ABCS 433 -2023 GF4.bin

ABCS 403: ENVIRONMENTAL PHYSIOLOGY Bioluminescence & Semiochemicals Godfred Futagbi 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 1  Bioluminescence Bioluminescence is the production and emission of light by...

ABCS 403: ENVIRONMENTAL PHYSIOLOGY Bioluminescence & Semiochemicals Godfred Futagbi 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 1  Bioluminescence Bioluminescence is the production and emission of light by living organisms It is a chemical process-form of chemiluminescence The chemical reaction in bioluminescence: Luciferin (a light-emitting molecule) +Oxygen (with luciferase, an enzyme as a catalyst). Photoproteins such aequorin are used as catalyst in some species (jellyfish) instead of luciferase Cofactors, such as magnesium or calcium and sometimes ATP may be involved 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 2  Bioluminescence Luciferins does not vary much from species to species. For example, coelenterazine, is found in nine to11 different animal phyla However, some of the animals obtain it through feeding. On the contrary, luciferases vary widely between different species. Luciferin luciferase and oxygen is common to all bioluminescent organisms 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 3  Bioluminescence luciferase Luciferin + O2. Oxyluciferin + light energy + (CO2 + PP (pyrophosphate) or AMP as waste products) 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 4  Bioluminescence: Distribution Widely in marine. Both vertebrates and invertebrates, some fungi, bacteria Terrestrial: fungi, bacteria, Arthropods, especially insects - fireflies Symbiotic/ bacteriogenic. Seen in some animals in association with symbiotic bacteria, eg from the genus Vibrio. In marine coastal habitats, about 3% of organisms are bioluminescent in some pelagic habitats as high as about 76% of the main taxa of deep-sea animals are bioluminescent. 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 5  Bioluminescence: Distribution Vertebrates (ray-finned fish), arrow worms, molluscs (cephalopods), crustaceans, cnidaria (jellyfish , corals), radiolarians, protozoans (dinoflagellates), etc are found to produce light in the marine environment. Though some do not synthesize luciferin. 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 6  Bioluminescence Colours of light Most marine light-emission is in the blue and green spectrum of light But some fish produces red and infrared light and even yellow by some species 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 7  Bioluminescence: Uses Counterillumination camouflage Attraction – to lure prey Defence- startling prey, counterillumination camouflage, smoke screen or misdirection, distractive body parts, burglar alarm, sacrificial tag or waning coloration Warning- the the organism is unpalatable or poisonous, to repel predators Communication- light emission between the zooids Mimicry- to mimic other species-to attract prey etc. Illumination 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 8  Bioluminescence: Uses Uses in biotechnology: – biology, medicine-imaging, reporter genes. – light production 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 9 Semiochemicals in animal survival and interaction To be successful in an environment, an organism must communicate with the environment. It must be able to receive stimuli from the environment and also send its own messages to other organisms Organic compounds are used to convey messages between animals and the environment Semiochemicals are organic substances that are employed by animals, especially insects, to pass messages to others, to help them modify their behaviour or physiology Semiochemicals help the organism to counterbalance abiotic and biotic stressors 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 10  Semiochemicals in animal survival and interaction Semiochemicals are utilized by insects, in particular, to: – locate mate, – locate food source, – locate host, – avoid natural enemies – stay away from rivalry – overcome the defence mechanisms of their hosts Semiochemicals can be classified into – Pheromones (intraspecific semiochemicals) – Allelochemics (interspecific semiochemicals) 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 11  Semiochemicals in animal survival and interaction Pheromones: are volatile chemicals secreted into the external environment by members of one species that influences the behaviour or physiology of the receiving individual of the same species => intraspecific Allelochemicals: are volatile substances produced by members of one species that influences the behaviour or physiology of the receiving individuals of another species => interspecific 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 12 Semiochemicals in animal survival and interaction Semiochemicals Pheromones Allochemicals Intraspecific Interspecific Primer Releaser Induces but Kairomones Allomones Synomones Apneumones Immediate no Benefits Benefits Benefits From non-living behavioural immediate receiver emitter both material change beh. change Trail Alarm Aggregation Sex 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 13 Semiochemicals in animal survival and interaction Allelochemicals can be divided into several categories Kairomones benefit the receiving organism but cause disadvantage to the emitter – eg lactic acid in human sweat attracts the mosquito Aedes aegypti Allomones benefit the emitter but have no effect on the receiver – eg alkylpyrazine, odorous allomone that protects Metriorrhynchus beetle Synomones are beneficial to both producer and recipient – eg terpenes produced by damaged pines are kairomones for pest beetles, but it can be used by parasitoids to locate and attack the beetles, thus terpenes are acting as synomones 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 14 Semiochemicals in animal survival and interaction Apneumones are emitted by non-living material and benefits the receiver – eg hexanal and 2-methyl-2-butanol released from rabbit stools attract sandfly females for oviposition 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 15 Semiochemicals in animal survival and interaction Pheromones can also be classified as – Primer : chemical that induce physiological change but no immediate behavioural change Eg for development, reproduction, recognition learning – Releaser : chemicals that induce immediate behavioural change Eg for alarm signalling, making trails, aggregation, sexual behaviour, recruitment, territorial defence, kin recognition, home recognition etc So, releaser- can be further classified (four major classes) – Trail pheromones – Alarm pheromones – Aggregation pheromones – Sex pheromones 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 16 Semiochemicals in animal survival and interaction – Trail pheromones -appear to be a blend of metabolic by-products. for recruitment, for marking pathways to resources When released together with alarm pheromones, trail pheromones enable guards to surround a nest invader. Eg- 3-ethyl-2,5-dimethylpyrazine, in the poison glands of several species of Myrmica ants – Alarm pheromones- Eg. the mouse alarm pheromone 2-sec-butyl-4,5-dihydrothiazole (SBT) 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 17 Semiochemicals in animal survival and interaction – Aggregation pheromones: In termite, Reticulitermes speratus a pheromone consists of 2-phenylundecane- attractant cuticular hydrocarbons (pentacosane and heptacosane), fatty acids (palmitic acid and trans-vaccenic acid), and cholesterol- arrestants – Sex pheromones: In mammals=> mice) 1. male-specific exocrine gland-secreting peptide 1 (ESP1), secreted into tear fluids from the lacrimal glands and promotes female sexual behaviours 2. the major urinary protein (MUP), darcin or Mup20, in adult male urine enhances attraction of females 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 18  https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular- biology/mammalian-pheromones 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 19 Semiochemicals in animal survival and interaction Pictures on aggregation etc 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 20  Aggregation of bug nymphshttps://en.wikipedia.org/wiki/Pherom 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 21  https://www.earthlife.net/insects/aggregat.ht ml 13/02/2023 ABCS 433 by Dr. Godfred Futagbi 22