Knowledge of genetic diversity and barcoding of yam is lacking in Enugu and Ebonyi States of southern Nigeria. Therefore, DNA barcoding was used to facilitate identification and biodiversity studies of yam species fro...Knowledge of genetic diversity and barcoding of yam is lacking in Enugu and Ebonyi States of southern Nigeria. Therefore, DNA barcoding was used to facilitate identification and biodiversity studies of yam species from Southern Nigeria. Seventy five yam accessions were collected from Enugu and Ebonyi States, including International Institute of Tropical Agriculture for DNA extraction and amplification using a chloroplast DNA (cpDNA) ribulose-1,5-bisphosphate carboxylase (rbcL) marker. There was high level of similarity among the accessions and presence of 534 conserved and 7 variable sites. A transversional mutation of G/T at a consensus position of 335 was identified followed by transitions at 362 (A/G), 368 (A/G), 371 (C/T) and 391 (C/T) within the accessions. Phylogeny resolved the yam accessions into ten major groups with their bootstrap values ranging from 0 - 100. Phylogenetic diversity was highest in group X, followed by VII, VI and IX. The inter-group genetic distance based on Kimura 2-parameter model ranged from 0.5000 ± 0.4770 - 5.0560 ± 2.5760, while the intra-group had 0.5250 ± 0.5000 - 2.0103 ± 1.2579. The mean genetic diversity within the entire population was 0.7970 ± 0.06910. BLAST analysis of total bit score, query coverage, and percentage identity were in the ranges of 411 - 1011, 99% - 100% and 97% - 100%, respectively. However, the rbcL could not resolve the yam accessions well following the comparative assessment of some discrepancies in the detected number of species from phylogenetic groupings, genetic diversity indices and NCBI BLAST hits, thereby, exposing the inefficiency of this marker in discriminating the yam accessions. It was demonstrated that rbcL is not an effective marker;therefore, it should not be recommended as a standard-alone marker of choice for DNA barcoding of yam accessions, especially, when accurate identification, discrimination and estimation of genetic diversity of this vital crop are of paramount importance for crop improvement and germplasm conservation.展开更多
Background: Grass-fed and grain-fed Angus cattle differ in the diet regimes. However, the intricate mechanisms of different beef quality and other phenotypes induced by diet differences are still unclear. Diet affects...Background: Grass-fed and grain-fed Angus cattle differ in the diet regimes. However, the intricate mechanisms of different beef quality and other phenotypes induced by diet differences are still unclear. Diet affects mitochondrial function and dynamic behavior in response to changes in energy demand and supply. In this study, we examined the mtDNA copy number, mitochondria-related genes expression, and metabolic biomarkers in grass-fed and grainfed Angus cattle.Results: We found that the grass-fed group had a higher mtDNA copy number than the grain-fed group. Among different tissues, the mtDNA copy number was the highest in the liver than muscle, rumen, and spleen. Based on the transcriptome of the four tissues, a lower expression of mtDNA-encoded genes in the grass-fed group compared to the grain-fed group was discovered. For the mitochondria-related nuclear genes, however, most of them were significantly down-regulated in the muscle of the grass-fed group and up-regulated in the other three tissues. In which, COX6 A2, POLG2, PPIF, DCN, and NDUFA12, involving in ATP synthesis, mitochondrial replication,transcription, and maintenance, might contribute to the alterations of mtDNA copy number and gene expression.Meanwhile, 40 and 23 metabolic biomarkers were identified in the blood and muscle of the grain-fed group compared to a grass-fed group, respectively. Integrated analysis of the altered metabolites and gene expression revealed the high expression level of MDH1 in the grain-fed group might contribute to the mitochondrial NADH oxidation and spermidine metabolism for adapting the deletion mtDNA copy number.Conclusions: Overall, the study may provide further deep insight into the adaptive and regulatory modulations of the mitochondrial function in response to different feeding systems in Angus cattle.展开更多
Genetic diversity evaluation of mutant lines is essential to facilitate their conservation and utility in breeding programs. Characterization of plant genotypes using morphological markers has limitations which make t...Genetic diversity evaluation of mutant lines is essential to facilitate their conservation and utility in breeding programs. Characterization of plant genotypes using morphological markers has limitations which make the procedure inefficient. Application of molecular tools for characterization and diversity assessment has been found useful to complement phenotypic evaluation of plant population. Therefore genetic diversity of some cowpea mutant lines was studied using simple sequence repeats (SSR) markers. DNA barcoding marker, ribulose-1,5-bisphosphate carboxylase(rbcL) of the chloroplast DNA (cpDNA) was also used for characterization and identification of the mutants to species level. The mean polymorphic information content (0.51) obtained from the microsatellites showed high polymorphism in accessing wide genetic diversity among the mutants and their parents. Dendrogram generated revealed 8 groups with most mutants clustered separately from their parents. Sequence analysis revealed insertions/deletions (InDels) and base substitutions as the two main classes of mutations induced in the plastid DNA of the mutants studied. The nucleotide frequencies were 26.95% (A), 34.43% (T), 24.09% (C) and 14.53% (G). A total of 61.38% AT rich region was identified, while GC rich region was found to be 38.62%. Highest rate of mutations were observed in region 3 - 4 indicating that the region is less conserved in cowpea rbcL gene. The present study proved that SSR markers are useful for the genetic diversity assessment of cowpea mutants. It also proved the efficiency of rbcL markers in mutants’ identification. The results indicate that the mutants are valuable genetic resources that have been developed to widen cowpea genetic base.展开更多
Sorghum is a potential fodder crop for an alternative source of livestock feed in Kenya.A study was done to determine the levels of prussic acid,lignin and cellulose content in potential fodder sorghum varieties at Eg...Sorghum is a potential fodder crop for an alternative source of livestock feed in Kenya.A study was done to determine the levels of prussic acid,lignin and cellulose content in potential fodder sorghum varieties at Egerton University Field Station in Kenya.Twenty-five sorghum genotypes were grown in a randomized complete block design(RCBD)and replicated three times.The genotypes were sampled at 3-leaf stage and analyzed for prussic acid,lignin and cellulose.The data were subjected to statistical analysis of variance and correlation using Statistical Analysis System(SAS)program version 9.1.Prussic acid levels were significantly different even at an early stage,with local varieties producing more.Lignin and cellulose had an inverse relationship with respect to concentration.Fodder sorghum genotypes varied significantly in prussic acid,lignin and cellulose,even at an early growth stage.展开更多
A library of new 1,4-benzodioxane-6-carboxylic acid amide analogs was designed and synthesized. These analogs were obtained in six steps from gallic acid. Firstly, esterification of the commercially available gallic a...A library of new 1,4-benzodioxane-6-carboxylic acid amide analogs was designed and synthesized. These analogs were obtained in six steps from gallic acid. Firstly, esterification of the commercially available gallic acid in methanol in the presence of sulfuric acid afforded methyl 3,4,5-trihydroxybenzoate (9) in satisfactory yield. The ester 9 was then reacted with an excess of 1,2-dibromoethane in the presence of K<sub>2</sub>CO<sub>3</sub> in acetone to furnish the 6,8-disubstituted-1,4-benzodioxane (10) in 45% yield. The reaction of 10 with various mercaptans gave the sulfide derivative 11, 12, and 13 in moderate yield. Subsequent hydrolysis of the methyl ester in 13 followed by conversion to the acid chloride and reaction of the acid chloride intermediate with different commercially available primary and secondary amines gave the amide analogs 18 - 32 with an average yield of 43%. Conversion of the sulfide group in Compound 23 to Sulfoxide 33 or Sulfone 34 was accomplished by reaction with either 30% H<sub>2</sub>O<sub>2</sub>/TeO<sub>2</sub> or 30% H<sub>2</sub>O<sub>2</sub>, respectively. The structures of the synthesized compounds were characterized using FTIR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, and high-resolution ESI-MS.展开更多
Because of the importance of central nervous system (CNS) functions to productive capacity and quality of life, biomarkers of these functions will play a key role in evaluating the success of interventions targeting a...Because of the importance of central nervous system (CNS) functions to productive capacity and quality of life, biomarkers of these functions will play a key role in evaluating the success of interventions targeting aging processes. The CNS biomarkers may also be useful for predicting aging in other systems and in the organism as a whole. Age-related behavioral changes, the products of CNS aging, have content and predictive validity with respect to human functional capacities and may, therefore, represent important 'neurobehavioral' markers of functional aging. This article presents a discussion of some behavioral paradigms which are currently being considered as neurobehavioral biomarkers of aging in mice and the experimental approaches being employed in the assessment of their validity. Studies conducted in the authors' laboratory using dietary restriction and genetic comparisons to evaluate the validity of neurobehavioral biomarkers have revealed several methodological concerns, and hypothetical and empirical examples of these pitfalls are described and discussed. In spite of those concerns, it is concluded that approaches to validity using genetic comparisons and dietary restriction can be successfully implemented and should ultimately lead to identification of valid and useful neurobehavioral biomarkers of aging.展开更多
Finger millet(Eleusine coracana(L.)Gaertn.)is a drought resistant crop with potentially tremendous but under-explored source of nutraceutical properties as compared to other regularly consumed cereals in the era of dr...Finger millet(Eleusine coracana(L.)Gaertn.)is a drought resistant crop with potentially tremendous but under-explored source of nutraceutical properties as compared to other regularly consumed cereals in the era of drawback of nutritional security,these characteristics must be harnessed to develop finger millet as a novel functional food.Under-nutrition caused by inadequate diets,and other factors that influence nutritional status,is the underlying factor in 45%child deaths.In Kenya only 25%of young children are fed adequately diverse diets.The main objective of this study was to prepare baby food formulas using finger millets with pigeon peas as protein source and to analyze their nutritional profiles.Two finger millets varieties(i)Snapping Green Early,low altitude and medium altitude varieties and(ii)U-15)were studied to determine effects of environment on nutrient profiles.This study showed that Snapping Green Early had better nutrient profiles(12.13%protein and is high in Ca,Mg,Fe,Zn and P)than U-15(11.69%protein and lower nutrients(Ca,Mg,Fe,Zn and P)),and hence was selected for use in the malting process as best variety.As expected,the pigeon peas had the highest protein value(21%).The samples malted for 72 h resulted in reduction of tannin concentration from 0.091%to 0.03%and the amount of nutrients(Ca,Mg,Fe and Zn)doubled and in fact the protein profile increased by 8.31%.The appropriate ratio for the formulation of the baby food was 70:30.The composting resulted in 18.5%increase in protein.展开更多
Almost a decade after Dolly the sheep changed the history of biological clock turning,Takahashi and Yamanaka made headlines both in scientific journals,and in magazines such as TIME,by once again proving that the cloc...Almost a decade after Dolly the sheep changed the history of biological clock turning,Takahashi and Yamanaka made headlines both in scientific journals,and in magazines such as TIME,by once again proving that the clock could be turned back,even on somatic cells,by‘direct reprogramming.’(Takahashi and Yamanaka,2006;Park,2007;Takahashi et al.,2007)During the last decade,stem cells have been at the forefront of science,politics and the public forums due to the conflicting issues surrounding the use of embryonic stem cells in research and regenerative medicine strategies.展开更多
文摘Knowledge of genetic diversity and barcoding of yam is lacking in Enugu and Ebonyi States of southern Nigeria. Therefore, DNA barcoding was used to facilitate identification and biodiversity studies of yam species from Southern Nigeria. Seventy five yam accessions were collected from Enugu and Ebonyi States, including International Institute of Tropical Agriculture for DNA extraction and amplification using a chloroplast DNA (cpDNA) ribulose-1,5-bisphosphate carboxylase (rbcL) marker. There was high level of similarity among the accessions and presence of 534 conserved and 7 variable sites. A transversional mutation of G/T at a consensus position of 335 was identified followed by transitions at 362 (A/G), 368 (A/G), 371 (C/T) and 391 (C/T) within the accessions. Phylogeny resolved the yam accessions into ten major groups with their bootstrap values ranging from 0 - 100. Phylogenetic diversity was highest in group X, followed by VII, VI and IX. The inter-group genetic distance based on Kimura 2-parameter model ranged from 0.5000 ± 0.4770 - 5.0560 ± 2.5760, while the intra-group had 0.5250 ± 0.5000 - 2.0103 ± 1.2579. The mean genetic diversity within the entire population was 0.7970 ± 0.06910. BLAST analysis of total bit score, query coverage, and percentage identity were in the ranges of 411 - 1011, 99% - 100% and 97% - 100%, respectively. However, the rbcL could not resolve the yam accessions well following the comparative assessment of some discrepancies in the detected number of species from phylogenetic groupings, genetic diversity indices and NCBI BLAST hits, thereby, exposing the inefficiency of this marker in discriminating the yam accessions. It was demonstrated that rbcL is not an effective marker;therefore, it should not be recommended as a standard-alone marker of choice for DNA barcoding of yam accessions, especially, when accurate identification, discrimination and estimation of genetic diversity of this vital crop are of paramount importance for crop improvement and germplasm conservation.
基金supported by Maryland Agricultural Experiment Station(MAES),Jorgensen Endowment Funds。
文摘Background: Grass-fed and grain-fed Angus cattle differ in the diet regimes. However, the intricate mechanisms of different beef quality and other phenotypes induced by diet differences are still unclear. Diet affects mitochondrial function and dynamic behavior in response to changes in energy demand and supply. In this study, we examined the mtDNA copy number, mitochondria-related genes expression, and metabolic biomarkers in grass-fed and grainfed Angus cattle.Results: We found that the grass-fed group had a higher mtDNA copy number than the grain-fed group. Among different tissues, the mtDNA copy number was the highest in the liver than muscle, rumen, and spleen. Based on the transcriptome of the four tissues, a lower expression of mtDNA-encoded genes in the grass-fed group compared to the grain-fed group was discovered. For the mitochondria-related nuclear genes, however, most of them were significantly down-regulated in the muscle of the grass-fed group and up-regulated in the other three tissues. In which, COX6 A2, POLG2, PPIF, DCN, and NDUFA12, involving in ATP synthesis, mitochondrial replication,transcription, and maintenance, might contribute to the alterations of mtDNA copy number and gene expression.Meanwhile, 40 and 23 metabolic biomarkers were identified in the blood and muscle of the grain-fed group compared to a grass-fed group, respectively. Integrated analysis of the altered metabolites and gene expression revealed the high expression level of MDH1 in the grain-fed group might contribute to the mitochondrial NADH oxidation and spermidine metabolism for adapting the deletion mtDNA copy number.Conclusions: Overall, the study may provide further deep insight into the adaptive and regulatory modulations of the mitochondrial function in response to different feeding systems in Angus cattle.
文摘Genetic diversity evaluation of mutant lines is essential to facilitate their conservation and utility in breeding programs. Characterization of plant genotypes using morphological markers has limitations which make the procedure inefficient. Application of molecular tools for characterization and diversity assessment has been found useful to complement phenotypic evaluation of plant population. Therefore genetic diversity of some cowpea mutant lines was studied using simple sequence repeats (SSR) markers. DNA barcoding marker, ribulose-1,5-bisphosphate carboxylase(rbcL) of the chloroplast DNA (cpDNA) was also used for characterization and identification of the mutants to species level. The mean polymorphic information content (0.51) obtained from the microsatellites showed high polymorphism in accessing wide genetic diversity among the mutants and their parents. Dendrogram generated revealed 8 groups with most mutants clustered separately from their parents. Sequence analysis revealed insertions/deletions (InDels) and base substitutions as the two main classes of mutations induced in the plastid DNA of the mutants studied. The nucleotide frequencies were 26.95% (A), 34.43% (T), 24.09% (C) and 14.53% (G). A total of 61.38% AT rich region was identified, while GC rich region was found to be 38.62%. Highest rate of mutations were observed in region 3 - 4 indicating that the region is less conserved in cowpea rbcL gene. The present study proved that SSR markers are useful for the genetic diversity assessment of cowpea mutants. It also proved the efficiency of rbcL markers in mutants’ identification. The results indicate that the mutants are valuable genetic resources that have been developed to widen cowpea genetic base.
文摘Sorghum is a potential fodder crop for an alternative source of livestock feed in Kenya.A study was done to determine the levels of prussic acid,lignin and cellulose content in potential fodder sorghum varieties at Egerton University Field Station in Kenya.Twenty-five sorghum genotypes were grown in a randomized complete block design(RCBD)and replicated three times.The genotypes were sampled at 3-leaf stage and analyzed for prussic acid,lignin and cellulose.The data were subjected to statistical analysis of variance and correlation using Statistical Analysis System(SAS)program version 9.1.Prussic acid levels were significantly different even at an early stage,with local varieties producing more.Lignin and cellulose had an inverse relationship with respect to concentration.Fodder sorghum genotypes varied significantly in prussic acid,lignin and cellulose,even at an early growth stage.
文摘A library of new 1,4-benzodioxane-6-carboxylic acid amide analogs was designed and synthesized. These analogs were obtained in six steps from gallic acid. Firstly, esterification of the commercially available gallic acid in methanol in the presence of sulfuric acid afforded methyl 3,4,5-trihydroxybenzoate (9) in satisfactory yield. The ester 9 was then reacted with an excess of 1,2-dibromoethane in the presence of K<sub>2</sub>CO<sub>3</sub> in acetone to furnish the 6,8-disubstituted-1,4-benzodioxane (10) in 45% yield. The reaction of 10 with various mercaptans gave the sulfide derivative 11, 12, and 13 in moderate yield. Subsequent hydrolysis of the methyl ester in 13 followed by conversion to the acid chloride and reaction of the acid chloride intermediate with different commercially available primary and secondary amines gave the amide analogs 18 - 32 with an average yield of 43%. Conversion of the sulfide group in Compound 23 to Sulfoxide 33 or Sulfone 34 was accomplished by reaction with either 30% H<sub>2</sub>O<sub>2</sub>/TeO<sub>2</sub> or 30% H<sub>2</sub>O<sub>2</sub>, respectively. The structures of the synthesized compounds were characterized using FTIR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, and high-resolution ESI-MS.
文摘Because of the importance of central nervous system (CNS) functions to productive capacity and quality of life, biomarkers of these functions will play a key role in evaluating the success of interventions targeting aging processes. The CNS biomarkers may also be useful for predicting aging in other systems and in the organism as a whole. Age-related behavioral changes, the products of CNS aging, have content and predictive validity with respect to human functional capacities and may, therefore, represent important 'neurobehavioral' markers of functional aging. This article presents a discussion of some behavioral paradigms which are currently being considered as neurobehavioral biomarkers of aging in mice and the experimental approaches being employed in the assessment of their validity. Studies conducted in the authors' laboratory using dietary restriction and genetic comparisons to evaluate the validity of neurobehavioral biomarkers have revealed several methodological concerns, and hypothetical and empirical examples of these pitfalls are described and discussed. In spite of those concerns, it is concluded that approaches to validity using genetic comparisons and dietary restriction can be successfully implemented and should ultimately lead to identification of valid and useful neurobehavioral biomarkers of aging.
基金Special thanks go to Dr.Anne Osano for allowing the first author to be part of this research experience,and the National Science Foundation(NSF)for funding this research opportunity.
文摘Finger millet(Eleusine coracana(L.)Gaertn.)is a drought resistant crop with potentially tremendous but under-explored source of nutraceutical properties as compared to other regularly consumed cereals in the era of drawback of nutritional security,these characteristics must be harnessed to develop finger millet as a novel functional food.Under-nutrition caused by inadequate diets,and other factors that influence nutritional status,is the underlying factor in 45%child deaths.In Kenya only 25%of young children are fed adequately diverse diets.The main objective of this study was to prepare baby food formulas using finger millets with pigeon peas as protein source and to analyze their nutritional profiles.Two finger millets varieties(i)Snapping Green Early,low altitude and medium altitude varieties and(ii)U-15)were studied to determine effects of environment on nutrient profiles.This study showed that Snapping Green Early had better nutrient profiles(12.13%protein and is high in Ca,Mg,Fe,Zn and P)than U-15(11.69%protein and lower nutrients(Ca,Mg,Fe,Zn and P)),and hence was selected for use in the malting process as best variety.As expected,the pigeon peas had the highest protein value(21%).The samples malted for 72 h resulted in reduction of tannin concentration from 0.091%to 0.03%and the amount of nutrients(Ca,Mg,Fe and Zn)doubled and in fact the protein profile increased by 8.31%.The appropriate ratio for the formulation of the baby food was 70:30.The composting resulted in 18.5%increase in protein.
文摘Almost a decade after Dolly the sheep changed the history of biological clock turning,Takahashi and Yamanaka made headlines both in scientific journals,and in magazines such as TIME,by once again proving that the clock could be turned back,even on somatic cells,by‘direct reprogramming.’(Takahashi and Yamanaka,2006;Park,2007;Takahashi et al.,2007)During the last decade,stem cells have been at the forefront of science,politics and the public forums due to the conflicting issues surrounding the use of embryonic stem cells in research and regenerative medicine strategies.
