Glossina morsitans explained

Glossina morsitans is a species of tsetse fly in the genus Glossina. It is one of the major vectors of Trypanosoma brucei rhodesiense in African savannas.

Taxonomy

Glossina morsitans is variously classified into the subgenus Glossina or as the name species of a morsitans species group. Note that this includes both subspecies G. m. centralis and G. m. morsitans, and G. pallidipes.

G. m. submorsitans is a common substitute for G. m. morsitans,[1] or rarely as a full species G. submorsitans.

G.m.s. is further subdivided into a G. m. s. ugandensis.[2]

Morphology

Egg

About NaNmm long.

Larvae

First instar

1.8mm long.

Second instar

4.5mm long.

Third instar

NaNmm long.

Adult

Adults are 7.75mm. G. morsitans is occasionally distinguishable from congeners by the unaided eye - there are differences in gross coloration - if it can be observed resting. It is more readily distinguishable by microscopic examination.

Metabolism

Flight muscles are primarily powered by proline, which is synthesized from fatty acids mobilised out of the fat body. Proline is so efficiently used in muscle mitochondria because they are specialised towards proline oxidising enzymes, and away from enzymes using fatty acids and pyruvate.[3]

Distribution

thumb|rightG. morsitans is found heavily throughout East Africa and Equatorial Africa: Angola, Benin, Botswana, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Democratic Republic of the Congo, Ethiopia, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Kenya, Malawi, Mali, Mozambique, Namibia, Niger, Nigeria, Rwanda, Senegal, Sierra Leone, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia, and Zimbabwe.

Hosts

G. morsitans feeds upon warthogs, oxen, buffaloes, kudus, and humans. About 6% of G. m. s.s bloodmeals come from birds (excluding ostriches).

Genome

A sequence was made available in 2014. Among other results this reveals that G. morsitanss genome has incorporated some of its Wolbachia symbiont's genome (see also below). The sense of taste of G. m. m. lacks the sense of sweetness - which may be due to its exclusively hematophagous diet.

Genetics

G. morsitans carries 3 Ago2s according to data compiled by Mongelli & Saleh 2016[4] [5] and Dowling et al 2016 finds 2 Ago3s while Mongelli & Saleh's compilation shows 3.

Symbionts

G. m. m. is in obligate symbiosis with Wigglesworthia glossinidia and Wolbachia. Without Wigglesworthia, G. m. m. is sterile, and without Wolbachia they are reproductively incompatible with normal flies.

Economic impact

Trypanosomiasis transmitted by G. morsitans and other tsetse species is one of the largest economic problems Africa faces. It has radically altered the cattle agroeconomy across the middle of Africa, severely shrinking the cattle pastoral lifestyle by shrinking the extent of safe grazing lands. This has left about 10400000km2 of otherwise usable land devoid of cattle. Raising cattle in the manner common in 1963, this would have allowed for another 125,000,000 head - more than doubling the 114,000,000 being raised at the time.

Further reading

External links

Notes and References

  1. Gooding . R.H. . Krafsur . Elliot Scoville . Tsetse Genetics: Contributions to Biology, Systematics, and Control of Tsetse Flies . . . 50 . 1 . 2005 . 0066-4170 . 1462949. 10.1146/annurev.ento.50.071803.130443 . 101–123. 15355235 .
  2. Krafsur . Elliot Scoville . Tsetse flies: Genetics, evolution, and role as vectors . . . 9 . 1 . 2009 . 1567-1348 . 2652644 . 10.1016/j.meegid.2008.09.010 . 124–141. 18992846 . 2009InfGE...9..124K .
  3. Arrese . Estela L. . Soulages . Jose L. . Insect Fat Body: Energy, Metabolism, and Regulation . . . 55 . 1 . 2010 . 0066-4170 . 10.1146/annurev-ento-112408-085356 . 207–225. 19725772 . 3075550 .
  4. Mongelli . Vanesa . Saleh . Maria-Carla . Bugs Are Not to Be Silenced: Small RNA Pathways and Antiviral Responses in Insects . . . 3 . 1 . 2016-09-29 . 2327-056X . 10.1146/annurev-virology-110615-042447 . 573–589 . 38499958 . 27741406.
  5. Zhu . Kun Yan . Palli . Subba Reddy . Mechanisms, Applications, and Challenges of Insect RNA Interference . . . 65 . 1 . 2020-01-07 . 0066-4170 . 10.1146/annurev-ento-011019-025224 . 293–311. 31610134 . 204702574 . 9939233 .