Termites-Off With Their Head!
All winged members (alates) of Coptotermes testaceus ( a species of termite) collected by the wasp Polybia scrobalis surinama are decapitated prior to being stored in the nest, whilst the alates of Anoplotermes s.lat. spp. (another species of termite) are not.
This is because Coptotermes testaceus possesses a developed frontal gland containing defensive chemicals whereas Anoplotermes s.lat. spp. only possess a tiny frontal gland lacking in noticeable chemical defences.
If you want more information on frontal glands in termites, click this link http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0015761
Pictured-Polybia scrobalis surinama
Source- Braulio Hernandez, Instituto Nacional de Biodiversidad
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Siderophores
Siderophores are small compounds with a high affinity for Iron. They are produced by a variety of organism including bacteria, fungi, and some plants. They are essential to the survival of these organisms because iron has a very low bioavailability, principally because the main form of iron in nature (Fe3+) has a low solubility. Siderophores, once released, bind to Fe3+ and form a soluble complex that can be taken up by active transport. Once in the cells cytoplasm the iron is usually accessed by reducing it to Fe2+, which has little affinity for Siderophores. They bind iron so strongly that some are capable of removing it from iron containing proteins within the body.
An example of a siderophore is enterobactin (structure shown) which is produced by a variety of bacteria including E.Coli.
Curare
D-tubocurarine (commonly known as Curare) is a toxin produced by the plant Chondrodendron tomentosum. It works through antagonising the Acetylcholine receptors on the Neuromuscular Junctions, competing with Acetylcholine for the Ach-binding sites on Nicotinic Acetylcholine receptors. This prevents stimulation of the muscle and results in the paralysis of all voluntary muscle.
If found use as a muscle relaxant in surgery but has generally been replaced with derivatives associated with fewer side effects.
γ-Carboxyglutamate
γ-Carboxyglutamate is a modified amino-acid found in prothrombin and other proteins. It is derived through the carboxylation of glutamate via a Vitamin K dependant enzyme system. γ-Carboxyglutamate has a much higher affinity for Ca2+, this allows prothrombin to bind to plasma membranes and catalyse its conversion into thrombin and the initiation of the blood coagulation cascade.
The presence of Vitamin K antagonists such as warfarin, result in the inhibition of γ-Carboxyglutamate production and so slow down the rate of blood coagulation.
For More information on formation of γ-Carboxyglutamate see:
http://www.annualreviews.org/doi/pdf/10.1146/annurev.bi.46.070177.001105
Phytochrome
Phytochromes are a group of highly similar photoreceptors made by plants encoded by the Phy Genes (for instance PhyA) and exists in two forms Pfr and Pr . Pr is the inactive form and absorbs red-light, converting it to Pfr which is the active form of the photoreceptor and is converted back to Pr by absorbing far red light.
It has roles in determining time of germination and is able to do this because photosynthesis makes use of red and blue light. If phytochrome detects red light, it indicates that photosynthesis can occur, Pr absorbs the red light and is converted to the active form Pfr. If red light is unavailable, then the Pfr will be converted back to Pr by absorbing far red light (it is an equilibrium and in the absence of red light the backwards reaction will dominate). In germination, Phytochrome A is the dominant Phytochrome.
It also helps to set the circadian rhythm of plants (allowing them to regulate gene transcription according to the time of day) and Phytochrome is used to sense the start of the day.
In both cases, Pr is found in the cytosol whereas Pfr moves to the nucleus and induces changes in gene expression.
Volterra’s Principle
Volterra’s Principle states that:
An intervention in a prey-predator system that removes prey and predators in proportion to their population increases prey populations.
This means the number of prey at equilibrium will increase whilst the number of predators at equilibrium will decrease relative to the rate of removal, giving the seemingly contradictory conclusion that removing members of a population can result in the total population increasing.
Damaraland Mole Rat
The Damaraland Land Mole Rat is one of two eusocial mammals in existence, the other being the Naked Mole Rat.
Like the Naked Mole Rat, they have a low metabolic rate and lack Vitamin D (although they are still able to metabolise the necessary minerals). They also have a pair of “lips” behind their incisors which prevents dirt from falling into their mouths when they are digging, this feature is also shared with Naked Mole Rats. All non-queen females possess an underdeveloped reproductive system and are incapable of ovulation (though they can develop and have potential to form their own colonies), non-breeding males also produce little if any viable sperm and have underdeveloped testicles,.
Unlike Naked Mole Rats, though, the Damaraland Mole Rat has only one breeding male and female per colony (giving them a +1 on Traditional Family Values). They are found throughout much of southern Africa and are typically larger than Naked Mole Rats having a head-to-body length of up to 20cm and weighing generally between 100-280g (Naked Mole Rats (Non-Queen) in comparison tend to reach length of about 10cm and a weight of about 35g, with even the heavier queen usually weighing in at about 50g, with the maximum recorded weight only being about 80g)
Damaraland Mole Rats also have short fur which varies in colour between light-brown and near black, though all individuals have large white patch on top of their heads.
Preformationism
Preformationism is the historical scientific belief that all organisms develop from miniature versions of themselves and that all organisms have existed since the beginning of creation in a Russian-doll like fashion, with successive organism stored within each other in increasingly smaller sizes.
The theory has two main variations with perhaps the most well known, and most widely believed at the time, being the spermists, who believed that the miniature organism existed within the sperm and that the egg provided the material for its development. “Evidence” for this the fact that sperm are motile (suggesting complex development) and the claimed observation of these miniature organisms through microscopy. The other main group, the ovists, believed that the preformed organism existed within the egg. Preformationism as a theory continued within scientific circles up until and into the 19th century.
Pictured are the illustrations by Nicolaas Hartsoeker showing a miniature man curled up within the sperm, an image which is now iconic of Preformationism.
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Apple Maggots and Bacteria
The bacterial species Pseudomonas melophthora, can be found in the apple maggot, Rhagoletis pomonella. This can be considered a form of symbiosis as, amongst other things, the bacteria has the ability to degrade insecticides and so offers a form of protection to the apple maggot. I’m fully aware this is one of the most obscure topics I’ve posted about and so I declare this a Hipster Post. In apology, I give you a picture of the apple maggot fly which I think looks pretty cool.
Here is a link to one of the only open-access articles I can find on the topic, if you find others please message me :3
http://www.sciencedirect.com/science?_ob=MiamiImageURL&_cid=272392&_user=1495569&_pii=0022201168901584&_check=y&_origin=article&_zone=toolbar&_coverDate=31-Aug-1968&view=c&originContentFamily=serial&wchp=dGLzVlk-zSkzV&md5=ce142662c44fab4e4ab6c2085408b634&pid=1-s2.0-0022201168901584-main.pdf
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Cambrian Explosion
The Cambrian Explosion was the relatively rapid appearance of nearly all animal phyla and a huge increase in animal diversity that appears in the fossil record from the beginning of the Cambrian Period, around 542 million years ago.
One explanation for this is that the Cambrian saw a duplication of the number of Hox genes in an organisms genome, followed by a slight mutation in such genes which then could result in varying forms of life caused by different developmental pathways.
Pictured is an interpretation from fossil evidence of what the extinct genus Opabinia looked like. From what we know, these organisms ranged in size from 4-7cm and possessed 5 eyes along with a mouth that was under the head and faced backwards and a proboscis believed to deliver food to the mouth
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Teratoma
A teratoma is an encapsulated tumour that contains tissue or organ components from all three germ layers (ectoderm, mesoderm, and endoderm). These can include structures such as teeth, hair and bone and are generally benign.
If that’s not weird enough, several individuals also produce jewellery mimicking the tumour. If your interested here’s a link by which you can observe and purchase one (Note: Apparently some people think that there is no greater gift than giving someone a fake tumour on a necklace)
http://www.etsy.com/uk/listing/106913927/teratoma-tumor-necklace-glow-in-the-dark?
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Ultrabithorax (Ubx) Mutations
Ubx is a Hox gene that when expressed in the T3 segment of Drosophilia inhibits wing development and so allow development of halters (structures in some insects that act as a balancing and guidance system). However, if Ubx is subject to a mutation that inactivates the gene product, a transcription factor, then the resultant fly can develop two sets of wings.
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Antennapedia (Antp) Mutations
Antp is a gene that controls the formation of legs in Drosophilia spp (Fruit Flies). If the gene regulatory site is mutated causing misexpression, it results in a homeotic mutation whereby the antennae are replace with a set of legs.
Antibiotic Fact #4
Human Sweat contains an antimicrobial peptide called Dermicidin. It functions as part of our innate immune system and has activity against both Gram Positive and Gram Negative bacteria.
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Fibrodysplasia ossificans progressiva
Fibrodysplasia ossificans progressive (FOP) is a condition that effects approximately 1 in 2milion people. It causes fibrous tissue to be ossified (converted to bone) when damaged. Whilst this bone is independent it can fuse with the normal skeleton causing immobilisation and resulting in the disease having the nickname “Stone Man Syndrome”.
It is a genetic condition usually caused through spontaneous mutagenesis and new bone addition follows the pattern of bone formation in a developing foetus. The exception to this occurs after injury, when lymphocytes containing bone morphogenetic protein 4 (BMP-4) are deployed. They destroy the damage muscle and then initiate bone growth in replacement, this causes the additional problem that any attempt to remove the excess bone will result in the stimulation of more bone growth. Formation of new bone is usually preceded by a swelling around the region known as a “Flare-Up”.
Those who have the condition or will develop the condition can be identified through the fact that they possess misshapen big toes that are generally smaller, turned inwards and often lacking a joint. Research into the condition was pioneered by Dr. Michael Zasloff and Fred Kaplan.
Pictured is a photo of Harry Eastlack a sufferer of the condition next to a photo of his skeleton. He donated his body to science in order to aid the understanding of the condition.
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