Final Year of Decade-long National Elm Trial

Although many Dutch elm disease-resistant elm cultivars are available in the nursery trade, much of the public is hesitant to purchase and plant any elm trees. In order to promote interest in planting these trees, scientific data on growth, form, and pest resistance for existing Dutch elm disease resistant elm cultivars are essential

Distribution of the HIV resistance CCR5-Δ32 allele among Egyptians and Syrians

A mutant allele of the β-chemokine receptor gene CCR5 bearing a 32-basepair (bp) deletion that prevents cell invasion by the primary transmitting strain of HIV-1 has recently been characterized. Individuals homozygous for the mutation are resistant to infection, even after repeated high-risk exposure, but this resistance appears not absolute, as isolated cases of HIV-positive deletion homozygotes are emerging. The consequence of the heterozygous state is not clear, but it may delay the progression to AIDS in infected individuals. In order to evaluate the frequency distribution of CCR5-Δ32 polymorphism among Egyptians, a total of 200 individuals (154 from Ismailia and 46 from Sinai) were tested. Only two heterozygous individuals from Ismailia carried the CCR5-Δ32 allele (0.6%), and no homozygous (Δ32/Δ32) individuals were detected among the tested samples. The presence of the CCR5-Δ32 allele among Egyptians may be attributed to the admixture with people of European descent. Thus we conclude that the protective deletion CCR5-Δ32 is largely absent in the Egyptian population. © 2006 Elsevier B.V. All rights reserved

National Elm Trial

Although many Dutch elm disease-resistant elm cultivars are available in the nursery trade, much of the public is hesitant to purchase and plant any elm tree. In order to promote interest in planting these trees, scientific data on growth, form, and pest resistance for existing Dutch elm disease resistant elm cultivars are essential

Mammalian retroelements

The eukaryotic genome has undergone a series of epidemics of amplification of mobile elements that have resulted in most eukaryotic genomes containing much more of this \u27junk\u27 DNA than actual coding DNA. The majority of these elements utilize an RNA intermediate and are termed retroelements. Most of these retroelements appear to amplify in evolutionary waves that insert in the genome and then gradually diverge. In humans, almost half of the genome is recognizably derived from retroelements, with the two elements that are currently actively amplifying, L1 and Alu, making up about 25% of the genome and contributing extensively to disease. The mechanisms of this amplification process are beginning to be understood, although there are still more questions than answers. Insertion of new retroelements may directly damage the genome, and the presence of multiple copies of these elements throughout the genome has longer-term influences on recombination events in the genome and more subtle influences on gene expression

Testing a Warning System for Anthracnose Fruit Rot on Day-neutral Strawberry–Year 4

Anthracnose fruit rot (AFR) of strawberry is considered to be caused by three Colletotrichum spp. In the Midwest, however, only Colletotrichum acutatum is found. This pathogen can attach itself to healthy plants and spread throughout the field without causing symptoms on the foliage. When fruit begins to ripen and weather conditions are rainy and warm, AFR can suddenly cause large sunken lesions on the fruit. To protect against AFR where it has occurred in the past, growers need to spray every 7 to 10 days beginning at the start of bloom until harvest

Tracking Alu evolution in New World primates

BACKGROUND: Alu elements are Short INterspersed Elements (SINEs) in primate genomes that have proven useful as markers for studying genome evolution, population biology and phylogenetics. Most of these applications, however, have been limited to humans and their nearest relatives, chimpanzees. In an effort to expand our understanding of Alu sequence evolution and to increase the applicability of these markers to non-human primate biology, we have analyzed available Alu sequences for loci specific to platyrrhine (New World) primates. RESULTS: Branching patterns along an Alu sequence phylogeny indicate three major classes of platyrrhine-specific Alu sequences. Sequence comparisons further reveal at least three New World monkey-specific subfamilies; AluTa7, AluTa10, and AluTa15. Two of these subfamilies appear to be derived from a gene conversion event that has produced a recently active fusion of AluSc- and AluSp-type elements. This is a novel mode of origin for new Alu subfamilies. CONCLUSION: The use of Alu elements as genetic markers in studies of genome evolution, phylogenetics, and population biology has been very productive when applied to humans. The characterization of these three new Alu subfamilies not only increases our understanding of Alu sequence evolution in primates, but also opens the door to the application of these genetic markers outside the hominid lineage

Controlling Bacterial Wilt in Muskmelon with Perimeter Trap Cropping

Perimeter trap cropping (PTC) involves planting one or more rows of a cucurbit crop that is highly attractive to cucumber beetles around the border of a main cucurbit cash crop that is less attractive to the beetles. Cucumber beetles attempting to migrate into the field are concentrated in the relatively more attractive border crop, where they can be controlled by insecticides

On-farm Cooperator Trials: Effect of Extended-duration Row Covers on Muskmelon and Winter Squash on Bacterial Wilt and Yield

Susceptible cucurbit crops are difficult to grow in Iowa because of bacterial wilt, caused by Erwinia tracheiphila. Striped and spotted cucumber beetles transmit bacterial wilt. Other insect pests such assquash vine borer and squash bugs may also have an economic impact on yield, particularly in squash