An experiment with 2 trials (28 d/trial) was conducted to determine body composition, tissue deposition, and utilization of Lys for protein deposition (PD) of barrows and gilts fed -Lys·HCl (CLys) or protein-bound Lys in soybean meal (SBM). Thirty-two growing pigs (16 barrows and 16 gilts; average initial BW of 18.6 kg) were used in each of 2 trials. Four pigs (2 barrows and 2 gilts) were euthanized at the start of each trial to determine initial body composition. The remaining pigs were euthanized at the end of the trials to determine empty-body composition and deposition rates of water, protein, fat, ash, and AA. Pigs were randomly allotted to 1 of 7 dietary treatments. There were 2 replications per treatment in each trial for a total of 4 replications. Dietary treatments consisted of a corn-SBM basal diet (0.48% Lys) and diets containing 0.56%, 0.65%, and 0.74% standardized ileal digestible (SID) Lys that were achieved by adding Lys to the basal diet from either SBM or CLys. Pigs fed the CLys-supplemented diets at 0.65% SID Lys had more ( < 0.05) body water (663 vs. 624 g/kg) and less ( < 0.01) body protein (153 vs. 160 g/kg) than pigs fed the SBM-supplemented diets. Body fat content decreased ( < 0.01) as the dietary Lys increased similarly for pigs fed Lys from SBM and pigs fed CLys. Gilts had greater ( = 0.05) body Lys content in body protein than barrows (7.68 vs. 7.52 g/100 g). Empty-body ash contents were not different between pigs fed CLys or SBM-supplemented diets. Water deposition and PD increased linearly ( < 0.01) with dietary Lys and were least ( < 0.01) in pigs fed the basal diet but were similar when comparing pigs fed CLys and SBM-supplemented diets at the same dietary Lys concentration. Lysine deposition showed a linear increase ( < 0.01) with dietary Lys but was not different between pigs fed the 2 Lys sources at the same concentration. Barrows and gilts did not differ in tissue deposition rates. Overall, empty-body contents and deposition rates of essential and nonessential AA were not different between pigs fed CLys and pigs fed SBM-bound Lys. The amount of SID Lys required for PD ranged between 0.09 and 0.13 g/g for both sources of Lys. The Lys deposition:SID Lys intake ratio was greater ( < 0.01) in gilts than barrows (0.62 vs. 0.56). Body composition, tissue deposition, and utilization of Lys for PD and Lys deposition were not different in pigs fed diets supplemented with -Lys·HCl with respect to protein-bound Lys in SBM.

An experiment consisting of two 4-wk trials was conducted to determine Lys use for growth and carcass traits in barrows and gilts fed individually or in groups. One hundred twelve growing pigs (56 barrows and 56 gilts; average initial BW of 18.6 kg) were used in each trial. Pigs were fed individually or in groups of 3. There were 28 pigs individually penned, and 84 pigs in 28 pens (3 pigs/pen). There were 2 replications per treatment in each trial for a total of 4 replications. Dietary treatments consisted of a corn-soybean meal (SBM) basal diet (0.48% Lys) and diets containing 0.56%, 0.65%, and 0.74% standardized ileal digestible (SID) Lys that were achieved by adding Lys to the basal diet from either SBM or crystalline source as L-Lys HCL (CLys). At the end of each trial, all pigs were scanned using real-time ultrasound to determine 10th-rib back fat depth and LM area, and fat-free lean gain (FFLG) was calculated. Blood samples were taken from all pigs weekly to determine plasma urea N (PUN). Pigs fed CLys and Lys from SBM were not different in final BW, ADG, ADFI, or G:F. The ADG and G:F increased linearly (P < 0.01) as dietary Lys concentration increased. The SID Lys intake increased linearly (P < 0.01) as dietary Lys concentration increased and was not different when comparing pigs fed diets with CLys or SBM. The amount of SID Lys required per unit of growth or BW gain increased linearly (about 13 to 15.50 g/kg) in pigs fed either CLys or SBM Lys. Pigs fed individually had a greater (P < 0.05) ADG (0.59 vs. 0.57 kg) and ADFI (1.36 vs. 1.29 kg) than pigs fed in groups. The SID Lys intake was greater (P < 0.05) in pigs fed individually in comparison with pigs fed in a group (8.51 vs. 8.06 g/d). Fat-free lean gain and LM area increased (P < 0.01) as dietary Lys concentration increased regardless of Lys source. Pigs fed CLys diets had a greater (P < 0.05) LM area than pigs fed SBM at 0.74% SID Lys. Gilts had a greater (P < 0.01) LM area (14.28 vs. 13.58 cm(2)) and FFLG (264 vs. 245 g/d) than barrows. Pigs fed individually with CLys had less (P < 0.01) PUN than pigs fed Lys from SBM. Barrows fed individually had less (sex × feeding method, P < 0.01) PUN than gilts (26.75 vs. 29.32 g/100 mL). The results indicate that Lys from SBM-bound and CLys source were utilized similarly for growth and carcass traits regardless of sex or feeding method.

Two 4-wk experiments were conducted to determine lysine utilization for protein deposition (PD) in barrows and gilts. Thirty-two growing pigs (16 barrows and 16 gilts; average initial BW of 18.3 kg) were used in each experiment. Pigs were randomly allotted to one of seven dietary treatments. Four pigs (two barrows and two gilts) were killed at the start and the remaining pigs were killed at the end of the experiments to determine body composition. There were two replications per treatment in each experiment for a total of four replications. Dietary treatments consisted of a basal diet (0.55% lysine) and diets containing 0.65, 0.75, and 0.85% lysine that were achieved by adding lysine to the basal diet from either soybean meal (SBM) or L-lysine·HCl (crystalline). Blood samples were taken from all pigs weekly to determine plasma urea concentration (PUC). Body protein concentration was greater (P < 0.01) in pigs fed the 0.75% crystalline-supplemented diet than pigs fed SBM at the same concentration (152.9 vs 160.4 g/kg). Body PD was affected by dietary lysine concentration (P < 0.01), but was not different between the two sources of lysine (SBM vs crystalline, respectively) at the same concentration (0.65% lysine: 77.9 vs 68.3; 0.75% lysine: 88.3 vs 96.2; 0.85% lysine: 97.3 vs 90.5 g/d). Barrows tended to have greater PD (P = 0.08) than gilts (88.2 vs 78.8 g/d) regardless of lysine source. Body fat concentration decreased (P < 0.001) as the dietary lysine concentration increased for both lysine sources at the same concentration; however, fat deposition was not affected by diet. Water deposition increased with dietary lysine concentration (P = 0.05). Ash variables were similar for both sources of lysine. There was a diet × week effect (P < 0.05) for PUC. The PUC decreased for pigs consuming crystalline-supplemented diets and increased for pigs consuming SBM-supplemented diets during the 4-week experimental period. The results suggest that PD of growing pigs fed lysine from SBM is similar to that of pigs fed crystalline lysine.

Two studies were conducted at two locations to evaluate growth performance and carcass characteristics of growing-finishing pigs fed diets containing either YieldGard Rootworm corn (MON 863), a non-transgenic genetically similar corn (RX670), or two conventional nontransgenic corn hybrids (DK647 and RX740). A randomized complete block design with a 2 x 4 factorial arrangement of treatments (two genders and four corn hybrids) was used. Study 1 used 72 barrows and 72 gilts (progeny of Danbred sires x [Danbred x NE White line] dams grown from 22.7 to 117.0 kg BW). Pigs were housed in a modified open-front building in single-gender groups of six (six pens per dietary treatment). Study 2 used 80 barrows and 80 gilts (progeny of PIC 337 sires x C22 dams) grown from 29.5 to 114.9 kg BW. Pigs were housed in an environmentally controlled finishing building in single-gender groups of five (eight pens per dietary treatment). The test corns were included at a fixed proportion of the diet in both studies. Animals had ad libitum access to feed and water. Pigs were slaughtered at the end of the growth period using standard procedures, and carcass measurements were taken. There were no diet x gender interactions for growth performance or carcass measurements in either study. In both studies, overall ADG, ADFI, and G:F were not affected by corn hybrid. There was no effect of corn hybrid on carcass or LM quality measurements in Study 1. In Study 2, LM protein content was less (P< 0.05) for pigs fed RX740 compared with those fed either MON 863 or RX670; however, there was no effect of corn hybrid on other LM composition measures or on quality traits. In both studies, differences between barrows and gilts for growth and carcass traits were similar to previous research. These results suggest that the YieldGard Rootworm corn (MON 863) results in equivalent growth performance and carcass quality to nontransgenic corn hybrids in growing-finishing pigs.

ter digestibility, apparent digestible energy and apparent metabo-lizable energy are similar to the published values of Adeola and Bajjalieh (1997) and NRC (1998). Total nitrogen intake was similar (P > 0.10) between the corn varieties (Table 3). The amount of nitrogen digested (0.03 and 0.03 lb/d) and retained (0.01 and 0.01 lb/d) were similar (P > 0.10) between the corn rootworm protected and non-transgenic corns, respectively. Likewise, nitrogen digestibility (77.30 and 78.30%; P > 0.10) was similar between corns. The values for nitrogen digestibil-ity of the corn varieties used in this experiment are similar to the values published by Lawrence et al. (1995) and Adeola and Bajjalieh (1997). In conclusion, results of energy and nitrogen balance with growing pigs demonstrate that the potential Table 3. Energy and nitrogen balance.

Three experiments were conducted to determine the fifth-limiting amino acid for growing pigs in an 11% CP, corn-soybean meal diet. In each experiment, 36 gilts (initial weight 19.5, 21.9, and 21.0 kg, respectively) were penned individually and fed one of six diets in a randomized block design for 35 d. Diets containing 16, 12, and 11% CP were fed in each experiment. All 12 and 11% CP diets were supplemented with lysine, tryptophan, threonine, and methionine to provide the same total concentrations as those in the 16% CP diet. In Exp. 1, the 11% CP diet was supplemented with isoleucine, valine, or isoleucine + valine to concentrations equal to those in the 16% CP diet. In Exp. 2, the 11% CP diet was supplemented with histidine, histidine + valine, or histidine + isoleucine + valine. In Exp. 3, the 11% CP diet was supplemented with valine, histidine + valine, or isoleucine + valine. Gilts were allowed free access to feed and water. In all experiments, ADG and feed efficiency (G/F) were reduced (P < or = 0.07) as dietary protein was reduced. Supplementation of isoleucine alone further reduced (P < 0.05) ADG, ADFI, G/F, and fat-free lean gain. In contrast, supplementation of valine alone resulted in numerical increases in ADG and ADFI in two experiments, although the differences were not significant (P > 0.05). Supplementation with histidine and valine together resulted in growth performance equal to or greater than that of pigs fed the 12% CP diet, but less than that of pigs fed the 16% CP diet. Supplementation of isoleucine and valine together resulted in better growth performance (P < 0.05) than supplementation of either amino acid alone. In two experiments (Exp. 1 and 3), supplementation of the 11% CP diet with isoleucine and valine together resulted in ADG that were not significantly different (P > 0.05) from those of pigs fed the 16% CP diet. Supplementation of all three amino acids (Exp. 2) did not improve performance over supplementations with histidine and valine. Plasma urea concentrations were reduced (P < 0.05) as dietary protein was lowered from 16 to 12%. Additions of crystalline amino acids did not affect plasma urea levels. Plasma amino acid concentrations reflected the dietary additions of crystalline amino acids, but did not assist in the identification of the sequence of limiting amino acids. These data suggest that valine is the fifth-limiting amino acid and that either histidine or isoleucine is the sixth-limiting amino acid in an 11% CP diet.

Two experiments were conducted to determine the CP concentration below which N retention and growth performance are reduced when low-protein, amino acid-supplemented, corn-soybean meal diets are fed. In a N balance trial (Exp. 1), 12 gilts (initial weight 41 kg) were fitted with urinary catheters and fed six different diets during three 7-d periods in an incomplete block design. The diets were: 1) 18% CP; 2) 14% CP + AA, 3) 16% CP; 4) 12% CP + AA; 5) 14% CP; and 6) 10% CP + AA. Amino acids (lysine, threonine, tryptophan, and methionine) were supplemented such that the concentrations in the low-protein diets were equal to those in their standard (4% CP higher) counterparts. Nitrogen retention (g/d) decreased (P < 0.01) as CP decreased, in both standard (27.10, 24.53, and 20.99) and low-protein (21.51, 19.18, and 15.83) diets, but was lower (P < 0.01) in low-protein diets. There were no differences among treatments (P > 0.05) in biological value (68.2% standard vs 71.0% low-protein). In a growth performance trial (Exp. 2), 36 gilts (initial weight 19.5 kg) were penned individually and fed one of six diets for 35 d in a randomized complete block design. Dietary treatments were a 16% CP standard diet and low-protein diets formulated to contain 15, 14, 13, 12, and 11% CP supplemented with crystalline lysine, tryptophan, threonine, and methionine to equal the total concentrations in the standard diet. Protein concentration affected (P < or = 0.05) ADG, ADFI, feed efficiency, fat-free lean gain, longissimus muscle area, plasma urea, and plasma concentrations of most essential AA. For most of these traits, the major difference was poor performance of pigs fed the 11% CP diet. Thus, in Exp. 1, at AA concentrations from deficient to excess, low-protein, amino acid-supplemented diets failed to produce the same N retention as the equivalent corn-soybean meal diets. However in Exp. 2, the same performance was obtained with 16, 15, 14, 13, and 12% CP. Based on these data, we suggest that N balance is more sensitive than growth to amino acid adequacy andthat other AA (e.g., isoleucine and valine) may limit growth performance when the protein concentration is reduced by more than four percentage units.

Green fluorescent protein (GFP) was first isolated in the early 1970s for experimental use from coelenterates or the Pacific jellyfish, Aequorea victoria (Morin and Hastings, 1971). GFP has since become a favored biomarker in the photophysical analysis of molecular and cell biology because of its strong intrinsic visible fluorescence and the feasibility of fusing it to other proteins without affecting their normal functions (Creemers et al., 2000). Here we report using Bacillus subtilis expressing GFP to evaluate the influence of different environmental pH conditions on GFP fluorescence. Emission acquisitions were configured to excite at 471 nm and detect at an emission from 490 to 650 nm at 1-nm increments. Fluorescence intensity was significantly better at pH 7 (4.2 x 105 cps; P-value < 0.01) than at acid or alkaline conditions. GFP is a good biomarker for environments near netural conditions: however, GFP may be unsuitable where soils or waters are below or above pH 7 because of loss in fluorescence intensity. Alternative fluorescent markers and delivery systems must be examined in different environments to optimize responses from bioreporter molecules. (C) 2002 Elsevier Science Ltd. All rights reserved.

Two techniques are compared using total luminescence spectroscopy to detect endospore material in preparations equivalent to 3.0 X 10(5) / ml spores. The first method applied intrinsic, steady-state photoluminescence for detection. The second approach used a binding fluorochrome derived from 4-p-dimethylaminostyrylpyridinium (DASP) to signal the presence of spore material. Comparative fluorescence emission signatures (excited at 469 nm) showed greater calibrated signal recovery (4 X 10(6) cps) for spore material at longer wavelengths using DASP. The intrinsic fluorescence emission of endospores (excited at 346 nm) occurred at shorter wavelengths and showed a reduced calibrated intensity (1.4 X 10(5) counts per second (cps). One major advantage of DASP appears to be its longer wavelength excitation (469 nm) that is out of the range of associated biological materials that compete for absorption at shorter UV wavelengths.

In a laboratory test, total luminescence spectroscopy was used to detect and measure the in vivo presence of a biohazard surrogate, endospores of Bacillus megaterium, within the parasitoid wasp C. congregata (Say) (Hymenoptera:Braconidae). Upon emergence, exposed wasps were allowed to feed on five different concentrations of endospores suspended in 5 mL of honey solution. After 12 h insects were chilled at −80 °C for 5 min to permit capture. Aqueous suspensions were prepared by homogenizing the wasps in 3 mL of deionized water. The total excitation-emission matrix (EEM) was measured for each suspension by using an SLM Series 2 luminescence spectrometer. For wasps exposed to spore concentrations of 3.0 × 102 to 3.0 × 106 colony forming units (CFU)/mL, two intensity maxima were observed. The emission for tryptophan was identified at excitation (Ex) 300 nm and emission (Em) 350 nm. A second emission that resulted from other biological materials including nitroheterocyclic compounds and endospores occurred at Ex 350 nm and Em 420 nm. Changes in the ratio of intensity between the tryptophan and second emission were found to be related to endospore material present in the suspensions at original feeding concentrations of 15 000 to 15 million spores. Intensity ratios for the positive samples equaled 0.9, while the intensity ratios for the control equaled 1.9. One notable difference recorded for the emission spectra was an apparent, but minor, red shift of approximately 5 nm of the second emission when compared against a signature library of pure cultures. Diagnostic information such as this should contribute to methods for the detection and potential identification of biohazard materials with the use of photoluminescence.

A fundamental problem in biology is to understand how fertilization initiates reproductive development. During plant reproduction, one sperm cell fuses with the egg to form an embryo, whereas a second sperm cell fuses with the adjacent central cell nucleus to form the endosperm tissue that supports embryo and/or seedling development. To understand the mechanisms that initiate reproduction, we have isolated mutants of Arabidopsis that allow for replication of the central cell and subsequent endosperm development without fertilization. In this project we have cloned the MEA gene and showed that it encode a SET- domain polycomb protein. Such proteins are known to form chromatin-protein complexes that repress homeotic gene transcription and influence cell proliferation from Drosophylla to mammals. We propose a model whereby MEA and an additional polycomb protein we have cloned, FIE , function to suppress a critical aspect of early plant reproduction and endosperm development, until fertilization occurs. Using a molecular approach we were able to determine that FIE and MEA interact physically, suggesting that these proteins have been conserved also during the evolution of flowering plants. The analysis of MEA expression pattern revealed that it is an imprinted gene that displays parent-of- origin-dependent monoallelic expression specifically in the endosperm tissue. Silencing of the paternal MEA allele in the endosperm and the phenotype of mutant mea seeds support the parental conflict theory for the evolution of imprinting in plants and mammals. These results contribute new information on the initiation of endosperm development and provide a unique entry point to study asexual reproduction and apomixis which is expected to improve crop production.