Sow Reproductive Stress and Its Syndrome

In this paper, we put forward ＂Reproductive Stress＂ hypothesis, and the main viewpoints are as below. The special reproductive tasks such as estrus, pregnancy, childbirth and lactation themselves are stressors which cause violent stress, and this kind of stress was called reproductive stress. Fetus is also a special stressor for female. The corticotropin releasing hormone （CRH） and fetal glucocorticoid （GC） secreted by fetus and placenta also cause stress, and this kind of stress was named female passive stress. Fetus develops in uterus, and the stress caused by uterine tension and intrauterine environment was named fetal intrauterine stress. Humans and animals need stress mechanisms to help themselves accomplish reproductive tasks, e. g., involvement of CRH, adrenocorticotropic hormone （ACTH） and epinephrine. Therefore, childbirth may be origi- nally motivated by the fetal intrauterine stress. Under the conditions of not enough nutrition or heavier reproductive tasks, females have to mobilize body reservoir to assure reproducing that aggravates reproductive stress. Moreover, reproductive stress is a long lasting experience for female, which must cause changes in endocrine secretion （ e. g., constant increasing of CRH and GC）. It thereby weakens the female＇s immune functions, causes body damages and makes them more susceptible to diseases. The main clinic symptoms include leg and foot weakness syndrome, anoestrus, subinvolution of uterus and endometritis. We summarized the causes, main clinical symptoms and pathogenesis of reproductive stress and provided applicable measures to prevent sows from reproductive stress.

Oxidative Stress and Role of Natural Plant Derived Antioxidants in Animal Reproduction

The experimental knowledge on the role of oxidative stress,and beneficial and detrimental effects of plant derived antioxidants in male and female animal reproduction are reviewed in this article.Free radical-induced oxidative stress in animal reproduction causes great loss to livestock industry.Antioxidant therapy has been implicated to be effective in preventing diseases resulted from oxidative stress.Considering the advantages of lower side effects of natural antioxidants than those of synthetic antioxidants,plants or their extracts have been extensively utilized in animals.Although many advances have been gained on application of plant derived antioxidants in alleviating oxidative stress,debatable issues still exist.Because many opposite effects were observed even using plant extracts containing similar bioactive substances in the same animal species.Therefore,plant derived antioxidants,like free radicals,are ＂double-edged swords＂ in animal reproduction,representing that they may exhibit beneficial or detrimental effects in animal reproduction,including spermatogenesis,semen functions,estrous cycles,ovulation,ovary functions,endometrium,embryo development,and pregnancy.Besides dose-dependent manner as an explanation of plant extracts＇ dual function,future studies are needed to investigate the mechanism of double-edged actions of plant derived antioxidants in different animal reproduction systems.

Transcriptome analysis of hsp18.3 functions and regulatory systems using RNA-sequencing in the red flour beetle,Tribolium castaneum

The red flour beetle, Tribolium castaneum, is a major agriculture pest of stored grain, cereal products and peanuts for human consumption. It is reported that heat shock protein 18.3 of T. castaneum（Tchsp18.3） plays a significant role in stress resistance, development and reproduction. However, the regulatory systems of Tchsp18.3 remain unknown. Therefore, we compared the global transcriptome profiles of RNA interference（RNAi）-treated larvae（ds-Tchsp18.3） and control larvae of T. castaneum using RNA sequencing. Overall, we obtained 14 154 435 sequence reads aligned with 13 299 genes. Additionally, 569 differentially expressed genes（DEGs） were identified from the ds-Tchsp18.3 and control groups, of which 246 DEGs were annotated in the 47 Gene Ontology（GO） functional groups and 282 DEGs were assigned to 147 Kyoto Encyclopedia of Genes and Genomes（KEGG） biological signaling pathways. The DEGs encoding viperin, dorsal, Hdd11, PGRP2, defensin1 and defensin2 were simultaneously related to immunity and stress responses, which suggests that cross-talk might exist between the immunity and stress responses of T. castaneum. The knockdown of Tchsp18.3 gene expression suppressed the antioxidant activity process, which most likely modulated the effects of Tchsp18.3 on development and reproduction. Furthermore, the DEGs, including Blimp-1, Gld, Drm, Kinesin-14, Pthr2, Delta（11）-like and EGF-like domain protein 2, were also associated with the development and reproduction of ds-Tchsp18.3 insects. Additionally, knockdown of Tchsp18.3 amplified the serine protease（SP） signaling pathway to further regulate stress responses and innate immunity as well as development and reproduction of the red flour beetles. These results provide valuable insight into the molecular regulatory mechanism of Tchsp18.3 involved in insect physiology and further facilitate the research of suitable and sustainable management for pest control.

Effects of UV-A exposures on longevity and reproduction in Helicoverpa armigera, and on the development of its F1 generation

Helicoverpa armigera adults display a conspicuous positive phototactic behavior to light stimuli, and are especially sensitive to ultraviolet （UV） light. The effects of UV-A （longwave） exposures on adult longevity and reproduction in H. armigera were investigated, as well as the development of the Ft generation. Paired adults were exposed to UV-A for various time periods （0, 1, 5 and 9 h/day）, until the end of adult life. The results showed that adult longevity decreased with increasing exposure time for both sexes, and a significant decrease was observed after exposure for 5 and 9 h/day. Fecundity increased when adults were exposed for 1 and 5 h/day, and a significant difference was observed in the 5 h/day group. Oviposition rates of females in all treatments were significantly higher than in the control. Exposure to UV-A for longer periods （5 and 9 h/day） caused a decline in cumulative survival of F1 immature stages, but no significant differences were found in egg hatch, pupation and eclosion. The developmental periods of F1 larvae were significantly prolonged after exposure to UV-A for 5 and 9 h/day. UV-A radiation had no significant effects on F1 pupal period.