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Canada News.Net
a day ago
- Canada News.Net
Scientists discover that tomato is "mother" of potato
BEIJING, Aug. 1 (Xinhua) -- A surprising discovery by scientists has revealed that an ancient genetic marriage roughly 9 million years ago gave rise to what is now the world's third-largest staple crop: the potato. And the tomato, it turns out, is the mother of the potato. The study was conducted by a research team from the Agricultural Genomics Institute in Shenzhen, the Chinese Academy of Agricultural Sciences and a domestic researcher from Lanzhou University, in collaboration with scientists from Canada and the U.K. It showed that the potato originated from an ancient hybridization event between the tomato plant and a potato-like plant about 9 million years ago. This cross also led to the creation of a novel organ: the tuber. Published in the latest issue of the Cell journal, these findings provide a groundbreaking theoretical perspective for the genetic breeding of potatoes. As the world's most important tuber crop, the potato is native to South America. Valued for its high nutritional content and wide adaptability, it has spread worldwide. Huang Sanwen, who led the study, explained that the potato's origin had long puzzled scientists. In appearance, modern potato plants are almost identical to a potato-like species called Etuberosum, which does not carry tubers. However, potato plants are more closely related to tomatoes based on phylogenetic analysis. To unravel the mystery of the potato's origin, the research team analyzed 101 genomes and 349 resequenced samples from cultivated potatoes and their 56 wild relatives -- effectively a comprehensive DNA paternity test for all potatoes. They found that all potatoes examined carried stable, balanced genetic contributions from both the Etuberosum and the tomato. From this, they inferred that the potato was the hybrid offspring of the two. To validate this hypothesis, the team further assessed the divergence times of the three species. Their results showed that the Etuberosum and the tomato began diverging around 14 million years ago. Approximately 5 million years after their divergence, the two hybridized, leading to the emergence of the earliest tuber-bearing potato plants around 9 million years ago. "The tomato served as the maternal parent of the potato, while the Etuberosum was the paternal parent," Huang said. However, what continued to puzzle the researchers was why only the potato develops tubers, while its parents lack them. The tomato has neither underground stems nor tubers, and the Etuberosum has underground stems but no swollen tubers. Huang's team proposed a bold explanation: The tuber could be the product of genomic rearrangement. After the two ancestral lineages crossed, their genes recombined in a way that accidentally created the tuber as a new organ. The team further traced the origin of the key tuber formation genes, which are a combination of genetic material from each parent. They found the SP6A gene, which acts like a master switch that tells the plant when to start making tubers, came from the tomato side of the family. Another important gene, IT1, which helps control the growth of the underground stems that form tubers, came from the Etuberosum side. Without either piece, the hybrid offspring would be incapable of producing tubers. This ancient marriage not only produced the tuber but also enriched the genetic diversity of the potato plant's lineage. The team also discovered that different potato individuals exhibit a "mosaic" pattern of parental genetic contributions. When subjected to varying environmental stresses, this mosaic genetic combination allows for the selection of optimal gene sets, enabling potatoes to adapt to diverse habitats ranging from temperate grasslands to alpine meadows. The tuber has an underground survival advantage. It stores water and starch, helping potatoes endure drought and cold, and allows reproduction without seeds or pollination, as new plants can sprout directly from the buds on tubers. "Evolving a tuber gave potatoes a huge advantage in harsh environments, fueling an explosion of new species and contributing to the rich diversity in the potatoes we see and rely on today," Huang said.


CBC
6 days ago
- CBC
Destined to be a boy mom? New study suggests baby's sex isn't always random
Ashley Clouthier says she hoped her first child would be a boy, so when he was, she was ecstatic. Clouthier, 39, of Almonte, Ont., grew up with an older brother, and wanted the same experience for the large family she was planning with her husband. And when their next child was also a boy, well, even better. Best buds close in age, she thought, and two big brothers for their brood of future children. But then their third child was a boy. And their fourth. Today, Clouthier's boys are ages 13, 12, 10 and four — and she says she's not planning to have any more children. But if she did? "I'm sure it would be a boy," she said with a laugh. There just might be some truth to that, according to a new study that suggests a child's sex at birth might not be entirely random. The study, published July 18 in the journal Science Advances, examined the maternal and genetic factors that influence the sex of offspring after several of the co-authors observed examples of friends, colleagues and family members who had produced either all boys or all girls, which, they say, raised questions about chance. Researchers at the Harvard T.H. Chan School of Public Health examined a dataset of 58,007 U.S. women with two or more singleton live births and found that "each family may have a unique probability of male or female births," they wrote in the study. "The data suggested that there may be families that are more likely than not to have only girls, [and] families that are more likely than not to have only boys," Dr. Jorge Chavarro, a professor of nutrition and epidemiology and one of the authors of the study, told CBC News. 'A weighted coin' Specifically, mothers with three or more children were more likely to have either all boys or all girls, which challenges the traditional view that the probability is "random and independent," or that you have a 50-50 chance of having a boy or a girl each pregnancy, the authors wrote. They calculated that, in families with three boys, the probability of having another boy was 61 per cent, and in families with three girls, the probability of having another girl was 58 per cent. "Akin to flipping a weighted coin with roughly a 60-40 probability," Chavarro explained. The study suggests that there are subtle biological or genetic influences at play, rather than pure chance, which is what we know to be true of most things in life, said Dr. Sebastian Hobson, the head of labour and delivery at Mount Sinai hospital in Toronto and a maternal fetal medicine specialist. Hobson, who is also the chair of obstetrics for the Society of Obstetricians and Gynaecologists of Canada and who was not involved in the study, noted that the Harvard study is large and methodologically rigorous, but as with any study, the results should be interpreted with caution. The observed effects are small, he said, don't determine cause and effect, and the large population was predominantly white and U.S.-based, so can't be generalized globally. They also didn't gather any information about the biological fathers, he added. "Biology can nudge these probabilities slightly, but predicting a child's sex remains highly uncertain," Hobson said. "I think this is a great study, but it's not the be all and end all of sex determination." WATCH | Is gentle parenting too rough on parents? Why more parents are ditching the gentle approach 5 months ago 'Lose the birth lottery' Previous studies have found that parents are more likely to have a third child if their first two are the same sex, often in hopes the third child will be the opposite. And you only have to spend some time at school pickups, playgrounds and community pools to see that, well, it doesn't always work out that way. One recent study in the Journal of Behavioral and Experimental Economics refers to those who have three boys or three girls as parents who "lose the birth lottery." "If I got paid $1 for every time someone said, 'Are you going to try for a girl?' I'd be a millionaire," said Krystyna Recoskie, 48, also of Almonte, Ont., and a friend of Clouthier's. She has three boys, ages 15, 13 and 11. "For a while, it made me feel like I had failed. Like it was bad. How ridiculous is that?" she added. "I am blessed. I am complete." In the Harvard study, the researchers found that two-child families were actually more likely to be opposite sexes, or boy-girl, which they suggested implies that "couples are more inclined to stop reproducing when a balanced sex was reached." As for why some mothers were more likely to give birth to all-boys or all-girls, the authors suggested some women are at high risk of producing offspring of a specific sex due to factors affecting sperm survival. As well, procreation behaviour can be strongly influenced by the sex of previous children, they added. In addition, the authors found that older maternal age at first birth could be a risk factor for repeatedly giving birth to children of only one sex. This may be due to biological changes in the body, they said, like shorter follicular phase and lower vaginal pH. 'Four boys, poor you' Other studies have explored the idea of gender disappointment, or the feeling of sadness a parent may experience when their child's sex doesn't match with what they'd hoped for, and suggest it's more prevalent than we may think. "Gender disappointment in Western cultures is mostly related to the desire for 'gender balance' in the family — having a child of each gender to experience being a mother to sons as well as daughters," notes a 2023 study in the BJPsych Bulletin journal. Clouthier says she's never been disappointed about having four boys, and any negativity she experiences comes from other people. In a lot of ways, it's easier to have four kids all the same sex, she explained, between the hand-me-downs and gear they already have on hand. Birthday party themes can also overlap. And yes, it can get loud, and rough, and there are kid-sized holes in the drywall, but she notes her boys are also sweet, sensitive and cuddly. "I still get comments all time time, where people say, 'Four boys, poor you,'" Clouthier said. And I'll say, 'Yeah, lucky me!'"


Toronto Star
21-07-2025
- Toronto Star
Bees have some ways to cope with a warming Earth, but researchers fear for their future
WILLIAMSPORT, Ohio (AP) — Sweat covers Isaac Barnes's face under his beekeeper's veil as he hauls boxes of honeycomb from his hives to his truck. It's a workout in what feels like a sauna as the late-morning June temperatures rise. Though Barnes was hot, his bees were even hotter. Their body temperatures can be up to 27 degrees Fahrenheit (about 15 Celsius) higher than the air around them. As global temperatures rise under climate change, scientists are trying to better understand the effects on managed and wild bees as they pollinate crops, gather nectar, make honey and reproduce.