| 释义 |
sporocyst
spo·ro·cyst S0663500 (spôr′ə-sĭst′)n.1. A resting cell that produces asexual plant spores.2. A protective structure containing the infective sporozoites of an apicomplexan parasite.3. A saclike larval stage in many trematodes, from which the rediae emerge.sporocyst (ˈspɔːrəʊˌsɪst; ˈspɒ-) n1. (Zoology) a thick-walled rounded structure produced by sporozoan protozoans, in which sporozoites are formed2. (Zoology) the saclike larva of a trematode worm that produces redia larvae by asexual reproduction3. (Biology) any similar structure containing sporesspo•ro•cyst (ˈspɔr əˌsɪst, ˈspoʊr-)
n. 1. a. a case produced by a sporozoan. b. the sporozoan within such a case. 2. a resting or dormant cell that produces spores. 3. the first, saclike stage of many trematode worms, giving rise to cercariae by budding. [1860–65] Sporocyst
sporocyst[′spȯr·ə‚sist] (botany) A unicellular resting body from which asexual spores arise. (invertebrate zoology) A resistant envelope containing an encysted sporozoan. An encysted sporozoan. The first reproductive form of a digenetic trematode in which rediae develop. Sporocyst (l) A stage in the development of some unicellular animals of the class Sporozoa, for example, coccidians and grega-rines. Embryos, or sporozoites, develop in sporocysts. In coccidians sporocysts develop as a result of division of the zygote into several mononuclear cells. The entire zygote in gregarines is converted into sporocyst. (2) The first parthenogenetic generation in trematodes whose larvae are miracidia. In most trematodes the miracidia are transformed into sporocysts as soon as they penetrate the tissues of the intermediate host, a gastropod. A sporocyst is saccular or tubular in shape. In some species sporocysts have excretory organs, or protonephridia. The second parthenogenetic generation, the redia, usually develops from embryonic cells in the body cavity of the sporocyst. Only in a few species, for example, the lancet fluke, does another generation of sporocysts form from the embryonic cells. sporocyst
sporocyst [spor´o-sist] 1. any cyst or sac containing spores or reproductive cells; the oocyst of certain protozoa in which sporozoites develop.2. the larval stages of flukes in snails.spo·ro·cyst (spō'rō-sist), 1. A larval form of digenetic trematode (fluke) that develops in the body of its molluscan intermediate host, usually a snail; the sporocyst forms a simple saclike structure with germinal cells that bud off internally and develop into other larval types that continue this process of larval multiplication (considered to be a form of polyembryony).
See also: miracidium, redia, cercaria. 2. A secondary cyst that develops within the oocyst of Coccidia, a group of sporozoans that includes many of the most important disease agents of domestic animals and fowl; the sporocyst develops from a sporoblast and produces within itself one or several sporozoites, the infective agents for infection and multiplication in the next host. [sporo- + G. kystis, bladder] sporocyst (spôr′ə-sĭst′)n.1. A resting cell that produces asexual plant spores.2. A protective structure containing the infective sporozoites of an apicomplexan parasite.3. A saclike larval stage in many trematodes, from which the rediae emerge.spo·ro·cyst (spōr'ō-sist) 1. A larval form of digenetic trematode (fluke) that develops in the body of its molluscan intermediate host, usually a snail.
See also: cercaria2. A secondary cyst that develops within the oocyst of Coccidia, a group of sporozoans that includes many of the most important disease agents of domestic animals and fowl. [sporo- + G. kystis, bladder]sporocyst a cyst producing asexual spores. |