Transovarian and Transstadial Transmission

Transovarial or transovarian transmission (transmission from parent to offspring via the ovaries) occurs in certain

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...

vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

s as they transmit

pathogens In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a ger ...

from parent to offspring. This process, used by a wide variety of parasites, is also known as vertical transmission. For example, '' Rickettsia rickettsii'', carried within

tick Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living ...

s, is passed on from parent to offspring tick by transovarial transmission. This is in contrast to parasites such as '' Rickettsia prowazekii,'' which are not passed on by transovarian transmission due to killing the vector that carries it (in this case, the human louse). Other examples of parasites that use this mechanism of transmission include the

aedes ''Aedes'' is a genus of mosquitoes originally found in tropical and subtropical zones, but now found on all continents except perhaps Antarctica. Some species have been spread by human activity: '' Aedes albopictus'', a particularly invasive sp ...

mosquito vector of the

yellow fever Yellow fever is a viral disease of typically short duration. In most cases, symptoms include fever, chills, loss of appetite, nausea, muscle pains – particularly in the back – and headaches. Symptoms typically improve within five days. ...

virus and in phlebotomine sandflies that transmit

pappataci fever Pappataci fever (also known as Phlebotomus fever and, somewhat confusingly, sandfly fever and three-day fever) is a vector-borne febrile arboviral infection caused by three serotypes of Phlebovirus. It occurs in subtropical regions of the East ...

. Richard Dawkins in "The Extended Phenotype" notes that "bacterial endosymbionts of insects which are transmitted transovarially" share an interest in the "success of their host's gametes.....as well as the survival of their host's body." In this case, "the interest of the host genes and parasite genes might not be quite identical, but they would..... be very much closer than the case of fluke and snail." where host and parasite have different means of propagation into the next generation, and therefore more divergent interests.

References

* Murray, Patrick R.; Rosenthal, Ken S.; Pfaller, Michael A. Medical Microbiology, Fifth Edition. United States: Elsevier Mosby, 2005 Parasitology Epidemiology {{Biology-stub

See also

References