Genetic studies on the muscle protein turnover rate of coturnix quail

The validation of the urinary excretion of N-methylhistidine (N-MH) by quail as an index of the muscle protein turnover rate was tested using the criterion of the rate of recovery of radioactivity in urine following an intraperitoneal dose of l-[3-¹⁴C]methylhistidine. A genetic study on muscle protein turnover in quail was conducted using three genetically diverse lines (LL, large body size; SS, small body size; RR, random-bred control line) selected for body size. When l-[3-¹⁴C]methylhistidine was administered to 20-week-old male and female coturnix quail by direct intraperitoneal injection, approximately 90% of the l-[3-¹⁴C]methylhistidine was recovered by 96 hr postinjection. Recoveries were low in the egg and muscle. These results show that N-MH released from myofibrillar protein is not reutilized and the excretion of N-MH is a satisfactory index of muscle protein breakdown. In all lines, the amount of urinary N-MH excretion and fractional synthesis (K_s) and degradation (K_d) rates at the high growing period were higher than those at the low growing period. The K_s and K_d are significantly different among selected lines at both 3 and 6 weeks of age. At 3 weeks of age, the fractional rate of synthesis of the LL line (13.2%/day) was higher than that of the RR line (11.5%/day), whereas the SS (8.1%/day) was lower than that of the RR line (11.5%/day). The fractional rates of degradation of both the LL line (4.1%/day) and the SS line (5.6%/day) were lower than that of the RR line (7.0%/day) at 3 weeks of age. From these results, it was recognized that selection for body size gave rise to the changes in the muscle protein turnover rate.     

The changes in body temperature,oxygen consumption,CO2 production and muscle protein turnover rate by selection for body size in Japanese quail,Coturnix coturnix japonica

• 1.1. Body temperature, oxygen consumption, CO₂ production and muscle protein degradation rate were measured in the three quail lines selected for body size, a random bred line (RR) and two lines selected for large (LL) or small (SS) body size.
• 2.2. The body temperature at 15 weeks of age was highest for small body size line and lowest for large body size line.
• 3.3. The body temperature, oxygen consumption and CO₂ production of females were significantly higher than that of males.
• 4.4. The fractional degradation rate of muscle protein of SS, RR and LL lines were measured as 2.4, 1.6 and 1.2% per day in male, and 2.6, 1.7 and 1.4% per day in female.

     

Variation among lines selected for body size in the fractional rate of degradation of protein and acid protease activity in the muscle of quail (Coturnix coturnix japonica)

Fractional rates (%/day) of degradation of muscle protein were determined by measuring the output of NT-methylhistidine (NT-MH) in the excreta at 2 and 10 weeks of age in three lines of quail, a random-bred line and two lines selected for body size, one for increased and the other for decreased size. In all lines, fractional rates of degradation of muscle protein at 2 weeks of age were higher than those at 10 weeks of age. The fractional rate of degradation at 2 weeks of age was highest for the RR line, 9.1-9.2%/day. However, at 10 weeks of age, the rank order changed, and the RR line showed the lowest rate, 1.8-1.9%/day. The SS line (5.8-6.2%/day at 2 weeks and 5.8-5.9%/day at 10 weeks of age) was significantly higher than the LL line (4.1-4.2%/day at 2 weeks and 2.1-2.2%/day at 10 weeks of age). Acid protease activities in supernatants of homogenized muscle of the three lines of quail at 2 and 10 weeks of age were measured. In all lines, the acid protease activities in supernatant of homogenized muscle decreased from 2 to 10 weeks of age. At 2 weeks, the protease activity of the RR line was significantly higher than that of the LL and SS lines, which did not differ significantly. However, at 10 weeks of age, the SS line had higher activity in both sexes than the LL and RR lines. The results suggest that selection for body size brings about significant changes in both fractional degradation rate and acid protease activity in the muscle.     

Genetic parameters of body weight, muscle weight and skeletal characteristics in Japanese quail

Heritability, phenotypic and genetic correlations of body weight, muscle weight and skeletal characteristics of Japanese quail males at 8 weeks of age were investigated to obtain basal information on breeding and on genetic monitoring by morphometrical methods. For this study, 221 male progenies were used. Measurements were taken on body weight, muscle weight and four kind of skeletal characteristics (skeletal weight, skeletal length, skeletal width and skeletal height). Heritability estimates were 0.67 for body weight, 0.36 to 0.56 for muscle weight, 0.79 to 0.94 for skeletal weight, 0.35 to 0.77 for skeletal length, 0.17 to 0.32 for skeletal width and 0.41 to 0.84 for skeletal height, respectively. The phenotypic and genetic correlations were found to be highly positive between body weight, muscle weight and skeletal length. A high degree of genetic correlation was observed between femur length, ossa cruris length and ossa metatarsalia length. These results suggest that the body weight, muscle weight and skeletal characteristics can be improved by breeding and that these genetically determined skeletal characteristics might serve for strain identification and genetic monitoring in Japanese quail.     

Juvenile body weight and gonad development in a diallel cross among lines of Japanese quail (Coturnix coturnix japonica)

Summary The influence of growth on the extent of heterosis for juvenile body weight and gonad development was studied in a diallel cross among two lines of Japanese quail differing in adult body size. A total of 1,096 birds (563 males and 533 females) was slaughtered between 25 and 49 days of age. Reciprocal cross differences were non-significant. Heterosis showed a curvilinear course with age peaking during early growth (body weight) and during sexual maturity (gonad percentage). Overall advanced physiological development of the crossbreds probably begins as early as during the embryonic stages and results in earlier sexual maturity. In females, heterosis for percentage gonads was biased strongly by the presence of a hard-shelled egg in the uterus.     

Metabolic turnover rate: a physiological meaning of the metabolic rate per unit body weight.

In analogy to “specific gravity” or “specific heat” the expression “weight specific metabolic rate” (Ultsch, 1973) would be correct if the metabolic rate were directly proportional to body weight. In that case the quotient metabolic rate divided by body weight would be a constant, independent of body weight like density or specific heat are constants. The metabolic rate, however, is not proportional to body weight but to its $\text{3}\text{4}$ power. I have stated that heat flow per unit body weight has no proper physical or physiological meaning (Kleiber, 1970), but since found such a physiological meaning: in work with tracers turnover rates are measured as quotients of transfer rates/pool content. For similometric animals pool contents are proportional to body weight. For such animals therefore the quotient metabolic rate/body weight may have a proper physiological meaning, namely the turnover rate of chemical energy in the animal body.The usefulness of the turnover rate is limited. For the calculation of the energy requirement of horizontal animal locomotion, for example, the calculation from the metabolic rate per animal is preferable to the calculation based on the metabolic rate per unit body weight.     

Oviposition patterns and photoresponsivity in Japanese quail (coturnix coturnix japonica)

Abstract

Plots of oviposition times for an unselected group of 84 female Coturnix using the circular mean time for each bird on a central index time indicated a regularity in the data for individual birds. An analysis of pooled data using a moving average showed agreement with the temporal occurrence of the photoresponsive interval reported in the literature for gonadal development. These data were used to support a modification of existing hypothesis on the control of oviposition and ovulation.     

The effect of the dw gene on the muscle protein turnover rate in chickens

Fractional rates (%/day) of muscle protein synthesis and degradation of the genotypes Dw/Dw and dw/dw of male White Plymouth Rock chickens were determined by measuring the output of N-methylhistidine (N-MH) in the excreta at 2, 4, and 8 weeks of age. The fractional growth rate of dw/dw was significantly lower (P<0.05) than that of Dw/Dw at 2 weeks of age but not at 4 and 8 weeks of age. No significant differences in the degradation rate (K _d; %/day) were found at any age. A significant difference (P<0.05) between genotypes in the rate of synthesis (K _s; %/day) was found at 2 weeks of age (Dw/Dw=11.8, dw/dw=9.9) but not at 4 and 8 weeks of age. These results suggest that the dw gene has a depressing effect on the synthesis rate of muscle protein, and the difference between genotypes in the growth rate at the early stage is a reflection of this effect.     

Growth and muscle protein turnover in the chick

The growth rates of young chicks were varied from 0 to 10% per day by manipulation of the adequacy of the amino acid and energy supply. The rates of protein synthesis in the white breast (pectoralis thoracica) muscle and the dark leg (gastrocnemius and peronaeus longus) muscles were estimated by feeding l-[U-¹⁴C]tyrosine in amino acid/agar-gel diets (`dietary infusion'). This treatment rapidly and consistently produced an isotopic equilibrium in the expired CO₂ and in the free tyrosine of plasma and the muscles. Wholebody protein synthesis in 2-week-old chicks was estimated from the tyrosine flux and was 6.4g/day per 100g body wt. In 1-week-old chicks the rate of protein synthesis was more rapid in the breast muscles than in the leg muscles, but decreased until the rates were similar in 2-week-old birds. Synthesis was also more rapid in fast-growing Rock Cornish broilers than in medium-slow-growing New Hampshire×Single Comb White Leghorn chicks. No or barely significant decrease in the high rates of protein synthesis, in the protein/RNA ratio and in the activity of RNA for protein synthesis occurred in non- or slow-growing chicks fed on diets deficient in lysine, total nitrogen or energy. Thus the machinery of protein synthesis in the young chick seems to be relatively insensitive to dietary manipulation. In the leg muscles, there was a small but significant correlation between the fractional rate of growth and protein synthesis. A decrease in the fractional rate of degradation, however, appeared to account for much of the accumulation of muscle protein in rapidly growing birds. In addition, the rapid accumulation of breast-muscle protein in rapidly growing chicks appeared to be achieved almost entirely by a marked decrease in the fractional rate of degradation.     

Hatch weight selection: effect on post-hatch growth in the Japanese quail (Coturnix coturnix japonica)

The post-hatch growth of Japanese quail, weight selected at hatch, was investigated. The quail were grouped according to hatch weight as follows: Group I, 5.5-6.2 g; Group II, 6.3-7.0 g; and Group III, 7.1-7.6 g. Group III quail were 25 and 12% heavier at hatching than Group I and II quails, respectively, and reached a mature body weight which was 38 and 12% heavier than Group I and II quails, respectively. Gompertz growth parameters were not different in any of the groups. Feed and water consumption (g/kg body weight) rates were not significantly different among the three groups.     

Comparison of activities of several enzymes and protein constituents of oviducal and breast muscle of Japanese quail,Coturnix coturnix Japonica

• 1.1. Activities of several enzymes and protein constituents of magnum, isthmus, shell gland and breast muscle (pectoralis major) of Japanese quail, Coturnix coturnix japonica were compared.
• 2.2. The respective activity per g wet weight of lactate dehydrogenase, malate dehydrogenase and l-glycerol 3-phosphate dehydrogenase in pectoralis major was approx 20 times that of these enzymes in isthmus which showed the highest activity among oviducal tissues. On the other hand, the respective activity of lactate dehydrogenase was similar to that of malate dehydrogenase and was approx 10–20 times that of l-glycerol 3-phosphate dehydrogenase in each tissue.
• 3.3. Among NADPH-producing enzymes, NADP⁺-isocitrate dehydrogenase showed the highest activity in all tissues. The activity of malic enzyme was lowest in oviducal tissues, but was next to NADP⁺-isocitrate dehydrogenase in pectoralis major.
• 4.4. Sodium dodecyl sulfate polyacrylamide gel electrophoretic patterns of the whole homogenate, the supernatant and the precipitate fraction of magnum, isthmus, shell gland and pectoralis major showed tissue specific protein compositions. Proteins with molecular weight of 55,000, 70,000, 110,000 and 130,000 were observed in the respective precipitate (myofibrilar) fraction of magnum, isthmus and shell gland, but not in that of pectoralis major. It was noteworthy that the amount of myosin heavy chain of magnum was markedly less than that of other three tissues.

     

Heterosis among lines of mice selected for body weight

Summary After treatment of one strain of A. bitorquis and 12 strains of A. bisporus in modified monokaryotization solution, three types of mycelia were received: one is the original di- or heterokaryon, the other two were proven to be neohaplonts in A. bitorquis and two strains of A. bisporus. In neohaplonts of good fruiting strains, homokaryotic fruiting was observed.     

Heterosis among lines of mice selected for body weight

Summary To examine the effect of selection on levels of heterosis, crosses were made between three groups of six lines of mice, one group unselected (controls) and the other two selected for high (large lines) and low (small lines) 6-week body weight, respectively. The coefficient of inbreeding of each line was about 0.60. Each line was crossed reciprocally to one line from each of the parental groups, as well as producing purebred progeny. Heterosis for 3-week weight, 6-week weight and 3–6 week gain averaged 0.0%, 2.4% and 4.2%, respectively, and was higher for males than for females. Heterosis was more extensive in crosses involving large or control lines than in crosses with small lines. There was no detectable heterosis in several measures of developmental rate, such as age at vaginal opening. Food conversion efficiency and carcass composition were measured on a sample of the animals. Food consumption, gonadal fat pad weight, and hindquarters weight, each expressed as a proportion of body weight, exhibited –4.0%, 5.6%, and 2.3% heterosis, respectively.     

Soy germ protein concentrate diet decreased body fat weight and increased hindlimb muscle weight in rats

The purpose of this study was to investigate the effects of soy germ protein intake on body composition. Wistar rats were fed experimental diets for 16 weeks. These consisted of soy germ protein, soy protein, or casein. Abdominal adipose tissue weights significantly lower and hindlimb muscle weights were significantly higher in the soy germ protein group than in the casein group.     

Moulting cycles in European quail (Coturnix coturnix coturnix) under constant photoperiodic conditions

Abstract

Male and female European quails (Coturnix coturnix coturnix) were studied whilst being maintained in LD 12:12, at 20° C, for four years from birth. The birds exhibited the following phases: end of the first phase of the post‐juvenile moult, fattening and a period of nocturnal activity. Then sexual development is observed up to complete maturation at the age of four months. The second part of post juvenile moulting occurs towards the age of 5 to 6 months. During the following 6 months an important phase of reproduction is observed, thus completing their first year of life. The same sequence is repeated during the following years: a moult which lasts for 6 months in two (sometimes three) partial phases separated by episodes of reproduction; then an important period of reproduction (6 months) without moulting. The birds are capable of reproducing at all times except during moulting. The sequence of moulting begins each year in the same months as those for natural French populations. It thus seems that the annual periodicity and the organisation itself of the phenomenon of moulting is controlled in European quail by an endogenous circannual rhythm. In contrast, the natural cyclic expression of sexuality appears to be dependent on abiotic environmental and social factors.