Scientists can now create accurate mugshots using only DNA

(PLoS Genetics)

Even though DNA analysis is still stuck in the past when applied by law enforcement today, scientists are still pushing the envelope with work that can turn DNA into a more effective investigative tool. In a new study published this week, researchers at Penn State and the Catholic University of Leuven (KUL) created a statistical model for mapping accurate facial structures using racial, gender, and genetic markers. It's hoped that the model not only be used for forensic analysis, but also for creating a clearer picture of humanity's ancestors.

PUSHING FORENSICS FORWARD

The team, led by geneticist Mark Shriver and imaging specialist Peter Claes, enlisted 600 volunteers with mixed European and West African ancestry to account for variations in facial structure. After capturing a 3D image of each volunteer's face, the researchers created a mesh of 7000 points that were used to precisely measure how genes attached to ancestry and gender affect the face's structural makeup.

They then tested each volunteer for 76 genetic variants that could cause facial abnormalities when mutated, and were able to isolate 20 that could be reliably traced back to facial shape. This method has already proven to be more accurate than previous models, and, according to New Scientist, Shriver is already using the research to aid in two serial rape cases in Pennsylvania. Perhaps even more promising, Shriver hopes that the tool can be used to improve images for ancient hominins, whose accepted appearance today is mostly the result of educated guesswork based on fossilized remains.

There's more work to be done, however. The research team now needs to conduct similar studies in different populations and successfully replicate their findings. Meanwhile, the results of this kind of facial analysis are not admissible in court, but can be used as a guide for identifying potential suspects. However, if the legal system can be cajoled into making better use of computer-based DNA analysis, it's easy to imagine this research serving a useful function in the future.

VIA GIZMODO

SOURCENEW SCIENTISTPLOS GENETICS

ORIGINAL:  The Verge

By Kwame Opam Email @kwameopam

March 21, 2014

The Mechanism Determining Plant Height and Leaf and Seed Size - Balance between three proteins controls plant-cell elongation -

ORIGINAL: AIST

- Balance between three proteins controls plant-cell elongation -
(Translation of AIST press release on November 19, 2012) Points
Identification of three types of protein controlling plant-cell elongation
Elucidation of a new mechanism by which each of the three types of protein antagonistically affects the activity of others
Expectations of the development of new crops and garden plants with modified plant height, leaf and seed size, and morphology Summary

Masaru Ohme-Takagi (Invited Senior Researcher), Miho Ikeda (Collaborative Researcher, Restart Postdoctoral Fellow of Japan Society for the Promotion of Science), and co-workers of Plant Gene Regulation Research Group, the Bioproduction Research Institute (Director: Yoichi Kamagata) of the National Institute of Advanced Industrial Science and Technology (AIST; President: Tamotsu Nomakuchi), have confirmed that the length of a plant cell is controlled by the antagonistic actions of three types of protein.

Cell length directly affects plant height and leaf and seed size. The researchers have identified two proteins, PRE1 and ACE, which act as a positive regulator for cell elongation, and one protein, AtIBH1, which inhibits cell elongation. They have found that ACE directly induces cell elongation, whereas AtIBH1 inhibits the activity of ACE by interacting with it. PRE1 indirectly promotes elongation by interfering the activity of AtIBH1. Final cell length is determined by the balance between the three proteins.

These proteins are transcription factors controlling functions of several genes. Use of these transcription factors would make it possible to modify plant height, leaf and seed size, flower and plant morphology, etc. They are expected to be applicable to a variety of areas, including improvement in the efficiency of farming, creation of large plants suitable for biofuel production, and development of unique garden plants.

Details of the results will be published in a US scientific journal, The Plant Cell.

Effect of differences in cell length on plants (Arabidopsis thaliana).

Social Background of Research

Plants, which are important resources, have been traditionally used as food, clothing, and home-building materials, and have comforted people as garden plants. Recently plant-based pharmaceuticals, biofuels, and industrial materials become popular and their application has been increasing. Modifying plant morphology and size to suit different applications should increase the efficiency of production.

From this perspective, modification of plant-cell length is an important subject of breeding studies because it directly affects tree and plant height and leaf and seed size. There are various environmental factors that determine cell length, including sun exposure, temperature, water contents, and nutrient ratios. It is not known how a plant determines its cell length in response to these environmental conditions.

History of Research

AIST has been studying plant genes, particularly the transcription factors that control the actions of many genes, in order to apply them to the production of industrial materials, medicines, and food. The Chimeric REpressor Gene Silencing Technology (CRES-T) and the transcription factor library developed in these studies are being used worldwide as general-purpose tools for a variety of basic and applied transcription factor studies. In addition to the development of such general-purpose tools, AIST is also studying functions of individual transcription factors involved in various phenomena, such as plant morphology, size, and substance production. In the present study, the researchers investigated the mechanism by which plant-cell elongation is controlled.

This study was supported by a grant-in-aid for JSPS Fellows, titled “Isolation of Transcription Factors Controlling Branching, Dwarfing, and Differentiation Potency Applicable to General Crops and their Use (FY2011–2013).”

Details of Research

Plants control cell elongation in response to various environmental conditions, such as sun exposure, temperature, water, and nutrient ratios, and to grow into forms adapted to their environment (e.g. a sunny or a shady location). When, and which, cells are to be elongated is related to seasonal differences in growth (e.g. the elongation of shoots in spring) and to changes in growth over time (e.g. young plants grow vigorously, whereas old plants grow very little). In addition, plant-cell elongation is involved not only in simple growth but also in important plant functions, such as the blooming of a flower and the turning of a flower toward the light when a plant falls over (Fig. 1).

Figure 1 : Examples of phenomena in which plant cell elongation is involved

The researchers have identified three transcription factors from a model plant, Arabidopsis thaliana: PRE1 and ACE, which enhance cell elongation, and AtIBH1, which inhibits cell elongation. These three transcription factors control plant size by regulating cell elongation, without affecting the number of cells. ACE activates the expression of enzyme genes that promote cell elongation. AtIBH1 inhibits cell elongation by interacting with ACE and interfering with its function. PRE1 interacts with AtIBH1 and thus interferes with its inhibition of ACE, thus promoting cell elongation. The researchers named the mechanism of this antagonistic inhibition by ACE, AtIBH1, and PRE1 a tri-antagonistic bHLH system (Fig. 2). Similar mechanisms of antagonistic inhibition, but between only two factors, have been reported in human beings, but mechanisms of antagonistic inhibition by three factors have not been reported before in plants or animals. The tri-antagonistic system is thus a new control mechanism.

Of the three types of transcription factor that were discovered, PRE1 was abundant in stem tips and young leaves and seeds, whereas AtIBH1 was abundant in hardened stem bases, old leaves, and mature seeds. This suggests that the antagonistic inhibition by the three factors, ACE, AtIBH1, and PRE1, regulates the elongation of various cells in each growth stage of the plant.

Figure 2 : Tri-antagonistic bHLH system controlling plant-cell elongation

Future Plans
The researchers aim to develop a technology for modifying plant height and leaf, flower, and seed size by partially enhancing or inhibiting with the functions of PRE1, AtIBH1, and ACE. They will then apply the technology to crop breeding. It is expect that manipulation of these three factors will change plant morphology, as well as its metabolism. They intend to conduct research in the effect of these factors on the metabolic system of plants.

This otherworldly amphibian has a completely transparent underbelly

ORIGINAL: IO9

 Robert T. Gonzalez

Sept 12, 2012

Top photo by Heidi & Hans-Jurgen Koch, via National Geographic

The cloud forests of South America are home to some of Earth's most extraordinary creatures, but few are as intriguing as the glassfrog. Seen from above, most glassfrog species looks pretty nondescript, but a glimpse of their underbelly reveals a fascinating anatomical anomaly: translucent abdominal skin. From underneath, a glassfrog's heart, liver, and various other internal organs are completely visible.

Why would an animal evolve such a trait? We spoke with an expert to find out.

Understanding the anatomy of a glassfrog requires a broad understanding of its ecological role. How and where does this creature live? What are its behavioral quirks? What makes this variety of frogs (known formally as Centrolenidae, the family encompasses roughly 150 known species) so unique that it would evolve a physical trait like transparency?

To find out, we spoke with evolutionary biologist Juan Manuel Guayasamin, who studies glassfrogs extensively as a researcher at Universidad Tecnológica Indoamérica's Center for Research on Biodiversity and Climate Change.(Ecuador)

"Glassfrogs are fascinating for several reasons," explained Guayasamin in an interview with io9. "They combine a morphology and behaviors that are seldom seen in amphibians." Parental care, for instance, is provided exclusively by males. "Females flee as soon as they have delivered the eggs. Then males stay during weeks in close proximity of the egg clutch, improving its survival probability by maintaining it wet and, sometimes, scaring away predators." The tendency for male frogs to protect their young from predators bespeaks another trait unique to glassfrogs: the males can be extremely aggressive.

"It is a funny scene looking at two tiny frogs fighting for hours," explains Guayasamin. "The fights usually include... grappling and dangling, with their feet firmly attached to the leaves above. Males hits each other with bony spines that they have on their arms and that can produce severe injures. Fights end when one of the frogs (the loser) falls."

Of course, a glassfrog's most noteworthy physical feature is its clear abdomen. The extent of this transparency can vary from species to species, but some glassfrogs are completely clear, revealing all of their internal anatomy.

"It is really a beautiful and unusual thing to be able to see a beating heart," Guayasamin says. "My work is try to understand the origin and evolution of all the aforementioned traits. This task combines natural history observations and an evolutionary framework, meaning that we first need to understand how the 150 species of this family are related, and then trace how behavior and morphology have evolved in this tree."

But uncovering the purpose of a transparent underbelly, let alone the environmental forces driving its evolution, is incredibly complex; to date, there is no clear explanation for the evolution of complete ventral transparency. That's frustrating, says Guayasamin, but it doesn't prevent researchers from coming up with hypotheses. Here's what they know so far:

Complete transparency has evolved multiple independent times. This suggests that a translucent underbelly provides some evolutionary advantage.

"Most frogs are not transparent because this would expose organs to the deleterious effects of sunlight and heat," explains Guayasamin. But in transparent glassfrogs, key organs like the liver and digestive tract are covered by a thin layer of light-reflecting organelles called iridiphores. These iridescent cellular subunits may provide a layer of protection from heat and sunlight, a feature that Guayasamin says could give glassfrogs the ability to optimize their internal homeostasis by simply moving about, "covering each organ at a time, as opposed to the entire body cavity."

Guayasamin says another hypothesis holds that transparency evolved to help glassfrogs avoid predators (an ability commonly referred to as "crypsis").

"Most glassfrogs are green and reflect light almost as a leaf. For predators (and amphibiologists), it is quite difficult to find a glassfrog if it is not, for example, calling."

However, these are just conjectures. "There are no experiments showing that ventrally transparent glassfrogs are more cryptic than those with partial or zero transparency," he explains, and there are no tests to confirm or reject the hypothesis on the regulation of internal homeostasis. How does one test ideas such as these? Guayasamin has some ideas:

Ideally, we would find two closely related species, one with a completely transparent abdomen and iridophores around key organs, and the other with an opaque abdomen and organs not covered by iridophores. Then, we would need to measure if the organs are equally efficient or not.

For crypsis, we could manipulate the transparency of some frogs and determine if that affects its cypsis in relation to the leaves. We would need to measure the reflectance of transparents glassfrogs, non-transparent glassfrogs and compare them to leaves´reflectance.

Read more about Guayasamin's research in this extensive review of glassfrog taxonomy, and at UTI's Center for Research on Biodiversity and Climate Change [In Spanish].

Top photo by Heidi & Hans-Jurgen Koch, via National Geographic; view of glassfrog from above and below by Martín Bustamante; dangling glassfrogs photographed by Rebecca Abuza