Mutualism

Ambrosia beetle/fungus mutualism

2002-detected in a survey trap near Port Wentworth, GA. 2005-in SC, GA and FL. Beetles live in nutritional symbiosis with ambrosi fungi.

Ant/Acacia Mutualism

Acacia spp. Widespread group of trees, common in tropics. Provides food to ant colony that lives in the hollows of its thorns. Pseudomyrmex ants. Defend tree from herbivores, defoliate adjacent tree sp. so that the tree doesn't get blocked out of the sun.

Benefits to the ants in Acacia mutualism

Ants receive shelter, nutrition: sugar and liquid from extra floral nectaries. Beltian bodies: leaflet tips modified into concentrated source of oils and protein.

Ambrosia Beetle/Fungus benefits

Beetle Benefits: Fungus is the sold source of beetle's nutrition. Fungus Benefits: Fungus gets dispersed by beetles.

GFP

Green Fluorescent Protein. Glofish are genetically modified fish. GFP uses a jellyfish protein.

Aphid/PAUS mutualism benefit to the aphid

Heat tolerance (Russell and Moran 2006) heat shock proteins. Defense against parasitoid (Oliver et al. 2003) PAUS generates immune response. When parasitoid lays egg, PAUS generates an encapsulation response, builds a layer of cells around egg to keep it from hatching.

Aphid/Buchnera mutualism

Intra-cellular (within the cells) bacteria in specialized host cells (bacteriocytes) Closely related to E.coli but genome much reduced (only 600 of 4,000) ancestral genes retained. Provides nutrients to host, allowing use of a diet that would be inadequate-aphids make 10 AA, bacteria make other 10 AA.

PAUS

Pea aphid U-type symbiont. Bacteria called Regiella insecticola. PAUS is facultative, don't have to have it. Maybe spread by parasitoid sting?

Types of mutualistic relationships

Pollination: bees/plants, moth/orchids, yucca moth/yucca. Nutritional: ants/fungus gardens, aphid/Bunchnera(obligate). Defensive: ants/acacias, aphid/PAUS (facultative)

Benefit to Buchnera

Safe place to reside inside an organism. Rapid dispersal, transmission from mother to offspring

Mutualism

a symbiosis where both organisms benefit

An ambrosia beetle excavates

a tunnel in a live tree, then releases fungal spores. The fungus penetrates the plant's xylem tissues, digests it, and concentrate nutrients.

Benefit to the ants

ants excavate a cavity in the soil. Bring leaves to the fungus. Inoculate leaves with the fungus. Fungus grows by decomposing cellulose. Ants eat fungus. Cellulose->fungal biomass->ant biomass. Ants also acquire cellulase from the fungi, they can continue degrading cellulose in their guts, using enzymes from the fungus.

Ant/fungus mutualism

ants live in "super organism" colonies. Attine ants subsist on the fungus, eat it, don't eat the leaves

Acacia suckers with ants survive

at twice the rate of suckers without ants. (Janzen 1966)

When symbiosis is disrupted

disease often occurs

What might the altered timing of sexual morph production result in?

don't get mating between the populations, changed timing of different populations sexual change. This causes speciation, no geographic barrier, just don't mate with other populations

Aphid/PAUS mutualism

experiments comparing pea aphid lines: the same genotype, but different secondary symbionts. Lines established by microinjection: inherited in all aphids.

Yucca/yucca moth mutualism

female yucca moth taking pollen from stamens of a yucca plant. Coils it in her mouthparts. pollinates another yucca, tamps pollen down in stigma. Lays eggs below stigma. Moth larvae eat seeds from the fruit their mothers fertilized.

Benefit to the fungus

fungal garden breaks down without ants. ants protect fungus from competitors, fungus gets dispersed by ants. Ants will take the fungus to new colonies when they leave.

How many seeds can a moth larva eat?

if it starts eating too many, the plant will abort the fruit. doesn't eat all of the seeds.

Mutualisms are widespread, occur

in almost all ecosystems. Mutualism take many forms and can involve more than two species

In response to crowding,

insects can trigger wing induction. (Leonardo and Mondor 2006.) Less likely to produce offspring with wings if the insects have PAUS. They have an altered timing of sexual morph production (Leonardo and Mondor 2006)

Ants live

inside of the thorns. Bullhorn Acacia-Model Acacia. Extra-floral nectary: sugar producing structure outside of flower.

Leaf cutter ants example

lcants tend a fungus have little pits on their bodies that carry bacteria, bacterial produce antibiotics that help them with staving off the fungus.

Darwin's hawk moth

madagascan moth, long proboscis, 30-35 cm

Most animals and plants live symbiotically with

microorganisms

Obligate symbiosis

neither symbiont nor host can survive without the other

Bees have pollen baskets

on the hind tibia. Flap that they stuff pollen in. Colony consumes 20 kg of pollen and 60 kg of honey each year. (130 lbs)

Plants cheating insects

orchid that try to mimic insects-look like a female, male will try to mate with the flower, plant puts pollen on his back. A lot of them don't produce scent/nectar.

Benefit for the plant

plants need many pollinator visits for seed set. Pollination is the most important service that insects provide

Benefit for the insect bee nourishment

pollen, nectar .all from these 2 sources. Carries 10-20 mg of protein at a time.

Honeybees are a generalist

pollinator, collecting pollen and nectar (protein and sugar (carbs))

The tree responds to a fungal infection by

producing a blue stain, can also be a black stain.

Benefits to the trees in Ant/Acacia Mutualism

protection from herbivory and competition. Worker ants attack other herbiv. on the host plant, prune back toher plants when they encroach.

Facultative symbiosis

symbiont and host can both survive without the other

Endosymbiosis

symbiont lives within the body tissues of another organism. (embedded in the tissue)

Insects cheating plants

taking nectar from bas of corolla without pollinating. Some bees chew a hole through the corolla tube

Buchnera is obligate to

the host

Specific pollinators of orchids

the madagascar orchid has a nectar spur about 30 cm long. Darwin predicted that there was a moth with a proboscis long enough to pollinate the orchid

Ectosymbiosis

the symbiont lives on the body surface of the host including internal surfaces (e.g. intestines) has a connection to the outside

Pollination mutualisms

types: generalist/specialist. Specialists only pollinate one or very closely related plants.