DNA

Nature is full of patterns. Among them are tiling patterns, which mimic what you’d see on a tiled bathroom floor, characterized by both tiles and interfaces—such as grout—in between. In nature, a giraffe’s coloring is an example of a tiling pattern. But what makes these natural patterns form?

A new University of Arizona (UArizona) study uses bacteria to understand how tiles and interfaces come to be. The findings have implications for understanding how complex, multicellular life might have evolved on Earth and how new biomaterials might be created from biological sources. 

In many biological systems, tiling patterns are functionally important. For example, a fly’s wings have tiles and interfaces. Veins, which provide stability and contain nerves, are interfaces, which break up a wing into smaller tiles. And the human retina at the back of the inner eye contains cells that are also arranged like a mosaic of tiles to process what’s in our field of view.

A great deal of research has looked at how such patterns can be established through biochemical interactions. However, patterns can also be established through mechanical interactions. That process is not as well understood.

A new paper published in Nature shines new light on mechanical pattern formation. It was led by former UArizona postdoctoral fellow Honesty Kim. Ingmar Riedel-Kruse, an associate professor in the UArizona Department of Molecular and Cellular Biology, is the paper’s senior author.

The Riedel-Kruse lab, in partnership with researchers from the Massachusetts Institute of Technology’s Applied Mathematics Department, used bacteria to model how tiling patterns can arise through mechanical interactions.

The team developed various adhesive, or sticky, molecules that were placed on the surface of bacterial cells, allowing for different cell types to selectively stick together. When these altered bacteria were then placed on a petri dish, the bacteria started growing toward each other. Whenever two different bacterial types met, an interface was either formed or not, depending on whether their surface adhesion molecules were complementary or not. Interfaces were typically half a millimeter wide and three to 10 millimeters long, containing millions of bacteria. Many such interfaces then resulted in a variety of complex tiling patterns—depending on the initial bacterial placements on the petri dish.

The authors then investigated what types of tiling patterns could be generated, and whether an…

As the effects of climate change mount, ecosystem restoration in the US West has garnered significant public attention, bolstered by President Joe Biden’s America the Beautiful plan to conserve 30 percent of US land and water by 2030. Writing in BioScience, William J. Ripple and 19 colleagues follow up on the Biden plan with a proposal for a “Western Rewilding Network,” comprising 11 large reserve areas already owned by the federal government. The authors advocate for the cessation of livestock grazing on some federal lands, coupled with the restoration of two keystone species: the gray wolf and the North American beaver.

Wolves and beavers, according to the authors, are notable for their ability to produce broad ecosystem effects. For instance, they say, “by felling trees and shrubs and building dams, beavers enrich fish habitat, increase water and sediment retention, maintain water flows during drought, provide wet fire breaks, improve water quality, initiate recovery of incised channels, increase carbon sequestration, and generally enhance habitat for many riparian plant and animal species.” Wolves share a similar potential to reshape ecosystems, and “could assist in the natural control of overabundant native ungulates,” allowing native vegetation to regrow in previously degraded areas.

The rewilding plan would produce profound cascading effects, say the authors, and could ultimately benefit many of the “92 threatened and endangered species across nine taxonomic groups: five amphibians, five birds, two crustaceans, 22 fishes, 39 flowering plants, five insects, 11 mammals, one reptile, and two snail species.”

The authors cite a number of costs to their bold initiative, including payments to any livestock farmers, who should get just reimbursement for lost grazing allotments on federal lands. Ripple and colleagues argue that these challenges will ultimately prove navigable, in part because meat derived from forage on federal lands accounts for only about two percent of the nation’s production. Furthermore, say the authors, the time is ripe for “ultra-ambitious action,” given the “unprecedented period of converging crises in the American West, including extended drought and water scarcity, extreme heat waves, massive fires triggered at least partly by climate change, and biodiversity loss.”

– This press release was provided by the American Institute of Biological Sciences

The birth of every new life is to be celebrated. During the first trimester of pregnancy, doctors from the department of gynecology and obstetrics may suggest pregnant mothers undertake noninvasive prenatal testing (NIPT) prenatal testing to screen whether the baby might face increased risk due to chromosomal abnormalities.

During pregnancy, some of the baby’s DNA passes into the mother’s bloodstream. NIPT analyses the genetic information contained in this DNA to screen whether your baby is at increased risk of:

– Down syndrome (trisomy 21)
– Edwards syndrome (trisomy 18)
– Patau syndrome (trisomy 13)
 
For example, Down syndrome, often presents moderate to severe intellectual disability and physical developmental abnormalities and has an incidence of about 1 in 800 to 1 in 1000, which increases significantly with maternal age. 

Timely and comprehensive prenatal screening not only helps parents to better understand the health status of the mother and baby, but also helps expectant parents detect abnormalities early and plan for treatment in consultation with doctors from the department of gynecology and obstetrics.

Traditional Down syndrome screening is mainly done through biochemical markers, which is usually performed between the 11th and 19th week of pregnancy and has an estimated 88 percent detection rate. However, next-generation sequencing based (NGS-based) NIPT can be performed as early as the 10th week, while raising the detection rate of Down syndrome to an estimated 99 percent detection rate. 

With NIPT, invasive testing can be minimized, and false negatives are significantly reduced. Therefore, NIPT is widely recommended by authoritative organizations in this field, such as the American College of Medical Genetics and Genomics (ACMG) and the American College of Obstetricians and Gynecologists (ACOG), for the screening of many chromosomal abnormalities.

With the guidance of their doctors, NIPT is suitable for pregnant women, such as singleton and twin pregnancy, and pregnancies with a history of trisomy, high risk of aneuploidy (having missing or extra chromosomes), contraindications for invasive procedures, or in-vitro fertilization.

NIPT consists of the following steps: 5-10ml of blood of the pregnant woman at 10-24 weeks is drawn and sent for testing under the advice and guidance of doctors from the department of gynecology and obstetrics; the laboratory conducts a DNA test on the…

STONY BROOK, N.Y.–(BUSINESS WIRE)–Applied DNA Sciences, Inc. (NASDAQ: APDN) (the “Company”), a leader in polymerase chain reaction (“PCR”)-based technologies, today announced that The City University of New York (CUNY), the largest urban university in the United States, has extended its health services contract for COVID-19 testing and vaccine policy management with the Company’s wholly-owned clinical laboratory subsidiary, Applied DNA Clinical Labs, LLC (ADCL), for 12 months through July 2023 and at the prior contract terms. ADCL’s COVID-19 testing volumes, including the CUNY contract, fueled the Company’s record fiscal 2021 revenues and consecutive quarterly record revenues in the first half of fiscal 2022 ended March 31, 2022.

The contract has been successfully operational since August 2021. Through a partnership with Cleared4 software platform, ADCL provides a wide range of COVID-19 related health services to help CUNY mitigate COVID-19 associated risks. These services, which are provided to CUNY’s 25 campuses and covering 300,000+ students, employees, auxiliary workers, contractors and visitors, include: (i) high-throughput RT-PCR COVID-19 testing (weekly testing and a robust randomized testing program); (ii) vaccination policy and documentation management; and, (iii) facility access control.

“We commend the CUNY Board of Trustees for taking a forward-thinking approach to ensure the continued health and safety of all CUNY stakeholders while remaining committed to the promise and value of in-person learning. As New York City grapples with a resurgence of infections fueled by the Omicron BA.5 subvariant that can potentially elude rapid test detection and more easily reinfect people, including those who have been vaccinated, boosted and/or previously infected, our ability to deliver rapid PCR-based results with actionable reporting and access management for safeCircle clients remains a standout,” stated Dr. James A. Hayward, president and CEO of Applied DNA. “Given our infrastructure and client concentration in New York City, we are pleased to continue servicing CUNY while we expand our test offering and services.”

About safeCircle™

safeCircle is a fully integrated health testing platform that offers a customized suite of services to institutions and their personnel/members that encompasses: program design, RT-PCR and rapid antigen testing, sample kit distribution and collection, test site management,…

Dr Shiva Murarka, Senior Scientist-Reproductive Genomics & Vishakha Mali, Genetic Counsellor, Neuberg Centre for Genomic Medicine explains that the usual IVF workup includes commonly recommended genetic tests like- couple karyotype, Y chromosome microdeletion, and sperm DNA fragmentation

Today, IVF or in-vitro fertilization, is a household name. It is the most common assisted conception for couples facing difficulty in achieving a successful pregnancy. IVF entails fusing sperm and eggs outside of the body in a laboratory. The uterus receives the embryo or embryos after they have been formed. This might sound easy theoretically, but there are a lot of complex biological processes that go on in an IVF procedure. Not all IVF cycles end in a successful pregnancy. Thus, many times, in the hope of a healthy pregnancy, couples have to undergo multiple IVF cycles. The usual IVF workup includes commonly recommended genetic tests like- couple karyotype, Y chromosome microdeletion, and sperm DNA fragmentation.

However, there are upcoming molecular/ genetic tests which are used increasingly in the modern day. Advent of genetic testing in an IVF clinic has increased the rate of healthy pregnancy outcomes. These tests include either testing the embryos or screening the intrauterine environment.

Couples facing infertility, recurrent pregnancy losses or couples who are known to be carriers of a genetic condition can be additionally benefitted from the following tests:

Screening of embryos:

Also termed as Preimplantation Genetic Testing (PGT). The embryos can be screened for the following:

• For chromosomal aneuploidies- PGT-A

Around 10-15 per cent of first trimester pregnancy losses are attributed to genetic causes, like chromosomal aneuploidies. PGT-A screens for chromosomal aneuploidies in the embryos thereby increasing the chances of a successful pregnancy.

Indications for PGT-A include advanced maternal age, recurrent implantation failure, severe male factor and couples with normal karyotypes who have experienced recurrent miscarriage.

• For structural aneuploidies- PGT-SR

For an individual known to be a carrier of a balanced chromosomal translocation (like inversion, reciprocal translocation or Robertsonian translocation), there is a risk of unbalanced chromosomal translocation in every pregnancy which might lead to pregnancy loss. The test-PGT SR aids in identifying the embryos with unbalanced chromosomal translocation, thereby filtering them out and increasing…