Toplam 106 içerik listeleniyor
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Research reveals trend in bird-shape evolution on islands
Found throughout the Caribbean, the bananaquit has smaller flight muscles and longer legs on islands with fewer predators. In groundbreaking new work, Natalie Wright, a postdoctoral fellow at the University of Montana, has discovered a predictable trend in the evolution of bird shape.
https://www.biyologlar.com/research-reveals-trend-in-bird-shape-evolution-on-islands-haber-8716 -
Fossil find reveals just how big carnivorous dinosaur may have grown
Here is an artist's drawing of the abelisaur. An unidentified fossilised bone in a museum has revealed the size of a fearsome abelisaur and may have solved a hundred-year old puzzle.
https://www.biyologlar.com/fossil-find-reveals-just-how-big-carnivorous-dinosaur-may-have-grown-haber-8721 -
Yayınlanan Haritaya Göre Dünya’nın Son Vahşi Yaşam Alanlarının %70’i Beş Ülkenin Sınırları İçinde
Dünyadaki el değmemiş ekosistemlerin ilk haritası, bu alanların çoğundan sadece beş milletin sorumlu olduğunu gösteriyor. Photograph: Nature
https://www.biyologlar.com/yayinlanan-haritaya-gore-dunyanin-son-vahsi-yasam-alanlarinin-70i-bes-ulkenin-sinirlari-icinde -
Yayınlanan Haritaya Göre Dünya’nın Son Vahşi Yaşam Alanlarının %70’i Beş Ülkenin Sınırları İçinde
Dünyadaki el değmemiş ekosistemlerin ilk haritası, bu alanların çoğundan sadece beş milletin sorumlu olduğunu gösteriyor. Photograph: Nature
https://www.biyologlar.com/yayinlanan-haritaya-gore-dunyanin-son-vahsi-yasam-alanlarinin-70i-bes-ulkenin-sinirlari-icinde -
Scientists reconstruct ancient impact that dwarfs dinosaur-extinction blast
Picture this: A massive asteroid almost as wide as Rhode Island and about three to five times larger than the rock thought to have wiped out the dinosaurs slams into Earth. The collision punches a crater into the planet's crust that's nearly 500 kilometers (about 300 miles) across: greater than the distance from Washington, D.C. to New York City, and up to two and a half times larger in diameter than the hole formed by the dinosaur-killing asteroid. Seismic waves bigger than any recorded...
https://www.biyologlar.com/scientists-reconstruct-ancient-impact-that-dwarfs-dinosaur-extinction-blast -
Firefly protein enables visualization of roots in soil
Plants form a vast network of below-ground roots that search soil for needed resources. The structure and function of this root network can be highly adapted to particular environments such as desert soils where plants like Mesquite develop tap roots capable of digging 50 meters deep to capture precious water resources. Excavation of root systems reveals these kinds of adaptations but is laborious, time consuming, and does not provide information on how growing roots behave. A new imaging tool...
https://www.biyologlar.com/firefly-protein-enables-visualization-of-roots-in-soil -
Genome-wide search reveals new genes involved in long-term memory
A new study has identified genes involved in long-term memory in the worm as part of research aimed at finding ways to retain cognitive abilities during aging. The study, which was published in the journal Neuron, identified more than 750 genes involved in long-term memory, including many that had not been found previously and that could serve as targets for future research, said senior author Coleen Murphy, an associate professor of molecular biology and the Lewis-Sigler Institute for...
https://www.biyologlar.com/genome-wide-search-reveals-new-genes-involved-in-long-term-memory -
Epigenetic signatures that differentiate triple-negative breast cancers
The new study, published in Nature Communications, compares the breast cancer DNA 'methylome' with that of healthy individuals. The methylome provides a new picture of the genome and shows how it is epigenetically 'decorated' with methyl groups, a process known as DNA 'methylation'.
https://www.biyologlar.com/epigenetic-signatures-that-differentiate-triple-negative-breast-cancers -
New brain mapping reveals unknown cell types
Using a process known as single cell sequencing, scientists at Karolinska Institutet have produced a detailed map of cortical cell types and the genes active within them. The study, which is published in the journal 'Science', marks the first time this method of analysis has been used on such a large scale on such complex tissue. The team studied over three thousand cells, one at a time, and even managed to identify a number of hitherto unknown types. "If you compare the brain to a fruit...
https://www.biyologlar.com/new-brain-mapping-reveals-unknown-cell-types -
Odd histone helps suppress jumping genes in stem cells, study says
A family of proteins known as histones provides support and structure to DNA, but for years, scientists have been puzzling over occasional outliers among these histones, which appear to exist for specific, but often mysterious reasons. Now, researchers have uncovered a new purpose for one such histone variant: preventing genetic mutations by keeping certain so-called "jumping genes" in place. This research, which began at Rockefeller University and was published May 4 in Nature, reveals a...
https://www.biyologlar.com/odd-histone-helps-suppress-jumping-genes-in-stem-cells-study-says -
Algae use their 'tails' to gallop and trot like quadrupeds
Long before there were fish swimming in the oceans, tiny microorganisms were using long slender appendages called cilia and flagella to navigate their watery habitats.
https://www.biyologlar.com/algae-use-their-tails-to-gallop-and-trot-like-quadrupeds -
Biodiversity: 11 new species come to light in Madagascar
Madagascar is home to extraordinary biodiversity, but in the past few decades, the island's forests and associated biodiversity have been under greater attack than ever. Rapid deforestation is affecting the biotopes of hundreds of species, including the panther chameleon, a species with spectacular intra-specific colour variation. A new study by Michel Milinkovitch, professor of genetics, evolution, and biophysics at the University of Geneva (UNIGE), led in close collaboration with colleagues...
https://www.biyologlar.com/biodiversity-11-new-species-come-to-light-in-madagascar -
CRISPR gene editing reveals new therapeutic approach for blood disorders
This is a scanning electron micrograph of sickled and other red blood cells.
https://www.biyologlar.com/crispr-gene-editing-reveals-new-therapeutic-approach-for-blood-disorders -
CRISPR gene editing reveals new therapeutic approach for blood disorders
This is a scanning electron micrograph of sickled and other red blood cells.
https://www.biyologlar.com/crispr-gene-editing-reveals-new-therapeutic-approach-for-blood-disorders -
First imagery from echolocation reveals new signals for hunting bats
The ability of some bats to spot motionless prey in the dark has baffled experts until now. By creating the first visual images from echolocation, researchers reveal we have been missing how bats sense their world. Publishing in the journal eLife, scientists from Queen Mary University of London (QMUL) and the University of Bristol suggest that instead of searching for prey directly, bats intimately learn the layout of a home range - down to the surface of individual leaves and stones. When one...
https://www.biyologlar.com/first-imagery-from-echolocation-reveals-new-signals-for-hunting-bats -
New DNA research reveals genetic heritage of elusive vaquita
A new method of teasing information from scarce and highly degraded genetic samples is helping NOAA Fisheries and Mexican scientists unravel the genetic heritage of the enigmatic vaquita, the most endangered marine mammal on Earth. Genetic studies are important to the international effort to conserve the vaquita because the DNA that holds their genetic code can unlock the secrets of how they came to be. For instance, it can reveal the story of how - and how long ago - the animals evolved into...
https://www.biyologlar.com/new-dna-research-reveals-genetic-heritage-of-elusive-vaquita -
New DNA research reveals genetic heritage of elusive vaquita
A new method of teasing information from scarce and highly degraded genetic samples is helping NOAA Fisheries and Mexican scientists unravel the genetic heritage of the enigmatic vaquita, the most endangered marine mammal on Earth. Genetic studies are important to the international effort to conserve the vaquita because the DNA that holds their genetic code can unlock the secrets of how they came to be. For instance, it can reveal the story of how - and how long ago - the animals evolved into...
https://www.biyologlar.com/new-dna-research-reveals-genetic-heritage-of-elusive-vaquita -
Butterfly mimicry through the eyes of bird predators
In the natural world, mimicry isn't entertainment; it's a deadly serious game spanning a range of senses - sight, smell and hearing. Some of the most striking visual mimics are butterflies. Many butterflies become noxious and unpalatable to predators by acquiring chemical defences from plants they ingest as caterpillars. Other butterflies mimic the 'aposematic' or warning colouration and conspicuous wing patterns of these toxic or just plain foul-tasting butterflies. In a new study, scientists...
https://www.biyologlar.com/butterfly-mimicry-through-the-eyes-of-bird-predators -
An unexpected origin for calming immune cells in the gut
Biologically speaking, we carry the outside world within us. The food we ingest each day and the trillions of microbes that inhabit our guts pose a constant risk of infection--and all that separates us from these foreign entities is a delicate boundary made of a single layer of cells. The immune cells that swarm about this threshold must exercise a precise balancing act. They must be vigilant, yet also tolerant of harmless substances so that they don't cause harmful overreactions. New research...
https://www.biyologlar.com/an-unexpected-origin-for-calming-immune-cells-in-the-gut -
Fossil find reveals just how big carnivorous dinosaur may have grown
An unidentified fossilised bone in a museum has revealed the size of a fearsome abelisaur and may have solved a hundred-year old puzzle. Alessandro Chiarenza, a PhD student from Imperial College London, last year stumbled across a fossilised femur bone, left forgotten in a drawer, during his visit to the Museum of Geology and Palaeontology in Palermo Italy. He and a colleague Andrea Cau, a researcher from the University of Bologna, got permission from the museum to analyse the femur. They...
https://www.biyologlar.com/fossil-find-reveals-just-how-big-carnivorous-dinosaur-may-have-grown -
Research reveals trend in bird-shape evolution on islands
In groundbreaking new work, Natalie Wright, a postdoctoral fellow at the University of Montana, has discovered a predictable trend in the evolution of bird shape.
https://www.biyologlar.com/research-reveals-trend-in-bird-shape-evolution-on-islands -
UMD researchers discover a way that animals keep their cells identical
Roundworms (Caenorhabditis elegans) with a disabled eri-1 gene can lose their ability to control repetitive DNA. In the absence of eri-1, even two age-matched siblings can look dramatically different. Cancers arise in skin, muscle, liver or other types of tissue when one cell becomes different from its neighbors. Although biologists have learned a lot about how tissues form during development, very little is known about how two cells of the same tissue stay identical for an animal's entire...
https://www.biyologlar.com/umd-researchers-discover-a-way-that-animals-keep-their-cells-identical -
UMD researchers discover a way that animals keep their cells identical
Roundworms (Caenorhabditis elegans) with a disabled eri-1 gene can lose their ability to control repetitive DNA. In the absence of eri-1, even two age-matched siblings can look dramatically different. Cancers arise in skin, muscle, liver or other types of tissue when one cell becomes different from its neighbors. Although biologists have learned a lot about how tissues form during development, very little is known about how two cells of the same tissue stay identical for an animal's entire...
https://www.biyologlar.com/umd-researchers-discover-a-way-that-animals-keep-their-cells-identical -
TSRI researchers find 'lead actors' in immune cell development
Authors of the new paper include (left to right) Changchun Xiao, David Nemazee, Alicia Gonzalez Martin and Maoyi Lai of The Scripps Research Institute
https://www.biyologlar.com/tsri-researchers-find-lead-actors-in-immune-cell-development -
NIH-funded study reveals how differences in male and female brains emerge
Nematode worms may not be from Mars or Venus, but they do have sex-specific circuits in their brains that cause the males and females to act differently.
https://www.biyologlar.com/nih-funded-study-reveals-how-differences-in-male-and-female-brains-emerge -
NIH-funded study reveals how differences in male and female brains emerge
Nematode worms may not be from Mars or Venus, but they do have sex-specific circuits in their brains that cause the males and females to act differently.
https://www.biyologlar.com/nih-funded-study-reveals-how-differences-in-male-and-female-brains-emerge -
Penn study reveals how fish control microbes through their gills
Oriol Sunyer, a professor at the University of Pennsylvania School of Veterinary Medicine, has described fish as "an open gut swimming."
https://www.biyologlar.com/penn-study-reveals-how-fish-control-microbes-through-their-gills -
'Jumping gene' took peppered moths to the dark side
A mating pair of melanic peppered moths
https://www.biyologlar.com/jumping-gene-took-peppered-moths-to-the-dark-side -
'Jumping gene' took peppered moths to the dark side
A mating pair of melanic peppered moths
https://www.biyologlar.com/jumping-gene-took-peppered-moths-to-the-dark-side -
Octopus genome reveals cephalopod secrets
Researchers from UC Berkeley, the Okinawa Institute of Science and Technology Graduate University and the University of Chicago have sequenced and annotated the first cephalopod genome
https://www.biyologlar.com/octopus-genome-reveals-cephalopod-secrets -
Karıncalar Konuşarak Anlaşıyor
Bir dahaki sefer, koşuşturan bir karınca ordusu görecek olursanız, onların verilen emirlere itaat ediyor olduklarını hatırlayın. Bilim adamları, böceklerin birbirleri ile konuştuğunu ve sanılından daha zeki olduklarını gösterdiler. Ayrıca, karıncaların bir mızrapa benzeyen vücut parçası ile karınlarında doğal olarak bulunan "çamaşır yıkama tahtası"na benzer yapıyı oğuşturarak iletişim kurduklarını keşfettiler. Bilim adamları, onlarca yıldır...
https://www.biyologlar.com/karincalar-konusarak-anlasiyor -
Acorn worm genome reveals gill origins of human pharynx
The acorn worm Saccoglossus kowalevskii is common in brackish, shallow water on the Atlantic coast. Its newly sequenced genome is telling biologists about the genes responsible for pharyngeal gills
https://www.biyologlar.com/acorn-worm-genome-reveals-gill-origins-of-human-pharynx -
Acorn worm genome reveals gill origins of human pharynx
The acorn worm Saccoglossus kowalevskii is common in brackish, shallow water on the Atlantic coast. Its newly sequenced genome is telling biologists about the genes responsible for pharyngeal gills
https://www.biyologlar.com/acorn-worm-genome-reveals-gill-origins-of-human-pharynx -
Bird genomes contain 'fossils' of parasites that now infect humans
The researchers found DNA 'fossils' of parasitic nematodes in seven groups of birds (clockwise): trogons, mesites, parrots, hummingbirds, hornbills, manakins, tinamous.
https://www.biyologlar.com/bird-genomes-contain-fossils-of-parasites-that-now-infect-humans -
Bird genomes contain 'fossils' of parasites that now infect humans
The researchers found DNA 'fossils' of parasitic nematodes in seven groups of birds (clockwise): trogons, mesites, parrots, hummingbirds, hornbills, manakins, tinamous.
https://www.biyologlar.com/bird-genomes-contain-fossils-of-parasites-that-now-infect-humans -
Ribozom evrim çalışmaları RNA Dünyası hipotezine meydan okuyor!!
Uzun zamandır kabul gören ve yaşamın ortaya çıkışını anlatan RNA Dünyası hipotezine göre, hücrenin protein üretim merkezi olan ribozomun ortaya çıkışından önce, ortamda RNA adını verdiğimiz ve hücrede hayati görevler yürüten ribonükleik asitler vardı. Ancak yeni yapılan bir analize göre ise, ribozomun protein sentezi için gerekli birçok çalışan parçası bir araya getirilmeden önce, proteinler zaten ortada vardılar ve RNA ile etkileşim halindeydiler. Bu...
https://www.biyologlar.com/ribozom-evrim-calismalari-rna-dunyasi-hipotezine-meydan-okuyor -
Galaktozeminin Genetiği
Galaktozemiden etkilenmeyen (ne taşıyıcı ne de galaktozemik) biri, GALT enzim (galaktozu vücut için kullanılabilir hale getirmek için gerekli enzim) üretimi için iki normal gen devralır. Bu kişinin genotipi N/N' dir ve enzim aktivitesi normal olur. Klasik galaktozemi taşıyıcısı biri bir ebeveynden normal, diğerinden de klasik galaktozemiye yol açan hatayı kapsayan bir gen alır. Bu kişinin genotipi G/N' dir ve enzim aktivitesi normalden az ama tıbbi komplikasyonlara yol...
https://www.biyologlar.com/galaktozeminin-genetigi -
TRANSGENİK BİTKİLER (GDO) 'İN İNSAN SAĞLIĞINA ETKİLERİ
Transgenik bitkiler ya da diğer bir ifadeyle Genetiği Değiştirilmiş Organizmalar (GDO)'ın insan sağlığı üzerine olası etkilerini allerjik, antibiyotik dayanıklılık, yabancı DNA'nın yenmesi, karnabahar mozaik virüsü ve gıda kalitesi açısından incelemek mümkündür. Transgenik Bitkilerin Olası Allerji Etkileri. Belirli gıdalara karşı allerjisi bulunan bireyler, herhangi bir ürünü satın aldıklarında bunun içeriğini inceleyerek allerjik reaksiyona sebep olan...
https://www.biyologlar.com/transgenik-bitkiler-gdo-in-insan-sagligina-etkileri -
Ökaryotlarda Homolog rekombinasyon
Homolog rekombinasyonun olması çoğu ökaryotik hücrede mitoz ve mayoz için esastır. Mitoz sırasında homolog rekombinasyon, iyonlaştırıcı radyasyon veya DNA'ya hasar verici kimyasalların neden olduğu çift iplikli kırıkları tamir etmeye yarar.[21] Bunların tamir edilmemesi durumda somatik hücrelerde kromozom parçaları arasında büyük ölçekli yer değişimlerine (rearrangement) yol açar,[22] bu da kansere neden olabilir. Mayozda homolog rekombinasyon, profaz I...
https://www.biyologlar.com/okaryotlarda-homolog-rekombinasyon -
Rett sendromu
Rett sendromu, yaygın gelişimsel bozukluklardan birisi olarak sınıflandırılan beyinsel gelişim bozukluğudur. Ancak bunun yanlış bir sınıflandırma olduğunu ve benzer şekilde otistik belirtiler gösteren frajil X sendromu, tüberoz skleroz ya da Down sendromunun yaygın gelişimsel bozukluklar olarak sınıflandırılabileceğini önesüren görüşler bulunmaktadır. Bu sendromun belirtileri kolaylıkla otizm ve Angelman sendromunun belirtileriyle karışır. Klinik belirtiler...
https://www.biyologlar.com/rett-sendromu -
Yeryüzünün En Sıradışı Genomu
Canlılık işlevleri için gerekli olan bütün talimatlar DNA tarafından kodlanır. DNA’da, kromozom adı verilen paketçikler halinde paketlenir. Biz insanoğlunda da bu paketçiklerden 46 tane bulunmaktadır. Kromozom sayısı canlı türleri arasında farklılık gösterebildiği gibi aynı da olabilir. Mesela moli balığıyla insanlardaki kromozom sayısı birbirine eşittir. Fakat, insan ve moli balığının kromozom sayıları eşit olsa da eşit gelişmişlik düzeyine sahip...
https://www.biyologlar.com/yeryuzunun-en-siradisi-genomu -
X Şeklindeki Kromozomlar Ne Kadar Gerçekçi? Kromozomun Şeklini Biliyor Muyuz?
İnsan vücudunda yer alan kromozomlar üzerinde onlarca yıldan beri araştırmalar yapılıyor. Bir asırdan fazla süredir yapılan bu araştırmalarda kromozomların şekli hep X harfine benzer olarak biliniyor ve kabul görüyordu.
https://www.biyologlar.com/x-seklindeki-kromozomlar-ne-kadar-gercekci-kromozomun-seklini-biliyor-muyuz -
Kalıtsal Hastalıkların Varlığı Bulaşıcı Hastalıklara Karşı Korunmamızın Bedeli
Genlerimizin yaklaşık yarısı, hastalıkların başlangıç noktası konumunda. Bilim insanları, insan genomunda hastalıklara neden olabilecek 11.000 gen tanımladı.
https://www.biyologlar.com/kalitsal-hastaliklarin-varligi-bulasici-hastaliklara-karsi-korunmamizin-bedeli -
Erkek Denizatı ve İnsan Hamileliği Çok Benzer
Denizatları, hayvanlar alemindeki erkeğin hamile kaldığı tek aile – Syngnathidae – olarak ünlenmiştir.
https://www.biyologlar.com/erkek-denizati-ve-insan-hamileligi-cok-benzer -
Çok Hücreliliğin Temel Mekanizması Tek Hücreli Canlıda Gözlemlendi
Hayvanlar aleminin ilk üyelerinin yaklaşık 800 milyon yıl önce tek hücreli atalarından evrildiği biliniyordu.
https://www.biyologlar.com/cok-hucreliligin-temel-mekanizmasi-tek-hucreli-canlida-gozlemlendi -
Ağrının Kadın ve Erkeklerdeki Temel Farklılığı
Nature Neurosciencereveals ‘de yayımlanan yeni bir araştırma; ağrının, erkek ve dişi farelerde farklı hücreler kullanılarak işlendiğini ortaya çıkardı.
https://www.biyologlar.com/agrinin-kadin-ve-erkeklerdeki-temel-farkliligi -
Kırkayak Genom Dizilimi tamamlandı
Kırkayak, çok sayıda bacağı ve ürkütücü görüntüsü ile evlerimizde ve bahçelerimizde karşımıza çıkarlar.Kırkayak genomunun baz dizilimleri haritalandı ve tamamen ortaya çıkarıldı.
https://www.biyologlar.com/kirkayak-genom-dizilimi-tamamlandi -
Bir Kromozomun Yalnızca Yarısını DNA Oluşturuyor
Yeni bir çalışma, daha önce sanılanın aksine, DNA molekülünün kendisinin, bir kromozomu oluşturan materyallerin yalnızca yarısı olduğunu ortaya koydu.
https://www.biyologlar.com/bir-kromozomun-yalnizca-yarisini-dna-olusturuyor -
Kromozomun Şeklini Biliyor muyuz
İnsan vücudunda yer alan kromozomlar üzerinde onlarca yıldan beri araştırmalar yapılıyor. Bir asırdan fazla süredir yapılan bu araştırmalarda kromozomların şekli hep X şeklinde olarak biliniyor ve kabul görüyordu.
https://www.biyologlar.com/kromozomun-seklini-biliyor-muyuz -
Genlerin Her Bireydeki İşlevi Aynı Olmayabiliyor
Danimarka Aarhus Üniversitesi’nden bir grup bilimcinin, Güney Amerika’da yaşayan 50 farklı kuş çeşitindeki hemoglobine dayanarak yaptıkları çalışma sonucunda, evrimin içsel mekanizmalarına ilişkin önemli bulgular elde edildi.
https://www.biyologlar.com/genlerin-her-bireydeki-islevi-ayni-olmayabiliyor