Comparison of α and β keratin in reptiles

Summary The different patterns of keratin formation that have evolved in the class Reptilia are all variations of a common process. In Squamata (snakes and lizards), a sequence of layers composed of or keratin is formed periodically, after which the old epidermal generation is shed. In Chelonia (turtles and tortoises), the epidermis of the shell is composed of only keratin, whereas the skin of the neck and leg is composed exclusively of keratin. Molting in toto does not occur and shedding is a continuous process comparable to that in avian and mammalian epidermis. In Crocodilia (crocodiles, caimans, alligators) there is only a single layer of cornified cells, but the composition of the layer varies in different parts of the scale. The hinge regions have many of the morphological characteristics of and keratin whereas the center resembles keratin. The living cells beneath contain accumulations of keratohyalin.There are four ultrastructural characteristics of a keratinized layer: 1) cellular outlines remain distinct, 2) a thickened plasma membrane forms during keratinization, 3) 80 Å filaments embedded in an amorphous matrix can be seen, and 4) PAS-positive material accumulates in extracellular spaces between the desmosomes.The layer exhibits none of these features. Instead the cells more or less (depending on species) coalesce into a compact layer which becomes attenuated in the hinge regions. A 30 Å filament pattern can be seen.The mesos layer of squamates resembles the hinge region of crocodilians, exhibiting a combination of the characteristics of both and keratin.This study constitutes publication No. 464 from the Oregon Regional Primate Research Center, supported in part by NIH Grant No. FR-00163.     

Effect of cadmium on physiological parameters of cereal and millet plants—A comparative study

Metal load is an abiotic stress that becomes stronger by continual industrial production, wastage, and long-range transport of contaminants. It deteriorates the conditions of agricultural soil that leads to lower growth of cereals as well as decreasing nutritional value of harvested grains. Cadmium (Cd) entry by food chain also affects the health of population. The present study is focused on finding out the superior cereal variety under increasing Cd regime. The plants were grown in increasing Cd levels (0–1000 µM) in the medium and were investigated on 15th day of the exposure. Various parameters like antioxidative enzymes and osmoprotectant levels were studied in both roots and shoots. Cd accumulation in plant organs was determined by atomic absorption spectrophotometry (AAS). Analysis of stress tolerance mechanisms through reactive oxygen species (ROS) scavenging and better partitioning of Cd in roots indicated kodo millet to be more stress tolerant than wheat.     

Genome-wide association study of porcine hematological parameters in a Large White × Minzhu F2 resource population

Hematological traits, which are important indicators of immune function in animals, have been commonly examined as biomarkers of disease and disease severity in humans and animals. Genome-wide significant quantitative trait loci (QTLs) provide important information for use in breeding programs of animals such as pigs. QTLs for hematological parameters (hematological traits) have been detected in pig chromosomes, although these are often mapped by linkage analysis to large intervals making identification of the underlying mutation problematic. Single nucleotide polymorphisms (SNPs) are the common form of genetic variation among individuals and are thought to account for the majority of inherited traits. In this study, a genome-wide association study (GWAS) was performed to detect regions of association with hematological traits in a three-generation resource population produced by intercrossing Large White boars and Minzhu sows during the period from 2007 to 2011. Illumina PorcineSNP60 BeadChip technology was used to genotype each animal and seven hematological parameters were measured (hematocrit (HCT), hemoglobin (HGB), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular volume (MCV), red blood cell count (RBC) and red blood cell volume distribution width (RDW)). Data were analyzed in a three step Genome-wide Rapid Association using the Mixed Model and Regression-Genomic Control (GRAMMAR-GC) method. A total of 62 genome-wide significant and three chromosome-wide significant SNPs associated with hematological parameters were detected in this GWAS. Seven and five SNPs were associated with HCT and HGB, respectively. These SNPs were all located within the region of 34.6-36.5 Mb on SSC7. Four SNPs within the region of 43.7-47.0 Mb and fifty-five SNPs within the region of 42.2-73.8 Mb on SSC8 showed significant association with MCH and MCV, respectively. At chromosome-wide significant level, one SNP at 29.2 Mb on SSC1 and two SNPs within the region of 26.0-26.2 Mb were found to be significantly associated with RBC and RDW, respectively. Many of the SNPs were located within previously reported QTL regions and appeared to narrow down the regions compared with previously described QTL intervals. In current research, a total of seven significant SNPs were found within six candidate genes SCUBE3, KDR, TDO, IGFBP7, ADAMTS3 and AFP. In addition, the KIT gene, which has been previously reported to relate to hematological parameters, was located within the region significantly associated with MCH and MCV and could be a candidate gene. These results of this study may lead to a better understanding of the molecular mechanisms of hematological parameters in pigs.     

A comparative study of renal function in male and female spiny mice – sex specific responses to a high salt challenge

Background

There is a significant body of evidence to suggest that hormone levels, receptor density and structural differences between males and females can significantly alter renal hemodynamics. We compared the renal hemodynamic and excretory profile of female and male spiny mice under baseline conditions and in response to a high-NaCl diet.

Methods

Adult male and female spiny mice were fed either a normal or high salt diet for 7 days. Renal excretory profile was obtained from 24 h urine samples, and renal hemodynamic measurements using anaesthetised renal clearance techniques. Kidneys were excised, weighed and frozen for qPCR analysis.

Results

Under basal conditions, conscious and anaesthetised renal functions were similar between male and female spiny mice when adjusted for body weights. Male and female spiny mice on the high-NaCl diet had significantly greater GFR than sex matched controls (P_DIET < 0.001). However the magnitude of the effect of salt was sex dependent (P_SEX < 0.001; P_INT < 0.01). Male spiny mice showed a greater increase in GFR (84% higher than normal salt males) compared to females (33% higher than normal salt females), despite similar increases in renal plasma flow. In response to 7 days of high salt diet, female spiny mice showed a greater increase in 24-hour water consumption (45% more) and urinary output (50% more) compared to males (P_INT < 0.01). These sex differences could not be explained by differences in renal expression of the V2R or AQP3 channel.

Conclusion

These studies have identified major differences between male and female spiny mice in their renal response to a high-NaCl load suggesting that renal hemodynamics may be differentially regulated for the sexes.

     

Biological yields through agricultural extension activities and services: A case study from Al-Baha region – Kingdom of Saudi Arabia

PurposeThis research determines the extent to which farmers benefit from agricultural extension activities and services through realizing higher biological crop yields in the Al-Baha region of the Kingdom of Saudi Arabia. Additionally, the nature of the relationship between the personal, economic and social characteristics of farmers and the degree to which they benefit from agricultural extension activities and services are studied.MethodologyA simple random sample representing the community of 315 farmers was drawn. Data were collected through a personal interview with a pre-tested questionnaire to satisfy the objectives of the study. Data are subjected to analyses and are interpreted in terms of percentages, arithmetic averages, and standard deviations in addition to the simple Pearson correlation coefficients.ResultsThe results show that most of the respondents depend on personal experience, friends, family and neighbors, merchants and sellers of agricultural production supplies as sources of agricultural information for enhanced crop yields. Multiple regression analysis reveals that both the educational status and the agricultural information sources are important factors that increase farmers benefit from extension activities. Farmers receive most benefits from the extension activities and services from bringing in foreign workers, conducting field trips to farms, and identifying problems faced by farmers.Research limitations/implicationsThe outcome of this questionnaire limits generalization of the findings for other parts of the Kingdom due to geographical and natural resources variations.Practical implicationsThe personal and socio-economic characteristics of the surveyed population provide the extension service with insight into their composition – a basis to formulate workable extension programs. For the extension planners of the area, this effort provides a baseline study and may assist with targeting the appropriate farmers and catering the right solutions to the problems. Such a study will help devise meaningful extension programs and save time and resources.Originality/valueLittle previous research on the usefulness of the Extension Service has been conducted in the region.ConclusionsEffective, well-planned extension programs targeting the educated and mature farmers provided more benefits and helped them obtain higher crop yields.     

Quasirandom distribution of α and β regions in globular proteins

Distributions of α and β regions in globular proteins among clusters containing different numbers of adjacent α-helices, adjacent β regions, and “overlapping” βαβ units are considered. It is shown that these distributions do not differ greatly from what can be expected for random distributions of α and β regions along protein chains. In particular, it is shown that the amounts of relatively long α, β and βαβ clusters (which provide the basis for the conventional classification of globular proteins or domains into α, β, or α/β types) in random sequences also do not differ very much from those in real globular proteins. It follows that the possibility of structural classification of globular proteins (domains) does not imply the existence of a correlation in protein primary structure. This possibility exists even in random sequences of amino acid residues and therefore may not be the result of biological evolution.     

Energy expenditure and water flux of Rüppell's foxes in Saudi Arabia

Scattered populations of Rüppell's foxes (Vulpes rueppelli) occur across the deserts of northern Africa and Arabia. Little is known about the biology of these canids, especially the physiological mechanisms that contribute to their ability to live in such harsh environments. For individuals from Saudi Arabia, we tested the hypotheses that Rüppell's foxes have a reduced basal metabolic rate and total evaporative water loss (TEWL), parameters measured in the laboratory, and a reduced field metabolic rate (FMR) and water flux when free-living. Under basal conditions in the laboratory, males, which averaged 1,858 g in body mass, had an oxygen consumption of 914.9 mL O(2)/h, whereas females, which weighed on average 1,233 g, consumed 682.9 mL O(2)/h; rates of oxygen consumption translated to 441.4 kJ/d and 329.4 kJ/d, respectively. TEWL averaged 52.6 g H(2)O/d for males and 47.5 g H(2)O/d for females. We found no evidence that basal metabolism is reduced in Rüppell's foxes, but their TEWL was remarkably low: 50.9% of allometric prediction for males and 64.5% for females. In the wild during winter, males expended energy at a rate of 1,306.5 kJ/d, whereas females had an expenditure of 722.8 kJ/d. Analysis of covariance with FMR as the dependent variable, sex as a fixed factor, and body mass as a covariate showed no statistical difference in FMR between sexes. Water flux did not differ significantly between sexes and averaged 123 mL H(2)O/d, a value 30% lower than the kit fox from the deserts of southwestern North America. FMR was positively related to nocturnal activity levels as FMR (kJ/d) = -2,900.1+55.5 (% of time moving). The water content of prey items varied between 1.9 and 4.1 g H(2)O/g dry matter consumed. Based on these values and knowledge of their diet, we calculated that foxes captured about one rodent and a variety of anthropods per night of foraging.     

The presence and distribution of α and β glucosidase in root tip

A comparison was made of post and simultaneous azocoupling procedures for β glucosidase localization on unfixed and fixed root tips ofZea mays. Using this object, more detailed studies of β glucosidase distribution were undertaken, concerning the time course of enzyme reaction, its pH dependence, the effect of various buffers, the comparison of several diazonium salts and the use of different naphtholic substrates. The indigogenic reaction was also applied. Attempts were made by means of azocoupling procedures to localize a and β glucosidase in root tips ofCucurbita pepo, Lupinus albus, Piswm sativum andVicia faba in comparison withZea mays. In addition to certain technical problems, the questions of constitutive and adaptive enzymes, sugar distribution and histogenesis versus function are discussed in relation to the presence and distribution of ß glucosidase in the studied objects.     

Identification of heterotrimeric G protein α and β subunits in rice

Like those in mammals, heterotrimeric G protein complexes have been implicated in signal transduction pathways in plants; however, the subunits themselves have not been isolated. In this study, the rice heterotrimeric G protein subunits α (Gα) and β (Gβ) were purified by affinity chromatography using anti-Gα and -Gβ antibodies and SDS-PAGE. Six and seven peptides, respectively, were identified by mass spectrometry and identified as the translation products of the Gα gene RGA1 and Gβ gene RGB1. During purification, the subunits dissociated easily from the G protein complex.     

Food waste posing a serious threat to sustainability in the Kingdom of Saudi Arabia – A systematic review

Worldwide, food waste is one of the prime issues threatening food security and the Kingdom of Saudi Arabia (KSA) is not an exception. With 427 kg of food wasted per capita per year, the country ranks among the top food wasters. Ironically, the Kingdom has limited arable lands and scarce water resources to support mass-scale agriculture and to feed its increasing population, KSA relies heavily on imports and subsidized food to meet needs. Yet, food is wasted at restaurants, caterers, cafeterias and, especially, by households such that food waste is the single-largest component of the landfills. The review article is based on the grey and scientific literature published in the English and Arabic languages on the issue of food waste in Saudi Arabia. Information sources like Web of knowledge, online resources and the databases available through the King Saud University, Saudi Arabia were accessed and used to collect information on food waste, its social, cultural, economic and environmental impacts and related topics. Since food items and groceries are abundantly available to all living in KSA and they are highly subsidized, the residents take food for granted. According to a recent survey, about 78% of food purchased in KSA is discarded each week in order to make room for new groceries. The factors responsible for food waste include: lack of awareness; and insufficient and inappropriate planning when shopping. Food waste in restaurants, celebrations, social events and occasions are enormous. Waste is common in festivals and special events where the customs is to provide more food than required. There is a need to change society’s food culture, particularly among the women and the youth, as they are largest segment of the society and the prime food wasters. The analysis of the factors responsible for food waste, identified in this article suggests a “Stop Wasting Food” campaign should be launched. It is also recommended to determine and activate the role of extension education to reduce food waste in the KSA through vibrant capacity building programs for youth and women, in particular, and society in general.     

Multiple linked β and α globin genes in Atlantic cod: A PCR based strategy of genomic exploration

Allozyme variation in Atlantic cod hemoglobins shows various signs of natural selection. We report a genomic exploration of globin genes in this non-model organism. Applying a PCR based strategy with a strict criterion of phylogenetically informative sites we estimate the number of linked β and α globin genes. We estimate PCR error rate by PCR of cloned DNA and recloning and by analysis of singleton variable sites among clones. Based on the error rate we exclude variable sites so that the remaining variation meets successively stricter criteria of doubleton and triplet variable site. Applying these criteria we find ten clusters of linked β/α globin genes in the genome of Atlantic cod. Six variable amino acid changes in both genes were found in linkage disequilibrium with silent nucleotide substitutions. A phylogenetic tree, based on our strictly phylogenetically informative sites among 57 clones from 19 individuals, is split into two major branches by an amino acid change in a β gene. This change is supported by extensive linkage disequilibrium between the amino acid change and numerous other phylogenetically informative silent nucleotide sites. The different gene sets in the genome may represent different loci encoding different globins and/or allelic variation at some loci.     

Expression of estrogen receptor α and β in rat astrocytes in primary culture: effects of hypoxia and glucose deprivation

Estrogen replacement therapy could play a role in the reduction of injury associated with cerebral ischemia in vivo, which could be, at least partially, a consequence of estrogen influence of glutamate buffering by astrocytes during hypoxia/ischemia. Estrogen exerts biological effects through interaction with its two receptors: estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), which are both expressed in astrocytes. This study explored effects of hypoxia and glucose deprivation (HGD), alone or followed by 1 h recovery, on ERα and ERβ expression in primary rat astrocyte cultures following 1 h exposure to: a) 5 % CO(2) in air (control group-CG); b) 2 % O(2)/5 % CO(2) in N(2) with glucose deprivation (HGD group-HGDG); or c) the HGDG protocol followed by 1 h CG protocol (recovery group-RG). ERα mRNA expression decreased in HGDG. At the protein level, full-length ERα (67 kDa) and three ERα-immunoreactive protein bands (63, 60 and 52 kDa) were detected. A significant decrease in the 52 kDa band was seen in HGDG, while a significant decrease in expression of the full length ERα was seen in the RG. ERβ mRNA and protein expression (a 54 kDa single band) did not change. The observed decrease in ERα protein may limit estrogen-mediated signalling in astrocytes during hypoxia and recovery.     

Methyl cyanide induces α to β transition and aggregation at high concentrations in E-state of human serum albumin

We have studied the effect of 2,2,2-trifluoroethanol (TFE), an α-helix inducer, versus methyl cyanide (MeCN), a β-sheet inducer, on acid-denatured human serum albumin (HSA) using far-UV circular dichroism, intrinsic fluorescence, 1-anilino-8-naphthalene sulfonate binding, and acrylamide quenching studies. Interestingly, at pH 2.0, where the recovery and resolution of the protein in reverse phase chromatography is high, its secondary structure remains unchanged even in the presence of very high concentration (76% v/v) of MeCN. Gain of 23 and 34% α-helicity was observed in the presence of 20 and 50% TFE, respectively. At pH 7.3, HSA aggregates in the presence of 40% MeCN, but it remains soluble up to 75% MeCN at pH 2.0. The results seem to be important for HSA isolation and purification.     

Differential roles of estrogen receptors α and β in control of B-cell maturation and selection

It is clear that estrogen can accelerate and exacerbate disease in some lupus-prone mouse strains. It also appears that estrogen can contribute to disease onset or flare in a subset of patients with lupus. We have previously shown estrogen alters B-cell development to decrease lymphopoiesis and increase the frequency of marginal zone B cells. Furthermore, estrogen diminishes B-cell receptor signaling and allows for the increased survival of high-affinity DNA-reactive B cells. Here, we analyze the contribution of estrogen receptor α or β engagement to the altered B-cell maturation and selection mediated by increased exposure to estrogen. We demonstrate that engagement of either estrogen receptor α or β can alter B-cell maturation, but only engagement of estrogen receptor α is a trigger for autoimmunity. Thus, maturation and selection are regulated differentially by estrogen. These observations have therapeutic implications.     

Metabolic fate of a high concentration of glutamine and glutamate in rat brain slices: a ¹³C NMR study

This study was performed to analyze the metabolic fate of a high concentration (5 mM) of glutamine and glutamate in rat brain slices and the participation of these amino acids in the glutamine-glutamate cycle. For this, brain slices were incubated for 60 min with [3-13C]glutamine or [3-13C]glutamate. Tissue plus medium extracts were analyzed by enzymatic and 13C NMR measurements and fluxes through pathways of glutamine and glutamate metabolism were calculated. We demonstrate that both substrates were utilized and oxidized at high rates by rat brain slices and served as precursors of neurotransmitters, tricarboxylic acid (TCA) cycle intermediates and alanine. In order to determine the participation of glutamine synthetase in the appearance of new glutamine molecules with glutamine as substrate, brain slices were incubated with [3-13C]glutamine in the presence of methionine sulfoximine, a specific inhibitor of glutamine synthetase. Our results indicate that 36.5% of the new glutamine appeared was glutamine synthetase-dependent and 63.5% was formed from endogenous substrates. Flux through glutamic acid decarboxylase was higher with glutamine than with glutamate as substrate whereas fluxes from α-ketoglutarate to glutamate and through glutamine synthetase, malic enzyme, pyruvate dehydrogenase, pyruvate carboxylase and citrate synthase were in the same range with both substrates.     

α- and β-adrenoceptors of zebrafish in melanosome movement: a comparative study between embryo and adult melanophores

Zebrafish, like other teleosts, display rapid skin color change in response to the background through sympathetic nerves. Here, the α- and β-adrenoceptors of melanophores were studied pharmacologically both in zebrafish embryo and adult scale. In vitro experiments on adult scale melanophores demonstrated that both α₁- and α₂-adrenoceptors are functional in melanosome aggregation, the α₂ subtype being predominant. Most melanophores in zebrafish embryos were able to concentrate melanosomes to α₂-adrenergic agonist α-methylnorepinephrine when they first appeared. This ability increased at least in the following 48 h, showing melanophores at these stages have developed functional adrenoceptors and these receptors increase independently before sympathetic innervation. However, even high concentration (10⁻³ M) of α₁-adrenoceptor agonist phenylephrine was not able to evoke any paling of the embryos. In adult scales, propranolol enhanced the melanosome-aggregating response of epinephrine and isoproterenol, but not norepinephrine, indicating β-adrenoceptor mediates melanosome-dispersing response in adult zebrafish. Similar response was not observed in embryos until 60 h post-fertilization (hpf). The melanophore adrenoceptor blocking effects of phentolamine and propranolol in embryos were much lower than that in adult zebrafish, suggesting these adrenoceptors in developing melanophores are less sensitive to the classical antagonists.     

A comparative study of hydrolysis and transglycosylation activities of fungal β-glucosidases

β-glucosidases (BGs) from Aspergillus fumigatus, Aspergillus niger, Aspergillus oryzae, Magnaporthe grisea, Neurospora crassa, and Penicillium brasilianum were purified to homogeneity, and investigated for their (simultaneous) hydrolytic and transglycosylation activity in samples with high concentrations of either cellobiose or glucose. The rate of the hydrolytic process (which converts one cellobiose to two glucose molecules) shows a maximum around 10–15 mM cellobiose and decreases with further increase in the concentration of substrate. At the highest investigated concentration (100 mM cellobiose), the hydrolytic activity for the different enzymes ranged from 10% to 55% of the maximum value. This decline in hydrolysis was essentially compensated by increased transglycosylation (which converts two cellobiose to one glucose and one trisaccharide). Hence, it was concluded that the hydrolytic slowdown at high substrate concentrations solely relies on an increased flow through the transglycosylation pathway and not an inhibition that delays the catalytic cycle. Transglycosylation was also detected at high product (glucose) concentrations, but in this case, it was not a major cause for the slowdown in hydrolysis. The experimental data was modeled to obtain kinetic parameters for both hydrolysis and transglycosylation. These parameters were subsequently used in calculations that quantified the negative effects on BG activity of respectively transglycosylation and product inhibition. The kinetic parameters and the mathematical method presented here allow estimation of these effects, and we suggest that this may be useful for the evaluation of BGs for industrial use.