growth and meat quality, muscle bundle characteristics have not been studied in poultry. Therefore, this study aimed to compare the histological characteristics of myofibers and muscle bundles in muscles between male broiler (Ross broiler breed) chickens and layer (Hy-Line) chickens. Chicken muscles, pectoralis major (PM) and gastrocnemius (GM), were sampled at the age of 49 days and stained to analyze histological characteristics. Expectedly, body weights (BWs) and weights of PM and GM muscles in 49-day-old broilers were significantly heavier than those in layers. Within PM, broilers exhibited greater number and cross-sectional area (CSA) of myofibers than layers (3.3- and 3.3-fold, respectively). The total number and CSA of PM muscle bundles were approximately 1.5 and 6.6 times greater, respectively, in broilers than layers. Moreover, broilers exhibited 2 times greater number of myofibers per bundle of PM muscle than layers. Within GM, myofiber number and CSA were 2.3- and 2.4-fold greater, respectively, in broilers than layers. In addition, the total number of muscle bundles and bundle CSA were 2.5- and 2.1-fold greater, respectively, in broilers than in the layers. The novel findings of the current study provide evidence that greater muscle mass of broilers occurs by both hyperplasia and hypertrophy of muscle bundles and myofibers.
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Silicone-based fillers have been applied in several branches of medicine, such as soft tissue augmentation, because of their stability and durability. However, the inherently hydrophobic surfaces of silicone occasionally cause excessive deposition of the fibrous matrix in vivo, leading to severe fibrosis. In this study, we evaluated the use of a zwitterionic copolymer to offer a facile surface treatment method for silicone-based fillers and performed a preclinical trial of the formulation as-prepared. The copolymer has amphiphilic moieties, which act as macromolecular surfactants that can functionalize and stabilize the silicone particles during fabrication. The effectiveness and safety of the particle filler were evaluated histologically by scoring the peri-implant tissues into previously defined categories. Our results suggest that zwitterion-coated silicone fillers can inhibit protein adsorption, and thus, help attenuate foreign body reactions in a rat model. This demonstrates their potential for wide application in different fields within the discipline of medicine.