Circadian timing of behavior and physiology has direct implications for both survival and reproduction. A circadian pacemaker in the hypothalamic suprachiasmatic nucleus (SCN) coordinates the daily rhythms observed in most all aspects of biology and behavior, including reproductive and immune function. However, the precise mechanisms by which the SCN influences and interacts with these systems is not entirely clear. In these experiments we tested several hypotheses relevant to unresolved questions in the complex and bidirectional interactions between the circadian, reproductive and immune systems. In Chapter 3 we utilized a novel model of circadian arrhythmia in Siberian hamsters (Phodopus sungorus) to examine the consequences of circadian disruption on reproductive neuroendocrine function and fertility. In Chapter 4 we employed this model of circadian arrhythmia to determine whether circadian disruption compromised a major aspect of a coordinated immune response (cutaneous wound healing). Finally, in Chapter 5 we examined the molecular mechanisms by which the innate immune response to infection mediates suppression of reproductive function. Together, the work confirms and extends an emerging theme that the circadian system plays a pivotal role in the coordination and mediation of normal immune and reproductive function, and identifies novel phenomenology and mechanisms by which the circadian system may accomplish these effects.

Objective To study the feasibility of DNA barcoding in identification of host animals with plague.Methods Seven species were collected,including Lasiopodomys brandti,Spermophilus dauricus,Ochotona daurica,Phodopus campbelli,Allactaga sibirica,Meriones unguiculatus and Rhombomys opimus in the epidemic focus of Lasiopodomys brandti,Inner Mongolia,China.Liver was extracted and mitochondrial cytochrome oxidase subunit Ⅰ gene （CO Ⅰ） was analyzed.The GC content and genetic distance by Kimura-2-parameter（K2P） were calculated using MEGA5.0,and the phylogenetic trees were constructed with Neighbor-Joining （NJ） method.Results Sixty-one CO Ⅰ gene sequence fragments were barcoded,and each sequence was 657 bp in length.The GC% of A llactaga sibirica,Lasiopodomys brandti,Meriones unguiculatus,Ochotona daurica,Phodopus campbelli,Rhombomys opimus and Spermophilus dauricus were （46.945 ± 0.109）%,（43.836 ± 0.000）%,（40.313 ± 0.084）%,（47.514 ± 0.073）%,（41.838 ± 0.073）%,（40.335 ± 0.000）% and （39.467 ± 0.032）%,respectively,and the differences between them were significant（all P 〈 0.05）,except the difference between Rhombomys opimus and Meriones unguicalatus（P 〉 0.05）.The 1st codon GC contents of the seven species were （57.534 ± 0.000）%,（55.251 ± 0.000）%,（54.338 ± 0.000）%,（57.078 ± 0.000）%,（55.308 ± 0.057）%,（53.881 ± 0.000）% and （56.164 ± 0.000）%,respectively,and the differences between them were significant （all P 〈 0.05）,except the difference between Lasiopodomys brandti and Phodopus campbelli （P 〉 0.05）; the 3rd codon GC content of the seven species were （40.835 ± 0.328）%,（33.790 ± 0.000）%,（24.136 ± 0.253）%,（43.455± 0.218）%,（27.740 ± 0.207）%,（24.201 ± 0.000）% and （19.772 ± 0.097）%,respectively,and the differences were significant （all P 〈 0.05） among species,except the difference between Rhombomys opimus and Meriones unguicalatus （P 〉 0.05）.The average intraspecific genetic distance （K2P） was 0.003 and the average interspecific genetic distance was 0.234 8.A NJ tree showed 7 major clusters.Conclusion CO Ⅰ sequencing of DNA barcoding can be used to identify host animals with plague in the epidemic focus of Losiopodomys brandti,and can provide stronger evidences in identification of species based on morphology. Key words: DNA barcoding; CO Ⅰ gene; Plague

Beim HamsterPhodopus sungorus verhinderte Pinealektomie die durch lange Photoperioden bewirkte Beschleunigung der Entwicklung von Hoden und Anhangsdrusen. Die Befunde zeigen, dass die Epiphyse nicht ausschliesslich antigonadotroph wirkt, sondern auch an der progonadotrophen Wirkung langer Photoperioden beteiligt ist.