“KU professor says monarch population decimated - Wichita Eagle” plus 3 more |
- KU professor says monarch population decimated - Wichita Eagle
- Chance discovery leads to plant breeding breakthrough - Science Centric
- First court appearance for professor charged with ... - Minneapolis Star Tribune
- 'Glow-in-the-Dark' Sperm Sheds Light on Reproductive Biology, Sexual Selection and Speciation - Science Daily
| KU professor says monarch population decimated - Wichita Eagle Posted: 25 Mar 2010 11:28 AM PDT The Associated PressLAWRENCE, Kan. - The director of the University of Kansas Monarch Watch program says bad weather has decimated the monarch butterfly population. Chip Taylor says storms in the area of Mexico where the butterflies spend the winter have dropped the monarch population by at least 50 percent. Taylor, a professor of ecology and evolutionary biology, has led monarch-tagging efforts in the city and elsewhere for years. Taylor says it will take several consecutive years with favorable conditions for the butterfly population to recover. Information from: Lawrence Journal-World, http://www.ljworld.com Five Filters featured article: Chilcot Inquiry. Available tools: PDF Newspaper, Full Text RSS, Term Extraction. |
| Chance discovery leads to plant breeding breakthrough - Science Centric Posted: 25 Mar 2010 06:06 AM PDT A reliable method for producing plants that carry genetic material from only one of their parents has been discovered by plant biologists at UC Davis. The technique, to be published March 25 in the journal Nature, could dramatically speed up the breeding of crop plants for desirable traits. The discovery came out of a chance observation in the lab that could easily have been written off as an error. 'We were doing completely 'blue skies' research, and we discovered something that is immediately useful,' said Simon Chan, assistant professor of plant biology at UC Davis and co-author on the paper. Like most organisms that reproduce through sex, plants have paired chromosomes, with each parent contributing one chromosome to each pair. Plants and animals with paired chromosomes are called diploid. Their eggs and sperm are haploid, containing only one chromosome from each pair. Plant breeders want to produce plants that are homozygous - that carry the same trait on both chromosomes. When such plants are bred, they will pass the trait, such as pest resistance, fruit flavour or drought tolerance, to all of their offspring. But to achieve this, plants usually have to be inbred for several generations to make a plant that will 'breed true.' The idea of making a haploid plant with chromosomes from only one parent has been around for decades, Chan said. Haploid plants are immediately homozygous, because they contain only one version of every gene. This produces true-breeding lines instantly, cutting out generations of inbreeding. Existing techniques to make haploid plants are complicated, require expensive tissue culture and finicky growing conditions for different varieties, and only work with some crop species or varieties. The new method discovered by Chan and postdoctoral scholar Ravi Maruthachalam should work in any plant and does not require tissue culture. Ravi and Chan were studying a protein called CENH3 in the laboratory plant Arabidopsis thaliana. CENH3 belongs to a group of proteins called histones, which package DNA into chromosomes. Among the histones, CENH3 is found only in the centromere, the part of the chromosome that controls how it is passed to the next generation. When cells divide, microscopic fibres spread from each end of the cell and attach at the centromeres, then pull the chromosomes apart into new cells. That makes CENH3 essential for life. Ravi had prepared a modified version of CENH3 tagged with a fluorescent protein, and was trying to breed the genetically modified plants with regular Arabidopsis. According to theory, the cross should have produced offspring containing one mutant gene (from the mother) and one normal gene (from the father). Instead, he got only plants with the normal gene. 'At first we threw them away,' Chan said. Then it happened again. Ravi, who has a master's degree in plant breeding, looked at the plants again and realised that the offspring had only five chromosomes instead of 10, and all from the same parent. The plants appear to have gone through a process called genome elimination, Chan said. When plants from two different but related species are bred, chromosomes from one of the parents are sometimes eliminated. Genome elimination is already used to make haploid plants in a few species such as maize and barley. But the new method should be much more widely applicable, Ravi said, because unlike the process for maize and barley, its molecular basis is firmly understood. 'We should be able to create haploid-inducing lines in any crop plant,' Ravi said. Once the haploid-inducing lines are created, the technique is easy to use and requires no tissue culture - breeders could start with seeds. The method would also be useful for scientists trying to study genes in plants, by making it faster to breed genetically pure lines. After eliminating half the chromosomes, Chan and Ravi had to stimulate the plants to double their remaining chromosomes so that they would have the correct diploid number. Plants with the haploid number of chromosomes are sterile. The research also casts some interesting light on how species form in plants. CENH3 plays the same crucial role in cell division in all plants and animals. Usually, such important genes are highly conserved - their DNA is very similar from yeast to whales. But instead, CENH3 is among the fastest-evolving sequences in the genome. 'It may be that centromere differences create barriers to breeding between species,' Chan said. Ravi and Chan plan to test this idea by crossing closely-related species. Chan, who arrived UC Davis in 2006 in his first academic position, described the result as a 'game changer' for his laboratory, opening up new research areas, funding sources and recognition. Source: University of California - DavisFive Filters featured article: Chilcot Inquiry. Available tools: PDF Newspaper, Full Text RSS, Term Extraction. |
| First court appearance for professor charged with ... - Minneapolis Star Tribune Posted: 23 Mar 2010 04:28 AM PDT A message left on what was believed to be Proulx's Facebook account wasn't immediately returned. Proulx's father, Donald Proulx Sr., said his son lives in Florida but he doesn't know where or how to reach him. He told the AP on Tuesday that he met Bishop's husband "a couple of times, that's it. I have no relationship with him." Gray testified that Bishop, during a taped interview that lasted more than two hours, was not agitated but "seemed calm, she seemed very intelligent" as she denied anything to do with the shooting. "She said it was no way she was there, no way it happened. 'I wasn't there.' That kept being a recurring thing throughout the interview," Gray said. Bishop's attorney has said that that she doesn't remember the shootings, and she herself said the shootings "didn't happen" in her only public comments since the killings. "What about the people who died?" a reporter asked as she was led to a police car hours after the killings. "There's no way. They're still alive," she responded. Bishop, wearing white socks and flip-flops with a thick chain around both ankles, appeared to be paying attention to the proceedings Tuesday but was mostly expressionless. She at times fidgeted with her hands and tapped her leg. Sometimes she whispered answers to questions from her attorney, Roy Miller. Bishop is charged with capital murder, which can bring the death penalty if she's convicted, although prosecutors have not made a decision on whether they will seek a death penalty. Miller has said he will argue that Bishop was insane. He has told reporters she has shown signs of being unable to relate to reality. District Judge Ruth Ann Hall issued a gag order last week for the prosecution, defense and law enforcement personnel, barring them from talking to the media. Hall says the order will ensure a fair trial. At the time of the shooting, Bishop was in her last semester of teaching at UAH, which had denied her the job protections of tenure. Colleagues said she was angry over the tenure decision. The university fired her after the rampage. Five Filters featured article: Chilcot Inquiry. Available tools: PDF Newspaper, Full Text RSS, Term Extraction. |
| Posted: 19 Mar 2010 04:33 AM PDT ScienceDaily (Mar. 19, 2010) — Previously unobservable events occurring between insemination and fertilization are the subject of a groundbreaking new article in Science magazine (March 18) by Mollie Manier, John Belote and Scott Pitnick, professors of biology in Syracuse University's College of Arts and Sciences. By genetically altering fruit flies so that the heads of their sperm were fluorescent green or red, Belote and his colleagues were able to observe in striking detail what happens to live sperm inside the female. The findings may have huge implications for the fields of reproductive biology, sexual selection and speciation. According to Pitnick, many advances in reproductive and evolutionary biology have been constrained by the inability to discriminate competing sperm of different males and by the challenges of observing live sperm inside the female reproductive tract. The solution? Glow-in-the-dark sperm. "Our first goal with these flies was to tackle the mechanisms underlying sperm competition," says Pitnick. "Whenever a female mates with more than one male -- and female promiscuity is more the rule than the exception in nature -- there are conflicts between the sexes over paternity, as well as competition between rival ejaculates to fertilize eggs. Such postcopulatory sexual selection is a powerful force for evolutionary change." Pitnick explains that major advances in reproductive biology came with the advent of molecular tools that determine paternity. "Until now, the door to most of the mechanisms responsible for patterns of paternity has been closed. But not anymore." By quantifying sperm movement and fate within females inseminated by a green-sperm male and a red-sperm male (including real-time analyses of sperm motility in vivo), Manier and colleagues were able to unambiguously discriminate among hypothesized mechanisms underlying sperm precedence. "Despite nearly a century of intensive and innovative work on the reproductive biology of the fruit fly [Drosophila melanogaster], much of what we know about the female reproductive tract is a mystery," continues Pitnick. "Our jaws hit the floor the first time we looked through a microscope and saw these glowing sperm. It turns out that they are constantly on the move within the female's specialized sperm-storage organs and exhibit surprisingly complex behavior." Pitnick says his team has created similar glowing sperm populations for other species, including ones that hybridize, so he can observe what happens when sperm and the female are evolutionarily mismatched. "I suspect we have just scratched the surface of using this material," he says. Story Source: Adapted from materials provided by Syracuse University, via EurekAlert!, a service of AAAS. Journal Reference:
Note: If no author is given, the source is cited instead. Five Filters featured article: Chilcot Inquiry. Available tools: PDF Newspaper, Full Text RSS, Term Extraction. |
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