投影片 1
... next 34 years. Mendel's work has been thought to exemplify everything from the failure of traditional modes of scientific communication (Bush [1945]) to the phenomenon of "premature scientific discovery" ( Stent [1978]). In 1900, Mendel's work was cited by three botanists, writing in different parts ...
... next 34 years. Mendel's work has been thought to exemplify everything from the failure of traditional modes of scientific communication (Bush [1945]) to the phenomenon of "premature scientific discovery" ( Stent [1978]). In 1900, Mendel's work was cited by three botanists, writing in different parts ...
Protection of Drosophila chromosome ends through minimal
... protein. In these rescued animals, GFP–HipHop protein was detected as discrete foci in the nuclei of germline stem cells (GSCs) and their progeny, spermatogonial cells (see Fig. 1A for a schematic description of Drosophila spermatogenesis; Fig. 1B,B′,D). Then, the intensity of GFP–HipHop foci decrea ...
... protein. In these rescued animals, GFP–HipHop protein was detected as discrete foci in the nuclei of germline stem cells (GSCs) and their progeny, spermatogonial cells (see Fig. 1A for a schematic description of Drosophila spermatogenesis; Fig. 1B,B′,D). Then, the intensity of GFP–HipHop foci decrea ...
Chapter 6 GENETIC LINKAGE AND MAPPING IN EUKARYOTES
... the two parental phenotypes, five other phenotypic combinations appeared that were not found in the parental generation. How did Morgan explain these data? He considered the studies conducted in 1909 of the Belgian cytologist Frans Alfons Janssens, who observed chiasmata under the microscope and pro ...
... the two parental phenotypes, five other phenotypic combinations appeared that were not found in the parental generation. How did Morgan explain these data? He considered the studies conducted in 1909 of the Belgian cytologist Frans Alfons Janssens, who observed chiasmata under the microscope and pro ...
How imprinting is relevant to human disease - Development
... chromosomes demonstrating that these children are the biological offspring of the purported father. In each case, the child is homozygous for maternal markers at all loci tested on chromosome 7. Thus, all the evidence supports maternally derived isodisomy of chromosome 7. These appear to be cases of ...
... chromosomes demonstrating that these children are the biological offspring of the purported father. In each case, the child is homozygous for maternal markers at all loci tested on chromosome 7. Thus, all the evidence supports maternally derived isodisomy of chromosome 7. These appear to be cases of ...
zChap07_140901 - Online Open Genetics
... is relatively rare). If meiosis results in recombination, the products are said to have a recombinant genotype. On the other hand, if no recombination occurs during meiosis, the products have their original combinations and are said to have a nonrecombinant, or parental genotype. Recombination is im ...
... is relatively rare). If meiosis results in recombination, the products are said to have a recombinant genotype. On the other hand, if no recombination occurs during meiosis, the products have their original combinations and are said to have a nonrecombinant, or parental genotype. Recombination is im ...
X Chromosome Aneuploidy: A Look at the Effects of X Inactivation
... Meiosis I and Meiosis II. During Meiosis I homologous chromosomes are separated. During Meiosis II sister chromatids are separated. This is followed by cytokinesis, resulting in the production of four haploid cells. Within Meiosis I, there are four stages: Prophase I, Metaphase I, Anaphase I, and Te ...
... Meiosis I and Meiosis II. During Meiosis I homologous chromosomes are separated. During Meiosis II sister chromatids are separated. This is followed by cytokinesis, resulting in the production of four haploid cells. Within Meiosis I, there are four stages: Prophase I, Metaphase I, Anaphase I, and Te ...
On the mechanism of Wolbachia
... bi-directional incompatibility because paternal and maternal chromosomes affected by different slowing-down factors would be asynchronous. Two different hypotheses must be distinguished here. First, different slowing down factors might bind to the same sites on host chromosomes. Maternal and paterna ...
... bi-directional incompatibility because paternal and maternal chromosomes affected by different slowing-down factors would be asynchronous. Two different hypotheses must be distinguished here. First, different slowing down factors might bind to the same sites on host chromosomes. Maternal and paterna ...
IGA 8/e Chapter 2
... a. What can be deduced from these results regarding the inheritance of the small-colony phenotype? (Invent genetic symbols.) b. What would an ascus from this cross look like? Answer: a. A diploid meiocyte that is heterozygous for one gene (for example, s+/s where s is the allele that confers the sma ...
... a. What can be deduced from these results regarding the inheritance of the small-colony phenotype? (Invent genetic symbols.) b. What would an ascus from this cross look like? Answer: a. A diploid meiocyte that is heterozygous for one gene (for example, s+/s where s is the allele that confers the sma ...
Unusual chromosome structure of fission yeast DNA in mouse cells
... chromosome morphology, because of the complex and largely undefined nature of the DNA involved. One way to resolve this problem would be to introduce more defined, but still cytologically visible, pieces of DNA into mammalian cells and examine the ensuing affects on chromosome structure. Allshire et ...
... chromosome morphology, because of the complex and largely undefined nature of the DNA involved. One way to resolve this problem would be to introduce more defined, but still cytologically visible, pieces of DNA into mammalian cells and examine the ensuing affects on chromosome structure. Allshire et ...
Functional Analysis of Maize RAD51 in Meiosis and
... In Saccharomyces cerevisiae, Rad51p plays a central role in homologous recombination and the repair of double-strand breaks (DSBs). Double mutants of the two Zea mays L. (maize) rad51 homologs are viable and develop well under normal conditions, but are male sterile and have substantially reduced se ...
... In Saccharomyces cerevisiae, Rad51p plays a central role in homologous recombination and the repair of double-strand breaks (DSBs). Double mutants of the two Zea mays L. (maize) rad51 homologs are viable and develop well under normal conditions, but are male sterile and have substantially reduced se ...
8. Principles of Genetics and Cytogenetics
... naturalist. According to him, each part of the animal body produces a minute copy of its own, called gemmule or pangene. The gemmules are collected in the reproductive organs. The gemmulues were passed on to the gametes. The young one formed from the gametes would be having all the gemmules characte ...
... naturalist. According to him, each part of the animal body produces a minute copy of its own, called gemmule or pangene. The gemmules are collected in the reproductive organs. The gemmulues were passed on to the gametes. The young one formed from the gametes would be having all the gemmules characte ...
Here - Events
... distinct developmental fates. The pause in cell cycle is analogous to the midblastula transition observed in many organisms and is associated with the degradation of a subset of maternally supplied mRNAs and large-scale transcriptional activation of the genome. In my talk, I will describe experiment ...
... distinct developmental fates. The pause in cell cycle is analogous to the midblastula transition observed in many organisms and is associated with the degradation of a subset of maternally supplied mRNAs and large-scale transcriptional activation of the genome. In my talk, I will describe experiment ...
Control of the proliferation versus meiotic development decision in
... a stem cell population that covers a region of approximately 20 cell diameters in length (Fig. 1A) (Crittenden et al., 1994; Hansen et al., 2004). Cells immediately proximal to the stem cells, in the transition zone, have entered meiotic prophase and continue to progress through meiosis as they move ...
... a stem cell population that covers a region of approximately 20 cell diameters in length (Fig. 1A) (Crittenden et al., 1994; Hansen et al., 2004). Cells immediately proximal to the stem cells, in the transition zone, have entered meiotic prophase and continue to progress through meiosis as they move ...
A haploid genetics toolbox for Arabidopsis thaliana
... (Supplementary Table 1). In contrast, the mottled GFP seeds (Supplementary Fig. 3l) gave rise to seedlings devoid of GFP (Supplementary Fig. 3p), in agreement with our embryo dissection experiments (Supplementary Fig. 3i,j). When the seedlings were grown to maturity, 91% of these were haploids and t ...
... (Supplementary Table 1). In contrast, the mottled GFP seeds (Supplementary Fig. 3l) gave rise to seedlings devoid of GFP (Supplementary Fig. 3p), in agreement with our embryo dissection experiments (Supplementary Fig. 3i,j). When the seedlings were grown to maturity, 91% of these were haploids and t ...
Publizieren ist ein essentieller Bestandteil des wissenschaftlichen
... motor proteins1, 2. The bipolar organization of spindles is essential for proper segregation of chromosomes, and requires plus-end-directed homotetrameric motor proteins of the widely conserved kinesin-5 (BimC) family3. Hypotheses for bipolar spindle formation include the 'push−pull mitotic muscle' ...
... motor proteins1, 2. The bipolar organization of spindles is essential for proper segregation of chromosomes, and requires plus-end-directed homotetrameric motor proteins of the widely conserved kinesin-5 (BimC) family3. Hypotheses for bipolar spindle formation include the 'push−pull mitotic muscle' ...
Recent Advances in Cytology
... second problem vexing cytology was whether the chiasmata were the result, or rather the cause of such crossing-over. Working almost entirely in isolation, Darlington was able within a few short years to produce an axiomatic account of chromosome mechanics. In three simple laws he summed up the entir ...
... second problem vexing cytology was whether the chiasmata were the result, or rather the cause of such crossing-over. Working almost entirely in isolation, Darlington was able within a few short years to produce an axiomatic account of chromosome mechanics. In three simple laws he summed up the entir ...
Slide 1
... During sexual reproduction, male and female reproductive cells join in a process known as fertilization to produce a new cell. Pea flowers are normally self-pollinating, which means that sperm cells fertilize egg cells from within the same flower. Mendel’s garden had several stocks of pea plants tha ...
... During sexual reproduction, male and female reproductive cells join in a process known as fertilization to produce a new cell. Pea flowers are normally self-pollinating, which means that sperm cells fertilize egg cells from within the same flower. Mendel’s garden had several stocks of pea plants tha ...
On algebraic properties of the human ABO
... (sex cells) which carry a single set of chromosomes. A parent with blood group O produces gametes with alleles O. A parent with blood group AB produces gametes with alleles A or B. A parent with blood group A produces gametes with alleles A or O if his genotype is OA, and only A if it is of AA. When ...
... (sex cells) which carry a single set of chromosomes. A parent with blood group O produces gametes with alleles O. A parent with blood group AB produces gametes with alleles A or B. A parent with blood group A produces gametes with alleles A or O if his genotype is OA, and only A if it is of AA. When ...
Meiotic Recombination inSchizosaccharomyces pombe: A Paradigm
... Homologous genetic recombination plays two important roles during meiosis, the special nuclear divisions during which chromosome number is reduced from two (diploid) to one (haploid). First, recombination provides the physical connection between homologs that aids their pairing and proper segregatio ...
... Homologous genetic recombination plays two important roles during meiosis, the special nuclear divisions during which chromosome number is reduced from two (diploid) to one (haploid). First, recombination provides the physical connection between homologs that aids their pairing and proper segregatio ...
Isolation and characterization of a repeated sequence (RPS1) of
... aqueous phases were mixed with 2 vols 99% (v/v) ethanol. After storage at - 20 "C overnight, the precipitates were removed and washed once with 70% ethanol. Dried precipitates were dissolved in 8 ml TE (10 mM-Tris/HCl, 1 mM-EDTA, pH 8.0) and stored at 4 "C. Southern hybridizations. Southern hybridiz ...
... aqueous phases were mixed with 2 vols 99% (v/v) ethanol. After storage at - 20 "C overnight, the precipitates were removed and washed once with 70% ethanol. Dried precipitates were dissolved in 8 ml TE (10 mM-Tris/HCl, 1 mM-EDTA, pH 8.0) and stored at 4 "C. Southern hybridizations. Southern hybridiz ...
Have a break: determinants of meiotic DNA double strand break
... the efficient initiation of recombination at a certain locus in the mouse and human genomes (Baudat et al., 2009; Myers et al., 2009; Parvanov et al., 2009). In a remarkable approach, Myers and co-workers analysed >30 000 human hot spots (deduced from linkage disequilibrium patterns) of certain well ...
... the efficient initiation of recombination at a certain locus in the mouse and human genomes (Baudat et al., 2009; Myers et al., 2009; Parvanov et al., 2009). In a remarkable approach, Myers and co-workers analysed >30 000 human hot spots (deduced from linkage disequilibrium patterns) of certain well ...
the far c-terminus of tpx2 contributes to spindle morphogenesis
... genetic code that each cell uses to generate the proteome. As life evolved on Earth, organisms developed methods to ensure the delivery of replicated DNA to their progeny. Prokaryotes undergo binary fission – a process in which genomic DNA is replicated, attached to the cell wall and separated durin ...
... genetic code that each cell uses to generate the proteome. As life evolved on Earth, organisms developed methods to ensure the delivery of replicated DNA to their progeny. Prokaryotes undergo binary fission – a process in which genomic DNA is replicated, attached to the cell wall and separated durin ...
A Retrospective Study of Balanced Chromosomal Translocations in
... However there are some cases of carriers with mental retardation or phenotypic other abnormalities. It was estimated that 30–50% of the de novo balanced translocations with abnormal phenotype were associated with causative cryptic imbalances (Gribble et al. 2005; De Gregori et al. 2007; Sismani et a ...
... However there are some cases of carriers with mental retardation or phenotypic other abnormalities. It was estimated that 30–50% of the de novo balanced translocations with abnormal phenotype were associated with causative cryptic imbalances (Gribble et al. 2005; De Gregori et al. 2007; Sismani et a ...
understanding heredity
... The process of heredity belongs to this most inclusive category. Every type of living being, from the bacteria through the microscopically small inhabitants of a drop of water to more familiar plants and animals, low and high, has the faculty for reproducing its kind, which is really the ability to ...
... The process of heredity belongs to this most inclusive category. Every type of living being, from the bacteria through the microscopically small inhabitants of a drop of water to more familiar plants and animals, low and high, has the faculty for reproducing its kind, which is really the ability to ...
Meiosis
Meiosis /maɪˈoʊsɨs/ is a specialized type of cell division which reduces the chromosome number by half. This process occurs in all sexually reproducing single-celled and multi-celled eukaryotes, including animals, plants, and fungi. Errors in meiosis resulting in aneuploidy are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells each with half the number of chromosomes as the original parent cell. The two meiotic divisions are known as meiosis I and meiosis II. Before meiosis begins, during S phase of the cell cycle, the DNA of each chromosome is replicated so that it consists of two identical sister chromatids. In meiosis I, homologous chromosomes pair with each other and can exchange genetic material in a process called chromosomal crossover. The homologous chromosomes are then segregated into two new daughter cells, each containing half the number of chromosomes as the parent cell. At the end of meiosis I, sister chromatids remain attached and may differ from one another if crossing-over occurred. In meiosis II, the two cells produced during meiosis I divide again. Sister chromatids segregate from one another to produce four total daughter cells. These cells can mature into various types of gametes such as ova, sperm, spores, or pollen.Because the number of chromosomes is halved during meiosis, gametes can fuse (i.e. fertilization) to form a zygote with a complete chromosome count containing a combination of paternal and maternal chromosomes. Thus, meiosis and fertilization facilitate sexual reproduction with successive generations maintaining the same number of chromosomes. For example, a typical diploid human cell contains 23 pairs of chromosomes (46 total, half of maternal origin and half of paternal origin). Meiosis produces haploid gametes with one set of 23 chromosomes. When two gametes (an egg and a sperm) fuse, the resulting zygote is once again diploid, with the mother and father each contributing 23 chromosomes. This same pattern, but not the same number of chromosomes, occurs in all organisms that utilize meiosis. Thus, if a species has 30 chromosomes in its somatic cells, it will produce gametes with 15 chromosomes.