Maternal Effect Of Food With Different Tannic And Protein Levels On House Mice (Mus Musculus)

Maternal effect is a situation where the phenotype of an organism is determined not only by the environment it experiences and its genotype, but also by the environment and phenotype of its mother, and can be found in several aspects including morphology, physiology and behavior of offsprings. This effect is also a phenotype reaction of offsprings themselves to the environmental heterogeneity. It is an important source of evolutionary dynamics, and might be a mechanism of population regulation. In this research, the maternal effect of food quality on house mice (Mus musculus) was studied, and we aimed to understand how the nutritious conditions during gestation of parents influence its offspring. The experimental food with different tannin (0% and 5%) and protein (15%,20% and 25%) were provided to healthy adult breeding groups and nonbreeding groups respectively for two weeks. Then we studied the effect of food with different tannic and protein on protein metabolistic rate, digestive tract morphology, immunological status, reproductive and agonistic behaviors, maternal nutrition on growing development, digestive tract morphology, immunology, reproductive and agonistic, nesting behavior of offspring in house mice (Mus musculus). This paper also tested the effects of age on nest-building of house mice. The major results from this research are as follows:1) Food with different tannin or protein had no obvious effect on food-intake in mice, however, significant positive correlation between feces amount in 24 hours and protein content. Tannin-added food would inhibit the increase of bodymass of adult non-breeding individuals, but there is no significant difference among protein groups. This indicated that tannin-based food can inhibit the increase of bodyweight and impact protein digestibility.2) Fed with tannin-added food have a significant inhibition on the dry weight of small intestine or colon and the length of small intestine of house mice; while the protein content positively correlated to dry weight of small intestine; but there is no significant difference between the other length and mass of digestive tracts and food quality. The weight of digestive system during pregnancy is heavier than that in nonbreeding period. Animal can adjust their digestive tract to certain extent based on trade-off between energy need and food quality.3) Fed with tannin-added food can greatly increase adrenal gland index and cortin content, but there is no significant inhibition on the index of spleen; however, the protein content positively correlated to index of spleen, but there is no significant difference with adrenal gland index and cortin content; the index of spleen were greatly increase during breeding period. The uterine index, testosterone, estradiol levels all display a significant positive correlation with food quality and demand of energy.4) Tannin-added food would partly restrain aggressive behavior between female and male (FMA), while defending behavior between male and male (MMD) exhibited a negative relationship with protein level in food, but there is no significant difference between other agonistic behaviors frequence and food quality and the attacking behavior and the defensive behavior show a low level. The breeding has a positive relationhip with non-social behavior, but a negative relationship for social behavior. This may be a regulating mechanism of house mice to decrease the energy expenditure by reducing activity.5) During pregnant period fed with food of different tannin and protein have no significant influences on sex ratio, bodymass, and survival of offspring, but can greatly inhibit morphological and neurological development of offspring. The protein levels positively correlated to litter size and triiodothyronine content in serum, but a negative relationship for Thyroxine content.6) During pregnant period, tannin-added food has a significant inhibition on the dry weight of stomach, colon and length of small intestine, and testicular index; ehereas increase the weight of adrenal gland and the corticosterone levels in dejecta. However, the length of caecum and testosterone levels were both positively correlated with protein levels. This implied that deficient food nutrition during pregnancy would affect digestive tract traits, immunology and reproductive ability of offspring through maternal effect.7) Pregnant females fed tannin-added food would prohibit nesting ability of male offsprings; while the nesting ability of female offsprings was weakly and positively related to food proteinlevels. Food with different tannin and protein levels in during pregnant perriod exerted insignificant influence on agonistic behavior.8) House mice behaved good nesting capacity during sub-adulthood, the house mice nested well in both adult and subadult stages, because they could complete a stable cup-shaped nest, while the juvenile group could not establish stable nests, the difference of nesting capacity between male and female was not significant; and although the amount of cotton, nesting material, used by adults in four days were significantly higher than that in sub-adults, the nesting degree between the two groups was not significantly different after four days, which was related to the body size of experimental animals.In summary, the tannin and protein levels in food played important roles on protein digestibility, gastrointestinal morphology, immune, reproductive ability and social behavior, and showed great effects on morphological and neural development, digestive tract morphology, immunology, reproductive function and nesting behavior via maternal effects. We thus claimed that tannin and protein in food may be one of important regulators of population dynamics.