Fragestellungen der Evolution - Yegi Flashcards
(39 cards)
1
Q
Characteristics of beetles
A
- elytra
- divers mouthparts
- divers antennas
- 2-5 tarsi
- colour depends on feeding
- wing folding
- pronotum
- trochanter
2
Q
How is the life cycle of beetles?
A
- holometabole
- complete metamorphosis
- 3-6 stadiums
3
Q
Evolution of insects
A
- Orovician (480 Mya)
- insects
- land based
- Devonian (400 Mya)
- flying insects
- Permian (299-252 Mya)
- metamorphism
- Tirassic (252-199 Mya)
- modern insects
- Jurassic (201-199 Mya)
- insect families
- diversification
4
Q
Evolution of Coleoptera
A
- Protocoleoptera (acient beetles)
- 280 Mya
- elytra similar to Cupeddae
- modern coleopterans replaced
- 220-285 Mya
5
Q
Who is the sister taxon of the coleoptera?
A
Strepsiptera
6
Q
What are the characteristics of the Strepsiptera?
A
- free prothorax
- metathoracic hind wings
- larval development
7
Q
Which taxa include the coleoptera?
A
- Polyphaga
- Adephaga
- Myxophaga
- Archestomata
8
Q
Archestomata
A
- 5 families and 50 species
- mostly in Asiatic and Australian
- acient lineages
- similar to first beetles (250 Mya)
- antenna
- moniliform
- filiform
- notopleural present
9
Q
Myxophaga
A
- 4 families
- mostly feeding on algae
- mobile tooth
- lacking galea
- monophyletic
- antenna is clubbed mostly with 9 segments
- notopleural absent
10
Q
Adephaga
A
- 10 families and 40 000 species
- mostly predators
- terrestrial
- hydradephaga
- diverged form sister group
- Myxophaga
- permian age (240 Mya)
- abdominal sterna divied by hind coxae
- notopleura present
11
Q
Why are coleoptera so successful?
A
- based on diversification
- different habitats
- elytra supports them and gives them protection
12
Q
Polyphaga
A
- 177 families
- enourmous variety in spezialization and adaption
- hind coxa is not divided first ventral plates
- notopleural absent
13
Q
Wood-boring beetles
A
Scolytinae
- subfamily of Curculionidae (weevil)
- feeding on living and dead phloem
- various tree species
- few can kill live trees
- tree morality
- climate change
14
Q
Ambrosia Beetles
A
Scolytinae
- subfamily of Curculionidae
- mostly on dead wood (Xylemophagous)
- fungus farming
- symbiosis
15
Q
How did the evolution of tree killing proceed?
A
Intense interspecific competition on scarce and temporary resouces
16
Q
How was the evolution of tree killing possible?
A
- flexible host selection behaviors
- detoxifxing the defense compound
- association with symbiosis
17
Q
Phylogeny of ambrosia beetles
A
- monophyletic
- Scolytini -> earliest lineage
- sexual dimorphism (+haplodiploid)
- fungus farming groups:
- Corthylini
- Subfamily Platypodinae
- Xyloborini
18
Q
Mycangium
A
- structure inside
- Mycangia: spezialized membranous sructures with secretory glands
- specific to the genus -> complex or simple
- different types:
- mandibular mycangium
- elytral mycangium
- mesonotal mycangium
19
Q
Fungus stealing
A
- types of fungi can be shared among the beetle species
- stealing food of other species (bigger ones) by boring holes nearby
20
Q
Xylebroinus saxeseni
A
- fruit tree pinehole borer
- Xyloborini tree
- elytral mycangium
- carrying more types of fungi
- very different types
- beetles can only carry the yeast phase in the mycangium
21
Q
Conclusion ambrosia beetles
A
- the DNA analyses showed that 10 Raffalea spp. are very closely related to Leptographium spp.
- two very distinct phenotypes are found in this Leptographium-like clade
- Raffaelea hybridized with Leptographium?
22
Q
Which phenotypes are found in the Leptographium-like grade?
A
- R. sulphurea type has large conidia, conidiophores with swellings, no yeast phase and reddish brown mycelium
- R. montety type has small conidia, simple conidiophores, yeast phase and are not pigmented
23
Q
What is Wolbachia?
A
- Gram negative bacteria
- Rickettsiales
- α-proteobacteria
- Cytoplasmically inherited
- reproductive tissues
24
Q
Why is Wolbachia important?
A
- worldwide distribution
- evolutionary interactions
- potential biocontrol agent
25
Methods of Wolbachia
* feminization
* male killing
* cytoplasmatic incompatibility
* parthenogenesis
26
What problem occures through the methods of Wolbachia?
extreme sex ration
27
Which types of CI occur?
28
Which outcomes does CI have?
* Sex determination
* only transmitted by females
* favor the production of daughters to sons
* biased sex ratio
* Pathogen defense
* CI would cause the spread in population
* prevent the transmission of viral diseases
* Speciation
29
Population dynamics within Wolbachia
* Low prevalence of CI inducing Wolbachia
* probability for an uninfected female to lose progeny because of mating with an infected male is low.
* High prevelance of CI inducing Wolbchia
* probability for an uninfected female to lose progeny because of mating with an infected male is low.
30
Mod-Res Model (CI)
* Sperm of infected male somehow modified before the conclusion of spermatogenesis, and only in eggs infected with the same type of Wolbachia can this sperm function properly and be “rescued“.
* Two way incompatibility
* bidirectional
* genetic isolation
31
Lock-key Model (CI)
* Wolbachia produce a lock binding to paternal chromosomes
* bacteria saved in a waste bag structure with most of the cytoplsm
* sperm cell with locked paternal chromosomes enters an uninfected egg
* in the absence of a key to remove the locks, paternal chromosoms lose their function
* so only maternal chromosomes function normally during the mitosis
32
What can also infect beside Wolbachia?
* *Cardinium hertigii*
* maternally inherited reproductive parasite
* Horizontal transmission may also occur
* If co-infected
* higher Wolbachia density
* lack of competition within host
* Different from Wolbachia
* Male development, yet female mortality
33
*Wolbachia vs. Cardinium*
* Genome comparison
* only a functional overlap of proteins
* No common ancestor
* No evidence of laterally transferred elements
* Dependent evolution of CI
* comparative genomics
34
Bacteriophage
* Virus that infects and replicates within bacteria
* know as Phage
* As small as 4 genes or as big as 100 of genes
* 70% of marine bacteria
* Alternative to antibiotics
* Prophage
* bacteriophage genome
* Latent form of gene
* viral genes are present in the bacterium
* no disruption of bacterial cell
* Important agent
* Horizontal gene transfer
35
Role of phage in Wolbachia
* Bacteriophage WO
* Significant role on the symbiosis relationship
* Virulence varies
* Gene alteration
* Secreting enzyme
* sialidase
* affect Wolbachia’s ability to scavenge nutrients from the host
36
Dipteran CI Polymorphism
* Various strain strains
* ≈ 80% inducing CI
* WMel
* Culex pipiens
* blocking the transmission of dengue and Zika
* Successfully transfected to other non-dipteran hosts
* Cadra cautella (almond moth)
* agricultural importance
* varies in virulence
* Spatial spread of CI inducing strains
37
Hymenopteran CI Polymorphism
* Few species with CI inducing
* mostly parthenogenesis
* haplodiploid
* Family Pteromalidae
* Nasonia spp.
* parasitoid wasps
* Biocontrol agent
* evolved at faster rate, but why?
* Unidirectional CI
* inhibiting cell cycle timing
* infected sperm modified, no rescue in eggs
38
Coelopteran CI Polymorphism
* Various strains
* 6% of the beetles with CI inducing strain
* only out of 0.15% of all beetles tested
* Family Curcurlionidae and Crysomelidae
* mostly studied
* Family Tenebrionidae
* Tribolium confusum
* Impact on
* mating performance
* mating choice
* reproduction
* Unidirectional CI
* all geographical strains
39
Lepidopteran CI Polymorphism
* Various strains
* mostly male killing
* Mediterranean moth
* Ephestia kuehniella
* infected males transfer fewer fertile sperm
* Seasonal change in Wolbachia density
* temperature sensitive
