Read Through Reading 27 for Quiz Thursday!!Malaria and Natural Selection!!G6PD protects from severe malaria!" -males gave one x- chromosome!" -G6PD deficiency males ⅔ less likely to get severe malaria!" -homozygous females have the same protection!" -3 different G6PD mutations!!Thalassemia- defect in genes that control production of hemoglobin alpha and beta chain.!!Thalassemia ⍺ : !" -hemoglobin: two alpha chains, two beta chains!" -one or two altered alpha chains = anemia!" -Thalassemia Major if two alleles, Minor if one!" -widespread in SE Asia, Middle East, China, Africa!" -reduced rates of severe malaria!" -most common genetic disorder in humans!Thalassemia β :!" -mediterranean most common!" -affected beta chains= low to moderate anemia!" -major form less severe than thalassemia alpha!" -RBCs are small!" -more susceptible to vivax, but less to falciparum!!//////end protozoan parasite lecture/////!!!Parasites: Nematodes (round worms) Nematodes: among the most numerous multi-cellular creatures on earth!-many are free living (non-parasites)!-some are parasites!" -parasitize insects, wants, animals [0.3 milimeters-8 meters in size]!" Filariasis -a namatode carried by mosquitoes!" " -adult form- in lymphatic vessels!" " -3 species can cause elephanititis!" " -disease of the tropics!""-Filariasis is not life-threatening!" " " -swelling of limbs, genitals!" " " -interferes with immune response!" " " -general malaise!" " " -5% of people with this will display the fluid collection problems!""-Filariasis comes from repeated mosquito bites!" " " -70 mosquito vectors!" " " -mosquitos obtain microfilaria from humans!" " " -larvae develop in mosquito in 7-21 days!""-Filarial larvae infect humans!" " " -move into lymphatic system!" " " " -mature to adulthood there!" " " " -adult worms: 2-50 cm long!" " " " -live up to 7 years!""-Sexual reproduction in humans!" " " -sexual reproduction!" " " -females produces millions of microfilariae/day!" " " -microfilariae in blood: no effect on human!" " " " -microfilariae die in a few hours!" Microfilariae release time adapted to highest activity period of local mosquitos South Pacific: active in daytime!" " " " -microfilariae numbers highest in daytime!" " " Other regions: most active st night!" " " " -microfilariae highest from 10pm-2am!" Sickness comes from lymphatic obstruction!" " -many adults needed!" Primary effect is on individual productivity!" " -120 million affected!" " -mostly SE Asia tropics!" " -some African topics!!Soil-Transmitted Nematodes!" "unholy trinity" - three solid-dwelling nematodes!""!" " 1) Ascaris lumbricoides - giant round worms!" " -fecal oral route!" " -5-14 inches long!" " -900 million affected!" " -Egyptians report - 5th century BC!" Ascaris lumbracoides!" " -protein digestions problems!" " -absorption of fats, lactose, vitamin A!" " -stunted child growth!" " -can cause intestinal obstruction!" " -cognitive function, memory affected!!" " 2) Whipworm (Trichuris)!" " " -fecal-oral route!" " " - 1-2 inches long!" " " -600 million affected!" " " -reduced appetite, protein loss!" " " -colitis(inflammation of the colon,) dysentery, stunted growth!" " " -releases antigens, causing a hypersensitivity reaction!" " " -immune system response may lead to colitis!""!" Ascaris and Whipworm probably come form pigs originally !"!" " 3) Hookworm (ankylostomiasis)!" " " -two species of hookworm that affect humans!""""-Ancylostoma duodenale!""""-Necator americanus!"""Symptoms: !" " " -mild diarrhea" !"""In Children, pregnant women with heavy infection: !" " " " -anemia (blood loss)!" " " " -protein deficiency !"""Hookworm comes from contaminated soil:!" " " " -from !" " " " " -walking barefoot!" " " " " -consuming soil!"""Hookworm eggs hatch in soil:!" " " " -must be warm, moist, and shaded!"""Hookworms are barely visible when hatched!" " " " -via skin of bare foot/hand!" " " " -to lungs by blood!" " " " -coughed up and swallowed!" " " " -enter intestine!" " " " " -attach to small intestine wall!" " " " " -survive by sucking blood!"""Adult Hookworms =10mm!" " " " -10K- 25K eggs/day!" " " " " -eggs passed in feces!" " " " " " -infective in 7 days!"""Hookworms affect 700 million humans -A. duodenale - temperate regions!" " " " " -mostly Old World, northern hemisphere!""""-N. americanus - tropical and subtropical climates; americas, subsaharan africa, S. India!" " " " - Mixed infections seen in SE Asia !"""Modern Distribution affected by migration:!""""-N. americanus brought to the Americas by African slaves!" " " " " -no footwear (children)!" " " " " -limited outhouses!" " " " " -feces as fertilizer!"""Dog and Cat hookworms: !" " " " -dog/cat feces!" " " " -cannot mature in humans!" " " " -migrate under skin for weeks!"""""-"creeping eruption" """!" " " Unholy Trinity!" " " Chinese study from 1980's!" " " " Fecal examinations of 1.5 million people!" " " " " Estimations from the samples taken:!" " " " " 531 million Ascariasis!" " " " " 212 million whipworm!" " " " " 194 million hookworm!" " " " Many rural villages in tropical Americas!" " " " " 70% of children = ascaris and hookworm! !" " " " -Tropical areas - children often have all three parasites!" " " " -Hookworm the most harmful of the three!" " " " Reduced wage eating capacity (43%)!" " " " Common in coastal areas !" " " " 25 hookworms in a child = iron deficiency!!Four ancient human parasites!" -Ascaris & whipworm - foragers!" -Hookworm - early farming (sedentism)!" -Filariasis - microfilariae evolved to not cause illness!" " -takes long time to