In mammals, adipose tissue stores energy in the form of fat. The ability to regulate fat storage is essential for the growth, development and reproduction of most animals, thus any abnormalities caused by excess fat accumulation can result in pathological conditions which are linked to several interrelated diseases, such as cardiovascular diseases, diabetes, and obesity. In recent years significant effort has been applied to understand basic mechanism of fat accumulation in mammalian system. Work in mouse has shown that the family of Krüppel-like factors (KLFs), a conserved and important class of transcription factors, regulates adipocyte differentiation in mammals. However, how fat storage is coordinated in response to positive and negative feedback signals is still poorly understood. To address mechanisms underlying fat storage we have studied two Caenorhabditis elegans KLFs and demonstrate that both worm klfs are key regulators of fat metabolism in C. elegans. These results provide the first in vivo evidence supporting essential regulatory roles for KLFs in fat metabolism in C. elegans and shed light on the human counterpart in disease-gene association. This finding allows us to pursue a more comprehensive approach to understand fat biology and provides an opportunity to learn about the cascade of events that regulate KLF activation, repression and interaction with other factors in exerting its biological function at an organismal level. In this review, we provide an overview of the most current information on the key regulatory components in fat biology, synthesize the diverse literature, pose new questions, and propose a new model organism for understanding fat biology using KLFs as the central theme.

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The development of wheat (Triticum aestivum L.) cultivars that are resistant to Wheat streak mosaic virus (WSMV), yet competitive in yield under nondiseased conditions, is an objective for breeding programs in the Great Plains. This field study was conducted to compare classical and transgenic sources of resistance to WSMV. Three sets of germplasm were evaluated. These included adapted cultivars with various levels of tolerance, transgenic wheat lines containing viral coat protein or replicase sequences from WSMV that showed resistance in greenhouse trials, and germplasm with resistance to WSMV due to a translocated segment of chromosome 4Ai-2 from Thinopyrum intermedium (Host) Barkworth and Dewey containing Wsm1. A replicated field trial was conducted at Bozeman, MT, over a two-year period to evaluate the effectiveness of these different sources of resistance to mechanical inoculation of WSMV. Adapted cultivars differed in their ability to tolerate WSMV with mean reductions in yield over the two years ranging from 41 to 74%. Incorporation of the replicase or coat protein gene from WSMV did not provide field resistance to viral infection and in general, transgenic lines yielded less than their parent cultivar, 'Hi-Line'. Wheat-Thinopyrum lines positive for a DNA marker linked to the Wsm1 gene had significantly reduced yield losses ranging from 5 to 39% compared with yield losses of 57 to 88% in near isogenic lines not having the Wsm1 gene. Yield of lines with Wsm1 in the absence of disease ranged from 11 to 28% less than yield of lines without Wsm1. Our results suggest Wsm1 provides the best source of WSMV resistance but a yield penalty may exist because of the presence of the translocation.

Wheat (Triticum aestivum) plants were stably transformed with the coat protein (CP) gene of wheat streak mosaic virus (WSMV) by the biolistic method. Eleven independently transformed plant lines were obtained and five were analyzed for gene expression and resistance to WSMV. One line showed high resistance to inoculations of two WSMV strains. This line had milder symptoms and lower virus titer than control plants after inoculation. After infection, new growth did not show symptoms. The observed resistance was similar to the 'recovery' type resistance described previously using WSMV NIb transgene and in other systems. This line looked morphologically normal but had an unusually high transgene copy number (approximately 90 copies per 2C homozygous genome). Northern hybridization analysis indicated a high level of degraded CP mRNA expression. However, no coat protein expression was detected.

Prey preference and feeding behaviour of Mononchoides gaugleri were studied using 11 phytoparasitic nematode species as prey. A full range of prey preferences were detected in no choice and paired choice predator-prey experiments. Meloidogyne incognita, Heterodera mothi and Anguina tritici juveniles (coefficient of preference = 0.92-1.00) were highly preferred as prey by M. gaugleri in all tests. The second tier of prey preference was occupied by the adult Hirschmanniella oryzae, Tylenchorhynchus mashhoodi, Xiphinema americanum and Paratrichodorus christiei (coefficient of preference = 0.19-0.67), and the third tier by Longidorus attenuatus and Helicotylenchus indicus (coefficient of preference = −0.15-−0.57). Hemicriconemoides mangiferae and Hoplolaimus indicus were not preyed upon. Mononchoides gaugleri attacked H. mothi and A. tritici (maximum strike rate (SR) = 92-94%), which has resulted in maximal prey wounding (encounters resulted in wounding (EW) = 46-47%). Longidorus attenuatus was attacked minimally (SR = 42%) with fewest casualties (EW = 21%). Hirschmanniella oryzae, H. mothi and M. incognita were most susceptible (prey susceptibility (PS) = 87.5-93.5%), whereas X. americanum and P. christiei were highly resistant prey species (prey resistance (PR) = 66.7-74.2%). Temperature and prey density governed predator feeding activities, with optimal search duration at 20-30 • C and 150-225 prey. The shortest and longest feeding durations of Mononchoides gaugleri were recorded for M. incognita and L. attenuatus, respectively. Predation was density-dependent.

of the disease include light green and yellow streaking of the leaves as well as curling of the leaves due to mite The development of wheat (Triticum aestivum L.) cultivars that activity. Infected plants typically exhibit stunted growth, are resistant to Wheat streak mosaic virus (WSMV), yet competitive in yield under nondiseased conditions, is an objective for breeding Published in Crop Sci

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