Age-related Expression Profiles Research Articles

The MADS-domain transcription factor DAL10 is a direct target of putative DAL1-mediated age pathway in conifers.

The optimal timing of the transition from vegetative growth to reproductive growth is critical for plant reproductive success, and the underlying regulatory mechanisms have been well studied in angiosperm model species, but relatively little in gymnosperms. DAL1, a MADS domain transcription factor (TF) that shows a conserved age-related expression profile in conifers, may be an age timer. However, how DAL1 mediates the onset of reproductive growth remains poorly understood. Here, we showed that PtDAL1 directly regulates PtDAL10 transcription by binding to its promoter region in vitro. Both in vitro and in Nicotiana benthamiana PtDAL1 forms ternary complexes with PtDAL10 and PtMADS11, two potential candidate regulators of the vegetative to reproductive transition in Chinese pine (Pinus tabuliformis). In new shoots PtDAL10 was progressively induced with age and was also expressed in male and female cones. Overexpression of PtDAL10 rescued the flowering of ft-10 and soc1-1-2 mutants in Arabidopsis. We provide insights into the molecular components associated with PtDAL1, which integrates the vegetative to reproductive phase transition into age-mediated progressive development of the whole plant in conifers.

Age-related expression profile of the SLC27A1 gene in chicken tissues

The solute carrier family 27 (SLC27, also known as fatty acid transport proteins [FATPs]) plays important biological roles in cells. However, there is no report about the expression profile of SLC27 member in chicken. In this study, we quantified the expression of SLC27A1 (FATP1) mRNA in a mountainous black-boned chicken breed (MB) and a commercial meat type chicken breed (S01), to discern the tissue and age-related specific expression pattern and their potential involvement in fat deposition and muscle fatty acid metabolism. Real-time quantitative PCR assays were developed for accurate measurement of SLC27A1 mRNA levels in different tissues from chicken with different ages (0-12 weeks). Expression of SLC27A1 mRNA was detected in all tissues examined. There was a significantly age-related change of the SLC27A1 mRNAs in heart, breast muscle (BMW), leg muscle (LMW), liver, and abdominal fat (AF) tissues (P < 0.05). The breast muscle and leg muscle tissues had the highest expression of SLC27A1 mRNA than the other tissues from the same individual at 0, 2 and 4 weeks. The overall SLC27A1 mRNA level exhibited a "rise-decline" developmental change in all tissues except for breast muscle, subcutaneous fat, and brain. The S01 chicken had a higher expression of the SLC27A1 mRNA in breast muscle, subcutaneous fat, and heart tissues than the MB chicken. Our results showed that the expression of SLC27A1 mRNA in chicken tissues exhibits specific developmental changes and age-related patterns.

Global Analyses of Age-Related Expression Profiles of Mouse Liver Proteins and Database Construction

Toward making an integrated understanding of age-related homeostasis, we carried out global analyses of age-related expression profiles of mouse liver proteins. Liver protein samples prepared from nuclear, cytoplasm and mitochondria fractions of mice (C57BL/6xSJL, male) at 1,3, 6, 12, 18, 21, and 24 months of age (n=10-20/age point) were subjected to quantitative analyses by 2DE (pH range 4-11) and MALDI-TOF/MS. For nuclear protein fraction, approximately 8000 protein spots separated on 2DE were analyzed by MALDI-TOF/MS for, and 4547 protein spots were identified by MASCOT protein identifier program with reasonable scores. After removing duplicated spots, 3113 protein spots were found unique, composed of 2534 single protein spots and 579 mixture protein spots. Single protein spots were subjected to quantitative analyses with a PDQuest program, generating agerelated expression profiles. GeneSpring software was then used for clustering and filtering analyses of the profiles. In addition to many complex age-related expression profiles, about a dozen unique and fundamental age-related profiles were identified. Many isomers, likely generated mostly by posttranslational modifications and/or by alternative splicings were found for about 40% of single protein spots. These findings suggested that there exist multiple, but a relatively small number of basic age-related regulatory mechanisms for liver nuclear proteins. These fundamental mechanisms may independently and/or in various combinations function, generating many complex age-related regulatory patterns. Similar studies have also been completed for cytosolic proteins. Analyses on mitochondrial proteins and female liver proteins are under progress. Continued

Global Analysis of Age-Related Expression Profiles of Mouse Liver Genes: Toward Understanding Age-Related Homeostasis.

For understanding aging as well as various age-related diseases, it is critical to establish the basic regulatory mechanisms underlying age-related homeostatsis. Through systematic analyses of transgenic mice carrying factor IX and protein C genes, we recently discovered the first molecular mechanism of age-related homeostasis, ASE/AIE-mediated age-related regulatory mechanism of gene expression (Kurachi et. al., Science 1999; Zhang et. al., J. Biol. Chem. 2002; J. Thromb. Haemost. 2005). This laid the foundation for further studies toward an integrated understanding of age-related homeostasis. Here we report global analyses of age-related expression profiles of mouse liver genes. For quantification of expression levels of liver genes of mice at 1, 3, 6, 12, 18 and 24 month of age, Affymetrix GeneChip® Mouse Expression Array 430A (MOE430A with 23,643 probes) were used. These microarray analyses detected 9148 probes as qualified meaningful and the data were subjected to extensive analyses by GeneSpring and IPA network analysis softwares. Real time PCR analyses of representative genes were performed for verifying excellent reproducibility of age-related expression profiles determined by microarray analyses. Age-related stages, particularly of puberty and aging, were identified as the major phases for age-related changes in gene expression. Strong relationships between expression level and ontology, indicating that the highest expression gene group, next highest expression group and lowest level expression gene group are of secreted proteins, mitochondoreal proteins and nuclear regulatory protein, respectively. Most importantly, we successfully identified about a dozen unique and fundamental age-related gene expression patterns including those of age-related stable, gradual increase or decrease, and aging-related dramatic increase or decrease types of expression. These findings led us to a new hypothesis that complex and dynamic age-related regulations of genes are produced by a relatively small number of fundamental regulatory mechanisms. These mechanisms may function independently or in various combinations, thus explaining an essential feature of age-related homeostasis.