Science Buzz Lunch in Mixer Room, Bldg 1, June 17th and 21st

Science Buzz Lunch in Mixer Room, Bldg 1, June 17th and 21st

Topics discussed included:

1) the paper

LBR and Lamin A/C Sequentially Tether Peripheral Heterochromatin

and Inversely Regulate Differentiation

by Irina Solovei et al. in Cell 152, 584-598, Jan. 31, 2013

The authors start by pointing out that the chromatin organization is highly exceptional in the rod photoreceptor cells of nocturnal mammals: to reduce light loss via scattering in the retina of these animals, the euchromatin is localized to the nuclear envelope, and heterochromatin occupies the interior part of the nucleus.

They found that this phenomenon, and indeed the normal distribution of chromatin in other cells, can be explained by the status in these cells of the two mechanisms that can tether heterochromatin to the nuclear envelope: an LBR (lamin B receptor)-dependent mechanism and a lamin-A/C-dependent mechanism. The rods of nocturnal mammals lack both of these mechanisms.

2) the paper

A Bilirubin-Inducible Fluorescent Protein from Eel Muscle

by Akiko Kumagai et al. in Cell 153, 1602-1611, June 13, 2013

The authors describe the first fluorescent protein identified in a vertebrate. They isolated this protein from the Japanese freshwater eel Anguilla aponica, and named it UnaG (after unagi, the Japanese name for this eel). UnaG fluoresces when it binds bilirubin, a naturally occurring breakdown product of hemoglobin.

3) the paper

High-molecular-mass hyaluronan mediates the cancer resistance of the naked mole rat

by Xiao Tian et al. in Nature(

Published online

 

19 June 2013)

Naked  mole rats are naturally strongly protected from developing cancer by their production of high levels of the extracellular matrix component h

igh-molecular-mass hyaluronan, which signals their cells to control cell division via induction of p16.

Hyaluronan makes skin supple, and the authors speculate that naked mole rats evolved to have high levels of hyaluronan in their skin to accomodate their life in tight underground tunnels.

Interestingly, the same group of scientists showed a few years ago that a second mole rat species (the blind mole rat) uses a different mechanism (secretion of beta interferon, and resultant cancer cell death) to achieve its high cancer resistance.

4) a discussion in Nature News online this week titled: 

Dog genetics spur scientific spat:

Researchers disagree over canine domestication.

Three research groups have recently reached significantly different conclusions about where and when dogs evolved from their wolf ancestors. It should be interesting to follow this research for the next few years to see how the conflicting ideas get resolved.