疟原虫
疟原虫（Plasmodium），是人疟疾的病原体。寄生于人体的疟原虫有四种，即间日疟原虫（P.vivax Grassi and Feletti，1890）、三日疟原虫（P.malariae Laveran，1881）、恶性疟原虫（P.falciparum Welch，1897）和卵形疟原虫（P.ovale Graig，1900），属于色藻界-顶复门-无类椎体纲-血孢子虫目-疟原虫科。这些疟原虫有蚊虫和人两个宿主，包括蚊体内的有性繁殖和人体内的无性增殖，携带疟原虫的按蚊通过叮咬人而传播，引起疟疾寒热往来发作，俗称“打摆子”。
疟原虫结果如下图：
疟原虫结构
疟原虫蚊虫内传播循环
A mosquito may ingest on the order of 10^3 to 10^4 gametocytes [配子体] from an infected human that quickly differentiate into male and female gametes[雌、雄配子] that mate to produce zygotes[合子], which, in turn, differentiate into ∼10^2 to 10^3 motile ookinetes[动合子]. Ookinetes then migrate within the blood bolus until they reach the midgut epithelium, where they then traverse and differentiate into oocysts[卵囊]. Upon maturation, each oocyst releases thousands of sporozoites[子孢子] into the hemocoel, followed by invasion of the mosquito salivary glands. The transmission cycle is completed when the infected mosquito bites the next vertebrate host and delivers some of the sporozoites with the saliva.
——Sibao Wang， PNAS, 2012
-
image.png
疟原虫侵染循环.jpg
核型多角体病毒BmNPV
家蚕核型多角体病毒(BmNPV)是蚕桑生产中危害最严重的病毒病，家蚕是BmNPV的唯一自然宿主。而BmNPV（NPV）病是养蚕生产上最常见的危害最严重的一类蚕病，家蚕患此病的后期常流出脓汁，内含大量的多角体病毒，俗称脓病。BmNPV（Bombyx mori Nucleopolyhedrovirus, 家蚕核型多角体病毒）
摄入的包涵体occlusion body在幼虫中肠的碱性环境中解离，释放出包埋在其中的 ODV(occlusion-derived virus)，ODV穿过中肠围食膜peritrophic membrance到达中肠上皮细胞的微绒毛处，在其中进行复制和增殖，从而引发原发性感染。在杆状病毒的原发性感染中，产生少量的子代病毒粒子出芽病毒BV( budded virus)，形成的BV进而侵染昆虫的其他组织，引起全身性感染。随着染病昆虫的死亡和组织细胞的破裂，OB被释放到自然环境中，从而起始下一轮生活周期。
-
The process of infection with BmNPV in silkworms
After passing through the peritrophic membrane, the viral nucleocapsid fuses with the epithelial cell membrane. It starts DNA replication and translation for the BVs, causing the secondary infection, which spreads in the host cells and tissues. While the ODVs can reassemble to form new viruses that spread among hosts.
——Fan, Y. X. Front Microbiol, 2023
网友评论