Characterization of a heterogeneous camel milk whey non-casein protein

A milk protein, occurring in the whey fraction, has been characterized from camel milk. Determination of the primary structure reveals the existence of two related types of chain with residue differences in at least the N-terminal region. A fragment representing an N-terminal part of the protein was also recovered (heterogeneous at the same positions). The absence of cysteine residues in the protein shows that no disulphide bridges are present. The pattern of fragments and a parent protein resembles that for casein and its fragments, showing that fragments and a multiplicity of forms may be typical for different milk proteins.     

Cytological studies on six cyprinid fishes

The chromosome complements of six cyprinid fishes were studied, using the routine air-drying Giemsa staining technique. The diploid chromosome number recorded is 2n = 50 (8m+18sm+14st+10t) with NF = 90 in Aspidoparia morar, 2n = 50 (8m+12sm+12st+18t) with NF = 82 in Crossocheilus latius latius, 2n = 50 (6m+12sm–16st+16t) with NF = 90 in Labeo pangusia, 2n = 70 (16m+6sm+16st–32t) with NF = 108 in Perilampus atpar, 2n = 48 (4m+6st+38t) with NF = 58 in Puntius chrysopterus and 2n = 50 (2m+2sm+4st+42t) with NF = 58 in P. tetrarupagus. Sex chromosomes are not identifiable in any of these species. A pair of marker chromosomes has been observed in all species excepting A. morar.     

The impact of different fixation procedures on staining of macromolecules in a microtiter system

Summary The effects of formaldehyde, glutaraldehyde, methanol, Clarke's fixative and microwave irradiation on the quantitative staining of proteins (Naphthol Yellow S) and nucleic acids (Ethyl Green—Pyronin) in a cell culture system have been investigated. Overall, glutaraldehyde rapidly yielded the highest and most consistent levels of staining when compared to all other chemical fixatives. Although microwave irradiation was found to be uneven, 4 min exposure to 700W was found to give higher levels of protein staining than those achieveable with glutaraldehyde. Time-dependent processes were observed with all procedures. In addition, dissociations in the trends of protein and nucleic acid staining were observed. It is suggested that these results domonstrate fixation events that have not previously been resolved from the effects of reagent penetration into tissue blocks.     

Genetics and evolution of the Lpm-system in American mink. VI. Identification, genetic control and phylogenesis of the new allotype Lpm13

Data on immuno- and biochemical identification, genetic control and phylogenesis of new allotype Lpm13 of the Lpm system in domestic mink are presented. This allotype is encountered in mink populations with the frequency 0.9 and higher. The availability of Lpm13 genetic marker permitted another haplotype to be revealed, in addition to the eight known Lpm haplotypes by means of genetic analysis. It was established that, alongside with the earlier described haplotype Lpm3,4,6,8,9,10,11 (abbreviation H3), there exists a similar haplotype, Lpm3,4,6,8,9,10,11,13 (abbreviation H3.13), containing the Lpm13 gene. Of the rest seven haplotypes, five have the Lpm13 gene and two do not. Taking into account this gene and corresponding antigenic marker, the differentiation of 28, instead of 25, phenotypes and 45, instead of 36, genotypes for the Lpm system became possible. Lpm13 antigenic specificity was found with no exception in all individual serum samples taken from ten species and interspecific hybrids of Mustelidae which are closely related to domestic mink. The data obtained give grounds to refer the newly identified Lpm13 gene to the first evolutionary conservative category of genes of the multigenic Lpm system which is also represented by the Lpm6, Lpm9, Lpm10 and Lpm11 genes. The hypotheses of instantaneous formation of polymorphism of the Lpm system in domestic mink are briefly regarded.     

Biochemical polymorphism of serum cholinesterase in populations of the Kurdamir region of the Azerbaijan SSR

Examination of 933 schoolchildren in the Kyurdamir district of Azerbaijan for the carriage of abnormal variants of serum cholinesterase (EC 3.1.1.8.) revealed high biochemical polymorphism of the enzyme. This was conditioned by high frequencies of mutant alleles of the E1-E1a and E1s loci responsible for atypical and "silent" enzyme variants. The cases of confusions of phenotypes of different heterozygotes are being analyzed using the material on pedigrees. Two types of the normal alleles (E1u)--E1u1 and E1u2--were shown to be present in the population analyzed.     

A complex medico-genetic study of West Siberian populations. I. Formulation of a problem. Goals and objectives of the study. Population genetic characteristics of Northern Khanty

Purposes and tasks of the complex medical and genetic study of West-Siberian inhabitants were formulated. Demographic parameters for the North Khanty inhabitants, such as size, dynamics of the tertiary sex ratio, marriage structure and migration processes were presented. Mating and intrapopulation migration patterns are determined by spatial subdivision, because of the vast territory and the traditional way of life, and by isolation by distance. Index of the isolocal endogamy equals to 0.364. The portion of mixed marriages is 22.7% and that of the gametic contribution of immigrants - 7.3%. Inbreeding coefficient by isonymy is 0.00097. Effective population size of the five subpopulations studied as a whole is 25% of their total number.     

Primary structures of two types of alpha-subunit of rat brain Na+,K+,-ATPase deduced from cDNA sequences

A rat brain cDNA library was screened by using as a probe a fragment of cDNA encoding the alpha-subunit of human Na+,K+-ATPase. Two different cDNA clones were obtained and analyzed. One of them was concluded to be a cDNA encoding the alpha-subunit of the weakly ouabain-sensitive rat kidney-type Na+,K+-ATPase. The deduced amino acid sequence consists of 1,018 amino acids. The alpha-subunit of the rat kidney-type Na+,K+-ATPase shows 97% homology in amino acid sequence with the alpha-subunit of human, sheep, or pig enzyme and 87% with that of Torpedo. Based on a comparison of the amino acid sequence at the extracellular domain of the alpha-subunit between weakly ouabain-sensitive rat kidney-type enzyme and the ouabain-sensitive human, sheep, pig, or Torpedo enzyme, it was proposed that only two significant amino acid replacements are unique to the rat kidney-type alpha-subunit. Another cDNA clone obtained showed 72% homology in nucleotide sequence with the former cDNA coding the alpha-subunit of the rat kidney-type Na+,K+-ATPase and the deduced amino acid sequence exhibited 85% homology with that of the alpha-subunit of rat kidney-type Na+,K+-ATPase.     

Constitutive expression of the SOS response in recA718 mutants of Escherichia coli requires amplification of RecA718 protein.

In recA718 lexA+ strains of Escherichia coli, induction of the SOS response requires DNA damage. This implies that RecA718 protein, like RecA+ protein, must be converted, by a process initiated by the damage, to an activated form (RecA) to promote cleavage of LexA, the cellular repressor of SOS genes. However, when LexA repressor activity was abolished by a lexA-defective mutation [lexA(Def)], strains carrying the recA718 gene (but not recA+) showed strong SOS mutator activity and were able to undergo stable DNA replication in the absence of DNA damage (two SOS functions known to require RecA activity even when cleavage of LexA is not necessary). lambda lysogens of recA718 lexA(Def) strains exhibited mass induction of prophage, indicative of constitutive ability to cleave lambda repressor. When the cloned recA718 allele was present in a lexA+ strain on a plasmid, SOS mutator activity and beta-galactosidase synthesis under LexA control were expressed in proportion to the plasmid copy number. We conclude that RecA718 is capable of becoming activated without DNA damage for cleavage of LexA and lambda repressor, but only if it is amplified above its base-line level in lexA+ strains. At amplified levels, RecA718 was also constitutively activated for its roles in SOS mutagenesis and stable DNA replication. The nucleotide sequence of recA718 reveals two base substitutions relative to the recA+ sequence. We propose that the first allows the protein to become activated constitutively, whereas the second partially suppresses this capability.