Biology Fact of the Day

[Tank]

Four Winged Dinosaur.

[youtube:62zy6yqn]http://www.youtube.com/watch?v=yL0UIzU0EEc[/youtube:62zy6yqn]

[Tank]

Catalog Details 1.25 Million Species of Organisms Across the World

ScienceDaily (May 18, 2010) â€" The world's most valuable asset, on which we all depend, is silently slipping through our fingers -- it is the world's astounding biodiversity, in some cases lost before it is even discovered.

[Tank]

Close encounter with a bizarre venomous beast

http://news.bbc.co.uk/1/hi/science_and_ ... 149148.stm

(It's actually rather cute!)

[Sophus]

Close encounter with a bizarre venomous beast

http://news.bbc.co.uk/1/hi/science_and_ ... 149148.stm

(It's actually rather cute!)

Mmmm.... maybe a little cute. Dunno about that nose though.  

[Tank]

Vaginal Microbes Vary Among Healthy Women

â€" The delicate balance of microbes in the vagina can vary greatly between healthy women, according to a new study led by the University of Maryland School of Medicine's Institute for Genome Sciences. Researchers hope further study will lead to personalized reproductive medicine for women, allowing doctors to tailor each woman's treatment and health maintenance strategies to her individual microbial make-up.

[Tank]

How Whales Have Changed Over 35 Million Years

â€" Whales are remarkably diverse, with 84 living species of dramatically different sizes and more than 400 other species that have gone extinct, including some that lived partly on land. Why are there so many whale species, with so much diversity in body size?

[KDbeads]

I saw this on a discovery special a while back, now that I want to watch it again I can't find the video  
http://www.biology-blog.com/blogs/perma ... ction.html

Retroviruses are unique for their ability to permanently insert their genetic material into the DNA of host cells, he said. During evolution of mammals, some retroviruses infected the germline (cells of the ovary and testis that have genetic material that are passed to their offspring) of the host, which is then inherited by their children. These retroviruses, known as endogenous retroviruses, are present in the genome of all mammals, including humans. Consequently, endogenous retroviruses can be considered remnants of ancient retroviral infections, Spencer said.

[Tank]

^^^ Well I'll be darned!

[Squid]

I saw this on a discovery special a while back, now that I want to watch it again I can't find the video  
http://www.biology-blog.com/blogs/perma ... ction.html

Retroviruses are unique for their ability to permanently insert their genetic material into the DNA of host cells, he said. During evolution of mammals, some retroviruses infected the germline (cells of the ovary and testis that have genetic material that are passed to their offspring) of the host, which is then inherited by their children. These retroviruses, known as endogenous retroviruses, are present in the genome of all mammals, including humans. Consequently, endogenous retroviruses can be considered remnants of ancient retroviral infections, Spencer said.

Approximately 8% of the human genome is composed of HERVs or human endogenous retroviruses:

The precise count of repeats is obviously underestimated because the genome sequence is not finished, but their density and other properties can be stated with reasonable confidence. Currently recognized SINEs, LINEs, LTR retroposons and DNA transposon copies comprise 13%, 20%, 8% and 3% of the sequence, respectively. We expect these densities to grow as more repeat families are recognized, among which will be lower copy number LTR elements and DNA transposons, and possibly high copy number ancient (highly diverged) repeats.

International Human Genome Sequencing Consortium. (2001). Initial sequencing and analysis of the human genome. Nature, 409, 860â€"921.

Analysis of the human genome revealed that some 45% of it consists of various kinds of transposable elements. Around 8% of the human DNA is derived from retrovirus-like elements. They originate from ancient retroviral infections or are relics of retroviral transposomal activity in the germ-line cells. Human endogenous retroviruses (HERVs) comprise a part of these elements. They have undergone substantial changes such as mutations of all kinds, deletions and insertions of other transposons, recombinations and mini- and micro-satellite expansion. This is why it is often difficult to identify individual retroviral genes and other retroviral DNA regions.

Pačes, J., Pavlíček, A. and Pačes, V. (2002). HERVd: database of human endogenous retroviruses. Nucleic Acids Research, 30, 205-206.

Retroviruses work by using an enzyme (reverse transcriptase) to copy their RNA into a host DNA. These insertions can be copied into the germline cells making it so that they are passed on to offspring.

The retroviruses carry within their virion the enzyme reverse transcriptase, which enables them to make a DNA copy of their RNA. This is a very important step in the life cycle of these viruses because the DNA copy can be integrated into the cell's DNA (pp. 330).

Batzing, B. (2002). Microbiology. Pacific Grove: Wadsworth/Thomson Learning.

[KDbeads]

Thanks for the references!!!  Now to find that video....

[AtheistBrit]

I love biology! This was one of the most amazing things I ever saw about the natural world:

[youtube:2p7bkhu0]http://www.youtube.com/watch?v=VjE0Kdfos4Y[/youtube:2p7bkhu0]

[xSilverPhinx]

Kiss of Death: Research Targets Lethal Chagas' Disease Spread by Insect That Bites Lips

ScienceDaily (May 2, 2010) â€" It makes your skin crawl -- a bug that crawls onto your lips while you sleep, drawn by the exhaled carbon dioxide, numbs your skin, bites, then gorges on your blood. And if that's not insult enough, it promptly defecates on the wound-and passes on a potentially deadly disease.

:eek:

This is the bug: Triatoma infestans and there are plenty of them here in Brazil.

I'm afraid it really won't help if you close your mouth while sleeping, they usually bite your face or neck (in Portuguese the common name for this insect is 'barbeiro', which means 'barber'). If they themselves are infected with the protozoa responsible for Chagas disease, and if the poo they lay on your skin after digesting your blood does not enter the wound, their bites itches and so you'll scratch it while sleeping, putting it right into the broken skin. The protozoa will then travel to your heart and nest themselves inside your cardiac cells, enlargening them and causing numerous heart conditions (thicker muscle walls inside the heart lead to insuficiency). There is no cure.

Yeah I was a bit too fond of parasitology a while back...

[Cecilie]

I'm never going to South America...

[Tank]

I'm never going to South America...

Big place South America. There are a lot of places where you won't get bitten by bugs that then defecate on your face!  

[Thumpalumpacus]

Vaginal Microbes Vary Among Healthy Women

â€" The delicate balance of microbes in the vagina can vary greatly between healthy women, according to a new study led by the University of Maryland School of Medicine's Institute for Genome Sciences. Researchers hope further study will lead to personalized reproductive medicine for women, allowing doctors to tailor each woman's treatment and health maintenance strategies to her individual microbial make-up.

I'll be happy to help the research.