田野小家鼠种群特征研究

近年,关于种群特征的研究,当首推夏武平等(1982)对长爪沙鼠的种群动态及其调节的研究,国内对种群特征间关系的进一步探研尚不多见,而该工作对动物种群动态的预测是至关重要的。 小家鼠(Mus musculus L.)的种群特征包括诸多方面,如性比、年龄结构、胎仔数、怀孕率和身体大小等,它们的变化均与一定的种群数量相联系,今在过去工作的基础上作一些新的探求。     

Response to Divergent Selection for Nesting Behavior in MUS MUSCULUS

Replicated bidirectional selection (with control lines) for nest-building behavior in Mus musculus, where nesting scores consisted of the total weight of cotton pulled through the cage lid during four days of testing, yielded an eight-fold difference between high and low lines after 15 generations of selection. The overall realized heritability pooled across lines and replicates was 0.18 ± 0.02 (0.15 ± 0.03 for high nesting scores and 0.23 ± 0.04 for low nesting scores), or 0.28 ± 0.05 when adjusted for within-family selection. Across the 15 generations and the entire experiment, average body weight and number of infertile matings increased, while average litter size decreased, although these changes were not consistent across lines. Inbreeding could account for average decreases in the fertility traits, but there was also a correlated response to selection, since both high lines showed increased litter size and decreased infertile matings.     

Chromosome Markers in MUS MUSCULUS: Strain Differences in C-Banding

The mitotic chromosomes of several inbred strains of mice and a series of F(1) hybrids have been analyzed by quinacrine staining and further characterized by the centromeric heterochromatin banding (C-banding). Inbred strains had the same amount of C-banding material on homologous chromosomes but showed variation in the amount on different chromosomes. F(1) hybrids showed characteristics of each parent and it appears that the amount of C-banding on each chromosome is a simple inherited polymorphism. In this study 12 different chromosomes could be distinguished by their C-banding, and these can be used as normal chromosome markers.     

Q- and C-Band Chromosome Markers in Inbred Strains of MUS MUSCULUS

Differences in the number of chromosomes with secondary constrictions and in the size of the C-band region on certain chromosomes have been observed among the following inbred strains of Mus musculus: C57BL/10J, C57BR/cdJ, DBA/1J, CBA/J, BALB/cJ, and AKR. These differences are useful as indicators of the location of rRNA genes and as normal chromosome markers. The size of each C-band region appears to remain constant over many generations. Only one probable change in the size of a C-band region was found.     

Nucleolus Organizers in MUS MUSCULUS Subspecies and in the Rag Mouse Cell Line

Silver staining has been used to detect active nucleolus organizer regions (NOR's). By this criterion six mouse chromosomes, numbers 12, 15, 16, 17, 18 and 19, can have an NOR. The number and distribution of chromosomes with NOR's vary among inbred strains of Mus musculus musculus (C57BL/6J, BALB/cJ, C3H/HeJ and C3H/StCr1BR) and in M. musculus molossinus. In a musculus x molossinus F₁ hybrid, nucleolus organizers from each parent are silver stained.—Chromosomes which have NOR's in diploid cells also show them in tetraploid cells and in established cell lines. The BALB/cJ strain shows Ag-staining of NOR's on chromosomes 12, 15, 18 and occasionally 16. In the RAG cell line, which was derived from BALB/c, active NOR's are seen on 12, 15 and 18, even after these chromosomes have undergone structural rearrangements in the cell line. Some correlation exists between the amount of Ag-stain and the size of a secondary construction region, with a large amount of Ag-stain present on a chromosome which has a prominent secondary constriction. There is no correlation between the amount of Ag-stain and the presence or absence of C-band material.     

Comparative Autosomal Linkage in Mammals: Genetics of Esterases in MUS MUSCULUS and RATTUS NORVEGICUS

Recombination between Esterase-4 and Esterase-2 in the rat was not observed in 278 backcross offspring. Es-4 is thus included within the "esterase cluster" in Linkage group V. A new map of this region was constructed and the relationship of the four esterase loci was found to be: Es-4-(9.6+/-1.6 cM)-Es-2, Es-4-(1.5+/-0.7cM)-Es-3. Homology of this region with a region of Linkage Group XVIII (Chromosome 8) of the mouse was proposed on the basis of tissue distribution, subcellular localization and response of enzymes to inhibiotrs. Specifically, rat Es-1 was suggested as the homolog of mouse Es-6. An autosomal segment comprising at least 15cM of the rat and mouse genomes appears to have remained relatively intact with respect to genetic content during rodent speciation. In addition, a new polymorphism for mouse esterase was described. The locus was designated Esterase-10 (Es-10) and proposed as the mouse homolog of human Esterase D. Linkage of Es-10 with nucleoside phosphorylase-1-(Np-1) on Chromosome 14 was established.     

Quantitative Genetic Analysis of Temperature Regulation in MUS MUSCULUS. I. Partitioning of Variance

Heritabilities (from parent-offspring regression) and intraclass correlations of full sibs for a variety of traits were estimated from 225 litters of a heterogeneous stock (HS/Ibg) of laboratory mice. Initial variance partitioning suggested different adaptive functions for physiological, morphological and behavioral adjustments with respect to their thermoregulatory significance. Metabolic heat-production mechanisms appear to have reached their genetic limits, with little additive genetic variance remaining. This study provided no genetic evidence that body size has a close directional association with fitness in cold environments, since heritability estimates for weight gain and adult weight were similar and high, whether or not the animals were exposed to cold. Behavioral heat conservation mechanisms also displayed considerable amounts of genetic variability. However, due to strong evidence from numerous other studies that behavior serves an important adaptive role for temperature regulation in small mammals, we suggest that fluctuating selection pressures may have acted to maintain heritable variation in these traits.     

草原兔尾鼠和昆明白小鼠卵透明带3 DNA疫苗免疫不育效果的研究

为探讨不同种类小鼠卵透明带3（zp,）的免疫不育效果,并筛选高效且具有物种特异性的DNA抗生育疫苗,本研究选择草原兔尾鼠卵透明带3（Lzp3）和昆明白小鼠卵透明带3（Mzp3）构建不同的DNA抗生育疫苗表达载体,pcDNA3-mzp3（pcD-M）、pcDNA3-1zp3（pcD-L）、pcDNA3-aat-comp-mzp3（pcD-ACM）和pcDNA3-aat-comp-lzp3（pcD-ACL）分别免疫NIH小白鼠。研究中用水动力转染技术取代传统的Hela细胞真核转染检测小鼠体内真核表达情况．结果表明四种质粒均能在小鼠肝脏中进行表达;ELISA图示表明重组质粒均能使小鼠激发较高水平的特异性抗体;抗生育结果表明四种DNA疫苗均具有免疫不育的效果（P〈0．05）,其中pcDNA3-aat-comp-mzp3（pcD-ACM）的免疫效果最好（P〈0．01）;卵巢病理切片H．E染色结果显示pcD-M和pcD-L组卵巢结构与对照小鼠区别不大,而pcD-ACL和pcD-ACM组卵巢结构发生病理性变化。结果初步说明草原兔尾鼠和昆明白小鼠卵透明带3对NIH小白鼠均有抗生育效果,但不具有物种特异性。     

SPATIAL DISTRIBUTION OF FEEDING ACTIVITY IN THE WILD HOUSE-MOUSE (MUS MUSCULUS L.)

Solitary house mice confined in a large pen were supplied with wheat in wooden trays distributed evenly throughout the area, and the number of grains removed daily from each was counted. A mouse tended to feed sporadically over the whole area, but feeding was more intense at a few trays, not necessarily near the nest, and not the same on successive nights. When new sources of the same food were introduced a mouse tended to patronize them during the first night. At the same time there was a significant drop in the number of the old trays visited. This suggested that new food sources stimulated investigation rather than avoidance.     

小家鼠种群中长期预测—灰色系统模型及随机序列分析

小家鼠种群中长期波动受很多因素影响,采用灰色系统模型及随机序列分析的方法可以较好地从宏观上预测其波动趋势。本文以灰色系统GM(1,1)模型为基础,利用历年小家鼠种群数量的调查值,对其变动趋势进行预测;然后,对预测剩余误差进行随机序列分析,建立线性预测式预测随机项;趋势预测值与随机项预测值的和,做为小家鼠种群中长期波动的预测。对新疆天山北麓农区1969年至1979年小家鼠自然种群数量的模拟结果表明,本文中的方法是较为简便有效的。