Significance
Phylogenies are the basis of many ecological and evolutionary studies. However, zokor phylogeny and speciation patterns are heavily debated. This study disentangled the phylogeny and speciation of zokors genomically. Six species of the
Eospalax
were separated into high-altitude
E. baileyi
and
E. smithi
and the rest four low-altitude species by recent Qinghai-Tibet Plateau uplift 3.6 million y ago.
E. rothschildi
and
E. smithi
speciated south of the Qinling–Huaihe Line, where refuges were supplied during glaciation. Introgression and incomplete lineage sorting led to the complex phylogeny of zokors. Genomic islands were formed due to ancient polymorphisms and divergence hitchhiking. This study concluded that climatic, geological, and tectonic events shaped the phylogeny and speciation of zokors in China.
The effect of combined levonorgestrel (P) and quinestrol (E) on the fertility of striped field mouse (Apodemus agrarius) has not been evaluated. We performed a series of experiments in both the laboratory and field to assess the effect of P and/or E on the fertility of A. agrarius. In the laboratory, to test the time-dependent anti-fertility effects of P and E, as well as their mixtures, 90 male striped field mice were randomly assigned to 6 treatment groups (n = 60), and a control group (n = 30). Mice in 3 treatment groups were administered 1 of the 3 compounds (1 mgkg -1 [body weight] EP-1, 0.34 mgkg -1 E, 0.66 mgkg -1 P) for 3 successive days (another half for 7 successive days) via oral gavage; mice were then sacrificed 15 and 45 days after initiating the gavage treatment. Our findings indicated that E and EP-1 treatment, but not P or control treatment, significantly decreased the sperm count in the caudal epididymis, as well as the weight of the testes, epididymides, and seminal vesicles. Additionally, fertile female mice mated with E-and EP-1-treated males produced smaller pups. These data indicate that E and EP-1 can induce infertility in male A. agrarius. In the field, the population density of A. agrarius was significantly influenced by EP-1, and the rodent density in the treatment group was lower than that in the control group. Overall, our results indicate that EP-1 is an effective contraceptive in A. agrarius, a dominant rodent species in the farmland.
Animal‐mediated seed dispersal is an important ecological process in which a strong mutualism between animals and plants can arise. However, few studies have examined how a community of potential seed dispersers interacts with sympatric seed trees. We employed a series of experiments in the Qinling Mountains in both semi‐natural enclosure and the field to assess the interactions among 3 sympatric rodent species and 3 Fagaceae tree seeds. Seed traits all showed similar tannin levels but markedly different physical traits and nutritional contents. We found that seeds with heavy weight, thick coat, and high nutritional contents were less likely to be eaten in situ but more often to be eaten after dispersal or hoarded by rodents. These results support both the handling time hypothesis and the high nutrition hypothesis. Surprisingly, we also found that rodents, maybe, preferred to consume seeds with low levels of crude fiber in situ, and to harvest and hoard those with high levels of crude fiber for later consumption. The sympatric rodent species, Cansumys canus, the largest rodent in our study, harvested and hoarded more Quercus variabilis seeds with high physical and nutritional traits, while Apodemus draco, the smallest rodent, harvested more Q. serrata seeds with low physical and nutritional traits, and Niviventer confucianus harvested and hoarded more Q. aliena seeds with medium physical and nutritional traits. Our study demonstrates that different seed traits play different roles in influencing the seed fate and the shaping of mutualism and predation interactions within a community of rodent species.
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