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SUMMARY: The existence of pathogenic microorganisms in the poultry industry associated with the progression of antimicrobial resistance highlights the need to explore natural antimicrobial agents in maintaining poultry antibacterial standards. Essential oils are broad-spectrum natural agents against bacteria, showing a remarkable ability to combat bacterial resistance. These natural compounds demonstrate more effective antibacterial activity against multidrug-resistant strains than synthetic chemical antibiotics. Therefore, this review identifies the antibacterial benefits of Syzygium aromaticum essential oil in bacterial control of poultry and poultry products. The compilation of researched studies confirms that Syzygium aromaticum essential oil has proven to be a safe and effective oral antibiotic, promoting the preservation of eggs and meat without adverse impacts. Eugenol is the most significant contributor to its antibacterial activity. [ABSTRACT FROM AUTHOR]

Coatings of rice flour (RF), reinforced or not with rosemary essential oil (ROS), were used to evaluate changes in the internal quality of quail eggs stored at room temperature. Quality parameters [egg weight loss (EWL, %), Haugh unit (HU), yolk index (YI), albumen and yolk pH], microbiological (counts of total aerobic mesophilic bacteria and Enterobacteriaceae) and sensory (colour, aroma, odour, texture, taste, and general acceptability) parameters were evaluated during the experiment. Compared to the number of total aerobic mesophilic bacteria on the shell of uncoated eggs (2.02 ± 0.49; 1.78 ± 0.20 log10 CFU mL−1), RF/ROS exhibited significant inhibition effects for these bacteria on 0. (1.16 ± 0.25 log10 CFU mL−1) and 21. (0.84 ± 0.11 log10 CFU mL−1) days of storage at room temperature. On days 7, 14, and 21, RF had no effect on HU (P > 0.05), but eggs coated with RF/ROS had significantly higher HU (P < 0.05) than uncoated eggs from day 14, maintaining grade AA (73.88 ± 2.67) on day 21, while uncoated eggs had grade A (68.90 ± 1.55) at that time. The RF coating reinforced with ROS was a bioactive, efficient, and safe formulation for application based on internal quality, microbiological and sensorial aspects of quail eggs. [ABSTRACT FROM AUTHOR]

Biofilms of the fungal pathogen Candida albicans include abundant long filaments called hyphae. These cells express hypha-associated genes, which specify diverse virulence functions including surface adhesins that ensure biofilm integrity. Biofilm formation, virulence, and hypha-associated gene expression all depend upon the transcription factor Efg1. This transcription factor has been characterized extensively in the C. albicans type strain SC5314 and derivatives, but only recently has its function been explored in other clinical isolates. Here we define a principal set of Efg1-responsive genes whose expression is significantly altered by an efg1Δ/Δ mutation across 17 clinical isolates. This principal gene set includes 68 direct Efg1 targets, whose 5' regions are bound by Efg1 in five clinical isolates, and 42 indirect Efg1 targets, whose 5' regions are not detectably bound by Efg1. Three direct Efg1 target genes encode transcription factors—BRG1, UME6, and WOR3 –whose increased expression in an efg1Δ/Δ mutant restores expression of multiple indirect and direct principal targets, as well as biofilm formation ability. Although BRG1 and UME6 are well known positive regulators of hypha-associated genes and biofilm formation, WOR3 is best known as an antagonist of Efg1 in the sexual mating pathway. We confirm the positive role of WOR3 in biofilm formation with the finding that a wor3Δ/Δ mutation impairs biofilm formation in vitro and in an in vivo biofilm model. Positive control of Efg1 direct target genes by other Efg1 direct target genes–BRG1, UME6, and WOR3 –may buffer principal Efg1-responsive gene expression against the impact of genetic variation in the C. albicans species. Author summary: Biofilm growth of the fungal pathogen Candida albicans is a prevalent source of infection. Biofilm gene regulation is well understood in derivatives of the type strain SC5314, but few studies have examined regulatory features in other clinical isolates. Here we characterize the phenotypic and gene regulatory impact of deletion of master regulatory gene EFG1 in seventeen clinical isolates that represent a range of clades and infection sites. The mutation abolishes biofilm formation in all isolates, but has widely variable gene expression impact, even among members of a clade. Fewer than 20% of the gene expression targets in any one isolate are principal targets, which are shared among all isolates. One principal target encodes the transcription factor Wor3, an antagonist of Efg1 in the sexual mating pathway. Our analysis shows that Wor3 has an unexpected role in which it promotes biofilm formation and the expression of principal Efg1-activated genes. [ABSTRACT FROM AUTHOR]

This study aimed to compare and evaluate the effects of different protein coatings on maintaining the quality of eggs stored for six weeks at 20 °C. 308 brown table eggs from ISA Brown hens were used for four treatments: uncoated eggs, coated with rice protein concentrate – RPC, soy protein concentrate – SPC, and whey protein concentrate – WPC. Eggs started with Haugh Units (HU) of 82.01 and reduced in proportions of 28.75% (control), 12.82% (RPC), 12.90% (SPC), and 10.54% (WPC) on the last day of storage. Coated eggs showed smaller reductions (P < 0.0001) in this response. Protein coatings can effectively maintain the quality of eggs stored for six weeks at 20 °C. However, the WPC coating maintained the highest egg rate and the best yolk index for eggs stored for six weeks at 20 °C. [ABSTRACT FROM AUTHOR]

The development, search for and use of increasingly complete coatings with minimal structural and functional deficiencies are currently being investigated for use on eggs for consumption. Coatings with essential oils or propolis have been studied by academia and industry to achieve extended egg quality. These safe, natural compounds have a versatile chemical composition that gives them characteristics and functionalities that make them available for participation in various formulations in the food industry. Considering the importance of minimising food waste, economic losses and unsafe food and maximising food preservation, using practical, known and commercially available products that do not induce severe harm to human health or the environment, we review the effects of biopolymers incorporated with essential oils or propolis on the quality of table eggs. These coatings can be produced by mixing biopolymers, propolis extract or essential oils, acetic acid, plasticisers and emulsifiers, among other components. Studies indicate that coatings with essential oils or propolis preserve the quality of albumen and egg yolk stored for several weeks at temperatures of 20°C or higher and guarantee their internal and external microbiological quality. In addition, essential oils and propolis have no harmful effects on eggshells. Future research needs to deepen the evaluations of coatings with these products, including assessing the complete sensory quality of the eggs, as available reports do not sufficiently address sensory factors. [ABSTRACT FROM AUTHOR]

Scientific advances are one of the reasons why natural sanitisers are sought after for use in poultry farming, of which garlic-based sanitiser is one. Therefore, this work provides a brief review of garlic's potential in sanitising hatching eggs. There are no reports of negative effects of garlic on the microbiological quality of the eggshell nor the main incubation evaluation parameter (hatchability). On the contrary, garlic in low concentrations has improved the number of chicks produced (higher hatchability) through reducing eggshell contamination. More studies are needed to support the complete effectiveness and optimise and further encourage the application of this compound in poultry farming. [ABSTRACT FROM AUTHOR]

The use of sanitisers, with natural compounds as active ingredients in their formulations, can be of great value in the sanitisation of hatching eggs. Here, we review the effects of sanitising hatching eggs with propolis on the eggshell microbiota, hatchability and survival of post-hatch chicks. We demonstrate that propolis is an appropriate and promising option for sanitising hatching eggs, as it helps in the reduction of microbial load on the eggshell (total aerobic mesophilic bacteria and fungi) and increases embryo safety. Typically, propolis does not negatively affect the hatchability percentage and can, in some cases, improve this rate by up to 11%. Thus, we reinforce the positive impact of natural products on poultry production. [ABSTRACT FROM AUTHOR]

Summary: Brazilian hair sheep constitute a genetic diversity hotspot. These animals are found in the harsh environments of the Brazilian Northwest (semi‐arid) region. Genotypes (50K SNP chip) from seven Brazilian sheep breeds (five hair and two coarse wool types) and 87 worldwide breeds were used to test for population structure, admixture and genetic diversity. Moreover, phylogenetic trees evaluating migration events between genetic groups were built. Brazilian Somali, a fat‐tailed breed, had a close relationship with East African breeds and clustered distinctly from other Brazilian breeds. Brazilian Blackbelly and Barbados Blackbelly had a close relationship. The Morada Nova breed did not show close relationships with European or African breeds, revealing a single migration event from an Algerian hair breed. Brazilian Fat‐tail and Morada Nova share a common ancestor, but the former showed introgressions from Brazilian Somali and Afrikaner breeds, explaining the fat‐tail phenotype. The Santa Inês breed received a substantial contribution from Brazilian Bergamasca and showed an admixed origin with recent introgressions from other breeds, mainly from Suffolk. Furthermore, Brazilian Somali and Brazilian Fat‐tail are the most endangered sheep genetic resources in Brazil and should be the focus for ex situ conservation programs. In conclusion, Brazilian hair sheep show an African origin and are characterized by diverse genetic composition, reinforcing the need for conservation of these genetic resources, and at the same time, this highly diverse group has variability that can be used in breeding programs. [ABSTRACT FROM AUTHOR]

Copyright of Archivos de Zootecnia is the property of Archivos de Zootecnia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Infrared thermography of the lateral side portion of the udder was taken from 38 lactating cows in a 6-day experiment. Thermograms were analyzed using specific software with the use of eight different methods. The experiment was aimed at correlating the different methods with each other and with rectal temperature (RT), in order to suggest a method to assess udder side temperature, and also at creating regression equations to enable RT calculation through the use of thermographic data. All methods of analyzing thermograms were highly correlated; correlations between thermograms and RT were significant (P < 0.01) and above 0.840. The highest correlation was between RT and the maximum temperature obtained using a horizontal rectangle placed within the lateral (side) portion of the udder (maximum temperature in a horizontal rectangle (MHR), 0.897). With the exception of the average temperature of a horizontal rectangle, linear regression coefficients were significant (P < 0.05) and coefficients of determination were higher than 75.51%. We suggest the use of MHR to evaluate udder side temperature. The ease of accessing the side of the udder, the welfare advantages of non-invasive observations, and the high correlation with RT suggest the use of thermograms in the lateral portion of the udder to assess animals’ temperature. [ABSTRACT FROM AUTHOR]

Summary: Some livestock breeds face the challenge of reduced genetic variation, increased inbreeding depression owing to genetic drift and selection. Hybridization can reverse these processes and increase levels of productivity and adaptation to various environmental stressors. Samples from American Brangus were used to evaluate the indicine/taurine composition through nine generations (~45 years) after the hybridization process was completed. The purpose was to determine how hybridization alters allelic combinations of a breed over time when genetic factors such as selection and drift are operating. Furthermore, we explored genomic regions with deviations from the expected composition from the progenitor breeds and related these regions to traits under selection. The Brangus composition deviated from the theoretical expectation, defined by the breed association, of 62.5% taurine, showing taurine composition to be 70.4 ± 0.6%. Taurine and indicine proportion were not consistent across chromosomes. Furthermore, these non‐uniform areas were found to be associated with traits that were probably under selection such as intermuscular fat and average daily gain. Interestingly, the sex chromosomes were predominantly taurine, which could be due to the composite being formed particularly in the final cross that resulted in progeny designated as purebred Brangus. This work demonstrated the process of new breed formation on a genomic level. It suggests that factors like genetic drift, selection and complementarity shift the genetic architecture into a uniquely different population. These findings are important to better understand how hybridization and crossbreeding systems shape the genetic architecture of composite populations. [ABSTRACT FROM AUTHOR]

Metabolic adaptation is linked to the ability of the opportunistic pathogen Candida albicans to colonize and cause infection in diverse host tissues. One way that C. albicans controls its metabolism is through the glucose repression pathway, where expression of alternative carbon source utilization genes is repressed in the presence of its preferred carbon source, glucose. Here we carry out genetic and gene expression studies that identify transcription factors Mig1 and Mig2 as mediators of glucose repression in C. albicans. The well-studied Mig1/2 orthologs ScMig1/2 mediate glucose repression in the yeast Saccharomyces cerevisiae; our data argue that C. albicans Mig1/2 function similarly as repressors of alternative carbon source utilization genes. However, Mig1/2 functions have several distinctive features in C. albicans. First, Mig1 and Mig2 have more co-equal roles in gene regulation than their S. cerevisiae orthologs. Second, Mig1 is regulated at the level of protein accumulation, more akin to ScMig2 than ScMig1. Third, Mig1 and Mig2 are together required for a unique aspect of C. albicans biology, the expression of several pathogenicity traits. Such Mig1/2-dependent traits include the abilities to form hyphae and biofilm, tolerance of cell wall inhibitors, and ability to damage macrophage-like cells and human endothelial cells. Finally, Mig1 is required for a puzzling feature of C. albicans biology that is not shared with S. cerevisiae: the essentiality of the Snf1 protein kinase, a central eukaryotic carbon metabolism regulator. Our results integrate Mig1 and Mig2 into the C. albicans glucose repression pathway and illuminate connections among carbon control, pathogenicity, and Snf1 essentiality. Author summary: All organisms tailor genetic programs to the available nutrients, such as sources of carbon. Here we define two key regulators of the genetic programs for carbon source utilization in the fungal pathogen Candida albicans. The two regulators have many shared roles, yet are partially specialized to control carbon acquisition and metabolism, respectively. In addition, the regulators together control traits associated with pathogenicity, an indication that carbon regulation is integrated into the pathogenicity program. Finally, the regulators help to explain a long-standing riddle—that the central carbon regulator Snf1 is essential for C. albicans viability. [ABSTRACT FROM AUTHOR]

Performance, nutrient apparent digestibility, ruminal parameters, enteric methane (CH4) emission and blood parameters were studied in sheep receiving spores of Bacillus thuringiensis (Bt) in their diet. Twenty Santa Inês lambs (10 castrated males and 10 females) with 18.0 ± 3.50 kg initial bodyweight (BW) and 3 months of age were maintained in individual stalls in a completely randomised design. They were divided into two groups with five males and five females each (Bt 2036 group (n = 10) and control group (n = 10)). The animals of the Bt 2036 group received daily 2.5 × 106 spores of Bt 2036/kg BW and control animals received a placebo. The diet consisted of Tifton-85 (Cynodon spp.) hay ad libitum and 300 g/animal.day of concentrate mixture, which was adjusted according to growth requirements. During 53 days, animal performance was evaluated, with feed intake measured three times per week and lambs weighed fortnightly. Blood samples were taken every 15 days to evaluate hematological and biochemical parameters. Rumen fermentation was investigated in three stages (start, middle and end of the experimental period) using parameters such as pH, ammoniacal nitrogen, short chain fatty acids, and populations of Fibrobacter succinogenes , Ruminococcus flavefaciens , anaerobic fungi, methanogenic archaea and protozoa. At the end of the performance experiment, 18 lambs (Bt 2036 (n = 9), control (n = 9)) were selected for a digestibility trial, and placed in metabolic cages to estimate apparent nutrient digestibility, nitrogen balance and microbial protein synthesis. Ten male (Bt 2036 (n = 5), control (n = 5)) lambs were used to evaluate CH4 production using the hexafluoride tracer technique. There was no effect (P > 0.05) of Bt 2036 on any of the evaluated parameters. The daily addition of 2.5 × 106 spores/kg BW of Bt 2036 in the ruminant diet did not cause any negative effects on hematological traits or animal poisoning, nor did it interfere with fermentation by rumen microorganisms, apparent digestibility of nutrients or animal performance. In the search for new alternatives in the treatment against gastrointestinal parasites of ruminants, Bacillus thuringiensis was highlighted by its nematicidal activity, related to the presence of toxic crystals. The rumen provides a favourable environment for the development of the microbial population and the inclusion of Bt 2036 spores in the sheep diet did not cause changes in the health of the animals. In this way, the supplementation of Bt 2036 spores, which contain toxic proteins, can be safely included in ruminant feed. [ABSTRACT FROM AUTHOR]

Genotype-phenotype relationships can vary extensively among members of a species. One cause of this variation is circuit diversification, the alteration of gene regulatory relationships among members of a species. Circuit diversification is thought to be a starting point for the circuit divergence or rewiring that occurs during speciation. How widespread is circuit diversification? Here we address this question with the fungal pathogen Candida albicans, which forms biofilms rich in distinctive hyphal cells as a prelude to infection. Our understanding of the biofilm/hyphal regulatory network comes primarily from studies of one clinical isolate, strain SC5314, and its marked derivatives. We used CRISPR-based methods to create mutations of four key biofilm transcription factor genes–BCR1, UME6, BRG1, and EFG1 –in SC5314 and four additional clinical isolates. Phenotypic analysis revealed that mutations in BCR1 or UME6 have variable impact across strains, while mutations in BRG1 or EFG1 had uniformly severe impact. Gene expression, sampled with Nanostring probes and examined comprehensively for EFG1 via RNA-Seq, indicates that regulatory relationships are highly variable among isolates. Our results suggest that genotype-phenotype relationships vary in this strain panel in part because of differences in control of BRG1 by BCR1, a hypothesis that is supported through engineered constitutive expression of BRG1. Overall, the data show that circuit diversification is the rule, not the exception, in this biofilm/hyphal regulatory network. [ABSTRACT FROM AUTHOR]

Dehorning is a common practice in cattle farming. Researchers suggest that pain during dehorning can be mitigated, although there is no conclusive evidence about the best technique and the best manner of pain relief. A systematic review-meta-analysis was performed to clarify the effect of dehorning on welfare indicators (cortisol concentration or average daily gain or vocalisation) in beef cattle up to 12 months of age. Five electronic databases were systematically searched, as well as conference proceedings and experts were contacted electronically. Pre-defined protocols were applied during all steps of the systematic review process. A random effect meta-analysis was conducted for each indicator separately with the mean of the control and treated groups. Four publications reporting seven studies and 69 trials were included in the MA involving 287 cattle. Heterogeneity between studies was observed for cortisol (I2 = 50.5%), average daily gain (I2 = 70.5%), and vocalisation (I2 = 91.9%). When comparing the non-dehorned group with amputation dehorning, the cortisol concentration was lower 30 min (P < 0.0001) and 120 min (P = 0.023) after procedure (0.767 nmol/L and 0.680 nmol/L, respectively). Local anaesthesia did not show a reduction in cortisol concentration at 30 min after dehorning by amputation. Non-dehorned animals had a tendency to decrease the number of vocalisation (P = 0.081; MD = 0.929) compared with the group dehorned by amputation. These results suggest that dehorning is a painful experience and that local anaesthesia did not alleviate short-term pain following dehorning. Further investigation into pain relief is required to improve confident decision making under practical conditions. Dehorning is a common practice in cattle farming, although it can generate a pain-induced response. Meta-analysis can provide new insights into animal welfare. Dehorned cattle showed higher cortisol concentration, whereas local anaesthesia did not reduce cortisol level and these animals tended to vocalise more. Finally, with the lack of pain-specific measures, the choice of indicators of welfare and their relationship with dehorning may be difficult. [ABSTRACT FROM AUTHOR]

Data from 294 045 records from a crossbred Angus × Nellore population were used to estimate fixed genetic effects (both additive and non-additive) and to test different non-additive models using ridge regression. The traits studied included weaning gain (WG), postweaning gain (PG), phenotypic scores for weaning (WC) and postweaning (PC) conformation, weaning (WP) and postweaning (PP) precocity, weaning (WM) and postweaning (PM) muscling and scrotal circumference (SC). All models were compared using the likelihood-ratio test. The model including all fixed genetic effects (breed additive and complementarity, heterosis and epistatic loss non-additive effects, both direct and maternal) was the best option to analyse this crossbred population. For the complete model, all effects were statistically significant (P < 0.01) for weaning traits, except the direct breed additive effects for WP and WM; direct complementarity effect for WP, WM, PP and PM and maternal epistatic loss for PG. Direct breed additive effect was positive for weaning traits and negative for postweaning. Maternal breed additive effect was negative for SC and WP. Direct complementarity and heterosis were positive for all traits and maternal complementarity and heterosis were also positive for all traits, except for PG. Direct and maternal epistatic loss effects were negative for all traits. We conclude that the fixed genetic effects are mostly significant. Thus, it is important to include them in the model when evaluating crossbred animals, and the model that included breed additive effects, complementarity, heterosis and epistatic loss differed significantly from all reduced models, allowing to infer that it was the best model. The model with only breed additive and heterosis was parsimonious and could be used when the structure or amount of data does not allow the use of complete model. The identification of the best crossbred sires is not an easy task as these animals are composed of distinct genetic materials from different breeds. The objective of the present study was to compare different models under ridge regression methodology to identify the best method for selecting crossbred bulls. This selection is a requisite to guide future multiracial genetic evaluations. The model that contemplated all tested effects (breed additive, complementary, heterosis and epistatic loss, both direct and maternal) proved to be the best. [ABSTRACT FROM AUTHOR]

Copyright of Archivos de Zootecnia is the property of Archivos de Zootecnia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archivos de Zootecnia is the property of Archivos de Zootecnia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: This study consisted of two experiments with the following objectives: to evaluate the effects of tannins from the tropical legume macrotiloma (Macrotyloma axillare) on total gas and methane (CH4) production, as well as on ruminal fermentation parameters by performing an in vitro bioassay, with samples incubated with and without polyethylene glycol (PEG) in a semi‐automatic system; and secondly in a 17 day in vivo experiment, to determine apparent total tract digestibility (ATTD) of dietary nutrients and ruminal fermentation parameters of 12 intact 8‐ to 9‐month‐old Santa Inês (averaging 24.95 ± 1.8 kg body weight) ewes fed tropical grass hay supplemented with macrotiloma hay. The ewes were divided into two treatment groups depending on their diet: chopped aruana grass hay (Panicum maximum cv. Aruana) (control—CON); and aruana grass hay supplemented with chopped macrotiloma hay (macrotiloma—MAC). The animals were kept for 5 consecutive days in metabolic cages for the ATTD assay, and at the end of this period, samples of rumen fluid were collected from each ewe to determine ammoniacal nitrogen (NH3‐N) and short‐chain fatty acid (SCFA) production, and protozoa count. For the in vitro assay, a decrease in total gas and CH4 production was observed for samples incubated without PEG (p < .05). No differences were observed for the other parameters evaluated (p > .05). In the in vivo experiment, increased intake and ATTD of crude protein were observed for the animals fed MAC when compared to CON (p < .05). For rumen fermentation parameters, increased NH3‐N, total SCFA and isobutyrate concentrations, as well as reduced protozoa count were observed for MAC when compared to CON (p < .05). The results observed here indicated the potential of macrotiloma for use as a ruminant feed, and antimethanogenic potential of this plant was noted. [ABSTRACT FROM AUTHOR]

Despite its peace process, Northern Ireland remains a deeply divided society. The legacy of a 30-year conflict has ensured that the state continues to be prone to outbreaks of violence over contentious issues such as Orange Order parading and the flying of national flags. This paper argues that in order to address this legacy, there is a need to confront the Othering processes that have helped to generate and sustain division. It will argue that programmes of adult education can play an important role in helping the conflicting groups to reimagine their ‘exclusive’ notions of the nation to one capable of incorporating the Other. [ABSTRACT FROM PUBLISHER]

Copyright of Archivos de Zootecnia is the property of Archivos de Zootecnia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The ability to predict the effects of climatic factors on animals and their adaptability is important for livestock production. The aim of the present study was to analyze whether existing indices are suitable for evaluating heat stress in Santa Ines and Morada Nova sheep, which are locally adapted hair sheep breeds from northeastern Brazil, and if the limits used to classify thermal stress are suitable for these breeds. Therefore, climatic, physiological, and physical parameters, as well as thermographic images, were collected in 26 sheep, 1 1/2 years old, from two genetic groups (Santa Ines 12 males and 4 females; Morada Nov. 7 males and 3 females) for 3 days in both morning (4:00 a.m.) and afternoon (2:00 p.m.) with six repetitions, totalizing 156 repetitions. Statistical analysis included correlations and broken-line regressions. Iberia and Benezra indices were the tolerance tests that best correlated with the assessed parameters. High correlations between environmental indices and rectal or skin surface temperatures was observed, which indicates that these indices can be used for Santa Ines and Morada Nova sheep raised in central Brazil. However, some indicative values of thermal discomfort are different from the existing classification. Therefore, in order to classify appropriately, the model used needs to be carefully studied, because these classifying values can vary according to the species and model. Further research is necessary to establish indicators of thermal stress for sheep breeds raised in the region. [ABSTRACT FROM AUTHOR]

In this study, the possibility of using Babassu ( Orbignya phalerata) and Mofumbo ( Combretum leprosum) leaves for lambs feed was verified. Performance, biochemical and haematological parameters, microbial protein synthesis, nutrient apparent digestibility and enteric production of methane ( CH4) were evaluated. The experimental treatments included diets with forage-to-concentrate ratios of 50:50, with the leaves of the experimental plants replacing 33% of the Cynodon dactylon (Tifton-85) hay with three treatments: control (no hay replacement) and substitution with Babassu or Mofumbo. For the performance study, 24 Santa Inês lambs were used, in a randomized experimental design with eight repetitions (5 male and 3 female) for each treatment and 48 days of experimental trial. After this period, for nine days, six animals from each treatment were allocated in metabolic cages to determine the apparent nutrient digestibility, microbial protein synthesis and nitrogen balance. Simultaneously, enteric CH4 was measured in vivo. The control group showed higher (p < 0.05) apparent digestibility of acid detergent fibre. Enteric CH4 production of lambs fed Mofumbo leaves did not differ from that of the control group, but was lower (p < 0.05) than in those fed with Babassu. The inclusion of Babassu and Mofumbo leaves showed no negative effects on animal health and did not compromise performance. Mofumbo also presented CH4 mitigating potential, indicating that those plants can be used as ingredients in the composition of lamb diets with the advantage of reducing methane production. [ABSTRACT FROM AUTHOR]

Copyright of Archivos de Zootecnia is the property of Archivos de Zootecnia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to evaluate the effects of concentrate supplementation on the performance and ingestive behaviour of lambs grazing tropical grasslands of Panicum maximum cv. IZ-5 and its effect on pasture characteristics. Different levels of daily supplementation with concentrate were compared: no supplementation; or supplemented at 1.5% and 2.5% of lamb liveweight. The grazing simulation technique was used for qualitative assessment of the pasture every 28 days. Herbage mass, pasture growth rate, sward height as well as botanical and morphological composition of the pasture were evaluated. Average daily gain, gain per hectare and ingestive behaviour were measured on the lambs. The forage supply was 4% of green leaves (4 kg dry matter per 100 kg of liveweight) in all treatments. Six 3-4-month-old Texel and Corriedale lambs were used per paddock. The design was a randomised block design with three replications. Concentrate supplementation had a direct effect on pasture structure, especially height (significant interaction treatment vs period - P = 0.0373). In the treatment without supplementation, the animals grazed for a longer period than the others. Idle time was higher in the treatment with the highest level of supplementation, and rumination time was similar among the treatments. Supplementation with 2.5% significantly increased the average daily gain (0.143 g vs 0.026 g for no supplementation) and gain per hectare (30 kg vs 258 kg for no supplementation vs supplementation at 2.5% of lamb liveweight, respectively). The results show the potential increase in production and productivity with the use of concentrate supplementation at 2.5% lamb bodyweight. Notwithstanding the increase in production, supplementation with concentrate provided a strong negative impact on pasture structure and behaviour of animals that should be considered when using concentrate supplementation for finishing lambs in tropical regions. [ABSTRACT FROM AUTHOR]

Copyright of Archivos de Zootecnia is the property of Archivos de Zootecnia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In species with a heterogametic sex, population genetics theory predicts that DNA sequences on the X chromosome can evolve faster than comparable sequences on autosomes. Both neutral and nonneutral evolutionary processes can generate this pattern. Complex traits like gene expression are not predicted to have accelerated evolution by these theories, yet a "faster-X" pattern of gene expression divergence has recently been reported for both Drosophila and mammals. Here, we test the hypothesis that accelerated adaptive evolution of cis-regulatory sequences on the X chromosome is responsible for this pattern by comparing the relative contributions of cis- and trans-regulatory changes to patterns of faster-X expression divergence observed between strains and species of Drosophila with a range of divergence times. We find support for this hypothesis, especially amongmale-biased genes, when comparing different species. However, we also find evidence that trans-regulatory differences contribute to a faster-X pattern of expression divergence both within and between species. This contribution is surprising because trans-acting regulators of X-linked genes are generally assumed to be randomly distributed throughout the genome. We found, however, that X-linked transcription factors appear to preferentially regulate expression of X-linked genes, providing a potential mechanistic explanation for this result. The contribution of trans-regulatory variation to faster-X expression divergence was larger within than between species, suggesting that it is more likely to result from neutral processes than positive selection. These data show how accelerated evolution of both coding and noncoding sequences on the X chromosome can lead to accelerated expression divergence on the X chromosome relative to autosomes. [ABSTRACT FROM AUTHOR]

The effect of shade on behavior and physiological attributes of grazing cows in a high altitude subtropical zone is not well established. This work aimed to investigate how social and ingestive behaviors, as well as physiological and other attributes of dairy cows such as milk production, change in a subtropical environment during the hot season either with or without free access to shade. Fourteen lactating cows were kept on pasture either with no shade or with free access to shade for 5 days and their behavior was recorded with instantaneous scan sampled every 10 min, from sunrise, 0530 h (Greenwich mean time, GMT−0200 h) to sunset, 2100 h (GMT−0200 h). Behavior traits included (1) time spent in activities such as grazing, ruminating, resting, lying, standing, walking, seeking shade and staying in the proximity to the water trough and (2) number of events such as water ingestion, aggressive interactions, as well as competition for shade and water. Physiological attributes such as heart and respiratory rates, rectal temperature, number of rumen movements, panting score, as well as milk yield, were evaluated. Time spent in behavioral activities, number of behavioral events and physiological attributes varied between groups (with and without access to shade). Cows with no shade showed increased respiratory and heart rates and panting score at 1300 h, higher values for time of permanence near the water trough, number of competition and aggression events for shade. On the other hand, they showed lower values for time spent resting while lying, ruminating while standing, seeking shade. Access to shade did not change time spent lying, standing, walking with the head up, ruminating while lying, resting while standing, as well as milk yield and number of ruminal movements. Significant interactions between access to shade and days of measurements were detected for time spent walking, ruminating, grazing, resting, number of water ingestion events, competition events near the water trough and for shade, as well as for rectal temperature and panting score measured at 1700 h. In the high altitude subtropical region, access to shade minimizes negative heat stress effects on behavior and physiological aspects of dairy cows. [ABSTRACT FROM PUBLISHER]

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The aim of this work was to evaluate the growth performance, carcass characteristics, 12th rib tissue composition, haematological and serum biochemical parameters, as well as the presence of gossypol residues in the meat of Santa Inês lambs fed cotton crop by-products. For an experimental period of 90 days, 24 intact male Santa Inês lambs (bodyweight (BW): 20.6 ± 1.9 kg; 4 months old) were fed a 50: 50 forage : concentrate diets fed ad libitum. Chopped Coast cross (Cynodon dactylon (L.) Pers) hay was used as forage. The animals were then allocated into four treatments, according to the cotton crop by-product included in the concentrate formulation: Control (CON) -- No cotton crop by-product used in formulation; Whole cottonseed (WCS); Cottonseed cake (CSC); and Cottonseed meal (CSM). The animals were weighed and blood collected every 15 days. At the end of the experimental period, the lambs were slaughtered and the evaluations of carcass characteristics, 12th rib tissue composition and presence of gossypol residues in the meat were carried out. Dry matter intake was higher (P < 0.05) for the diets containing cotton crop by-products, but BW gains were not different (P > 0.05). Despite these results the animals fed the highest level of gossypol (WCS) had lower (P < 0.05) carcass yield resulting in lower (P < 0.05) carcass weight, suggesting a possible negative effect of gossypol on carcass development. Serum urea was elevated on all treatments including CON, otherwise haematological and biochemical parameters were within reference ranges. No gossypol residues in meat were detected by the method used here, which had a minimum detection limit of 20 ppb. It is concluded that the cotton crop by-products may have impaired carcass production but did not leave gossypol residues in lamb meat. [ABSTRACT FROM AUTHOR]

Thirty Aberdeen Angus crossbred steers (281±16 kg) were used to test the effect of finishing feeding system on growth performance, meat quality and fatty acid (FA) profile in intramuscular fat. Steers were fed in confinement (forage:concentrate ratio of 50 : 50; DM basis) or with different levels of energy supplementation (0, 0.4, 0.8 and 1.2% BW) at pasture (Avena strigosa Schreb and Lolium multiflorum L.). There were no differences between treatments for ADG (average=1.60 kg/day), hot carcass weight (HCW) (average=229 kg) and subcutaneous fat depth (average=3 mm). Dressing % (P=0.06; tendency) and carcass ADG (P=0.02) linearly increased with level of supplementation for pasture steers. No differences were observed between treatments for tenderness, marbling, pH, color b*, or cooking loss and drip loss in samples of Longissimus dorsi. However L* increased linearly (P=0.05) with level of supplementation. The concentrations of myristic, palmitic, estearic and linoleic FA did not differ among treatments. The concentration of n-3 FA increased (P<0.001) in steers at pasture compared with confinement, but n-6 FA concentrations did not differ between feeding system. Supplementation up to 0.4% BW increase (P<0.001) conjugated linoleic acid (CLA) and linolenic FA concentrations in intramuscular fat when compared with confinement. The level of supplementation on pasture linearly decreased (P<0.001) n-3 and CLA and linearly increased (P=0.001) the n-6 : n-3 ratio. Finishing of steers grazing winter pasture with energy supplementation or in confinement fed a medium-concentrate diet did not affect meat quality (tenderness, marbling, parameter b* on the CIE L*a*b* scale, cooking and drip losses) except for a* and L*. However, intramuscular fat of animals finished at pasture with moderate level of supplementation compared to animals fed in confinement had greater concentration of CLA, linolenic, and n-3, and lower n-6 : n-3 in intramuscular fat. [ABSTRACT FROM PUBLISHER]

The current research was carried out to evaluate the use of crude protein and fibre components in faeces for estimating intake and digestibility in sheep fed with pearl millet (Pennisetum americanum (L.) Leeke). The equations were developed from four trials in metabolism cages with 16 sheep in each trial. Each animal received a different quantity of millet leaves in the diet: 0·015, 0·020 and 0·025 dry matter (DM) as a proportion of live weight (LW) and ad libitum with at least 0·2 of daily feed refusals. Organic matter intake (OMI, g/day) was measured, through the difference between offer and refusals; total faeces were collected for 5 days, which was used to determine faecal crude protein (CPf, g/day and g/kg of organic matter (OM)), faecal neutral detergent fibre (NDFf, g/day and g/kg OM), faecal acid detergent fibre (ADFf, g/day and g/kg OM) and OM digestibility (OMD). Linear regression equations were calculated to determine the relationship between OMI and CPf (P<0·001, R2=0·90, relative prediction error (RPE=14·02%). A multiple linear equation was generated for OMI including CPf and NDFf (P<0·001, R2=0·94; RPE=9·25%). Hyperbolic (single and multiple) and exponential models were tested to estimate OMD, where the hyperbolic multiple model including CPf and NDFf showed lower RPE (3·90%). These equations for estimating OMI and OMD were evaluated on sheep grazing P. americanum fertilized with increasing levels of nitrogen (N) (50, 100, 200 and 400 kg N/ha), comparing measured and estimated OMI. The intake estimated by multiple regression (CP and NDFf) showed a higher R2 (0·98) and lower RPE (5·25%) than the simple (CPf only) linear equation (R2=0·94; RPE=20·45%). The results demonstrated the feasibility of using the faecal index generated in metabolism cages for estimating intake and digestibility in sheep grazing P. americanum. [ABSTRACT FROM PUBLISHER]

A central challenge of developmental and evolutionary biology is to understand the transformation of genetic information into morphology. Elucidating the connections between genes and anatomy will require model morphogenetic processes that are amenable to detailed analysis of cell/tissue behaviors and to systems-level approaches to gene regulation. The formation of the calcified endoskeleton of the sea urchin embryo is a valuable experimental system for developing such an integrated view of the genomic regulatory control of morphogenesis. A transcriptional gene regulatory network (GRN) that underlies the specification of skeletogenic cells (primary mesenchyme cells, or PMCs) has recently been elucidated. In this study, we carried out a genome-wide analysis of mRNAs encoded by effector genes in the network and uncovered transcriptional inputs into many of these genes. We used RNA-seq to identify >400 transcripts differentially expressed by PMCs during gastrulation, when these cells undergo a striking sequence of behaviors that drives skeletal morphogenesis. Our analysis expanded by almost an order of magnitude the number of known (and candidate) downstream effectors that directly mediate skeletal morphogenesis. We carried out genome-wide analysis of (1) functional targets of Ets1 and Alx1, two pivotal, early transcription factors in the PMC GRN, and (2) functional targets of MAPK signaling, a pathway that plays an essential role in PMC specification. These studies identified transcriptional inputs into >200 PMC effector genes. Our work establishes a framework for understanding the genomic regulatory control of a major morphogenetic process and has important implications for reconstructing the evolution of biomineralization in metazoans. [ABSTRACT FROM AUTHOR]

Copyright of Animal Genetic Resources is the property of Cambridge University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Animal Genetic Resources is the property of Cambridge University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pedigree information available for Angus (ANG), Devon (DEV), Hereford (HER), and Shorthorn (SHO) cattle in Brazil was analyzed to appraise the genetic diversity and population structure of these breeds. Pedigree records collected from the beginning of the 20th century until 2010 were used in the analyses. Over time, the number of herdbook registrations declined in HER after a peak in the 1970s, remained low in DEV and SHO, and increased steadily in ANG since the 1990s, such that it the latter is now the leading British cattle breed in Brazil. The average number of offspring registered per sire ranged from about 12 (SHO) to 20 (DEV) and the mean generation interval ranged from about 6.0 (HER and SHO) to 6.4 (ANG) years. In the reference population (calves born in 2009 and 2010, plus those born in 2008 for SHO) the mean equivalent number of generations known ranged from about 7 (SHO) to 9 (HER). In the 4 breeds studied, nearly all animals born over the last few years are inbred, even though the mean level of inbreeding in the reference population is below 4% in all breeds. The rate of inbreeding per generation, computed from the individual increase in inbreeding, ranged from about 0.2 (ANG) to 0.5% (DEV), with a corresponding effective population size of 245 and 92, respectively, which is above the recommended minimum critical threshold. The number of founders/ancestors contributing with 50% of the reference population gene pool was 211/26 for ANG, 41/14 for DEV, 164/25 for HER, and 79/10 for SHO, with effective number of founders/ancestors/ founder genomes of 470/68/36, 89/33/16, 289/59/30, and 200/28/18 for ANG, DEV, HER, and SHO, respectively. The genetic contribution of different countries to the gene pool of each breed indicated that, throughout the period studied, DEV genes originated predominantly from the United Kingdom, while for the other breeds there was a changing pattern over time. Until the 1970s Argentina was the major supplier of ANG, while HER and SHO genes were mostly from Uruguay, but since then the United States took the leading role as supplier of ANG, HER, and SHO genes to Brazil. Our results reveal a mild increase in inbreeding in all breeds studied, with effective population size estimates indicating that reasonable levels of genetic diversity have been maintained in all 4 breeds. Continuous monitoring of inbreeding trends and of parameters derived from probability of gene origin should be ensured to warrant the long-term maintenance of genetic diversity. [ABSTRACT FROM AUTHOR]

Contents This study investigates the association of semen traits with boar fertility. The fertility outcome (farrowing rate - FR and total piglets born - TB) of 14 boars was obtained from a field trial conducted during 10 week of breeding period on a commercial farm using multiparous sows (n = 948) through single-sire mating with 2 × 109 motile sperm cells per artificial insemination (AI) dose. Sperm motion parameters, evaluated with computer-assisted semen analysis system in raw and stored semen at 17°C for 240 h, in addition to morphological sperm defects, measured on the collection day, were included in the analysis to determine which semen traits were important to discriminate the fertility potential of ejaculates from these boars. The data underwent multivariate cluster, canonical and discriminant analyses. Four clusters of boars were formed based on fertility outcome. One boar, with the lowest FR and TB values (89.7% and 11.98), and two boars, with the highest FR and TB values (97.8% and 14.16), were placed in different clusters. The other boars were separated in two distinct clusters (four and seven boars), including boars with intermediate TB (12.64 and 13.22) but divergent values for FR (95.9% vs 91.8%). Semen traits with higher discriminatory power included total motility, progressive motility, amplitude of lateral head displacement and cytoplasmatic droplets. Through multivariate discriminant analysis, more than 80% of the 140 ejaculates were correctly classified into their own group, showing that this analysis may be an efficient statistical tool to improve the discrimination of potential fertility of boars. Nevertheless, the validation of the relationship between fertility and semen traits using this statistical approach needs to be performed on a larger number of farms and with a greater number of boars. [ABSTRACT FROM AUTHOR]

The effects of oral supplementation of chromium picolinate (CrPic) on humoral and cellular immunity in sheep were investigated. Twenty-four male lambs divided into four treatments and received different dosages of CrPic: placebo (0), 0.250, 0.375, and 0.500 mg of chromium/animal/day during 84 days. The base ration was Panicum maximum cv Massai hay and concentrate. Blood samples were collected fortnightly for total and differential leukocyte counts. On days 28 and 56, the lambs were challenged with chicken ovalbumin I.M. Serum samples were collected on days 46 and 74 and subjected to an indirect enzyme-linked immunosorbent assay to measure IgG anti-ovalbumin. The cell-mediated immune response was determined by a delay-type hypersensitivity test using phytohemagglutinin. CrPic did not significantly affect humoral immunity in lambs but there was a negative effect on cellular immunity ( P < 0.05) as Cr supplementation increased. Therefore, the level of Cr supplementation for lambs must be better studied to address its effect on stressed animals or the possible toxic effects of Cr on the animal itself or its immune system. [ABSTRACT FROM AUTHOR]

A total of twelve lactating Jersey cows were used in a 5-week experiment to determine the effects of severe feed restriction on the permeability of mammary gland cell tight junctions (TJs) and its effects on milk stability to the alcohol test. During the first 2 weeks, cows were managed and fed together and received the same diet according to their nutritional requirements (full diet: 15 kg of sugar cane silage; 5.8 kg of alfalfa hay; 0.16 kg of mineral salt and 6.2 kg of concentrate). In the 3rd week, animals were distributed into two groups of six cows each. One group received the full diet and the other a restricted diet (50% of the full diet). In the 4th and 5th weeks, all animals received the full diet again. Milk composition and other attributes, such as titratable acidity, ethanol stability, pH, density and somatic cell count (SCC) were evaluated. Cortisol levels indicated the stress condition of the cows. Plasma lactose and milk sodium were measured to assess mammary TJ leakiness. Principal factor analysis (PFA) showed that the first two principal factors (PFs) contributed with 44.47% and 20.57% of the total variance in the experiment and, as feeding levels increased, milk stability to the ethanol test became higher and plasma lactose levels decreased, which indicates lower permeability of the mammary gland cell TJ. Correspondence analyses were consistent with PFA and also showed that lower feeding levels were related to reduced milk stability, high plasma lactose, high sodium in milk, low milk lactose (another parameter used to assess TJ permeability) and higher cortisol levels, indicating the stress to which animals were submitted. All observations were grouped in three clusters, with some of the above-mentioned patterns. Feeding restriction was associated with higher permeability of TJ, decreasing milk stability to the ethanol test. [ABSTRACT FROM PUBLISHER]

Genetic association studies, pharmacological investigations and analysis of mice-lacking individual genes have made it clear that Cocaine administration and Withdrawal have a profound impact on multiple neurotransmitter systems. The GABAergic medium spiny neurons of the nucleus accumbens ( NAc) exhibit changes in the expression of genes encoding receptors for glutamate and in the signaling pathways triggered by dopamine binding to G-protein-coupled dopamine receptors. Deep sequence analysis provides a sensitive, quantitative and global analysis of the effects of Cocaine on the NAc transcriptome. RNA prepared from the NAc of adult male mice receiving daily injections of Saline or Cocaine, or Cocaine followed by a period of Withdrawal, was used for high-throughput sequence analysis. Changes were validated by quantitative polymerase chain reaction or Western blot. On the basis of pathway analysis, a preponderance of the genes affected by Cocaine and Withdrawal was involved in the cadherin, heterotrimeric G-protein and Wnt signaling pathways. Distinct subsets of cadherins and protocadherins exhibited a sustained increase or decrease in expression. Sustained down-regulation of several heterotrimeric G-protein β- and γ-subunits was observed. In addition to altered expression of receptors for small molecule neurotransmitters, neuropeptides and endocannabinoids, changes in the expression of plasma membrane transporters and vesicular neurotransmitter transporters were also observed. The effects of chronic Cocaine and Withdrawal on the expression of genes essential to cholinergic, glutamatergic, GABAergic, peptidergic and endocannabinoid signaling are as profound as their effects on dopaminergic transmission. Simultaneous targeting of multiple Withdrawal-specific changes in gene expression may facilitate development of new therapeutic approaches that are better able to prevent relapse. [ABSTRACT FROM AUTHOR]

Summary: Genomic imprinting occurs when expression of an allele differs based on the sex of the parent that transmitted the allele. In D. melanogaster, imprinting can occur, but its impact on allelic expression genome-wide is unclear. Here, we search for imprinted genes in D. melanogaster using RNA-seq to compare allele-specific expression between pools of 7- to 10-day-old adult female progeny from reciprocal crosses. We identified 119 genes with allelic expression consistent with imprinting, and these genes showed significant clustering within the genome. Surprisingly, additional analysis of several of these genes showed that either genomic heterogeneity or high levels of intrinsic noise caused imprinting-like allelic expression. Consequently, our data provide no convincing evidence of imprinting for D. melanogaster genes in their native genomic context. Elucidating sources of false-positive signals for imprinting in allele-specific RNA-seq data, as done here, is critical given the growing popularity of this method for identifying imprinted genes. [ABSTRACT FROM AUTHOR]

Precursor mRNA (pre-mRNA) splicing can join exons contained on either a single pre-mRNA (cis) or on separate pre-mRNA5 (trans). It is exceedingly rare to have trans-splicing between protein-coding exons and has been demonstrated for only two Drosophila genes: mod(mdg4) and lola. It has also been suggested that trans-splicing is a mechanism for the generation of chimeric RNA products con- taining sequence from multiple distant genomic sites. Because most high-throughput approaches cannot distinguish cis- and trans- splicing events, the extent to which trans-splicing occurs between protein-coding exons in any organism is unknown. Here, we used paired-end deep sequencing of mRNA to identify genes that un- dergo trans-splicing in Drosophila interspecies hybrids. We did not observe credible evidence for the existence of chimeric RNAS gen- erated by trans-splicing of RNAs transcribed from distant genomic loci. Rather, our data suggest that experimental artifacts are the source of most, if not all, apparent chimeric RNA products. We did, however, identify 80 genes that appear to undergo trans-splicing between homologous alleles and can be classified into three cate- gories based on their organization: (i) genes with multiple 3' termi- nal exons, (ii) genes with multiple first exons, and (iii) genes with very large introns, often containing other genes. Our results suggest that trans-splicing between homologous alleles occurs more com- monly in Drosophila than previously believed and may facilitate expression of architecturally complex genes. [ABSTRACT FROM AUTHOR]