Eye size variation reflects habitat and daily activity patterns in colubrid snakes

The functioning of the vertebrate eye depends on its absolute size, which is presumably adapted to specific needs. Eye size variation in lidless and spectacled colubrid snakes was investigated, including 839 specimens belonging to 49 genera, 66 species and subspecies. Variations of adult eye diameters (EDs) in both absolute and relative terms between species were correlated with parameters reflecting behavioral ecology. In absolute terms, eye of arboreal species was larger than in terrestrial and semiaquatic species. For diurnal species, EDs of terrestrial species do not differ from semiaquatic species; for nocturnal species the ED of terrestrial species is larger than fossorial species but not different from semiaquatic species. In relative terms, ED did not differ significantly by habitat for diurnal species. Although the ED of terrestrial species is larger than fossorial species there were no differences for nocturnal species between semiaquatic and fossorial snakes. In contrast to other vertebrates studied to date, colubrid EDs in absolute and relative terms are larger in diurnal than in nocturnal species. These observations suggest that among colubrid snakes, eye size variation reflects adaptation to specific habitats, foraging strategies and daily activities, independently of phylogeny. J. Morphol. 2012. © 2012 Wiley Periodicals, Inc.     

Seasonal peculiarities of female hormonal response of females to conspecific chemical signals of the male in two species of the genus Phodopus

Changes in diestrous female blood plasma progesterone, estradiol, and cortisol in response to odors of urine and midventral gland secretion (MVGS) of conspecific males during different seasons have been studied in the desert hamster (Phodopus roborowskii and Djungarian hamster (P. sungorus). In desert hamster females, a statistically significant (p ?? 0.05) increase in the plasma hormonal level was observed: for progesterone in response to conspecific male MGVS in all seasons except winter, and to conspecific male urine in spring and summer; for cortisol in response to male MVGS and urine in all seasons except spring; and for estradiol in response to male MGVS in autumn. Djungarian hamster females demonstrated a statistically significant increase in the plasma progesterone level in response to conspecific male MVGS and urine in winter and summer, and no response to the estradiol and cortisol level for both odors in all seasons. The results showed important differences in the physiological response to odors of conspecific males between females of two species of dwarf hamsters.     

拟似然非线性模型中的置信域：几何法

对拟似然非线性模型在欧氏内积实间建立了修改的Ｂａｔｅｓ＆Ｗａｔｔｓ几何结构，基于此几何结构，导出了参数和子集系数的与统计曲率有关的三种近似置信域，进一步推广和发展了Ｈａｍｉｌｔｏｎ ｅｔ ａｌ．（１９８２）。Ｈａｍｉｌｔｏｎ（１９８６）和Ｗｅｉ（１９９４，１９９８）等人的相应结果。     

Study of β-III tubulin expression in human eye tissues during prenatal development

The expression of β-III tubulin, a marker protein of early neuronal cells, was studied by molecular genetic and immunochemical techniques. The study was performed with the eyes of human fetuses on weeks 8.5 to 27–28 of intrauterine development. Expression of β-III tubulin was detected immunochemically in the retina and lens fibers of fetuses at stages of 8.5 to 22–23 weeks. By means of PCR, a strong expression of the β-III tubulin gene was revealed in the retina of 9.5-week fetuses. Its level remained high until week 18, became slightly lower by week 24, and decreased to zero by week 27–28. The expression of this gene was also revealed in the lens of 9.5-week fetuses. Its level at stages of 15 to 24 weeks was very low, and no expression could be detected in 27-to 28-week fetuses. The results of PCR analysis were consistent with immunochemical data.     

Membranotropic activity of optical isomers of the neuropeptide kyotorphin and a cardiotonic agent, suphan

On modeled monolayer phospholipid (formed from azolectin) membranes, we studied the surface activity of optical isomers of a dipeptide, kyotorphin (Tyr-Arg), and a cardiotonic agent, suphan (N-succinyltryptophan potassium salt). It was found that the membranotropic activity of four studied isomers of kyotorphin is distributed in the order: LL>DL≈LD>DD, and two isomers (by tryptophan) of suphan as LL>DL. The data obtained suggest that the primary mechanism underlying binding of kyotorphin and suphan to the plasma membrane can be considered based on interaction of their molecules with the molecules of membrane phospholipids. Binding of molecules of kyotorphin and suphan by the lipid matrix to the plasma membrane and/or their incorporation into the matrix is a result of the above interaction.     

Identification of the ubiquinone-binding domain in the disulfide catalyst disulfide bond protein B.

Disulfide bond (Dsb) formation is catalyzed in the periplasm of prokaryotes by the Dsb proteins. DsbB, a key enzyme in this process, generates disulfides de novo by using the oxidizing power of quinones. To explore the mechanism of this newly described enzymatic activity, we decided to study the ubiquinone-protein interaction and identify the ubiquinone-binding domain in DsbB by cross-linking to photoactivatable quinone analogues. When purified Escherichia coli DsbB was incubated with an azidoubiquinone derivative, 3-azido-2-methyl-5-[(3)H]methoxy-6-decyl-1,4-benzoquinone ([(3)H]azido-Q), and illuminated with long wavelength UV light, the decrease in enzymatic activity correlated with the amount of 3-azido-2-methyl-5-methoxy-6-decyl-1,4-benzoquinone (azido-Q) incorporated into the protein. One azido-Q-linked peptide with a retention time of 33.5 min was obtained by high performance liquid chromatography of the V8 digest of [(3)H]azido-Q-labeled DsbB. This peptide has a partial NH(2)-terminal amino acid sequence of NH(2)-HTMLQLY corresponding to residues 91-97. This sequence occurs in the second periplasmic domain of the inner membrane protein DsbB in a loop connecting transmembrane helices 3 and 4. We propose that the quinone-binding site is within or very near to this sequence.     

Algorithm of Regulatory Signal Recognition in DNA Sequences

An algorithm is proposed for extracting regulatory signals from DNA sequences. The algorithm complexity is nearly quadratic. The results of testing the algorithm on artificial and natural sequences are presented.