Lab Confidential: Prokaryotic Partners

Wednesday, January 11 9:39 am

A technique called FISH causes bacteria in an adult hippopotamus leech to glow. © AMNH/S. Perkins

Each of the 41 intriguing images in Picturing Science: Museum Scientists and Imaging Technologies tells a fascinating story about research or conservation projects. Here’s the first in a series of four snapshots.

While researching bacteria found in blood-feeding leeches, Associate Curator Susan Perkins and Curator Mark Siddall have conducted fieldwork around the world, from French Guiana to South Africa.

But one of their most exciting discoveries took place in a Museum lab 10 years ago. DNA sequencing revealed that the symbiotic bacteria in turtle leeches belong to a group of bacteria that were previously found only in plants or as pathogens. As leeches have evolved and diversified, they’ve forged unique partnerships with bacteria at least three different times.

Dr. Perkins and Dr. Siddall confirmed they had sequenced the correct DNA using a technique called fluorescence in situ hybridization, or FISH. This method involves applying fluorescent DNA probes to thin slices of tissue that light up in the case of a DNA match. FISH also showed that symbiotic bacteria were present in young leeches that had never fed on blood, “suggesting the leeches pass the bacteria directly to their offspring,” explains Siddall. Images of glowing bacterial populations in leeches can be seen as part of Picturing Science: Museum Scientists and Imaging Technologies, curated by Siddall and now on view in the Akeley Gallery. Read more »

Picturing Science On View June 25

Monday, June 20 11:22 am

Whether Museum scientists are studying parasites, people, or planets in other solar systems, cutting-edge imaging technologies such as infrared photography, scanning electron microscopes, and CT scanners now make it possible to examine details that were previously unobservable. A new exhibition, Picturing Science: Museum Scientists and Imaging Technologies, features more than 20 sets of large-format images that showcase the wide range of research being conducted at the Museum as well as how various optical tools are used in scientific studies.

On Thursday, July 7, the Museum’s Tumblr and Twitter followers are invited to a special after-hours viewing of the exhibition, including visits to cutting-edge research labs, the opportunity to meet Museum scientists, and more. Visit the application page to find out more about the event and sign up for your chance to attend.

Picturing Science: Museum Scientists and Imaging Technologies is curated by Mark Siddall, curator in the Division of Invertebrate Zoology, and will be on exhibit at the Museum starting on June 25.

Two of Year’s Top Ten New Species Discovered by Museum Scientists

Tuesday, May 24 3:49 pm

Stereomicrograph of Tyrannobdella rex jaw showing large teeth on a single jaw. Image: Phillips, et al. 2010.

Two extraordinary new species discovered by scientists at the American Museum of Natural History — a toothy leech and a Louisiana batfish — have been named in the Top 10 New Species of 2011, a ranking compiled by the International Institute for Species Exploration (IISE) at Arizona State University. Every year taxonomists at the IISE review thousands of new species uncovered over the preceding calendar year.

One of the Top 10 is Tyrannobdella rex, which means “tyrant leech king,” a new species of blood sucker with ferociously large teeth lining a single jaw. It was discovered in Perú when the leech, which is less than 2 inches in length, was plucked from the nose of a girl who had recently been bathing in a river. T. rex was first brought to the attention of Mark Siddall, curator in the Museum’s Division of Invertebrate Zoology, when he received a specimen collected by Dr. Renzo Arauco-Brown, a Peruvian medical doctor. Siddall immediately recognized it as a new species. Part of the research for the paper, originally published in PLoS ONE, involved an expedition by two of Siddall’s students, Anna Phillips and Alejandro Oceguera-Figueroa, to gather new specimens for DNA analysis. Read more »

SciCafe: Expeditionary Gastronomy with Mark Siddall

Thursday, December 16 10:58 am

The hunt for parasites and blood-sucking leeches takes Museum Curator Mark Siddall, Division of Invertebrate Zoology, to many far-off destinations where life in the field presents its own culinary challenges. Whether gobbling guinea pigs or grubs, Dr. Siddall never loses his appetite for adventure.

Recorded at the Museum on November 3, 2010.

The next SciCafe takes place on January 5, 2011. Learn more about this popular, after-hours series of cocktails and discussion.

Podcast: Download | RSS | iTunes (1 hour, 5 mins, 78 MB)

Museum Links Evolutionary Biology and Human Health

Wednesday, June 09 6:22 pm

What does Darwin have to do with human disease? Quite a lot, it turns out, as the lessons of evolution, enhanced by sophisticated technologies such as gene sequencing, are being used to tease out the secrets of organisms that spread death and disability around the globe.

The American Museum of Natural History has taken a leading role in these efforts through ongoing collaborations between its evolutionary biologists and medical researchers to understand various threats to human health, from flu pandemics to malaria to the ravages of antibiotic-resistant bacteria.

This work was highlighted at a Science Breakfast panel discussion held last week at the Museum before an audience of medical and science writers.

Listen to the Podcast: Download | RSS | iTunes (1 hr 09 mins, 64 MB)

The panel included three curators from the Museum’s Division of Invertebrate Zoology who work under the auspices of the Sackler Institute for Comparative Genomics. Rob DeSalle, who moderated, Mark Siddall, and Ward Wheeler were joined by three medical scientists: New York University School of Medicine’s Jane Carlton, Albert Einstein College of Medicine’s Robert Burk, and Columbia University’s Paul Planet.

Museum scientists help medical researchers pin down the origin, evolution, and diversity of pathogens, and, perhaps most important, how they have adapted to us and we to them.

“Every doctor, whether they know it or not, is a natural historian,” said Planet, who studies infectious diseases in children and is also a research associate at the Museum.

Another key component of collaboration is the development of new tools to make sense of masses of raw data. Case in point: the Supramap, displayed by Wheeler, a powerful new computer application which allows researchers and public health officials to track the spread and mutation of a disease over time and place.

Of course, the ultimate goal of such supercomputing, genome-sequencing, and the building of evolutionary trees is to better predict pandemic outbreaks and to find better treatments, even cures.

Said Burk, who has worked with DeSalle on the molecular phylogeny of the human papillomavirus, which is linked to cervical cancer, for a decade:  ”From the medical perspective, I think it’s very clear that the better we understand the pathogenesis of any disease, the better we are able to intervene.”