Experimental data that prove the existence of the zygotic combinatorial process occurring in an embryogenesis-entering zygote are presented in the paper. The zygotic combinatorial process is found when analyzing F1 hy...Experimental data that prove the existence of the zygotic combinatorial process occurring in an embryogenesis-entering zygote are presented in the paper. The zygotic combinatorial process is found when analyzing F1 hybrid plants obtained from crossing homozygous forms different, minimum, in two marker enzymes, and it is found in that hybrid plant which, with one marker enzyme heterozygous spectrum, has a homozygous spectrum of the other. The zygotic combinatorial process leads to F1 hybrids uniformity aberration. The zygotic combinatory process revealed in the study is supposed to be conditioned by chromosome polyteny in mother plant cells and diminution of chromatin excess from the embryogenesisentering zygote. An obligatory condition for combinatorial process is the presence of free exchange of chromatides among homological chromosomes in an embryogenesis-entering cell, i.e. the presence of crossing-over analogous to the one proceeding at meiosis.展开更多
The effect of colchicine on phenotypic classes ratio of the enzyme locus controlling alcohol dehydrogenase (ADH1) in sugar beet agamospermous progenies was analysed. The obtained data are indicative of the thing that ...The effect of colchicine on phenotypic classes ratio of the enzyme locus controlling alcohol dehydrogenase (ADH1) in sugar beet agamospermous progenies was analysed. The obtained data are indicative of the thing that colchicine causes polytenization of homological chromosome regions carrying marker locus Adh1 alleles. Theoretical calculation of the formation of egg cells frequencies and those of further development of cells entering embryogenesis without fertilization, also the diminution calculation of excessive chromosome regions carrying marker locus alleles have been made. The coincidence of theoretical and experimental ratios of phenotypic classes indicates the existence of post-meiotic apozygotic combinatory process in plants.展开更多
This article focuses on the development of the method for the genetic classification of agamospermous reproduction types in plants using sugar beet as an example. The classification feasibility is ensured by the use o...This article focuses on the development of the method for the genetic classification of agamospermous reproduction types in plants using sugar beet as an example. The classification feasibility is ensured by the use of isozymes as genetic markers allowing the identification of all three phenotypic classes in the progeny of individual heterozygous diploid plant and is based on different phenotypic class ratios in the progenies obtained by meiotic and mitotic agamospermy. The data indicate that for studied forms of sugar beet meiotic agamospermy is the more typical because 10 of 12 explored progenies were classified as those which arisen under meiotic agamospermy and only 2 as arisen under mitotic agamospermy.展开更多
The estimation of the influence of external conditions on marker enzymes phenotypic classes ratios in agamospermous sugar beet progenies has been carried out. It has been shown that different ways of flowering sugar b...The estimation of the influence of external conditions on marker enzymes phenotypic classes ratios in agamospermous sugar beet progenies has been carried out. It has been shown that different ways of flowering sugar beet plant branches isolation lead to different ratios of marker enzyme phenotypes in a developing agamospermous seed progeny. The obtained data are an additional confirmation of the hypothesis about the presence of differential chromosomes polyteny and its dependence on external conditions.展开更多
Mitonucleon-initiated dome formation involves structural changes occurring over a 20 to 24 hour period in monolayer cells induced by a serum factor. The earliest observable change is the fusion of monolayer cells into...Mitonucleon-initiated dome formation involves structural changes occurring over a 20 to 24 hour period in monolayer cells induced by a serum factor. The earliest observable change is the fusion of monolayer cells into a syncytium in which nuclei aggregate and become surrounded by a membrane that stains for endogenous biotin. Each of these structures is further surrounded by a fraction of the mitochondria that arise in the syncytium following initiation of dome formation. The mitochondria fuse around the chromatin aggregate in a structure we have called a mitonucleon. Within mitonucleons, a gaseous vacuole is generated that can be seen in protrusions of the apical membrane pressuring chromatin into a pyknotic state. Eventually that pressure, together with whatever enzymatic changes have occurred in the bolus of chromatin, results in DNA fragmentation. The fragments drawn out through the syncytium by a unipolar spindle are arrayed in a configuration that appears open both to epigenetic changes and to DNA repair and replication by polyteny. The fragmented DNA stretched across the syncytial space, hardly detectable by light microscopy, becomes visible approximately half way through the differentiation as the filaments thicken in what looks like replication by polyteny. This “recycling” of attached monolayer cells into detached dome cells must include DNA replication since the number of cells in the resulting domes is greater than the number of monolayer cells by 30% or more. The resulting DNA associates into a mass of chromatin which will “segment” into polyploid structures and then into what appear to be diploid nuclei over a period of 2 to 4 hours. When the layer of nuclei has filled the syncytium, the nuclei are cellularized, forming dome cells rising up from the monolayer and arching over a fluid cavity. Dome cells can extend into gland-like structures by the same mitonucleon dependent amitotic process observed in dome formation. Some of the characteristics of this process resemble the amitotic process of schizogony among single-celled eukaryotic parasites of the apicomplexan phylum. Mitonucleon initiated amitotic proliferation results in synthesis of dozens of dome cell nuclei in a period of 20 to 24 hours, so it is much more efficient than mitosis. Cells generated by this process and their progeny would also not be sensitive to agents that inhibit mitosis suggesting that the process, as an alternative to mitosis, might be activated in cancers that become resistant to some cytotoxic drugs.展开更多
文摘Experimental data that prove the existence of the zygotic combinatorial process occurring in an embryogenesis-entering zygote are presented in the paper. The zygotic combinatorial process is found when analyzing F1 hybrid plants obtained from crossing homozygous forms different, minimum, in two marker enzymes, and it is found in that hybrid plant which, with one marker enzyme heterozygous spectrum, has a homozygous spectrum of the other. The zygotic combinatorial process leads to F1 hybrids uniformity aberration. The zygotic combinatory process revealed in the study is supposed to be conditioned by chromosome polyteny in mother plant cells and diminution of chromatin excess from the embryogenesisentering zygote. An obligatory condition for combinatorial process is the presence of free exchange of chromatides among homological chromosomes in an embryogenesis-entering cell, i.e. the presence of crossing-over analogous to the one proceeding at meiosis.
文摘The effect of colchicine on phenotypic classes ratio of the enzyme locus controlling alcohol dehydrogenase (ADH1) in sugar beet agamospermous progenies was analysed. The obtained data are indicative of the thing that colchicine causes polytenization of homological chromosome regions carrying marker locus Adh1 alleles. Theoretical calculation of the formation of egg cells frequencies and those of further development of cells entering embryogenesis without fertilization, also the diminution calculation of excessive chromosome regions carrying marker locus alleles have been made. The coincidence of theoretical and experimental ratios of phenotypic classes indicates the existence of post-meiotic apozygotic combinatory process in plants.
文摘This article focuses on the development of the method for the genetic classification of agamospermous reproduction types in plants using sugar beet as an example. The classification feasibility is ensured by the use of isozymes as genetic markers allowing the identification of all three phenotypic classes in the progeny of individual heterozygous diploid plant and is based on different phenotypic class ratios in the progenies obtained by meiotic and mitotic agamospermy. The data indicate that for studied forms of sugar beet meiotic agamospermy is the more typical because 10 of 12 explored progenies were classified as those which arisen under meiotic agamospermy and only 2 as arisen under mitotic agamospermy.
文摘The estimation of the influence of external conditions on marker enzymes phenotypic classes ratios in agamospermous sugar beet progenies has been carried out. It has been shown that different ways of flowering sugar beet plant branches isolation lead to different ratios of marker enzyme phenotypes in a developing agamospermous seed progeny. The obtained data are an additional confirmation of the hypothesis about the presence of differential chromosomes polyteny and its dependence on external conditions.
文摘Mitonucleon-initiated dome formation involves structural changes occurring over a 20 to 24 hour period in monolayer cells induced by a serum factor. The earliest observable change is the fusion of monolayer cells into a syncytium in which nuclei aggregate and become surrounded by a membrane that stains for endogenous biotin. Each of these structures is further surrounded by a fraction of the mitochondria that arise in the syncytium following initiation of dome formation. The mitochondria fuse around the chromatin aggregate in a structure we have called a mitonucleon. Within mitonucleons, a gaseous vacuole is generated that can be seen in protrusions of the apical membrane pressuring chromatin into a pyknotic state. Eventually that pressure, together with whatever enzymatic changes have occurred in the bolus of chromatin, results in DNA fragmentation. The fragments drawn out through the syncytium by a unipolar spindle are arrayed in a configuration that appears open both to epigenetic changes and to DNA repair and replication by polyteny. The fragmented DNA stretched across the syncytial space, hardly detectable by light microscopy, becomes visible approximately half way through the differentiation as the filaments thicken in what looks like replication by polyteny. This “recycling” of attached monolayer cells into detached dome cells must include DNA replication since the number of cells in the resulting domes is greater than the number of monolayer cells by 30% or more. The resulting DNA associates into a mass of chromatin which will “segment” into polyploid structures and then into what appear to be diploid nuclei over a period of 2 to 4 hours. When the layer of nuclei has filled the syncytium, the nuclei are cellularized, forming dome cells rising up from the monolayer and arching over a fluid cavity. Dome cells can extend into gland-like structures by the same mitonucleon dependent amitotic process observed in dome formation. Some of the characteristics of this process resemble the amitotic process of schizogony among single-celled eukaryotic parasites of the apicomplexan phylum. Mitonucleon initiated amitotic proliferation results in synthesis of dozens of dome cell nuclei in a period of 20 to 24 hours, so it is much more efficient than mitosis. Cells generated by this process and their progeny would also not be sensitive to agents that inhibit mitosis suggesting that the process, as an alternative to mitosis, might be activated in cancers that become resistant to some cytotoxic drugs.
