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1.
High level of divergence of male-reproductive-tract proteins, between Drosophila melanogaster and its sibling species, D. simulans 总被引:1,自引:0,他引:1
We compared male-reproductive-tract polypeptides of Drosophila melanogaster
and D. simulans by using two-dimensional gel electrophoresis. Approximately
64% of male-reproductive-tract polypeptides were identical between two
randomly chosen isofemale lines from these two species, compared with 83%
identity for third-instar imaginal wing-disc polypeptides. Qualitatively
similar differences were found between reproductive tracts and imaginal
discs when D. sechellia was compared with D. melanogaster and with D.
simulans. When genic polymorphism was taken into account, approximately 10%
of male- reproductive-tract polypeptides were apparently fixed for
different alleles between D. melanogaster and D. simulans; this proportion
is the same as that found for soluble enzymes by one-dimensional gel
electrophoresis. Strikingly, approximately 20% of male-reproductive- tract
polypeptides of either D. melanogaster or D. simulans had no detectable
homologue in the other species. We propose that proteins of the Drosophila
male reproductive tract may have diverged more extensively between species
than have other types of proteins and that much of this divergence may
involve large changes in levels of polypeptide expression.
相似文献
2.
Sex pili in Vibrio cholerae 总被引:1,自引:0,他引:1
3.
4.
The conformation of oxytocin, the neurohypophyseal nonapeptide hormone, in solution in deuterated dimethyl sulfoxide has been determined by 1H-nmr. The structural determination is based on the experimental data set of nuclear Overhauser effect restraints. Obtained after the restrained molecular dynamics simulation on an initial structure of extended conformation, five resultant structures satisfy the experimental restraints well. These structures resemble that of the crystal structure of deamino-oxytocin, an analogue of oxytocin, in terms of a close correlation observed both at two beta-turn regions of the 20-membered tocin ring and at the tripeptide tail end. Based on this comparison and analysis of restrained molecular dynamics trajectories, we found that, although the turns are stabilized by the formation of hydrogen bonds, the oxytocin molecule possesses a slight twist in DMSO solution relative to the orientation of deamino-oxytocin in the crystalline state. Analyses of oxytocin conformation indicate that the tripeptide tail is more flexible than the tocin ring. 相似文献
5.
Summary Larvae of the danid butterfly Danaus chrysippus, fed on the milkweeds Calotropis gigantea and Asclepias curassavica grew successfully during the 9-day feeding period and pupated. In the presence of these milkweeds, the larvae preferred to feed on C. gigantea. Their preference was more pronounced during the final 2 instars than during the initial 3 instars. They consumed 605 mg, defecated 308 mg, and converted 115 mg of C. gigantea; those receiving A. curassavica consumed 563 mg, defecated 287 mg and converted 85 mg. They assimilated either food with equal efficiency (: 46%; : 50%). But they differed significantly in their efficiency in converting the assimilated food. The presence of a greater amount of latex in C. gigantea than in A. curassavica and/or the nutritional inadequacy of the latter food may perhaps be the reason(s) for the preference of C. gigantea by D. chrysippus larvae over A. curassavica. 相似文献
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7.
A lethal factor in a strain of Vibrio El Tor 总被引:1,自引:0,他引:1
8.
M. Karthikeyan K. Radhika R. Bhaskaran S. Mathiyazhagan R. Sandosskumar R. Velazhahan 《Archives Of Phytopathology And Plant Protection》2013,46(6):407-417
Abstract Three antagonists: Pseudomonas fluorescens (Pf1), Bacillus subtilis and Trichoderma viride, were tested alone and in combination for suppression of onion leaf blight (Alternaria palandui) disease under glasshouse and field conditions. The average mean of disease reduction was 24.81% for single strains and 42.44% for mixtures. In addition to disease suppression, treatment with a mixture of antagonists promoted plant growth in terms of increased plant height and ultimately bulb yield. Though seed treatment of either single strain or strain mixtures alone could reduce the disease, subsequent application to root, leaves or soil further reduced the disease and enhanced the plant growth. The mixture consisting of Pseudomonas fluorescens Pf1 plus Bacillus subtilis plus Trichoderma viride was the most effective in reducing the disease and in promoting plant growth and bulb yield in greenhouse and field tests. 相似文献
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10.
Govindan Bhaskaran Steven P. Sparagana Karl H. Dahm Punee Barrera Kenneth Peck 《Invertebrate reproduction & development.》2013,57(1):87-99
Summary The kinetic profiles of vitellin accumulation in the oyster ovary during oocyte growth and the effects in vivo and in vitro of estradiol-17β (E2) on vitellin formation were examined in this study. The relative vitellin content measured by an enzyme-linked immunosorbent assay (ELISA) shows an apparent increase as the oocyte develops. Immunoblotting of the vitellin using anti-vitellin indicated that two main bands (179 and 110 kD), which begin to accumulate at an early stage of maturation, become pronounced during oocyte growth. Meanwhile, the major peak of the intact form of vitellin (530 kD) in gel filtration also enlarges with oocyte growth, supporting the results of immunoblot analysis and vitellin determination. E2 treatment in vivo causes significant increases in oocyte diameter and vitellin content in the female oyster. A similar trend was observed in ovarian tissues cultured in the presence of E2. It is concluded that E2 is one of the major factors which control the vitellogenesis in the oyster and that the ovary is undoubtedly the site of synthesis of vitellin. 相似文献