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51.
A molecular and evolutionary study of the beta-globin gene family of the Australian marsupial Sminthopsis crassicaudata 总被引:1,自引:0,他引:1
Cooper SJ; Murphy R; Dolman G; Hussey D; Hope RM 《Molecular biology and evolution》1996,13(7):1012-1022
Beta-globin gene families in eutherians (placental mammals) consist of a
set of four or more developmentally regulated genes which are closely
linked and, in general, arranged in the order 5'-embryonic/fetal genes-
adult genes-3'. This cluster of genes is proposed to have arisen by tandem
duplication of ancestral beta-globin genes, with the first duplication
occurring 200 to 155 MYBP just prior to a period in mammalian evolution
when eutherians and marsupials diverged from a common ancestor. In this
paper we trace the evolutionary history of the beta-globin gene family back
to the origins of these mammals by molecular characterization of the
beta-globin gene family of the Australian marsupial Sminthopsis
crassicaudata. Using Southern and restriction analysis of total genomic DNA
and bacteriophage clones of beta-like globin genes, we provide evidence
that just two functional beta-like globin genes exist in this marsupial,
including one embryonic- expressed gene (S.c-epsilon) and one
adult-expressed gene (S.c-beta), linked in the order 5'-epsilon-beta-3'.
The entire DNA sequence of the adult beta-globin gene is reported and shown
to be orthologous to the adult beta-globin genes of the North American
marsupial Didelphis virginiana and eutherian mammals. These results,
together with results from a phylogenetic analysis of mammalian beta-like
globin genes, confirm the hypothesis that a two-gene cluster, containing an
embryonic- and an adult-expressed beta-like globin gene, existed in the
most recent common ancester of marsupials and eutherians. Northern analysis
of total RNA isolated from embryos and neonatals indicates that a switch
from embryonic to adult gene expression occurs at the time of birth,
coinciding with the transfer of the marsupial from a uterus to a pouch
environment.
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53.
Mohammad?Abass?AhangerEmail author Megha?Tittal Rayees?Ahmad?Mir RM?Agarwal 《Protoplasma》2017,254(5):1953-1963
Present communication reports laboratory and pot experiments conducted to study the influence of water and osmotic stress on nitrogen uptake and metabolism in two wheat (Triticum aestivum L) cultivars with and without potassium supplementation. Polyethylene glycol 6000-induced osmotic stress/restricted irrigation caused a considerable decline in the activity of nitrate reductase, glutamate synthase, alanine and aspartate aminotransferases, and glutamate dehydrogenase. Potassium considerably improved nitrogen metabolism under normal water supply conditions and also resulted in amelioration of the negative impact of water and osmotic stresses indicating that potassium supplementation can be used as a potential tool for enhancing the nitrogen use efficiency in wheat for exploiting its genetic potential. 相似文献
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56.
Kjellman BM Fredrikson M Glad-Mattsson G Sjöberg F Huss FR 《Annals of surgical innovation and research》2011,5(1):4-8
Background
Hypothermia in burns is common and increases morbidity and mortality. Several methods are available to reach and maintain normal core body temperature, but have not yet been evaluated in critical care for burned patients. Our unit's ordinary technique for controlling body temperature (Bair Hugger®+ radiator ceiling + bed warmer + Hotline®) has many drawbacks e.g.; slow and the working environment is hampered. The aim of this study was to compare our ordinary heating technique with newly-developed methods: the Allon?2001 Thermowrap (a temperature regulating water-mattress), and Warmcloud (a temperature regulating air-mattress).Methods
Ten consecutive burned patients (> 20% total burned surface area and a core temperature < 36.0°C) were included in this prospective, randomised, comparative study. Patients were randomly exposed to 3 heating methods. Each treatment/measuring-cycle lasted for 6 hours. Each heating method was assessed for 2 hours according to a randomised timetable. Core temperature was measured using an indwelling (bladder) thermistor. Paired t-tests were used to assess the significance of differences between the treatments within the patients. ANOVA was used to assess the differences in temperature from the first to the last measurement among all treatments. Three-way ANOVA with the Tukey HSD post hoc test and a repeated measures ANOVA was used in the same manner, but included information about patients and treatment/measuring-cycles to control for potential confounding. Data are presented as mean (SD) and (range). Probabilities of less than 0.05 were accepted as significant.Results
The mean increase, 1.4 (SD 0.6°C; range 0.6-2.6°C) in core temperature/treatment/measuring-cycle highly significantly favoured the Allon?2001 Thermowrap in contrast to the conventional method 0.2 (0.6)°C (range -1.2 to 1.5°C) and the Warmcloud 0.3 (0.4)°C (range -0.4 to 0.9°C). The procedures for using the Allon?2001 Thermowrap were experienced to be more comfortable and straightforward than the conventional method or the Warmcloud.Conclusions
The Allon?2001 Thermowrap was more effective than the Warmcloud or the conventional method in controlling patients' temperatures. 相似文献57.
Using inbreeding theory as applied to neutral alleles inherited maternally,
we generate expected probability distributions of times to identity by
descent for random pairs of mitochondrial genotypes within a population or
within an entire species characterized by high gene flow. For comparisons
with these expectations, empirical distributions of times to most recent
common ancestry were calculated (by conventional mtDNA clock calibrations)
from mtDNA haplotype distances observed within each of three vertebrate
species--American eels, hardhead catfish, and redwinged blackbirds. These
species were chosen for analysis because census population size in each is
currently large and because both genetic and life-history data are
consistent with the postulate that historical gene flow within these
species has been high. The observed molecular distances among mtDNA
lineages were two to three orders of magnitude lower than predicted from
census sizes of breeding females, suggesting that rate of mtDNA evolution
is decelerated in these species and/or that long-term effective population
size is vastly smaller than present-day population size. Several
considerations point to the latter possibility as most likely. The genetic
structure of any species is greatly influenced by historical demography;
even for species that are currently abundant, mtDNA gene lineages appear to
have been channeled through fairly small numbers of ancestors.
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58.
One of the limitations of the use of phage antibody libraries in high throughput selections is the production of sufficient phage antibody library at the appropriate quality. Here, we successfully adapt a bioreactor-based protocol for the production of phage peptide libraries to the production of phage antibody libraries. The titers obtained in the stirred-tank bioreactor are 4 to 5 times higher than in a standard shake flask procedure, and the quality of the phage antibody library produced is indistinguishable to that produced using standard procedures as assessed by Western blotting and functional selections. Availability of this protocol will facilitate the use of phage antibody libraries in high-throughput scale selections. 相似文献
59.
D Deprez J Fransen M Lenoir RM Philippaerts R Vaeyens 《Biology of sport / Institute of Sport》2015,32(1):65-70
The aim of the study was to investigate test reliability of the Yo-Yo intermittent recovery test level 1 (YYIR1) in 36 high-level youth soccer players, aged between 13 and 18 years. Players were divided into three age groups (U15, U17 and U19) and completed three YYIR1 in three consecutive weeks. Pairwise comparisons were used to investigate test reliability (for distances and heart rate responses) using technical error (TE), coefficient of variation (CV), intra-class correlation (ICC) and limits of agreement (LOA) with Bland-Altman plots. The mean YYIR1 distances for the U15, U17 and U19 groups were 2024 ± 470 m, 2404 ± 347 m and 2547 ± 337 m, respectively. The results revealed that the TEs varied between 74 and 172 m, CVs between 3.0 and 7.5%, and ICCs between 0.87 and 0.95 across all age groups for the YYIR1 distance. For heart rate responses, the TEs varied between 1 and 6 bpm, CVs between 0.7 and 4.8%, and ICCs between 0.73 and 0.97. The small ratio LOA revealed that any two YYIR1 performances in one week will not differ by more than 9 to 28% due to measurement error. In summary, the YYIR1 performance and the physiological responses have proven to be highly reliable in a sample of Belgian high-level youth soccer players, aged between 13 and 18 years. The demonstrated high level of intermittent endurance capacity in all age groups may be used for comparison of other prospective young soccer players. 相似文献
60.
Developmental and wound-, cold-, desiccation-, ultraviolet-B-stress-induced modulations in the expression of the petunia zinc finger transcription factor gene ZPT2-2 下载免费PDF全文
van Der Krol AR van Poecke RM Vorst OF Voogt C van Leeuwen W Borst-Vrensen TW Takatsuji H van Der Plas LH 《Plant physiology》1999,121(4):1153-1162
The ZPT2-2 gene belongs to the EPF gene family in petunia (Petunia hybrida), which encodes proteins with TFIIIA-type zinc-finger DNA-binding motifs. To elucidate a possible function for ZPT2-2, we analyzed its pattern of expression in relation to different developmental and physiological stress signals. The activity of the ZPT2-2 promoter was analyzed using a firefly luciferase (LUC) reporter gene, allowing for continuous measurements of transgene activity in planta. We show that ZPT2-2::LUC is active in all plant tissues, but is strongly modulated in cotyledons upon germination, in leaves in response to desiccation, cold treatment, wounding, or ultraviolet-B light, and in petal tissue in response to pollination of the stigma. Analysis of mRNA levels indicated that the modulations in ZPT2-2::LUC expression reflect modulations in endogenous ZPT2-2 gene expression. The change in ZPT2-2::LUC activity by cold treatment, wounding, desiccation, and ultraviolet-B light suggest that the phytohormones ethylene and jasmonic acid are involved in regulating the expression of ZPT2-2. Although up-regulation of expression of ZPT2-2 can be blocked by inhibitors of ethylene perception, expression in plants is not induced by exogenously applied ethylene. The application of jasmonic acid does result in an up-regulation of gene activity and, thus, ZPT2-2 may play a role in the realization of the jasmonic acid hormonal responses in petunia. 相似文献