圈养大熊猫催产素水平与母性行为之间关系

Maintaining a good cub-rearing relationship is of great significance for the healthy development of newborn giant panda cubs. Oxytocin plays a key role in this cub-rearing relationship development during the breeding period. To investigate the relationship between oxytocin levels and maternal behavior, we sampled the maternal behavior of 6 adult female giant pandas (3 in lactation group, 3 in non-lactation group) at Chengdu Research Base of Giant Panda Breeding from June to September 2019 by using the focal sampling method, and tested the urine oxytocin level of each individuals by using enzyme-linked immunosorbent assay. The results showed that the oxytocin levels were significantly higher in the lactation group (278. 86 pg/mg ±44. 42 pg/mg) than in the non-lactation group. For the two types of breastfeeding groups, the level of oxytocin in the multiparous female pandas (185. 64 pg/mg ±44. 61 pg/mg) was significantly lower than that in the primiparous female pandas (465. 30 pg/mg ±82. 39 pg/mg). Compared with the primiparous female pandas, the multiparous female pandas had more embracing cub behavior (77. 45% ±1. 24%) and feeding behavior (15. 22% ±1. 62%), but less licking cub (14. 26% ±0. 91%) and position adjustment behavior (1. 69% ±0. 29%). Finally, we found the licking cub behavior was significantly positively correlated with the oxytocin level in the lactation group, and the embracing cub behavior was significantly negatively correlated with the oxytocin level in the lactation group. The results indicate that primiparous female pandas show more maternal behavior, less individual behavior and higher oxytocin levels. The results of this study suggest that the different reactions of oxytocin in the two types of giant panda females may help to improve the refined and differentiated breeding techniques for captive giant pandas in the future.     

薇甘菊萎蔫病毒寄主范围、传播媒介和危害特点

薇甘菊(Mikania micrantha H.B.K.)是华南地区重要的外来入侵植物.本文从田间薇甘菊萎蔫病株中分离获得薇甘菊萎蔫病毒(Mikania micrantha wilt virus,MMWV).在温室中通过人工摩擦将该病毒接种到9科27种植物上,发现MMWV能侵染其中的6科12种植物.利用透射电子显微镜观察该病毒颗粒呈球状,直径约30 nm.MMWV可由桃蚜(Myzus persicae)以非持久性方式传毒.薇甘菊植株接种MMWV毒30 d后,其茎的长度、叶、茎和根的鲜重分别比健康对照植株减少了75.3％、91.6％、79.5％和75.6％,被侵染的薇甘菊出现萎蔫、皱缩、叶畸形等症状.实验室和野外条件均观察到MMWV可以严重抑制薇甘菊的生长,利用MMWV控制薇甘菊的生物入侵有待进一步深入研究.     

基于转录组的肝细胞癌分子分型研究进展

肝细胞癌是恶性程度极高的肿瘤之一,患者的发病率和死亡率都位居恶性肿瘤前列.虽然传统临床病理诊断和分级治疗策略得到了极大的发展,并显著改善了肝细胞癌患者的生存情况,但至今肝细胞癌患者的5年生存率仍然较低.基因测序技术的进步和发展加速了肿瘤基因组学的研究,也帮助科学家认识了肿瘤的异质性及其发生、发展的分子机制.近20年,科学家基于转录组数据提出了许多与病理特征相关的肝细胞癌分子亚型,并对其生物学特性和分子特征进行了深入的挖掘.若能将转录组分子亚型与临床病理分级系统综合考虑,用于肝细胞癌病理诊断和分级治疗,将有望改善病人的生存情况,推进肝细胞癌病人的个体化医疗进程.