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1. Individual blood samples from 144 Bali (Banteng) cattle [Bos (Bibos) javanicus] in the Northern Territory of Australia and from 61 Bali cross cattle, were examined by zone electrophoresis to determine the variants of haemoglobin, serum albumin and transferrin that are present. 2. Of the common cattle haemoglobin variants (A and B) only variant B occurs in the Bali cattle samples. A second variant, designated CBali, occurs in Bali cattle either as the heterozygote (B CBali) or as the homozygote, the frequencies of occurrence indicating a two-allele system of inheritance without dominance. The CBali cross samples may exhibit the homozygous or heterozygous A variant. 3. The CBali variant has an electrophoretic mobility intermediate between those of the A and B variants at pH 8.6 and 9.1 but closer to B than to A (B greater than C greater than A). It appears to be similar in mobility to the C variants found in Indian Khillan (CKhillan) by Naik, Sukumaran and Sanghvi (Anim. Prodn, 1965 I, 275-277), and in Asian cattle by Oishi, Abe and Namikama (Immunogenet. Lett., 1968 5, 170-173) and Abe, Mogi, Oishi, Tanaka and Suzuki (Proc. XIIth Europ. Conf. Anim. Blood Groups Biochem. Polymorphisms 1972, pp. 225-228), but appreciably different from those in Kenyan and Rhodesian cattle (CRhodesia) found by Braend (Anim. Blood Grps Biochem. Genet., 1971 2, 15-21) and Carr (Rhod. J. agric. Res., 1964 3, 62-62A), respectively. It is also different in mobility from the C variant found by Winter, Mayr, Schleger, Dworak, Krutzler and Burger (Res. vet. Sci., 1984 36, 276-283) in the mithun.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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Pigment-based coloration is a common trait found in a variety of organisms across the tree of life. For example, calcareous avian eggs are natural structures that vary greatly in color, yet just a handful of tetrapyrrole pigment compounds are responsible for generating this myriad of colors. To fully understand the diversity and constraints shaping nature’s palette, it is imperative to characterize the similarities and differences in the types of compounds involved in color production across diverse lineages. Pigment composition was investigated in eggshells of eleven paleognath bird taxa, covering several extinct and extant lineages, and shells of four extant species of mollusks. Birds and mollusks are two distantly related, calcareous shell-building groups, thus characterization of pigments in their calcareous structures would provide insights to whether similar compounds are found in different phyla (Chordata and Mollusca). An ethylenediaminetetraacetic acid (EDTA) extraction protocol was used to analyze the presence and concentration of biliverdin and protoporphyrin, two known and ubiquitous tetrapyrrole avian eggshell pigments, in all avian and molluscan samples. Biliverdin was solely detected in birds, including the colorful eggshells of four tinamou species. In contrast, protoporphyrin was detected in both the eggshells of several avian species and in the shells of all mollusks. These findings support previous hypotheses about the ubiquitous deposition of tetrapyrroles in the eggshells of various bird lineages and provide evidence for its presence also across distantly related animal taxa.  相似文献   
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Membrane-bound immunoglobulin (mIg) is the antigen receptor on B lymphocytes mediating early events in antigen presentation and signal transduction. Wild-type human mIgM constructs transfected into the murine B-cell lymphoma A20 are expressed as transmembrane proteins with antigen presentation and signaling functions comparable to the endogenous mIgG2A; the transfected wild-type mIgM is internalized rapidly after anti-Ig cross-linking. Transfected constructs lacking the normal three-amino acid cytoplasmic tail are expressed exclusively as phosphatidylinositol-linked proteins, lack both antigen presentation and signal transduction functions, and are internalized slowly following anti-Ig binding. The molecular mass of the cytoplasmic tail-deleted phosphatidylinositol-linked Ig molecule is consistent with cleavage of the transmembrane residues during processing. Cytoplasmic domains may therefore regulate the mode of expression of membrane proteins and thereby influence their functional capabilities.  相似文献   
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The hinge in IgA1 and the linker in endoglucanase A (CenA) are quite similar. The IgA1 hinge is 18 amino acids long and contains only proline, threonine and serine. The linker in CenA is 27 amino acids long and contains only proline, threonine and a single serine. IgA proteases from Neisseria gonorrhoeae cleave Pro-Ser and Pro-Thr bonds within the IgA1 hinge sequence, but they do not attack CenA. When the linker sequence of CenA is replaced with the hinge sequence of IgA1, the hybrid polypeptide is susceptible to the N. gonorrhoeae proteases. It is cleaved within the hinge sequence at the same sites as IgA1.  相似文献   
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An SEM and TEM study revealed details of the development of the pronephros of Caretta caretta. The pronephros develops and degenerates over 13 days from day 7 to day 20 in embryos incubated at 33°C. Podocytes, with primary branches, secondary branches, and pedicles, on a basal lamina, can be seen from day 11, as can ciliated pronephric tubule ostia opening into the coelom. At this stage the embryo has four pharyngeal arches with unfused mandibular processes, and small fore-limb buds each with an apical ectodermal ridge. Maturation of the pronephros occurs between days 15 and 17. Degeneration begins around day 18 and is advanced by day 20 when the embryo has a fully developed face, fore-limbs with digits, and the carapace and plastron have formed.  相似文献   
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There have been reported epidemics of severe asthma in Barcelona, Spain, linked to a 10 kDa low molecular mass (LMM) allergen from soybean hulls that became airborne during unloading of ships. As a preliminary probe of the potential for dispersion of this allergen in USA cities, four automated air samplers were placed around a grain elevator in New Orleans and operated continuously from May to October 1990. The allergen was extracted from the filters and immunochemically assayed for soybean aeroallergen. On 31 separate days, the airborne allergen concentration in at least one of the samples was over 10000 U/m3 similar to those observed in Barcelona on some epidemic days. Areas North and East of the elevator were most affected. Serologie studies showed that of 50 asthmatics from New Orleans who were participants in an unrelated clinical study 4 or 8% demonstrated elevated titers of IgE antibody to LMM soybean allergen. Only 1 of 475 control sera (half of which were also asthmatic) obtained elsewhere in the US was positive for LMM soybean IgE antibody. Based on the findings in this study, there is a great possibility that on some days there is enough soybean allergen in the air and a sufficient frequency of soybean aeroallergen RAST positive asthmatics in New Orleans to warrant further investigation of the contribution of soybean aeroallergen to asthma around the port of New Orleans.Supported by NIAID # A121255. Mayo Clinic and Foundation and Minnesota Lung Association.  相似文献   
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