Woodring J, Chandler L J, Oray C T, McGaw M M, Blair C D, Beaty B J
Department of Microbiology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
Am J Trop Med Hyg. 1998 May;58(5):587-8. doi: 10.4269/ajtmh.1998.58.587.
La Crosse (LAC) virus is transmitted horizontally to vertebrates and vertically to progeny by Aedes triseriatus mosquitoes, and in northern midwestern states, this virus overwinters in diapausing eggs of the vector. In Florida, the vector remains active throughout the year and does not diapause. To determine if there is an association between diapause and vertical transmission efficiency of LAC virus, transovarial transmission (TOT), and filial infection (FI) rates were determined for geographic strains of Ae. triseriatus. The TOT rates were not significantly different for Ae. triseriatus originating from Florida (78%) and those from Wisconsin (85%). The FI rates did differ significantly between the two groups (33% and 45%, respectively, for the Florida and Wisconsin mosquitoes). Furthermore, a line of mosquitoes was selected from a Wisconsin colony that had a reduced diapause phenotype (the AD- strain). While this strain displayed TOT rates that were the same as the other Wisconsin mosquitoes (85%), the FI rates were significantly lower (34%), indicating a reduction in TOT efficiency. The role of vertical transmission capacity in LAC virus endemicity remains to be determined.
拉克罗斯（LAC）病毒通过三带喙库蚊在水平方向传播给脊椎动物，并在垂直方向传播给后代。在中西部北部各州，这种病毒在媒介的滞育卵中越冬。在佛罗里达州，媒介全年都很活跃，不会进入滞育状态。为了确定滞育与LAC病毒的垂直传播效率之间是否存在关联，测定了三带喙库蚊地理品系的经卵传递（TOT）和子代感染（FI）率。来自佛罗里达州的三带喙库蚊（78%）和来自威斯康星州的三带喙库蚊（85%）的TOT率没有显著差异。两组之间的FI率确实存在显著差异（佛罗里达州和威斯康星州的蚊子分别为33%和45%）。此外，从威斯康星州的一个蚊群中选择了一个滞育表型降低的品系（AD-品系）。虽然该品系的TOT率与其他威斯康星州蚊子相同（85%），但其FI率显著较低（34%），表明TOT效率降低。垂直传播能力在LAC病毒地方性流行中的作用仍有待确定。
