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1.
Diaphragms obtained from 40 fetal rabbits at gestational ages of 20, 22, 25 and 30 days were examined by light and transmission electron microscopes. The percentage of myogenic cells undergoing mitosis was calculated by counting mitotic nuclei in 1 micron sections. At 20 and 22 days gestation, myogenic cells (myoblasts and satellite cells) were actively proliferating with 2.66 +/- 0.41% (n = 15) and 2.18 +/- 0.20% (n = 23), of the cells in division, respectively. The myogenic cells undergoing mitosis appeared to be of both myoblasts and satellite cells at these stages of the development. The myotubes on day 20 of gestation contained a large number of lipid droplets and an abundance of glycogen particles which were reduced by day 22 of gestation. The mitotic rate on day 25 of gestation was reduced to 1.16 +/- 0.11% (n = 28). The muscle fibers were well differentiated at this stage and the majority of the dividing cells were considered to be satellite cells. In diaphragms from the full term fetuses (day 30), the mitotic rate was reduced to 0.31 +/- 0.05% (n = 24). It was suggested that myoblasts of the fetal rabbit diaphragm proliferated for the myotube formation during the earliest stage of the development (day 20 of gestation) and then the number of satellite cells increased after day 22 of gestation. Growth of the organ after day 25 of gestation appeared to be mostly due primarily to the hypertrophy and differentiation of the muscle fibers rather than proliferation of myoblasts. 相似文献
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The mesonephros, the gonad, the external genitalia and the developmental relationships between them were examined on 21 goat fetuses, 29 to 92 days old. Three fetuses were not sexually differentiated, however 11 were males and 7 females. The development of the gonad could be divided in a not differentiated stage and a gonadal and external genitalia differentiation stage. A close relationship between the fetal gonad and the mesonephros was found during the stage of differentiation. The epicenter of this relation is the giant mesonephric nephron, a peculiar structure of mesonephros, from which epithelial cells presumably migrate into the gonad. 相似文献
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樱桃谷鸭增重和饲料转化规律的研究 总被引：3，自引：0，他引：3
樱桃谷鸭在适宜的饲养管理条件下可达较高的生产性能,７周龄平均体重３６３７．９ｇ,饲料转化比２．４６。平均日增重５周龄前逐渐上升,５周龄达到最大,为９７．６ｇ,５周龄以后增重速度迅速降低,７周龄平均只有５５．１ｇ。公鸭前两周增重速度比母鸭慢,第３周龄起超过母鸭。累计饲料转化比随周龄增加呈逐渐增加的趋势,而各周龄饲料转化比在５周龄以后迅速增加,从第５周龄的２．４０上升到第７周龄的４．８７。但将饲料转化比换算成瘦肉饲料比,７周龄（１２．４７∶１）好于６周龄（１３．６２∶１）。７周龄的屠宰性能显著好于６周龄,尤其是胸肉率达到１５．１％,比６周龄（１１．３％）提高了３．８个百分点。 相似文献
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Salouci M Engelen V Gyan M Antoine N Jacqmot O Mignon Y Kirschvink N Gabriel A 《Anatomia, histologia, embryologia》2012,41(3):227-232
Purkinje cells are involved in many vital functions within the body. Twenty ovine fetuses ranging from 2 to 5 months of gestation, two lambs in the first week after birth and three adult sheep were studied. Sections of the cerebellum were stained with haematoxylin and eosin, cresyl violet and Klüver-Barrera. This study indicates that Purkinje cells began to appear after the 15(th) week of gestation. There were varying degrees of development of Purkinje cells in different zones of the cerebellum. Our findings in sheep fetuses suggest that the maturation of Purkinje cells starts in the caudal regions of the cerebellum and that the process begins in the vermis before it does in the cerebellar hemispheres. The alignment of Purkinje cells was found to be very regular in the caudal regions of the cerebellum. A partial absence of Purkinje cells in the rostral regions of the cerebellum was observed in both sheep fetuses and adult sheep. In the first post-natal week, some ectopic Purkinje cells were found in the white matter of the cerebellum. 相似文献
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In ovo L‐arginine supplementation stimulates myoblast differentiation but negatively affects muscle development of broiler chicken after hatching 
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下载免费PDF全文 Y. Li Y. Wang E. Willems H. Willemsen L. Franssens J. Buyse E. Decuypere N. Everaert 《Journal of animal physiology and animal nutrition》2016,100(1):167-177
In this study, we tested the hypothesis that in ovo feeding (IOF) of L‐arginine (L‐Arg) enhances nitric oxide (NO) production, stimulates the process of myogenesis, and regulates post‐hatching muscle growth. Different doses of L‐Arg were injected into the amnion of chicken embryos at embryonic day (ED) 16. After hatching, the body weight of individual male chickens was recorded weekly for 3 weeks. During in vitro experiments, myoblasts of the pectoralis major (PM) were extracted at ED16 and were incubated in medium containing 0.01 mm L‐Arg, 0.05 mm L‐Arg, and (or) 0.05 mm L‐nitro‐arginine‐methyl‐ester (L‐NAME), an inhibitor of nitric oxide synthase (NOS). When 25 mg/kg L‐Arg/initial egg weight was injected, no difference was observed in body weight at hatch, but a significant decrease was found during the following 3 weeks compared to that of the non‐injected and saline‐injected control, and this also affected the growth of muscle mass. L‐NAME inhibited gene expression of myogenic differentiation antigen (MyoD), myogenin, NOS, and follistatin, decreased the cell viability, and increased myostatin (MSTN) gene expression. 0.05 mm L‐Arg stimulated myogenin gene expression but also depressed muscle cell viability. L‐NAME blocked the effect of 0.05 mm L‐Arg on myogenin mRNA levels when co‐incubated with 0.05 mm L‐Arg. L‐Arg treatments had no significant influence on NOS mRNA gene expression, but had inhibiting effect on follistatin gene expression, while L‐NAME treatments had effects on both. These results suggested that L‐Arg stimulated myoblast differentiation, but the limited number of myoblasts would form less myotubes and then less myofibers, while the latter limited the growth of muscle mass. 相似文献
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Nakamura YN Iwamoto H Shiba N Miyachi H Tabata S Nishimura S 《British poultry science》2004,45(6):753-761
1. Growth changes of the collagen content and architecture in the pectoralis (PT) and iliotibialis lateralis (ITL) muscles were examined using cockerels from 1 to 14 weeks of age. 2. Total collagen content in PT muscle showed little change, but in ITL muscle reached a maximum at 5 weeks and thereafter decreased slightly until 14 weeks. The collagen content was markedly larger in ITL muscle after 5 weeks. Pyridinoline content of collagen increased abruptly from 5 to 14 weeks in both muscles, but no difference between muscle types was detected. 3. The cell size of the endomysial honeycombs increased with the development of myofibres, and the mesh size of the perimysium around the honeycombs enlarged. 4. In both muscles endomysia were an incomplete network of collagen fibrils with many foramina at one week, became a very thin membrane of felt-like fabric in 2 to 5 weeks and thereafter increased in thickness until 11 to 14 weeks. 5. Perimysial width around the secondary fasciculus differed between the muscle types after 5 weeks. In the wider perimysium of ITL muscle, the collagen fibres increased in number and size to make a stack of collagen bands around the fasciculus. In the narrower perimysium of PT muscle, a few platelets of collagen fibres also developed. 6. The perimysial collagen fibre at 1 to 2 weeks had a smooth surface and appeared to be composed of fine collagen fibrils. The fibre at 11 to 14 weeks showed a rugged surface and was composed of coarser collagen bundles that combined with each other into a net-like configuration with very slim meshes. 7. Our results showed that the collagenous components of chicken intramuscular connective tissue changed markedly during the early period of muscle growth in distribution, architecture and quality but with little difference in quantity. 相似文献
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Fbxw7β, E3 ubiquitin ligase,negative regulation of primary myoblast differentiation,proliferation and migration 下载免费PDF全文
下载免费PDF全文 Kyungshin Shin Sang‐Gu Hwang Ik Joon Choi Young‐Gyu Ko Jaemin Jeong Heechung Kwon 《Animal Science Journal》2017,88(4):712-719
Satellite cells attached to skeletal muscle fibers play a crucial role in skeletal muscle regeneration. During regeneration, the satellite cells proliferate, migrate to the damaged region, and fuse to each other. Although it is important to determine the cellular mechanisms controlling myoblast behavior, their regulators are not well understood. In this study, we evaluated the roles of Fbxw7 in primary myoblasts and determined its potential as a therapeutic target for muscle disease. We originally found that Fbxw7β, one of the E3 ubiquitin ligase Fbxw7 subtypes, negatively regulates differentiation, proliferation and migration of myoblasts and satellite cells on muscle fiber. However, these phenomena were not observed in myoblasts expressing a dominant‐negative, F‐box deleted Fbxw7β, mutant. Our results suggest that myoblast differentiation potential and muscle regeneration can be regulated by Fbxw7β. 相似文献
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试验旨在揭示ACTC1基因在秦川牛中的时空表达规律，为进一步研究ACTC1基因在肉牛肌肉发育和脂肪沉积等方面的功能奠定基础。利用实时荧光定量PCR技术检测了ACTC1基因在24月龄成年秦川牛13种组织和4日龄新生秦川牛12种组织中的表达规律，同时研究分析了该基因在秦川牛成肌细胞和前体脂肪细胞不同分化阶段（0、2、4、6、8 d）的表达特性。结果显示，ACTC1基因在秦川牛心脏中的表达量最高，骨骼肌中次之；除瘤胃和肾脏外，24月龄成年牛各组织中的表达量显著或极显著高于4日龄新生牛（P<0.05；P<0.01）；ACTC1基因在成肌细胞中的表达随着分化程度的增加呈现先升高后降低的趋势，在成肌细胞分化第2、4、6和8天ACTC1基因的表达量与第0天相比差异极显著（P<0.01），分别是第0天的2.6、4.7、5.6和4.2倍，这与成肌细胞的分化速率一致；在脂肪细胞中ACTC1基因的表达趋势为先降后升，第2、4天的表达量与第0天相比差异极显著（P<0.01），从分化第2天开始表达量随脂肪细胞分化程度增加而增加。ACTC1基因在不同年龄牛肌肉组织（心肌和骨骼肌）中的表达量最高，且其表达特性与肌细胞分化整体趋势一致；另外，ACTC1基因在脂肪细胞中的表达也有一定的规律。综上所述，推测ACTC1基因可能会影响牛肌肉组织的生长发育和脂肪沉积。 相似文献
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James E. Smallwood DVM MS Sandra M. Albright DVM Michael R. Metcalf DVM MS Donald E. Thrall DVM PHD Ben D. Harrington DVM 《Veterinary radiology & ultrasound》1989,30(3):98-110
The purpose of the project was to provide a reference for radiographic anatomy of the developing equine foredigit and metacarpophalangeal region. Using xeroradiographic techniques, both foredigits and meta-carpophalangeal regions of six Quarter Horse foals were radiographed at one day of age and at two-week intervals until the foals were six weeks old. The foals were then radiographed at four-week intervals until they were 12 months old. This report deals specifically with the first six months of postnatal development. Lateromedial and dorsopalmar xeroradiographs of each foredigit and metacarpophalangeal region and a dorsal 65° proximal-palmarodistal oblique view of the distal part of the digit were made for each examination. The foals were weighed and measured at the withers immediately prior to each examination. Representative xeroradiographs were selected and appropriately labeled to demonstrate normal radio-graphic anatomy of these regions. First radiographic appearance of distal epiphyseal ossification in metacarpal 2 and metacarpal 4 was extremely variable and ranged from four to 38 weeks. Radiographic closure of the proximal physis of the middle phalanx ranged from 18 to 30 weeks (mean = 26 weeks). Radiographic closure of the proximal physis of the proximal phalanx ranged from 22 to 38 weeks (mean = 30 weeks). Radiographic closure of the distal physis of metacarpal 3 ranged from 18 to 38 weeks (mean = 29 weeks). When xeroradiographic physeal closure times were compared with scintigraphic closure times from a companion study, results correlated very well. A crena marginis solearis was observed in ten of 12 forelimbs (83.3%); its first radiographic appearance ranged from four to 22 weeks (mean = 11–12 weeks). A consistent groove in the hoof wall, which formed near the time of birth and moved distally at about 3 mm per week, was noted. The groove's distance from the proximal hoof border may be useful in age estimation of foals less than 18–20 weeks old. 相似文献
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The aim of the present study was to define the effect of TGF-beta1 on C2C12 myoblasts myogenesis. TGF-beta1 together with its receptor is a negative auto-paracrine regulator of myogenesis, which influences the proliferation, differentiation, and functions of muscle cells. TGF-beta1 exerts highly significant inhibitory effect on differentiation of C2C12 mouse myoblasts manifested by the impairment of cell fusion and very low expression of myosin heavy chain. The study of differentiating C2C12 mouse myoblasts treated with TGF-beta1 revealed 502 genes (436 down-regulated and 66 up-regulated) with statistically different expression. TGF-beta1-regulated genes were identified to be involved in 29 biological processes, 29 molecular functions groups and 59 pathways. The strongest inhibiting effect of TGF-beta1 was observed in the cadherin and Wnt pathways. The key-genes that could play the role of TGF-beta1 targets during myoblasts differentiation was identified such as: Max, Creb1, Ccna2, Bax, MdfL, Tef, Tubg1, Cxcl5, Rho, Calca and Lgals4. 相似文献
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A total of 101 specimens were used; they came from 89 fetuses (4th to 40th week of gestation) and 12 neonates (1 to 14 days old). The age of the fetuses was determined according to the method of Kantorova (1960). The uterine veins were filled with latex using an automatic injection apparatus of our own construction. The study showed that blood left the uterus of the examined animals through constantly present veins (Ramus uterinus venae ovaricae, V. uterina and Ramus uterinus venae vaginalis) as well as through a number of inconstant veins to which belonged the Vv. vaginales accessoriae craniales et caudales. The constant uterine veins and their branches differed from their adult counterparts by being morphologically more differentiated, especially by having more branches of which some disappeared with time. The uterine veins developed toward the end of the fetal period. They arose either from the most caudal Vv. mesonephridicae lumbales (V. ovarica and its branches), or from the segmental, visceral veins of the pelvis (V. uterina and Vv. vaginales). 相似文献
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先后进行两次饲养试验和屠宰试验研究肉鸭胸肌厚度和胸肌质量、胸肌率的相关关系。试验1饲养大体型A品系和小体型B、C品系的北京鸭各150只至7周龄,每个品系随机选取8只公鸭和8只母鸭进行屠宰试验。探索超声波扫描技术活体测定北京鸭胸肌厚度的方法,建立北京鸭胸肌厚度与胸肌质量、胸肌率等指标的相关关系。试验2饲养B系肉鸭1900只至7周龄,随机选取100只公鸭和100只母鸭进行屠宰试验,测定胸肌厚度和主要屠体指标,进行相关分系。结果:超声波测定北京鸭的胸肌厚度,图象清晰;大体型品系北京鸭7周龄的胸肌厚度达到22.3mm,小体型为16.2和16.3mm。胸肌厚度与胸肌质量、胸肌率的相关系数分别为0.6328(P<0.01)、0.4721(P<0.01),均达到极显著水平。结果表明,超声波扫描技术能够准确地测定北京鸭的胸肌厚度;北京鸭的胸肌厚度与胸肌产量、胸肌率存在显著的正相关关系。 相似文献
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1. The purpose of this study was to investigate differences in the development of components of the cell/matrix linkage in two functionally different muscle types: the pectoralis muscle, a major locomotory muscle in birds but not particularly functional in chickens, and the quadriceps muscle, a smaller and more functionally active muscle in the chicken. 2. The development of the extracellular matrix, basal lamina and sarcomere in the pectoralis and quadriceps muscles in chick embryos was examined biochemically to determine differences in the rate of development between these two muscles. Samples of these muscle types were dissected out from chick embryos from embryonic day 10 until 8 weeks post hatch. 3. Using SDS-PAGE electrophoresis and western blotting with antibodies against sarcomeric actin, laminin and collagens I, III and IV, it was apparent that muscle development begins earlier in the quadriceps muscle than in the pectoralis, and that late in the developmental process (d 18) both muscle types were well differentiated. The final concentration of collagens in the mature muscle remained higher in the quadriceps than in the pectoralis muscle. 4. The onset of development of the extracellular matrix, basal lamina and sarcomere was earlier in the quadriceps than the pectoralis, which could have functional implications for these muscles as a whole. 相似文献
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Tilley RE McNeil CJ Ashworth CJ Page KR McArdle HJ 《Domestic animal endocrinology》2007,32(3):167-177
We have used a porcine model of spontaneous differential fetal growth to investigate the effects of fetal size on muscle development. We hypothesized that altered muscle development may occur in small fetuses as a consequence of modified expression of selected genes of the insulin-like growth factor system. We examined the development of the Longissimus muscle (m. Longissimus) in small fetuses and their average sized littermates. We collected small for gestational age fetuses and their average sized sibling on days 45, 65 and 100 of gestation (term is 113-116 days). Small fetuses had significantly lower body weight at all three stages of gestation (p<0.05) and significantly reduced secondary to primary muscle fibre ratio in m. Longissimus on day 100 (p<0.05) compared to their littermates. On day 65, the expression of insulin-like growth factor receptor 1 and insulin-like growth factor binding protein 3 were significantly higher (p<0.05) in m. Longissimus of the small fetuses compared with their average sized littermates. On day 100, the expression of insulin-like growth factor receptor 1 remained significantly higher (p=0.001), in addition to significantly higher levels of insulin-like growth factor receptor 2 and insulin-like growth factor binding protein 5 in the small fetuses (p<0.05). No difference in levels of myogenin was observed between the small and average sized littermates. In conclusion, we demonstrate that reduced fetal muscle development is associated with an increased expression of several genes of the insulin-like growth factor system in small fetuses in mid to late gestation. 相似文献
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Growth dependent changes of fat gain, the number of fat cells in the cutlet muscle and the size of the fat cells in the bacon of the back were studied in dependence on feeding intensity with a total of 145 male castrates of the genotype (L X E) XSF. Between their 5th and 32nd weeks of life the animals were butchered at intervals of 3 weeks and the parameters were determined. The gain of fat and the intramuscular fat content were highest in the high-level variant (daily weight gain 720 g) and lowest in the low-level variant (daily weight gain 530 g). The diameter of the fat cells in the middle layer of the bacon of the back increased up to an age of 26 weeks and then remained constant. Differences between the feeding groups were registered; the animals of the high-level group had the biggest fat cells from the 14th week onwards. A nutrition-caused difference between the number of fat cells per mm2 of the cutlet muscle could not be found. The calculated total number of fat cells in the cutlet muscle increased due to growth up to an age of 26 weeks. The results provided basic knowledge of fat gain and influences on it in pigs and they indicate possibilities of making statements on fat retention determining the microstructure of the fat tissue of the living animal by means of biopsy. 相似文献
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The development of the venous drainage from the equine hypophysis cerebri was investigated in embryos and fetuses ca. 22nd to 270th day of gestation. The early venous drainage was represented by the right and left retrohypophysial veins which were tributaries of the primary head veins. In later development an anastomosis was formed between the contralateral retrohypophysial veins. This anastomosis was named the retrohypophysial sinus which was identical with the caudal intercavernous sinus of the postnatal animals. The development of the rostral intercavernous sinus was not observed. The right and left cavernous sinuses developed secondarily from the retrohypophysial sinus. The venous drainage was directed rostrolaterad into the ophthalmic veins. In addition to the rostrolateral route, a caudoventral route, represented by the right and left ventral petrosal sinuses, developed from the retrohypophysial sinus relatively late in the fetal period. Both the rostrolateral and caudoventral routes joined eventually the external jugular system basically resembling postnatal conditions. 相似文献
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Fetuses from linebred lean (L) and linebred obese (O) and reciprocal crossmatings were examined at 110 d of gestation for line, maternal and heterotic effects. There was no significant heterotic effect for any trait measured. A significant maternal effect was observed for adipose tissue lipoprotein lipase (LPL) activity and for serum triglycerides. The enzyme activity and triglycerides concentration were higher in fetuses from O dams than in fetuses from L dams. In a lipid clearance test, no maternal effect was observed for changes in serum concentrations of triglycerides and free fatty acids or in optical density (associated with the disappearance of injected Liposyn). Linebred O fetuses exhibited higher LPL activity in both the biceps femoris muscle and sc adipose tissue compared with linebred L fetuses. The LPL activity of the adipose tissue was higher than that of the skeletal muscle. The percentage of dry matter, percentage of triglycerides and protein/DNA were higher in the muscle of linebred O fetuses than in that of linebred L fetuses. Based on tissue LPL activity and on muscle compositional traits, linebred O fetuses were more mature at 110 d of gestation than were the linebred L fetuses. Maternal obesity had little detectable influence on fetal development of the pig when measured at 110 d of gestation. 相似文献
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Nishimura S Oshima I Ono Y Tabata S Ishibashi A Iwamoto H 《British poultry science》2006,47(4):426-432
1. The characteristics of melanocyte distribution in skeletal muscles in the Silky fowl were investigated in association with growth. 2. Pectoralis (PT) and iliotibialis lateralis (ITL) muscles from 1-, 3-, 5-, 10-, 20- and 30-week-old Silky males were weighed and collagen type I was detected in frozen sections immunohistochemically. 3. Melanocytes were observed in the collagen type I-immunopositive endomysium and perimysium in both muscles. 4. Image analysis indicated that the total area occupied by melanocytes in histological sections sharply decreased from 0.61% to 0.16% in PT muscle and from 1.67% to 0.33% in ITL muscle at 1 to 3 weeks, and then gradually decreased. The melanocyte area was larger in ITL muscle than in PT muscle until 10 weeks of age. 5. We concluded that the proportion of intramuscular melanocytes in the Silky fowl differs between types of muscles in the early stages of development, and it decreases with growth. 相似文献