Brucellosis of the common vole (Microtus arvalis)

A systemic disease occurred in a wild population of the common vole Microtus arvalis in South Moravia (Czech Republic) during the years 1999-2003. Acute infections were characterized by edema of extremities, occasionally with colliquating abscesses, arthritis, lymphadenitis, perforations of the skin resulting from colliquated abscesses, orchitis, and peritoneal granulomas. From the clinical samples, small Gram-negative coccobacilli were isolated and identified as Ochrobactrum intermedium by API 20NE and colistin sensitivity profiles. However, subsequent rrs (16S rRNA) and recA (recombinase A) gene sequencing analysis of two isolates (CCM 4915=CAPM 6434; CCM 4916=CAPM 6435) identified them as Brucella sp. with sequence identities of 100% to other Brucella spp. Analysis of the omp2a/b genes confirmed the two isolates as Brucella. In AMOS polymerase chain reaction (PCR), a 2000-bp fragment was generated that was not seen in other brucellae. Experimental infection of outbred ICR mice with these isolates resulted in a mortality rate of 50%. Based on the results of the molecular investigations and the mortality observed in experimentally infected mice we conclude that the epizootic was caused by Brucella sp. and not by Ochrobactrum intermedium. The study demonstrates the limitations of commercial biochemical test systems in accurately differentiating among Ochrobactrum and Brucella.     

Impact of behavior on central and peripheral circadian clocks in the common vole Microtus arvalis, a mammal with ultradian rhythms

In most mammals, daily rhythms in physiology are driven by a circadian timing system composed of a master pacemaker in the suprachiasmatic nucleus (SCN) and peripheral oscillators in most body cells. The SCN clock, which is phase-entrained by light-dark cycles, is thought to synchronize subsidiary oscillators in peripheral tissues, mainly by driving cyclic feeding behavior. Here, we examined the expression of circadian clock genes in the SCN and the liver of the common vole Microtus arvalis, a rodent with ultradian activity and feeding rhythms. In these animals, clock-gene mRNAs accumulate with high circadian amplitudes in the SCN but are present at nearly constant levels in the liver. Interestingly, high-amplitude circadian liver gene expression can be elicited by subjecting voles to a circadian feeding regimen. Moreover, voles with access to a running wheel display a composite pattern of circadian and ultradian behavior, which correlates with low-amplitude circadian gene expression in the liver. Our data indicate that, in M. arvalis, the amplitude of circadian liver gene expression depends on the contribution of circadian and ultradian components in activity and feeding rhythms.     

生态保留带中普通田鼠种群活动格局的初步的研究

目的研究生态保留带地栖息环境质量对普通田鼠活动格局的影响和普通田鼠对周围农作物的扩散.方法用新型无线电自动跟踪器从2003年5～10月和2004年3～9月研究了生态保留带中的普通田鼠种群.结果普通田鼠的巢区大小分别在125 m2 (最小凸起多边形方法)和30 m2(Kernel法),巢区大小比较稳定,巢区日间重叠率达到90%左右,巢区基本在生态保留带之内,包括不同核心区;夏天普通田鼠的白日活动比较活跃,包括多阶段活动格局,阶段间隔时间为1.7 h.结论生态保留带对普通田鼠提供高质量的栖息环境,持续高种群密度,对周围农地不会产生危害.     

抗草原兔尾鼠抗体制备及特异性检测

目的研究生态保留带地栖息环境质量对普通田鼠活动格局的影响和普通田鼠对周围农作物的扩散。方法用新型无线电自动跟踪器从2003年5~10月和2004年3~9月研究了生态保留带中的普通田鼠种群。结果普通田鼠的巢区大小分别在125 m2(最小凸起多边形方法)和30 m2(Kernel法),巢区大小比较稳定,巢区日间重叠率达到90%左右,巢区基本在生态保留带之内,包括不同核心区;夏天普通田鼠的白日活动比较活跃,包括多阶段活动格局,阶段间隔时间为1.7 h。结论生态保留带对普通田鼠提供高质量的栖息环境,持续高种群密度,对周围农地不会产生危害。     

Genetic evidence for tula virus in Microtus arvalis and Microtus agrestis populations in Croatia

To determine the threat of hantavirus infection to U.S. Forces, small mammals were sampled from training areas within Croatia. Of the 152 samples, 20 were positive for Tula virus (TUL), 12 common voles (Microtus arvalis) and eight field voles (Microtus agrestis). Sequences from M. agrestis were found in five and sequences from M. arvalis were found in six of seven sequence groups. The high percentage of the same TUL sequences in M. agrestis and M. arvalis suggests the co-occurrence of this virus in both Microtus species is not an accident. If M. agrestis field voles were accidentally infected with TUL, the percentage of polymerase chain reaction-positive animals should be lower than that of M. arvalis. Because the infection rate in M. arvalis (11.8%) was less than half of that found in M. agrestis (27.6%), it is unlikely that the predominance of positive M. agrestis could be due to accidental exposure. It is much more likely that the Croatian virus is circulating between both rodent species.     

Tempo, mode, the progenote, and the universal root.

Early cellular evolution differed in both mode and tempo from the contemporary process. If modern lineages first began to diverge when the phenotype-genotype coupling was still poorly articulated, then we might be able to learn something about the evolution of that coupling through comparing the molecular biologies of living organisms. The issue is whether the last common ancestor of all life, the cenancestor, was a primitive entity, a progenote, with a more rudimentary genetic information-transfer system. Thinking on this issue is still unsettled. Much depends on the placement of the root of the universal tree and on whether or not lateral transfer renders such rooting meaningless.