Генетикийн далд ялгарал нь хүрэн могойг шинэ орчиндоо дасан зохицож, олшроход тусалсан болохыг шинэ судалгаагаар илрүүлжээ.
Австрали болон Өмнөд Номхон далай гаралтай хүрэн могой Дэлхийн хоёрдугаар дайны дараа цэргийн ачаа тээврээр дамжин Гуам аралд анх ирсэн бөгөөд орон нутгийн ойн шувууд устахад голлон нөлөөлж, цахилгаан хангамжид саатал учруулж эхэлжээ. Тус арал дээр цөөн тооны могоймоор эхэлсэн энэхүү популяци нь генетикийн хувьд гавьтай ялгаралгүй байх ёстой байсан ч эрдэмтдийн таамаглалыг эвдэж маш богино хугацаанд газар нутаг даяар хэт олширсон нь судалгааны гол анхаарлыг татсан байна.
Буффало дахь Нью-Йоркийн их сургууль болон АНУ-ын Геологийн албаны судлаачид хүрэн могойн геномыг нарийвчлан судалж, хуучин аргаар илрүүлж чаддаггүй байсан 19,000 гаруй бүтцийн хувьслыг олж илрүүлжээ. Урт уншлагатай ДНХ дарааллыг тогтоох технологийн тусламжтайгаар эрдэмтэд геномын томоохон хэсэг хуулбарлагдах, устах эсвэл байрлалаа өөрчлөх зэрэг томоохон өөрчлөлтүүдийг илрүүлсэн нь могойн хувьсалд чухал үүрэг гүйцэтгэснийг тогтоов.
Судалгаагаар эдгээр генетикийн ялгарал нь дархлаа болон үнэрлэх чадвартай холбоотой генүүдэд төвлөрсөн болохыг тогтоожээ. Могойнууд хоёр салаа хэлээрээ дамжуулан хүрээлэн буй орчныхоо химийн дохиог авч идэш тэжээлээ олохын сацуу хүчтэй үнэрлэх чадварынхаа ачаар төрөл төрөгсрөө таньж, ойр төрлийн цус холилдох үед бие бие рүүгээ дайрахгүй байх нөхцөлийг бүрдүүлдэг байна.
Энэхүү олдвор нь генетикийн гажуудал буюу цөөн тооны амьтдаас бүрдсэн популяциуд орчиндоо хэрхэн дасан зохицож чардгийг шинээр харууллаа. Эрдэмтэд эдгээр бүтцийн хувьслауд Гуам аралд ирэхээс өмнө байсан эсвэл аралд ирсний дараа үүссэнийг тодруулахаар эх нутгийн популяциудтай харьцуулан судлахаар төлөвлөж байна.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
A few brown tree snakes managed to trigger one of the most damaging wildlife invasions on Guam, and scientists now have a better idea of how it happened. A new study shows that hidden genetic diversity may have helped the snakes survive inbreeding, adapt to their new environment, and multiply across the island.
The story of the brown tree snake (Boiga irregularis) is one of the most striking examples of how an invasive species can transform an ecosystem. Native to Australia and the South Pacific, the snake likely arrived on Guam sometime after World War II, possibly by hiding aboard military cargo planes.
Once established, the species had a major impact. Brown tree snakes contributed to the disappearance of many native forest birds and became known for causing power outages by climbing utility poles and electrical equipment. In some areas, their numbers have reached around 30,000 snakes per square mile.
The success of the invasion has puzzled researchers for years. The Guam population is thought to have started with only a small number of snakes, which should normally create a serious genetic bottleneck. With fewer genetic differences available, populations often struggle to adapt and survive. A team from the University at Buffalo and the U.S. Geological Survey (USGS) looked deeper into the snake’s DNA to understand why this case was different.
Snake Genome Reveals Hidden Differences
The researchers used long-read DNA sequencing to study large parts of the brown tree snake genome. According to a study, published in Science Advances, this technology helped them detect genetic changes that older sequencing methods often missed. The team discovered more than 19,000 structural variants. These are large DNA changes where sections of the genome can be copied, removed, or moved to another location.
For years, scientists studying genetic diversity mainly focused on smaller DNA changes involving individual genetic letters. Long-read sequencing makes it possible to see much larger differences that can affect important parts of the genome. Levi Gray, a postdoctoral researcher involved in the study, explained that older methods were like comparing two books by looking at individual letters while missing the fact that entire paragraphs might have been moved or duplicated.
These structural variants appear to have given the species population an unexpected source of genetic diversity. That may have helped the snakes deal with the challenges of starting from a very small number of ancestors.
Genes That Helped Snakes Adapt
The study found that many of the genetic variations were concentrated in genes connected to immunity and olfaction, the ability to detect smells. For brown tree snakes, smell is a key survival tool. They use their forked tongues to collect chemical signals from the environment, helping them find prey and understand their surroundings.
The researchers also found a possible link between these smell-related genes and an unusual behavior on Guam. Brown tree snakes are known to eat other snakes in their native habitat, but there is little evidence that they frequently attack each other on the island. As explained by Levi Gray, the snakes’ strong sense of smell could help them identify other individuals as relatives rather than prey, especially in a population where inbreeding is common.
Trevor Krabbenhoft, PhD, associate professor at the University at Buffalo Department of Biological Sciences and the study’s corresponding author, said the snakes may not have extremely high genetic diversity overall. Their success may instead come from specific types of genetic variation that scientists had not previously recognized.
Inbred Populations Reveal New Secrets
The findings offer a new way to look at populations that have gone through severe genetic bottlenecks. The brown tree snake invasion suggests that even a small founding group can sometimes carry enough hidden variation to adapt and expand.
The results may also provide useful information for conservation efforts. Christopher Osborne, PhD, the study’s first author and an aquatic biologist at State University of New York Oswego, said that:
“It’s possible that endangered species may have more flexibility in their genes than we realize,”adding that: “We’re now getting a better understanding of unappreciated sources of genetic diversity that may explain how some inbred species can still respond to their environment.”
Researchers still need to determine when these structural variants appeared. They do not yet know whether the differences were already present before the snakes arrived on Guam or whether some developed after the invasion began. To answer that question, scientists will need to compare Guam’s snakes with populations from their original range in Australia and the South Pacific.
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