Hello to all my lovely readers

It is officially the Easter Weekend everybody, and I have a quick message to all my student readers. Use your easter holidays wisely. Most of your notes should be now completed so revise from these, and sit as many past papers as you possibly can!  Now onto today’s post. Thanks to Donald Trump and his stand on Climate Change this topic has once again been catapulted to the front of all our attention. Climate Change is a fact, but it is not the biggest threat to our planet's biodiversity.  

Over-exploitation and large-scale land use change (e.g. forest to farmland) are two of the largest threats to our biodiversity. Overexploitation is an umbrella time that covers overfishing as well as illegal wildlife trade. Sadly, there has been an increasing demand for rare animal meat and body parts, which have pushed many species closer to extinction including the Sumatran Rhinoceros, the Western Gorilla and Pangolins.

Pangolins have been practically wiped out in Vietnam, Cambodia and Lao PDR caused by relentless illegal trade. World Pangolin Day which was on February 20th succeeded in raising awareness for these scaled mammals. In fact, the King of Natural History himself, David Attenborough, deemed the Pangolin worthy of being one of ten animals he would choose to put on his own personal ark. But what is a pangolin?

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Sir David Attenborough, did not disappoint when he gifted Pangolins a ticket to board his personal Ark. Pangolins are the only mammals in the world that are covered in scales from head to toe. As a group, they are fairly small only comprising of 8 species, all of which, are found on two continents:  Africa (Black-bellied Pangolin, White-bellied Pangolin, Giant ground pangolin and the Temmicks ground Pangolin) and Asia (Indian Pangolin, Philippine Pangolin, Sundra Pangolin and the Chinese Pangolin. Image below).

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Pangolins are solitary and nocturnal animals. These scaly mammals share a dietary preference with anteaters, in that they dine exclusively on ants and termites. To help them out with their dietary choice Pangolins have extraordinarily long tongues, some of which can grow to over 40cm long. If you were lucky enough to stand in front of a Pangolin mid yawn then you would be able to see this long tongue for yourself, and that's it, as these guys are toothless! What they lack for in teeth they make up for with their stomachs. A Pangolins stomach is lined with keratinous spines to help grind up the ants and termites, they have even been spotted ingesting stones to further help this process along.

A Pangolins number one defence strategy, when faced with danger, is to roll into a ball, and if necessary lash their tails at the threat inflicting damage with those spines. Once in the safety of the ball, there is little that a predator can do to get to it as not even a big cat's canines can penetrate a Pangolins outer scales.

Sadly all eight species of Pangolins have been listed by the IUCN as either Vulnerable or Critically Endangered, and their population is constantly decreasing. 2016 was a good year for Pangolins everywhere, as CITES (Convention on International Trade in Endangered Species) successfully campaigned to transfer all 8 species of Pangolin to Appendix 1. This move has given them full protection against all international trade.

Each year, 100,000 Pangolins are captured across Africa and Asia. Despite the Pangolin becoming a protected species, they are still in demand for their scales and meat.  Cultural beliefs claim that their scales can reduce swelling and improve blood circulation. Even though it has been banned, China is still a key market for using Pangolin scales for traditional medicines (image below).

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Why are Pangolins still victims of illegal wildlife trade? Firstly Wildlife Trade is one of the most profitable businesses to be in, and the profits of pulling it off far outweigh the small consequences of getting caught. It all comes down to demand. If Pangolins have a chance we need to reduce the demand for their meat and scales. Campaigns are aiming to make it socially unacceptable to buy any products involving Pangolin sourced ingredients. A perfect example of how these campaigns can work is Tigers in Tibet,  by showing the Tigers dire situation the demand fell dramatically.

That brings us to the end of today’s post on these cute animals. I would like to think that we have all become Pangolin fans, this poor animal has suffered years of illicit trading with little awareness. The Zoological Society of London have actively engaged with the Pangolin's plight and fighting for them for more info click here. You can do this also by picking at least one fact from today's post and spreading the word.

Alright, guys, this is just a quick message before we head into the Easter Holidays. As I am a full-time tutor and this is fast becoming my busiest season I am not going to be able to keep to the usual blog schedule of every Friday! I am so super sorry for this but please be aware that during this time I am going to be stockpiling some incredible posts lined up for you, so that it is a summer you will not forget! Good luck to all student out there and I will be back here after the exam season.

Science in the City

xoxo

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Hello, again my loyal and lovely readers!

Friday has come around which can only mean one thing - post day. In the great anticipation of Mothers Day 2017, I thought we could take a look at some mothers in Nature that will make all of ours look like angels! 

Burying Beetles:

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The story begins when a mother beetle lays her larvae in the carcas of a mouse that they have buried underground. Larvae are unable to feed themselves, thereby, making them reliant on their mother to eat the meat and then regurgitate it. At feeding time, it is first come, first served as the larvae compete to get to the front of the line. Mother burying beetles only regurgitate a certain amount of food each time making the stakes high for the larvae who want to get fed. When the food runs out the last remaining starving larvae become the mother's meal!

Cruel as this sounds, mother burying beetles are making the best of a situation they, cannibalise on their own offspring as a way of ensuring that there is enough food to supply the rest. The saying Cruel to be Kind is coming to mind here.

Pandas:

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I know what you're thinking. Pandas 'bad mothers'? No way, they are the symbol for the World Wildlife Fund - well stick with me guys. Pandas have two babies on average, but like in many scenarios, the mother always has a favourite. This 'chosen' individual will benefit from all of the mother's resources and her time, leaving their small, weak and helpless sibling to fend for itself. The outcome of this will almost always be the death of the baby. 


In nature, this may be a mother's way of carrying out her own version of quality control. Instead of having two average offspring, the mother put all her resources into one to increase the chances of their survival.

Black Eagle:

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For everyone out there with younger or older siblings, then you know that sibling 'squabbles' are an inevitability. However, I think the majority of us can agree that they rarely end too violently...The chicks of Black Eagle's are locked in a battle of death from the moment they hatch, with older siblings murdering their younger siblings, all under the watchful eye of their mummy. 

This behaviour is common in large predatory birds as it helps the mother to allocate resources to those who survive the mini version of the hunger games. Strangely enough, these mothers are looking out for the continuity of the species by choosing the strongest offspring. 

Komodo Dragons:

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Surprise Surprise right? I know reptiles are not known for their amazing parental skills just look at the episode of Planet Earth where baby marine iguanas were left to face the garter snakes all on their own! 
It was an emotionally gripping episode, but let's turn our focus to dragons. Komodo's are the apex predators on a group of small islands in South Indonesia meaning that there isn't much on the island that is off the menu for a full sized Komodo Dragon - even other dragons. You know it's bad when your on mother looks at you as a potential food source from the moment you hatched!  Due to the threat of parental cannibalism young dragons will spend the first few years of their life up in the trees.  

There you have it, my lovely people, a mother's day post with a twist! Just in the nick of time to help you appreciate your mother even more now, so go forth and go that little bit extra this Mothers Day. To all the mothers and maternal figures whether they still be with us or not... I wish you a Happy Mothers Day. 
And to my special Mum who is my best friend 
Love you loads and a massive thank you for not being like any of the mothers mentioned in this post!

Have an awesome weekend everybody

Science in the City

xoxo

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Hello again everyone

I hope you have had an amazing week filled with productivity and hard work... No? Well you know that my blog is always here to alleviate some of the boredom and keep you on top on all your science need to know (by the way in case you didn't see they found a luminescent frog the other day!) Well I have a treat for you guys today! We have grown up with them in our fairytales and listened as parents told us that they never excited. I am of course talking about Dragons - and your parents lied! Meet the Komodo Dragon!

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Latin name: Varanus Komodoensis

Conservation Status: Vulnerable

Komodo Dragons are the largest extant lizards alive. Male Dragons can reach a length of 10ft with females measuring a length of 7.5ft. These giants are only found on a small set of remote islands in South Indonesia. Komodo’s are classified as Vulnerable by the IUCN as there are only 4,000 individuals left in the wild, due to the increasing demand for Palm Oil.

It was recently discovered that dragon blood may provide a novel way of fighting against superbugs. Blood samples were taken from Komodos and analysed, there were 8 proteins of great interest that showed an ability to fight off drug-resistant strains common in hospital infections. Such amazing discoveries could lead to people hunting these Dragons to get access to their blood, further driving this species to extinction. However, I have faith in each and every one of my readers to realise that this would be irresponsible and stupid. Why? Because we have this beautiful thing known as technology. Proteins are more than able to be replicated under lab conditions without killing any more of these amazing lizards.

What does a female Komodo Dragon have in common with Virgin Mary?

Both are able to produce offspring in the absence of a male! In nature, we call this Parthenogenesis, a process that is rare in vertebrates. This was first discovered in two female Komodo Dragons: Flora from the Chester Zoo and Sungai at London Zoo (now deceased). Sungai to the surprise of her keepers produced four eggs despite her last male encounter being 2.5 years ago. This lead the zookeepers to two possible explanations, either Sungai had stored the sperm from that male or she had just shown the keepers that Komodos are able to do parthenogenesis. DNA samples were taken from each of the offspring, to find that they were exact clones of their mother. It was obvious, parthenogenesis was the only explanation. This was further validated by Flora who produced 8 eggs and had never come in contact with a male dragon.

This ability to switch between sexual and asexual reproduction appears to be beneficial, initially. This trait highlights a female's adaptability in situations where mate availability is limited.  There is, however, a dark side to this also. Parthenogenesis carries the same implications as inbreeding, where the offspring suffer from reduced fitness and increase the risk of extinction.

A Venomous Giant

One observation made back in the 1970’s by Walter Auffenburg led to the development of a myth that plagued the image of this carnivore in the eyes of the public. It was long believed that the Komodo Dragon, with pieces of rotting flesh left in his its mouth, harboured such a deadly cocktail of bacteria and viruses that one bite would lead to the death of its victim.  For years we have seen these dragons as bacteria laden villains that kill their prey in the dirtiest and most unhygienic way… literally. However, thanks to the work of Bryan Fry this myth has lifted, and it turns out the dragons actual hunting method is a work of evolutionary genius.

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Bryan Fry began debunking this myth by identifying the bacteria strains found in the Dragon's saliva. What he found confirmed his initial thoughts - there was a lot of bacteria, but no more than your average carnivore. Upon the realisation that there was no bacterial strain present that could cause the onset of symptoms observed when an animal is bitten, Fry began answering the question of how a Dragon actually kills.  

It turned out that Komodo Dragons were one of few lizards that went down an evolutionary path similar to advanced snakes - the development of an extremely sophisticated venom delivery system. Komodo Dragons are similar to other predators in that they take their prey by surprise and deliver a really nasty bite to the hind of the animal using their 60 razor sharp serrated teeth. At this point, the Komodo Dragon hangs back and waits for its venom to do its job.

Unlike a snake the Komodos venom glands are located at two points along their mandible, these lead onto a series of ducts in between each of their teeth. Using a bite-and-pull approach the venom oozes into the wounds of their prey while the dragon delivers a frenzied attack. Once delivered the dragon's venom gets to work. It begins by hindering the animals ability to clot their blood leading to continual blood loss, paralysis of the animals smooth muscle then sets in and finally, it causes a drop in the animal's blood pressure. The chemical present in the Dragon’s venom that is responsible for the drop in blood pressure was found to be as potent as that found in the world’s most dangerous venomous snake! The Taipan.

Well, that completes today's blog post on our planet’s very own Dragon that may not kill with its fire, but instead, uses a dual combination of venom and a serious bite! One last fact at top speed these Komodo Dragons can reach a speed of 12 miles per hour - that is pretty fast. My golden piece of advice if you happen to visit Komodo Island make sure you go with someone who is slower than you!!

Have an amazing weekend,

Science in the City xoxo

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Good morning to my lovely readers

It is the best time of week again - Friday. In fact, this will be my first weekend working as a seasonal presenter for London Zoo on Sundays, so if you are around come and find me and say hi! Today's post title may sound slightly alarming, but by the end of this post, you will understand that it is not a gross over exaggeration.

Before I introduce you to the creepy crawlies a quick crash course in terminology is required: 

Anthropophilic: The Vector shows a strong preference for taking blood meals from humans. 

Zoophilic: The vector shows a strong preference for taking their blood meals from animals. 

Endophagy: A vector that takes their blood meal indoors.

Exophagy: A vector that consumes blood from their victim outdoors.

Endophily: When the vector eventually rests they remain indoors or sheltered from the external surroundings. 

Exophily: When the vector eventually rests they remain outdoors.

Allow me to introduce you to some of the vectors behind some of the worst diseases: 

What a great way to introduce you all to the world of vector-borne diseases. Now, these are not all the vectors known to us on Planet Earth but they are the ones that I selected for today  - make sure you keep an eye out for the next few to complete the series. 
As always everybody it was my greatest pleasure blogging for you. I am now of to learn more of my ZSL scripts for Sunday. 
Have an awesome weekend

Science in the City
xoxo

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Hello, lovelies!

It is officially post day!! Today's post is centred on that genetic editing technique that has kind of taken over headlines, generated a lot of public engagement on whether we have gone too far or not - CRISPR. To be honest with you, I am amazed at what this technique is able to do.  Then it hit me, that I do not actually know where this technique came from, it just suddenly appeared out of nowhere and took the world by storm. Have no fear after today's post you will have a better understanding of where the hell CRISPR came from. Enjoy. 

Molecular Biologists, Conservationists, Geneticists believe the discovery of CRISPR is the best thing, well - since sliced bread! With this technologies ability to modify wild and domestic populations, produce hypoallergenic eggs and possibly reverse extinction and bring back the woolly mammoth you could understand the excitement. However, there is a dark side to such technological advancements, CRISPR increases the risk of harmful biological agents being engineered. One question remains on the minds of many swept up by the CRISPR mayhem, what on earth is it?

CRISPR stands for clustered, regularly interspaced short palindromic repeats. Francisco Mojica, spotted these repeats when he was looking at the genome of a microbe known as Haloferax mediterranei. He found that there were 14 DNA sequences that repeated themselves and that they read the same forwards as they did backwards. Utterly transfixed by these repeating units he committed himself to learning more about their function and origins. In his lab, Franciso made the discovery that CRISPR was part of a sophisticated immune system found in bacteria.

Single-celled organisms such as Bacteria and Archaea are under constant threat from invading viruses. As it stands Viruses outnumber their victims ten to one leading to large scale losses in bacterial numbers every single day. In the face of such troubling odds, bacterias only choice for a chance at survival was to adapt and evolve defences against these genetic intruders. Bacteria and Archaea have done this very well with a range of weaponry, however, the most sophisticated system evolved belongs to those with the CRISPR-Cas system.

As it turns out, we share a similar immune response to bacteria. The CRISPR-Cas system used by bacteria and Archaea handles invading viruses in a way that mirrors how our immune system produces antibodies. Between each set of palindromic repeats in a bacterial genome, there are 'spacer' sequences. These sequences are inserted by CRISPR-associated proteins (Cas) and contain genetic remnants of viral invaders. Over time CRISPR-associated proteins build a genetic 'library' in the bacteria's genome. This library of past invasions aids the bacterium's fight against a virus that it has encountered before, by teaching Cas proteins to seek and destroy any genetic invaders (Viruses) with DNA matching the 'spacer' sequence.

Our immune system does a very similar method, the main difference being the scale through which it occurs. When our body is under attack by a pathogen, our immune response launches a counterstrike and eliminates the pathogen. After the attack phase of our response immune cells known as B Lymphocytes remain in our system, ready to remind our body how to deal with the pathogen should it invade again.

Bacteria with the CRISPR-Cas immunity must pay attention to what DNA they insert into the ‘spacer’ sequences. There are many similarities in viral DNA and host bacteria DNA,  as such the risk of inserting their own sequences into the ‘spacer’ would lead to suicide via the autoimmune response.  In single-celled Prokaryotes genetic storage is a problem due to limited available space it would prove difficult to store information on every viral invasion experienced.

When 'spacer' sequences were looked at in greater detail it was found that the sequences were from viruses never documented before. This finding shocked the scientific community as it may highlight just how little is known about the diversity of viruses. On the other hand, some argue that these sequences could belong to viruses that are now extinct, or to viruses that have now mutated their sequence so that they remain undetected by CRISPR. Ultimately, CRISPR-Cas system is likely to be more of a hindrance if the latter is true.  Many ‘spacer’ sequences would be a waste of space if they code for viruses that have gone extinct or have changed their sequence.

CRISPR is proving to be extremely popular for our species, but for Prokaryotes not so much. More than 90% of Archaea employ this system, in contrast to a third of bacteria investing in such a system. Issues with memory storage, mean that bacteria in contact with many viruses are likely to suffer more from ‘genetic burdens’ and not reap the rewards of CRISPR.

Molecular Biologists, Conservationists, Geneticists believe the discovery of CRISPR is the best thing, well - since sliced bread! With this technologies ability to modify wild and domestic populations, produce hypoallergenic eggs and possibly reverse extinction and bring back the woolly mammoth you could understand the excitement. However, there is a dark side to such technological advancements, CRISPR increases the risk of harmful biological agents being engineered. One question remains on the minds of many swept up by the CRISPR mayhem, what on earth is it?

CRISPR stands for clustered, regularly interspaced short palindromic repeats. Francisco Mojica, spotted these repeats when he was looking at the genome of a microbe known as Haloferax mediterranei. He found that there were 14 DNA sequences that repeated themselves and that they read the same forwards as they did backwards. Utterly transfixed by these repeating units he committed himself to learning more about their function and origins. In his lab, Franciso made the discovery that CRISPR was part of a sophisticated immune system found in bacteria.

Single-celled organisms such as Bacteria and Archaea are under constant threat from invading viruses. As it stands Viruses outnumber their victims ten to one leading to large scale losses in bacterial numbers every single day. In the face of such troubling odds, bacterias only choice for a chance at survival was to adapt and evolve defences against these genetic intruders. Bacteria and Archaea have done this very well with a range of weaponry, however, the most sophisticated system evolved belongs to those with the CRISPR-Cas system.

As it turns out, we share a similar immune response to bacteria. The CRISPR-Cas system used by bacteria and Archaea handles invading viruses in a way that mirrors how our immune system produces antibodies. Between each set of palindromic repeats in a bacterial genome, there are 'spacer' sequences. These sequences are inserted by CRISPR-associated proteins (Cas) and contain genetic remnants of viral invaders. Over time CRISPR-associated proteins build a genetic 'library' in the bacteria's genome. This library of past invasions aids the bacterium's fight against a virus that it has encountered before, by teaching Cas proteins to seek and destroy any genetic invaders (Viruses) with DNA matching the 'spacer' sequence (image below).

Image Source

Our immune system does a very similar method, the main difference being the scale through which it occurs. When our body is under attack by a pathogen, our immune response launches a counterstrike and eliminates the pathogen. After the attack phase of our response immune cells known as B Lymphocytes remain in our system, ready to remind our body how to deal with the pathogen should it invade again.

Bacteria with the CRISPR-Cas immunity must pay attention to what DNA they insert into the ‘spacer’ sequences. There are many similarities in viral DNA and host bacteria DNA,  as such the risk of inserting their own sequences into the ‘spacer’ would lead to suicide via the autoimmune response.  In single-celled Prokaryotes genetic storage is a problem due to limited available space it would prove difficult to store information on every viral invasion experienced.

When 'spacer' sequences were looked at in greater detail it was found that the sequences were from viruses never documented before. This finding shocked the scientific community as it may highlight just how little is known about the diversity of viruses. On the other hand, some argue that these sequences could belong to viruses that are now extinct, or to viruses that have now mutated their sequence so that they remain undetected by CRISPR. Ultimately, CRISPR-Cas system is likely to be more of a hindrance if the latter is true.  Many ‘spacer’ sequences would be a waste of space if they code for viruses that have gone extinct or have changed their sequence.

CRISPR is proving to be extremely popular for our species, but for Prokaryotes not so much. More than 90% of Archaea employ this system, in contrast to a third of bacteria investing in such a system. Issues with memory storage, mean that bacteria in contact with many viruses are likely to suffer more from ‘genetic burdens’ and not reap the rewards of CRISPR.

There you have it a brief introduction to CRISPR origins and what it is. Exploiting CRISPR-Cas's ability to insert genes into genomes of organisms make it beneficial for those who to engineer organisms, whether it be activating gene expression or correcting the 'typos' that cause the onset of genetic diseases.

That is all for this week my lovely people, have an awesome weekend!

Science in the City

xoxo

Image sources for header image:

Mammoth Mosquito Chick and the egg

Information gathered from Nature magazine and the Broader Institute.

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