Zoology
Recent studies indicate that in the phenomenon of obesity in Labrador Retrievers, a quarter is caused by genetic factors. Earlier findings showed that about 25% of Labrador Retrievers and 66% of Flat-Coated Retrievers carry a genetic mutation related to the pro-opiomelanocortin (POMC) gene. This mutation leads to an excessive craving for food, which in turn makes them prone to obesity.
In a study published on March 6th in the journal Science Advances, researchers explored how this kind of mutation affects dogs’ eating habits and energy expenditure. The results found that Labradors and Flat-Coated Retrievers carrying the POMC mutation did not need to consume additional food to feel satisfied. However, they tended to feel hungrier between meals.
In this study, the researchers conducted a series of experiments on 87 adult Labrador Retrievers (with normal or slightly overweight). They provided a can of dog food every 20 minutes until the dogs no longer ate. Dogs carrying the POMC mutation did not consume more food during the experiment. Then, three hours after breakfast, the researchers placed a transparent plastic box containing sausages to arouse their interest. The results showed that dogs with the mutation exhibited a stronger appetite, desiring the sausages inside the box.
Furthermore, by measuring the composition of gas exhaled during their sleep, it was found that Labrador Retrievers carrying the POMC mutation burned fewer calories than other dogs, a decrease of about 25%. This finding suggests that the genetic mutation not only makes dogs continuously feel hungry but also they have relatively lower energy expenditure. To help these dogs control their weight, the study suggests that owners can increase the frequency of feeding appropriately or use smart feeders to extend the dogs’ eating time.
Medicine
In the field of HIV research, recent cases suggest that timely treatment of newborns with HIV may yield positive outcomes. Approximately 10 years ago, a newborn in Mississippi, USA, who was confirmed to be infected with HIV, received prompt antiretroviral (ART) treatment. At nearly 2 years old, even after the child had stopped taking the medication, HIV was undetectable in the body, showing complete viral remission.
At an annual HIV/AIDS conference in the USA, researchers from Johns Hopkins University shared cases of six children who received treatment shortly after birth and displayed similar signs. The research team followed 54 newborns from 11 countries who were quickly diagnosed as HIV positive right after birth. These newborns began standard antiretroviral drug treatment within 48 hours.
In the study, six children showed excellent responses to the medication, with no detection of the HIV virus in their bodies for at least four years. However, a few weeks after interrupting the treatment, HIV was again detected in these children, so they resumed treatment and returned to a stable state. Four of the children remained in remission for 48 weeks, and another girl maintained remission up to 80 weeks. Later, the same girl showed signs of the virus infection again and restarted treatment.
Recent studies have shown that pregnant women who receive antiretroviral therapy and achieve complete viral suppression rarely transmit the HIV virus to their fetuses. Scientists believe that through more precise treatment planning, it may be possible to help newborns avoid ongoing antiretroviral therapy and maintain immune status, preventing HIV infection.
Major discoveries in planetary science: Scientists have discovered a binary asteroid system composed of icy bodies in the Kuiper Belt, beyond the orbit of Neptune, named Mors-Somnus. This system has long lacked spectral data, but the latest research has now thoroughly analyzed their spectra for the first time using the James Webb Space Telescope (JWST). These findings are expected to help us gain a deeper understanding of the outer solar system and the evolutionary history of planets like Neptune. These icy bodies, known as trans-Neptunian objects (TNOs), are tiny remnants left over from the early stages of planetary formation. The study of their dynamics and components provides clues for understanding the early chemical and physical conditions of the solar system. Researchers detected that Mors-Somnus is composed of complex organic matter, carbon dioxide (CO2), carbon monoxide (CO), hydroxides (OH), and nitrogen-rich materials using JWST. This diverse composition of TNOs is crucial to studying the migration of Neptune and the formation of the solar system.
Zoological wonders: Lactation is a typical characteristic of mammals, but researchers have also found similar lactation behavior in birds, fish, insects, and spiders, among other organisms. The latest discovery comes from Brazil, where researchers observed a mother of a species known as the Siphonops annulatus secreting a high-fat, milk-like substance to feed its newly hatched young. Previous studies in Brazil had found that some worm-like amphibians secreted a milk-like fluid during reproduction to nourish their unborn offspring. These young hatch with teeth and shed their skin approximately every seven days, feeding on their mother’s nutritious skin. The significance of the new study lies in the fact that it marked the first observation of female Siphonops annulatus producing milk to nourish the born young, a behavior that was monitored for over 200 hours and documented for 16 of these amphibians and their offspring.
Recent research has revealed lactation-like behavior in a species of oviparous non-mammalian animals: Scientists have found that these animals’ offspring consume milk released from the mother’s cloaca. This milk, rich in lipids and carbohydrates, originates from the hypertrophied glands of the mother’s oviductal epithelium. The findings have broadened our understanding of parental care behavior in amphibians and were published in the distinguished academic journal Science on March 7.
In the field of botany, research on the domestication and spread of the cacao tree (Theobroma cacao) sheds light on the significant history of cacao as one of the world’s major crops: Cacao was first domesticated in the upper Amazon Basin, but its spread to other cultures in Mesoamerica and South America has always been somewhat of a mystery. The latest study, published in the journal ‘Scientific Reports,’ suggests that the cacao tree had already spread to other regions of Central and South America at least 5,000 years ago via trade routes. Researchers analyzed 352 ceramic residue samples from 19 pre-Columbian cultures dated between 5,900 and 400 years ago, testing for ancient cocoa DNA and the presence of three distinctive methylxanthines components— theobromine, theophylline, and caffeine. The study found that cacao was not only domesticated 5,000 years ago in the Amazon Basin but was also widely cultivated along the Pacific coast thereafter, particularly in the Valdivia coastal region of Ecuador. Researchers also discovered cacao genotypes originating from the Peruvian Amazon.
These findings confirm the widespread exchange of cacao varieties between nations, and their crossbreeding in new cultural environments for adaption to local conditions. Based on the in-depth analysis of ancient container residues, this study not only reveals the breeding process of different cacao varieties but also suggests that the use of cacao products in ancient cultures of Mesoamerica and South America was likely more common than previously understood.
