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Archive for the ‘genetics’ category: Page 74

Mar 3, 2023

Long-Puzzling Biologists: Cornell Study Reveals How Cells Prevent Harmful Extra DNA Copies

Posted by in categories: biotech/medical, genetics

According to a recent study by researchers at Weill Cornell Medicine, a protein that prepares DNA

DNA, or deoxyribonucleic acid, is a molecule composed of two long strands of nucleotides that coil around each other to form a double helix. It is the hereditary material in humans and almost all other organisms that carries genetic instructions for development, functioning, growth, and reproduction. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).

Mar 3, 2023

Small differences in mom’s behavior may show up in child’s epigenome

Posted by in categories: biotech/medical, genetics

Adding evidence to the importance of early development, a new study links neutral maternal behavior toward infants with an epigenetic change in children related to stress response.

Epigenetics are molecular processes independent of DNA that influence gene behavior. In this study, researchers found that neutral or awkward behavior of mothers with their babies at 12 months correlated with an epigenetic change called methylation, or the addition of methane and carbon molecules, on a gene called NR3C1 when the children were 7 years old. This gene has been associated with regulating the body’s response to stress.

“There is evidence of a relationship between the quality of maternal-infant interaction and methylation of this gene though these are small effects in response to a relatively small variation in interaction,” said Elizabeth Holdsworth, a Washington State University biological anthropologist and lead author of the study published in the American Journal of Human Biology.

Mar 3, 2023

Researchers provide proof of the helical coiling of condensed chromosomes

Posted by in category: genetics

The iconic X-shaped organization of metaphase chromosomes is frequently presented in textbooks and other media. The drawings explain in captivating manner that the majority of genetic information is stored in chromosomes, which transmit it to the next generation. “These presentations suggest that the chromosome ultrastructure is well-understood. However, this is not the case,” says Dr. Veit Schubert from IPK’s chromosome structure and function research group.

Several models have been proposed to describe the higher-order structure of metaphase based on data obtained using a range of molecular and microscopy methods. These models are categorized as helical and non-helical. Helical models assume that the chromatin in each sister chromatid at metaphase is arranged as a coil, whereas non-helical models suggest that chromatin is folded within the chromatids without forming a spiral.

The researchers revived the term “chromonema,” which was used for the first time at the beginning of the 20th century. Now, the IPK and IEB researchers provided a detailed description of its ultrastructure. Different experimental approaches, including chromosome conformation capture sequencing (Hi-C) of isolated mitotic chromosomes, polymer modeling, and microscopic observations of sister chromatid exchanges and oligo-FISH labeled regions at the super-resolution level provided an independent proof for the coiling of the chromonema.

Mar 2, 2023

Team releases 74,000 fruit fly brain images for neuroscience research

Posted by in categories: genetics, neuroscience

Neuroscience research just got a little bit easier, thanks to the release of tens of thousands of images of fruit fly brain neurons generated by Janelia’s FlyLight Project Team.

Over eight years, the FlyLight Project Team and collaborators dissected, labeled, and imaged the neurons of more than 74,000 fruit fly brains, taken from more than 5,000 different genetically modified fly strains.

Now, these images are being made freely available, enabling scientists to quickly and easily find the neurons they need to test theories about how the works.

Mar 1, 2023

Gene Therapy Clinical Trial for Frontotemporal Dementia Has Begun

Posted by in categories: biotech/medical, genetics, neuroscience

Bruce Willis has FTD. I always wondered if gene therapy could help. Apparently so did Passage Bio, and they are doing clinical trials.

FTD is a disorder that affects the frontal and temporal lobes of the brain, areas that control personality, executive function, and language. FTD is a form of early onset dementia and currently has no approved disease-modifying therapies. In approximately 5–10% of individuals with FTD, the disease occurs because of mutations in the GRN gene. These mutations cause a deficiency of progranulin that helps regulate cellular processes.

Continue reading “Gene Therapy Clinical Trial for Frontotemporal Dementia Has Begun” »

Feb 28, 2023

Social deficits and seizures in autism genetic subtype tied to overexcited brain circuits

Posted by in categories: biotech/medical, genetics, neuroscience

Northwestern Medicine scientists have identified the cause of a genetic subtype of autism and schizophrenia that results in social deficits and seizures in mice and humans.

Scientists have discovered a key feature of this subtype is a duplicated gene that results in overactive or overexcited brain circuits. The subtype is called 16p11.2 duplication syndrome.

“We found that mice with the same found in humans are more likely to have and also have ,” said lead author Marc Forrest, research assistant professor of neuroscience at Northwestern University Feinberg School of Medicine.

Feb 28, 2023

Precise multimodal optical control of neural ensemble activity

Posted by in categories: genetics, neuroscience

The authors present a new approach to create and edit custom spatiotemporal neural activity patterns in awake, behaving animals with extremely high spatial and temporal precision. They present novel opsins optimized for multiphoton optogenetics.

Feb 27, 2023

How the influenza virus achieves efficient viral RNA replication

Posted by in categories: biotech/medical, genetics, health

New insights on how subunits of the influenza virus polymerase co-evolve to ensure efficient viral RNA replication are provided by a study published October 3 in the open-access journal PLOS Pathogens by Nadia Naffakh of the Institut Pasteur, and colleagues. As the authors note, the findings could lead to novel strategies for antiviral drug development.

Because of their yearly recurrence and the occasional emergence of pandemics, influenza viruses represent a worldwide major public health threat. Enhancing fundamental knowledge about the influenza RNA–, which is an enzyme that consists of three subunits (i.e., a heterotrimer) and ensures transcription and of the viral genome, is essential to reach the goal of better prevention and treatment of disease.

In the new study, Naffakh and colleagues gained new insights into viral polymerase function. They showed that the polymerase subunits co-evolve to ensure not only optimal inter-subunit cooperation within the heterotrimer, but also proper levels dimerization—the process by which pairs of heterotrimers attach together—which appears to be essential for efficient viral RNA replication. The findings point to polymerase dimerization as a feature that can restrict genetic reassortment, a major evolutionary mechanism in which swap gene segments, and could become an attractive target for antiviral drug development.

Feb 27, 2023

VKORC1 single nucleotide polymorphisms in rodents in Spain

Posted by in categories: augmented reality, biotech/medical, food, genetics, health

Rodents are considered one of the animal pests with the greatest impact on agricultural production and public health, especially the brown or Norway rat (Rattus norvegicus), the black or roof rat (Rattus rattus) and the house mouse (Mus musculus). Its control is an increasing problem worldwide. The intensification of agricultural production methods as well as the increase in merchandise transport to sustain growing populations is leading to an increase in waste production causing the growth of these rodent populations. The estimated losses in crop production caused by rodents range from between 5% and 90% (Stenseth et al., 2003) and this can cause problems in food security during harvesting (Belmain et al., 2015). Other negative impacts result from some rodent species living very close to human environments that can have a direct influence not only on human health through potential transmission of gastroenteric diseases and zoonosis to householders but also on domestic livestock. Therefore, rodent pest control is crucial and nowadays, the only effective control method available is the use of anticoagulant rodenticides (ARs).

ARs are so named because they interfere with the blood coagulation processes. The processes of activating various coagulation factors depends on the amount of vitamin K in its reduced form that exists in the organism. ARs inhibit the enzyme vitamin K 2,3-epoxide reductase (VKORC1) that is responsible for reducing vitamin K and maintaining the balance between its oxidized and reduced forms. The inhibition of VKORC1 prevents the activation of the coagulation factors resulting in animal death by internal bleeding. However, the intensive use of ARs can cause rodents to lose their susceptibility and become resistant to them. Genetic resistances to ARs are mainly associated with mutations or single nucleotide polymorphisms (SNPs) in the gene that codes for VKORC1 (vkorc1), causing amino acid substitutions in the VKORC1 protein ( Pelz et al., 2005 ). There are studies on this topic in several countries of central and northern Europe detecting rodent populations resistant to AR. Currently, there are at least 13 mutations mainly located in the exon 3 of the vkorc1 gene described in various countries of the European Union that confer resistance to specific ARs ( Berny et al., 2014 ; Goulois et al., 2017 ). In Eastern and Southern European countries, the information on the incidence of resistances to rodenticides is scarce, and it is becoming increasingly important to generate information on this subject ( Berny et al., 2014). In Spain, a mice population at the coastal countryside showing an adaptive introgression between house mouse and Algerian mouse that confers anticoagulant resistance has been described ( Song et al., 2011 ). While recently, four VKORC1 mutations in black rat were found in Toledo, Segovia and Zaragoza ( Goulois et al., 2016 ; Damin-Pernik et al., 2022 ). Any increase in resistant in rodent populations would lead to pest control issues that may causing serious agricultural, farming and public health problems.

Scientific advances have revolutionized the study of anticoagulant resistances in terms of understanding their genetic basis, physiological mechanisms and geographical distribution. The techniques based on the extraction and partial sequencing of genomic DNA allow a fast and precise monitoring of possible genetic resistances. Most of these tests involve laboratory studies using live rodents or blood samples taken from animals in the field. However, the improvement of DNA extraction techniques now allows the analysis of faecal samples (stool), increasing the number of samples that can be taken without the need for sampling by trapping or the management of dead animals (Meerburg et al., 2014). The importance of initial detection of genetic resistances due to mutations is crucial. The hypothesis of work, presenting it as a null hypothesis, is that there will be no rodent mutations in the vkorc1 gene in Spain.

Feb 26, 2023

New Hope for Treatment of Rare Metabolic Brain Disease

Posted by in categories: biotech/medical, genetics, neuroscience

X-ALD is the most prevalent of the approximately 50 rare diseases that affect the white matter of the brain, referred to as leukodystrophies. The genetic damage in X-ALD is due to a defect in the X chromosome. Men who are affected by X-ALD experience a progressive deterioration of their mobility, balance, and sensory abilities, leading to issues such as incontinence and sexual dysfunction.

Although X-ALD is inherited through the X chromosome, female carriers can also experience symptoms of the disease. Approximately 30% of male children and 60% of adult men develop encephalitis, which is a fatal form of the disease that leads to death within two to three years. X-ALD affects roughly one in every 20,000 births globally.

Now, for the first time, scientists from all relevant leukodystrophy centers in Europe and the US have jointly succeeded in obtaining controlled trial data for X-linked adrenoleukodystrophy. Of the 116 patients, 77 received the drug leriglitazone and 39 a placebo. The drug had already shown in preclinical studies that it can prevent neurodegeneration and offer protection against the life-threatening inflammation of the brain.

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