Effect of Lincocin Treatment on the Greening Process in Bean (Phaseolus vulgaris) Leaves

The effect of lincocin (a plastid protein synthesis inhibitor) treatment on the greening process of bean (Phaseolus vulgaris L.) leaves have been studied. In comparison with control leaves treated ones had a decreased rate of chloroplast development. They had a marked chlorophyll deficiency and a decreased chlorophyll a/b ratio. Some long and short wavelength forms of chlorophyll a were lacking as evidenced from the absorption spectra at 25°C and the fluorescence spectra at 77°K. The –¹⁴CO₂ fixation was inhibited by 80–90% in treated leaves. The fluorescence induced by the measuring light was greater in the treated leaves than in the control ones, and the kinetics of the decline of the relative fluorescence intensity were also different. Electron microscopic studies showed macrogranum-like structures and incomplete membrane vesicles in the treated plastids. After longer treatment a destruction of membranes was observed. The results indicate some structural and functional membrane deficiencies and instability of the membranes.     

Lecithotrophic development and metamorphosis in the Indo-West Pacific brittle star Ophiomastix venosa (Echinodermata: Ophiuroidea)

Summary

The larval development of the ophiocomid ophiuroid Ophiomastix venosais described using SEM. The gastrula transforms into a uniformly ciliated early larva which progressively changes into a lecithotrophic late premetamorphic larva with a continuous bilateral ciliated band. This stage is short-lived and equivalent to a highly reduced ophiopluteus. Comparisons between O. venosa and other ophiuroid species whose development has been investigated suggest that, whatever the developmental mode (lecithotrophic or planktotrophic), a pluteus stage always occurs in ophiuroids with planktonic development. Two metamorphic stages were identified, the late metamorphic larva differing from the early one by the closure of the larval mouth. The appearance of the permanent mouth marks the end of the metamorphosis. The postlarva still possesses remnants of larval features. The transformation of the reduced ophiopluteus into a barrel-shaped metamorphic larva with transverse ciliated bands, a vitellaria larva, is followed. The possible occurrence of a unique type of metamorphic larva in non-brooding ophiuroids is discussed. Verification of this, however, needs further SEM investigations on metamorphic larva from species having “regular” planktotrophic development.     

Sex-linked erythrocyte antigens of the domestic pig

It has been demonstrated that the domestic pig has a blood group systems whose haplotypes (complex alleles) are formed by at least three closely linked loci that are located, like the MIC2 locus of human blood group systems, in the homologous region of sex chromosomes.     

Diversity of wild and domestic pig populations estimated by a set of serum allotypes

Variation of serum protein allotypes serving as genetic markers of the blood has been analyzed in 29 populations of the domestic pig and subspecies of the wild boar. The population biodiversity and genetic structure have been estimated by two methods: by the frequencies of allotype combinations and with the use of a map constructed in the space of two principal components. The results obtained are the basis for determining the characteristics of the microevolution of wild boars and formation of the breeds of domestic pigs.     

Age Variation of the Phenotypic Expression and the Inheritance of the IgG System of Immunoglobulin Allotypes in the Pig

The specificity of phenotypic expression and inheritance of immunoglobulin allotypes IgG1a and IgG2b in piglets are discussed. It was shown that a negative state by both these allotypes is repeatedly found among newborn piglets but is extremely rare in pigs older than one month. A model, which simultaneously describes the genetic determination of allogroups formed by allotypes IgG1a and IgG2b and the dynamics of ontogenetic expression of individual genotype by systemIgG with a result of a visually registered phenotype, was developed. Allele frequencies by system IgG were assessed in populations of domestic pigs of commercial breeds, laboratory miniature pigs, and Eurasian wild boar.