Mosquitoes

Mosquitoes -- Updated

    Perky rascals, aren't they?  Okay, so they have over 3500 different species within their ranks, big deal (more are being identified each year, however).  And so what if only the females are the ones that bite (the males generally feed on nectar, much as do hummingbirds, although the latter also eat tons of bugs).  And so it should be since the males only live about a week, and the females less than a month.  But they really are everywhere (except Antarctica) and now, because of Zika, are once again making the covers of magazines (Smithsonian being the most recent) each asking if we (humans) should get rid of mosquitoes entirely.  Our Congress of course, has used the mosquito rage to again mount an effort to give the pesticide industry a way around regulations (the industry runs a big lobby and adds to the re-election coffers of many in Congress) with the House passing the Zika Vector Control Act, a law which has little to do with mosquitoes (or the Zika virus) but would allow the spraying of pesticides in and near waterways and thus possibly into the drinking water systems of human populations (ironically, the House has voted against any funding* specifically aimed at just preventing the Zika virus which is said to already have arrived, at least the mosquitoes carrying it).  Said Think Progress: Republican lawmakers first introduced a version of the Zika Control Act in 2011, after court cases decided that anyone wanting to spray pesticides that could end up in a body of water must apply for a separate permit, under the Clean Water Act, in addition to the general permit required under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).  Under FIFRA, the EPA can approve a pesticide if it “will not generally cause unreasonable adverse effects on the environment.”  There is no consideration for whether the pesticides will pollute a specific body of water, and users are not required to report environmental impacts to the EPA.  Under the Clean Water Act permit, both are required.

    But the article in the magazine brought up a good question, should we eradicate a species on purpose, even mosquitoes (only about 400 of the 3500 or so species are known to carry and transmit diseases).  As they question, from mosquitoes would it then begin to move onto rats and whatever else we might deem a "pest."  Sharks?  Flies?  Maybe criminals?  All of this was enough for scientists to have a closed-door meeting some months ago (even the press was barred) to discuss the implications...apparently, gene manipulation is on the verge of success.  Here, according to the article, is how it works: Researchers had known for years that certain genes in bacteria had short, repeating chunks of DNA. (CRISPR stands for “clustered regularly interspaced short palindromic repeats.”)   When a virus invaded, the bacteria copied part of the virus’ genetic code, slotting it into the spaces between the repeating CRISPR chunks.  The next time the bacteria saw that piece of code, an enzyme called Cas9 would guide its RNA to exactly that sequence in the gene of the invading virus.  It would cut out the DNA with incredible precision and fuse the strand back together.  Doudna (researcher Jennifer Doudna) and her colleagues harnessed this process in the lab, using it to quickly and easily edit any part of a gene they targeted.  The following year, separate teams led by MIT bioengineer Feng Zhang and Harvard’s George Church showed it would work in living cells...It was the universality as well as the accuracy that set CRISPR-Cas9 apart from other gene-editing techniques.  Unlike the custom enzymes Crisanti (molecular biologist Andrea Crisanti) and his team had been painstakingly building, Cas9 seemed to work in any type of cell.  Researchers saw implications for treating genetic disorders, for improving agriculture—and for more sinister applications, such as creating biowarfare agents.

    But suppose such eradication could be limited, say to one area such as a tropical island (tests are being considered in parts of the Florida Keys, lest those in the U.S. feel that they are exempt); if you are bitten by a gene-manipulated mosquito, then what?  If the chicken, pig or cow is bitten and you eat the meat, then what? (as a reminder, Congress is against any sort of labeling of genetically-modified plant or animal)   Do the genes carry forward?  And what of the hundreds if not thousands of bird and insect species that feed on mosquitoes?  Will the manipulated genes move into their systems and if so, how does one reverse the process?  Mosquitoes are blamed for many diseases such as malaria, dengue fever, chikungunya and now Zika; but in actuality, mosquitoes rarely travel more than 100 feet from their territory, all at a slow 2.5 miles per hour (the housefly travels 4x faster)...so who's really to blame for the spread of any of those diseases, or at least the spread of those diseases outside of that perimeter?

    But consider if gene manipulation advances further, say eliminating Alzheimer's or Down's syndrome?  Sound far-fetched?  Here's another excerpt from the Smithsonian piece, written by author Jerry Adler: If CRISPR works in a mouse, it will almost certainly work in a human being.  The least controversial application would be for inherited diseases such as muscular dystrophy—which would most likely involve repairing the somatic (non-reproductive) cells of a child or an adult.  But Chinese scientists just announced the results of their second study of CRISPR in human embryos. (They used nonviable embryos from fertility clinics.)  The results revealed “serious obstacles” to the approach, but the technology is fast improving.  Harvard scientists, for instance, recently modified the CRISPR method so it can change a single letter of the genetic code, making it easier to prevent diseases like Alzheimer’s and breast cancer. CRISPR also opens the Pandora’s box of editing the germ line cells that pass on their genetic material to succeeding generations.  This could be of enormous benefit to a small number of people who carry genes for disorders such as Huntington’s disease.  More problematically, it could encourage parents to custom-build their offspring, deleting genes that are unwanted but not life-threatening (for lactose intolerance, say), or adding ones that convey traits such as athletic ability, longevity—or intelligence...This possibility has given rise to a lot of op-ed angst about “playing God,” which certainly should be taken seriously.  Leaving aside the philosophic objections, the practical downside is that we don’t know all of the genes that will actually make someone smarter (or taller, stronger, healthier, faster and so forth) and the only way to find out for sure is to try different combinations on various embryos and wait for them to grow up.  By that time, if we got it wrong, it would be too late to fix, not least for the humans who were the unwitting subjects of the experiments.

    So, next time you hear a mosquito (their wings create a pitch an octave higher than a honeybee, so quick are their wings' motions), you might just want to consider if that bite was good or bad, or another thought is to perhaps just fill your garden with dragonflies which fly nearly 20x faster and feed on mosquitoes.  Everything has a purpose and place; remove them (or us) and what would possibly move in to take the spot?   Perhaps even with one of the smallest and peskiest creatures there are wonders yet to be discovered...but once gone, we will never have the chance to find out. 

*The President has asked for $1.9 billion just for preventing and treating the Zika virus (to date, 123 women in the U.S., all having traveled to another country or having had sex with someone who has, have proven positive for the Zika virus)...the House has appropriated $600 million of that request but has yet to decide which programs to cut or reduce in order to fund that appropriation...thus, it remains unfunded and goes back to the Senate for a compromise offer).