scholarly journals Number of conceptuses in utero affects porcine fetal muscle development

Reproduction ◽  
2004 ◽  
Vol 128 (4) ◽  
pp. 443-454 ◽  
Author(s):  
S C Town ◽  
C T Putman ◽  
N J Turchinsky ◽  
W T Dixon ◽  
G R Foxcroft
Keyword(s):  
Muscle Fibre ◽  
Muscle Development ◽  
Weight Ratio ◽  
In Utero ◽  
Muscle Fibres ◽  
Semitendinosus Muscle ◽  
Muscle Weight ◽  
Cross Sectional ◽  
Fetal Organ ◽  
Muscle Cross Sectional Area

Unmodified, third parity, control sows (CTR; n = 30) or sows subjected to unilateral oviduct ligation before breeding (LIG; n = 30), were slaughtered at either day 30 or day 90 of gestation and used to determine the effects of numbers of conceptuses in utero on prenatal, and particularly muscle fibre, development. Ovulation rate, number of conceptuses in utero, placental and fetal size, and (day 90 sows) fetal organ and semitendinosus muscle development were recorded. Tubal ligation reduced (P < 0.05) the number of viable embryos at day 30 and fetuses at day 90. Placental weight at day 30 and day 90, and fetal weight at day 90, were lower (P < 0.05) in CTR sows. All body organs except the brain were lighter, and the brain:liver weight ratio was higher in CTR fetuses (P < 0.05), indicative of brain sparing and intrauterine growth restriction in fetuses from CTR sows. Muscle weight, muscle cross-sectional area and the total number of secondary fibres were also lower (P < 0.05) in CTR fetuses. The number of primary fibres, the secondary:primary muscle fibre ratio, and the distribution of myosin heavy chain-Iβ, -IIa, fetal and embryonic isoforms did not differ between groups. Thus, even the relatively modest uterine crowding occurring naturally in CTR sows negatively affected placental and fetal development and the number of secondary muscle fibres. Consequences of more extreme crowding in utero on fetal and postnatal development, resulting from changing patterns of early embryonic survival, merit further investigation.

scholarly journals SLCV–a supervised learning—computer vision combined strategy for automated muscle fibre detection in cross-sectional images

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7053
Author(s):  
Anika Rettig ◽  
Tobias Haase ◽  
Alexandr Pletnyov ◽  
Benjamin Kohl ◽  
Wolfgang Ertel ◽  
...  
Keyword(s):  
Computer Vision ◽  
Supervised Learning ◽  
Muscle Fibre ◽  
Cross Sections ◽  
Reconstruction Error ◽  
Muscle Fibres ◽  
Dice Similarity Coefficient ◽  
Cross Sectional ◽  
Staining Methods ◽  
Combined Strategy

Muscle fibre cross-sectional area (CSA) is an important biomedical measure used to determine the structural composition of skeletal muscle, and it is relevant for tackling research questions in many different fields of research. To date, time consuming and tedious manual delineation of muscle fibres is often used to determine the CSA. Few methods are able to automatically detect muscle fibres in muscle fibre cross-sections to quantify CSA due to challenges posed by variation of brightness and noise in the staining images. In this paper, we introduce the supervised learning-computer vision combined pipeline (SLCV), a robust semi-automatic pipeline for muscle fibre detection, which combines supervised learning (SL) with computer vision (CV). SLCV is adaptable to different staining methods and is quickly and intuitively tunable by the user. We are the first to perform an error analysis with respect to cell count and area, based on which we compare SLCV to the best purely CV-based pipeline in order to identify the contribution of SL and CV steps to muscle fibre detection. Our results obtained on 27 fluorescence-stained cross-sectional images of varying staining quality suggest that combining SL and CV performs significantly better than both SL-based and CV-based methods with regards to both the cell separation- and the area reconstruction error. Furthermore, applying SLCV to our test set images yielded fibre detection results of very high quality, with average sensitivity values of 0.93 or higher on different cluster sizes and an average Dice similarity coefficient of 0.9778.

The effect of maternal undernutrition on muscle fibre type in the newborn lamb

2003 ◽  
Vol 2003 ◽  
pp. 60-60
Author(s):  
A.J. Fahey ◽  
J.M. Brameld ◽  
T. Parr ◽  
P.J. Buttery
Keyword(s):  
Muscle Fibre ◽  
Meat Quality ◽  
Fibre Type ◽  
Muscle Development ◽  
Nutrient Supply ◽  
Muscle Fibre Type ◽  
Growth Potential ◽  
Muscle Fibres ◽  
General Hypothesis ◽  
Maternal Undernutrition

Muscle fibre type can influence meat quality (Maltinet al1997). Muscle fibre formation occurs during gestation and in the sheep the total number of fibres in a muscle is essentially fixed at birth. (Ashmereet al1972). Postnatal growth of muscle is entirely due to elongation and widening of the existing muscle fibres. Therefore the gestational period is important in the long-term growth potential of the animal. By investigating changes in muscle fibre type, the aim of this study was to test the general hypothesis that the poor carcass quality sometimes seen in ruminant animals may be due to poor nutrition at strategic time points during the animal’s development. As agricultural practices continue to become more extensive, variation in the nutrient supply to the animal is becoming more common. Therefore it is important to understand the effect of any changes in nutrient supply to the mother, during gestation on the subsequent muscle development of the fetus and ultimately the effects on meat quality.

Shift from slow- to fast-twitch muscle fibres in skeletal muscle of newborn heterozygous and homozygous myostatin-knockout piglets

2019 ◽  
Vol 31 (10) ◽  
pp. 1628 ◽  
Author(s):  
Mei-Fu Xuan ◽  
Zhao-Bo Luo ◽  
Jun-Xia Wang ◽  
Qing Guo ◽  
Sheng-Zhong Han ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Protein Expression ◽  
Muscle Development ◽  
Transforming Growth Factor ◽  
Myogenic Differentiation ◽  
Muscle Fibres ◽  
Skeletal Muscle Development ◽  
Cross Sectional ◽  
Gene And Protein Expression ◽  
Fast Twitch

Myostatin (MSTN) is a member of the transforming growth factor-β superfamily that negatively regulates skeletal muscle development. A lack of MSTN induces muscle hypertrophy and increases formation of fast-twitch (Type II) muscle fibres. This study investigated muscle development in newborn heterozygous (MSTN+/−) and homozygous (MSTN−/−) MSTN-knockout piglets. Detailed morphological and gene and protein expression analyses were performed of the biceps femoris, semitendinosus and diaphragm of MSTN+/−, MSTN−/− and wild-type (WT) piglets. Haematoxylin–eosin staining revealed that the cross-sectional area of muscle fibres was significantly larger in MSTN-knockout than WT piglets. ATPase staining demonstrated that the percentage of Type IIb and IIa muscle fibres was significantly higher in MSTN−/− and MSTN+/− piglets respectively than in WT piglets. Western blotting showed that protein expression of myosin heavy chain-I was reduced in muscles of MSTN-knockout piglets. Quantitative reverse transcription–polymerase chain reaction revealed that, compared with WT piglets, myogenic differentiation factor (MyoD) mRNA expression in muscles was 1.3- to 2-fold higher in MSTN+/− piglets and 1.8- to 3.5-fold higher MSTN−/− piglets (P&lt;0.05 and P&lt;0.01 respectively). However, expression of myocyte enhancer factor 2C (MEF2C) mRNA in muscles was significantly lower in MSTN+/− than WT piglets (P&lt;0.05). MSTN plays an important role in skeletal muscle development and regulates muscle fibre type by modulating the gene expression of MyoD and MEF2C in newborn piglets.

scholarly journals Variable maternal nutrition and growth hormone treatment in the second quarter of pregnancy in pigs alter semitendinosus muscle in adolescent progeny

2003 ◽  
Vol 90 (2) ◽  
pp. 283-293 ◽  
Author(s):  
Kathryn L. Gatford ◽  
Jason E. Ekert ◽  
Karina Blackmore ◽  
Miles J. De Blasio ◽  
Jodie M. Boyce ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Maternal Nutrition ◽  
Maternal Plasma ◽  
Cross Sectional Area ◽  
Muscle Fibres ◽  
Sectional Area ◽  
Large White ◽  
Semitendinosus Muscle ◽  
Gh Treatment ◽  
Cross Sectional

Maternal nutrition and growth hormone (GH) treatment during early- to mid-pregnancy can each alter the subsequent growth and differentiation of muscle in progeny. We have investigated the effects of varying maternal nutrition and maternal treatment with porcine (p) GH during the second quarter of pregnancy in gilts on semitendinosus muscle cross-sectional area and fibre composition of progeny, and relationships between maternal and progeny measures and progeny muscularity. Fifty-three Large White×Landrace gilts, pregnant to Large White×Duroc boars, were fed either 2·2 kg (about 35 % ad libitum intake) or 3·0 kg commercial ration (13·5 MJ digestible energy, 150 g crude protein (N×6·25)/kg DM)/d and injected with 0, 4 or 8 mg pGH/d from day 25 to 50 of pregnancy, then all were fed 2·2 kg/d for the remainder of pregnancy. The higher maternal feed allowance from day 25 to 50 of pregnancy increased the densities of total and secondary fibres and the secondary:primary fibre ratio in semitendinosus muscles of their female progeny at 61 d of age postnatally. The densities of secondary and total muscle fibres in semitendinosus muscles of progeny were predicted by maternal weight before treatment and maternal plasma insulin-like growth factor-II during treatment. Maternal pGH treatment from day 25 to day 50 of pregnancy did not alter fibre densities, but increased the cross-sectional area of the semitendinosus muscle; this may be partially explained by increased maternal plasma glucose. Thus, maternal nutrition and pGH treatment during the second quarter of pregnancy in pigs independently alter muscle characteristics in progeny.

Embryonic growth and innervation of rat skeletal muscles. - III. Neural regulation of junctional and extra-junctional acetylcholine receptor clusters

1981 ◽  
Vol 293 (1065) ◽  
pp. 287-314 ◽  
Keyword(s):  
Muscle Fibre ◽  
Nerve Terminal ◽  
Time Course ◽  
Muscle Development ◽  
Muscle Cells ◽  
Diaphragm Muscle ◽  
Muscle Fibres ◽  
The Mean ◽  
Receptor Clusters ◽  
Ach Receptors

The number and distribution of acetylcholine (ACh) receptors on muscle cells was studied during development of normal, paralysed and aneural embryonic rat diaphragm muscles. (i) ACh receptors initially are dispersed over the surface of rat embryo myotubes. At day 15| of gestation junctional receptor clusters (‘J-clusters’) form in a well ordered band across the midline of the diaphragm muscle; these also form in denervated and paralysed muscles. At about day 18 of gestation additional ‘EJ-clusters’ develop to either side of the midpoint of treated muscles. (ii) If a nerve terminal is present, J-clusters increase in length with time. The time course of generation of new endplates calculated from frequency distributions of J-cluster lengths accurately predicts the muscle growth curve established from muscle fibre counts. (iii) The mean length of J-clusters in paralysed muscles was greater than in controls, due to small new-formed clusters failing to appear. In muscles allowed to recover from paralysis the mean length was less, due to a preponderance of small, new-formed clusters. These observations show that development of new endplates, which is thought to reflect the development of new muscle cells, is halted in paralysed muscles, and recovery from paralysis is associated with the generation of many new endplates. (iv) J-clusters appeared, but failed to grow, in aneural muscles. In muscles denervated during the later stages of gestation, analysis of the distribution of J-cluster lengths shows that new clusters failed to appear, and existing clusters showed little or no increase in length after the time of removal of the nerve. (v) EJ-clusters form by aggregation of dispersed receptors, and their mean length increases with time. They do not appear to be stable entities, and are removed within 2 d of recovery from paralysis. In paralysed muscles, with both J-clusters and EJclusters present, only J-clusters attract nerve sprouts or become innervated. (vi) A curve is derived showing development of the total number of synaptic terminals in a muscle. This number increases during days 13-18 of gestation, reaching a peak of about 170 % of the adult value during dl8 and d l9 of gestation. There are two episodes of terminal elimination, one during days 19-21 of gestation, and another about 2 weeks postnatally. During the first postnatal week the number of terminals remains constant at about 140% of the adult number, while the average number of inputs per fibre goes down and the number of muscle fibres increases. (vii) Innervation is essential for muscle development. Motoneurons cannot regulate the number of muscle fibres by requiring a simple one-to-one relation between nerve terminal and muscle fibre, and if their role is regulatory as well as supportive of muscle development then some more complex relationship between nerve terminals and developing myotubes must be postulated.

Myogenesis in small and large ovine fetuses at three stages of pregnancy

2015 ◽  
Vol 55 (2) ◽  
pp. 207 ◽  
Author(s):  
S. P. Quigley ◽  
P. L. Greenwood ◽  
D. O. Kleemann ◽  
J. A. Owens ◽  
C. S. Bawden ◽  
...  
Keyword(s):  
Fetal Growth ◽  
Muscle Development ◽  
Muscle Growth ◽  
Mrna Levels ◽  
Myogenic Regulatory Factors ◽  
Semitendinosus Muscle ◽  
Cross Sectional ◽  
Fetal Sheep ◽  
Regulatory Factors ◽  
Stage Of Development

Perturbations of the prenatal environment may influence fetal muscle development. This study investigated muscle cellularity and mRNA abundance of myogenic genes in fetal sheep divergent in their patterns of growth. Muscle samples were obtained from small and large fetuses on Days 50, 92 and 133 of pregnancy. Number of myofibres in the semitendinosus muscle increased between Day 92 and 133 of pregnancy, but did not differ between small and large fetuses at either stage of pregnancy. The semitendinosus of small fetuses had smaller cross-sectional areas of myofibres than did those of their large counterparts on Day 133 of pregnancy. The semitendinosus of small fetuses also had lower DNA concentration on Day 92 and lower protein concentration on Day 133 than did those of large fetuses. The mRNA levels of the myogenic regulatory factors (MRFs), myostatin, the insulin-like growth factors and embryonic myosin in fetal muscles varied with the stage of development, but no differences occurred in response to divergent fetal growth. Myostatin mRNA was more abundant in the semitendinosus than in the supraspinatus muscle on Days 92 and 133, as were myogenic regulatory factors, myf-5, myf-6 and follistatin mRNA on Day 133. The results indicated that muscle growth but not the number of myofibres in fetal sheep is modified by restricted fetal growth, and that genes that regulate muscle development are affected by the stage of development in an anatomical muscle-specific manner.

The effects of age at slaughter, genotype and finishing system on the biochemical properties, muscle fibre type characteristics and eating quality of bull beef from suckled calves

1998 ◽  
Vol 66 (2) ◽  
pp. 341-348 ◽  
Author(s):  
C. A. Maltin ◽  
K. D. Sinclair ◽  
P. D. Warriss ◽  
C. M. Grant ◽  
A. D. Porter ◽  
...  
Keyword(s):  
Muscle Fibre ◽  
Fibre Type ◽  
Biochemical Properties ◽  
Cross Sectional Area ◽  
Muscle Fibres ◽  
Sectional Area ◽  
Cross Sectional ◽  
Percentage Area ◽  
Slow Twitch ◽  
Intramuscular Fat Content

AbstractMuscle fibre characteristics and biochemical properties of muscle recovered from young bulls of two genotypes (Aberdeen Angus × and Charolais ×), reared on two different diets (silage-based and barley-based) and slaughtered at varying ages between 10 and 19 months of age were established. These analyses were restricted to samples ofm. longissimus lumborum (LI) recovered at 48 h post mortem, vacuum packed and stored at 2°C for 14 days. Biochemical measurements included intramuscular fat content, intramuscular collagen content and its solubility, haem pigment concentration, sarcomere length and myofibril fragmentation. Muscle fibre type was classified according to the contractile nature of thefibres and their metabolic properties.Intramuscular fat content increased (P < 0·01) with age at slaughter and at a fixed age was greater for Angus × than Charolais × bulls (211·5 v. 295·8 mg/g dry matter, P < 0·01). Total intramuscular collagen and its solubility tended to decrease with age (P < 0·01). Differences in haem pigment concentration in samples of LI were detected between genotype (3·99 v. 3·59 mg/g for Angus × and Charolais × bulls; P × 0·01) and diet (3·97 v. 3·62 mg/g for bulls given barley and silage; P < 0·01), and increased with age at slaughter (P < 0·01). There was a significant increase in eye muscle cross-sectional area with increasing slaughter date (P < 0·01) and this was paralleled by an increase in cross-sectional area of individual muscle fibres (P < 0·001). Differences in cross-sectional area of individual muscle fibres between genotype and diet were small and inconsistent. Charolais × bulls had a greater percentage area of fast twitch glycolytic fibres than Angus × bulls (54·3 v. 49·3%; P < 0·01) and a smaller percentage area of slow twitch oxidative fibres (15·8 v. 18·9%; P < 0·05). Beef tenderness was positively correlated (r = 0·48; P < 0·01) with the frequency of slow twitch oxidative fibres and negatively correlated (r = -0·38; P < 0·05) with the frequency offast twitch glycolytic fibres.

In utero effects on livestock muscle development and body composition

2008 ◽  
Vol 48 (7) ◽  
pp. 921 ◽  
Author(s):  
John M. Brameld ◽  
Zoe C. T. R. Daniel
Keyword(s):  
Skeletal Muscle ◽  
Body Composition ◽  
Muscle Development ◽  
In Utero ◽  
The Body ◽  
Laboratory Animals ◽  
Muscle Fibres ◽  
Critical Window ◽  
Genetic And Environmental Factors

This review will focus on the evidence for in utero effects on development of skeletal muscle in farm and laboratory animals, particularly sheep and pigs. We will describe genetic and environmental factors that have been shown to alter the numbers of muscle fibres formed and outline our working hypothesis for the mechanism involved and the critical window during pregnancy when these effects are seen. We will then discuss the long-term consequences in terms of body composition. Although this review concentrates on skeletal muscle development, the mechanism we suggest might be equally applicable to other tissues in the body (e.g. the brain, kidneys or sex organs) and, therefore, impact on their physiological functions.

scholarly journals The effect of acute dietary restriction on muscle fibre number in weanling rats

1981 ◽  
Vol 45 (3) ◽  
pp. 475-481 ◽  
Author(s):  
Donald K. Layman ◽  
Patricia B. Swan ◽  
P. V. J. Hegarty
Keyword(s):  
Dietary Restriction ◽  
Fibre Diameter ◽  
Growth Potential ◽  
Control Group ◽  
Muscle Fibres ◽  
Sprague Dawley ◽  
Muscle Weight ◽  
Cross Sectional ◽  
Restricted Group ◽  
Fibre Number

1. Male Sprague-Dawley rats were allocated at 100 g into either an ad lib.-fed control group or a food-restricted group. The restricted group was fed for 9 d at 25% of ad lib. intake. Controls were killed at a body-weight of 100 g and 29 d of age and the restricted animlas were killed at 70 g and 38 d of age.2. The effects of food restriction on muscle weight, fibre number, fibre diameter, DNA, and protein were examined in three skeletal muscles, the soleus, plantaris and extensor digitorum longus (EDL).3. Acute dietary restriction caused body- and muscle-weight loss and a decrease in both the number and cross-sectional area of muscle fibres in each of the muscles.4. The restriction halted growth-related increases in DNA in all muscles and decreased the protein: DNA value in the plantaris and EDL.5. These results indicate that present theories describing cellular development are not adequate to define growth potential or growth retardation of skeletal muscle.

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