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In vertebrates and the cephalochordate, amphioxus, the closest vertebrate
relative, Hox genes are linked in a single cluster. Accompanying the
emergence of higher vertebrates, the Hox gene cluster duplicated in either
a single step or multiple steps, resulting in the four-cluster state
present in teleosts and tetrapods. Mammalian Hox clusters (designated A, B,
C, and D) extend over 100 kb and are located on four different chromosomes.
Reconstructing the history of the duplications and its relation to
vertebrate evolution has been problematic due to the lack of alignable
sequence information. In this study, the problem was approached by
conducting a statistical analysis of sequences from the fibrillar-type
collagens (I, II, III, and IV), genes closely linked to each Hox cluster
which likely share the same duplication history as the Hox genes. We find
statistical support for the hypothesis that the cluster duplication
occurred as multiple distinct events and that the four-cluster situation
arose by a three- step sequential process.
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Olga Pivovarova Christian von Loeffelholz Iryna Ilkavets Carsten Sticht Sergei Zhuk Veronica Murahovschi Sonja Lukowski Stephanie D?cke Jennifer Kriebel Tonia de las Heras Gala Anna Malashicheva Anna Kostareva Johan F Lock Martin Stockmann Harald Grallert Norbert Gretz Steven Dooley Andreas FH Pfeiffer Natalia Rudovich 《Cell cycle (Georgetown, Tex.)》2015,14(14):2293-2300
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M Onderci K Sahin N Sahin MF Gursu D Doerge FH Sarkar 《Archives of animal nutrition》2013,67(6):463-471
Genistein, a phytoestrogen found in soybeans, is a powerful antioxidant. We evaluated the effects of genistein supplementation on performance, carcass characteristics, levels of malondialdehyde (MDA), homocysteine, vitamins C, E, A in Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature of 34°C. Two hundred and forty Japanese quails (10 d old) were randomly assigned to eight treatment groups consisting of 10 replicates of three birds. The birds were kept in an environmental controlled room either for 24 h/d at 22°C with (thermoneutral, TN groups) or for 16 h/d at 22°C and for 8 h/d (09.00 am to 05.00 pm) at 34°C (heat stress, HS groups). Birds were fed either a basal (control) diet (TN and HS) or the basal diet supplemented with 200, 400 or 800 mg of genistein per kg of diet. Heat exposure decreased birds' performance when basal diet was fed. Increase in feed intake and body weight, and improvement of feed efficiency and carcass traits were found in genistein-supplemented quails reared under heat stress conditions. Growth rate and feed efficiency improved in quails reared under thermo-neutral conditions as well. Concentration of serum vitamins C, E, and A increased in supplemented birds reared at high temperature, while non-significant changes occurred in TN groups. With genistein supplementation homocysteine levels in serum and MDA levels in serum and liver decreased in all birds of both TN and HS groups. Effects of genistein were relatively greater in heat-stressed quails than in quails kept under thermo-neutral conditions. Results of the present study suggest that supplementation with genistein can be considered to be protective by reducing the negative effects of oxidative stress induced by heat stress in quail. 相似文献
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Monocrotaline (MCT) is a hepatotoxic pyrrolizidine alkaloid that is derived from plants; exposure may occur by consumption of contaminated grains, herbal teas and medicines. MCT can cause liver damage. We investigated the antioxidant effects of selenium (Se) and vitamin E against the toxic effects of MCT. Female Wistar albino rats were divided into four groups: a control group, an MCT group, an MCT + Se group, and an MCT + vitamin E group. Liver tissues were harvested, fixed, processed to paraffin and sections were cut. Anti-von Willebrand factor (vWF) immunohistochemistry, terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL), and hematoxylin and eosin staining were performed. Serum and liver tissue glutathione (GSH), catalase (CAT), and glutathione peroxidase (GPx) levels were measured. Histopathological and TUNEL data showed significantly increased liver damage in the MCT group compared to controls. Histopathological and TUNEL staining indicated significant improvements in the MCT + vitamin E and MCT + Se groups compared to the MCT group. MCT significantly reduced the serum GSH level and GPx activity, and liver GPx activity. Biochemical data indicated a significant improvement in serum GSH level in the MCT + vitamin E group compared to the MCT group. We suggest that vitamin E and Se afford limited protection against MCT hepatotoxicity. 相似文献
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M Gowda Y Zhao T Würschum C FH Longin T Miedaner E Ebmeyer R Schachschneider E Kazman J Schacht J-P Martinant M F Mette J C Reif 《Heredity》2014,112(5):552-561
The accuracy of genomic selection depends on the relatedness between the members of the
set in which marker effects are estimated based on evaluation data and the types for which
performance is predicted. Here, we investigate the impact of relatedness on the
performance of marker-assisted selection for fungal disease resistance in hybrid wheat. A
large and diverse mapping population of 1739 elite European winter wheat inbred lines and
hybrids was evaluated for powdery mildew, leaf rust and stripe rust resistance in
multi-location field trials and fingerprinted with 9 k and 90 k SNP arrays.
Comparison of the accuracies of prediction achieved with data sets from the two marker
arrays revealed a crucial role for a sufficiently high marker density in genome-wide
association mapping. Cross-validation studies using test sets with varying degrees of
relationship to the corresponding estimation sets revealed that close relatedness leads to
a substantial increase in the proportion of total genotypic variance explained by the
identified QTL and consequently to an overoptimistic judgment of the precision of
marker-assisted selection. 相似文献
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Single-copy nuclear DNAs (scnDNAs) of eight species of arvicoline and six
species of murine rodents were compared using DNA-DNA hybridization. The
branching pattern derived from the DNA comparisons is congruent with the
fossil evidence and supported by comparative biochemical, chromosomal, and
morphological studies. The recently improved fossil record for these
lineages provides seven approximate divergence dates, which were used to
calibrate the DNA-hybridization data. The average rate of scnDNA divergence
was estimated as 2.5%/Myr. This is approximately 10 times the rate in the
hominoid primates. These results agree with previous reports of accelerated
DNA evolution in muroid rodents and extend the DNA-DNA hybridization data
set of Brownell.
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