scholarly journals Meiosis in Polyploids and Implications for Genetic Mapping: A Review

Genes ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1517
Author(s):  
Nina Reis Soares ◽  
Marcelo Mollinari ◽  
Gleicy K. Oliveira ◽  
Guilherme S. Pereira ◽  
Maria Lucia Carneiro Vieira
Keyword(s):  
Oilseed Rape ◽  
Genetic Maps ◽  
Crop Species ◽  
Map Construction ◽  
Complex Process ◽  
New Gene ◽  
Specific Proteins ◽  
Bivalent Formation ◽  
Essential Knowledge

Plant cytogenetic studies have provided essential knowledge on chromosome behavior during meiosis, contributing to our understanding of this complex process. In this review, we describe in detail the meiotic process in auto- and allopolyploids from the onset of prophase I through pairing, recombination, and bivalent formation, highlighting recent findings on the genetic control and mode of action of specific proteins that lead to diploid-like meiosis behavior in polyploid species. During the meiosis of newly formed polyploids, related chromosomes (homologous in autopolyploids; homologous and homoeologous in allopolyploids) can combine in complex structures called multivalents. These structures occur when multiple chromosomes simultaneously pair, synapse, and recombine. We discuss the effectiveness of crossover frequency in preventing multivalent formation and favoring regular meiosis. Homoeologous recombination in particular can generate new gene (locus) combinations and phenotypes, but it may destabilize the karyotype and lead to aberrant meiotic behavior, reducing fertility. In crop species, understanding the factors that control pairing and recombination has the potential to provide plant breeders with resources to make fuller use of available chromosome variations in number and structure. We focused on wheat and oilseed rape, since there is an abundance of elucidating studies on this subject, including the molecular characterization of the Ph1 (wheat) and PrBn (oilseed rape) loci, which are known to play a crucial role in regulating meiosis. Finally, we exploited the consequences of chromosome pairing and recombination for genetic map construction in polyploids, highlighting two case studies of complex genomes: (i) modern sugarcane, which has a man-made genome harboring two subgenomes with some recombinant chromosomes; and (ii) hexaploid sweet potato, a naturally occurring polyploid. The recent inclusion of allelic dosage information has improved linkage estimation in polyploids, allowing multilocus genetic maps to be constructed.

scholarly journals Biochemical characterization of specific Alanine Decarboxylase (AlaDC) and its ancestral enzyme Serine Decarboxylase (SDC) in tea plants (Camellia sinensis)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Peixian Bai ◽  
Liyuan Wang ◽  
Kang Wei ◽  
Li Ruan ◽  
Liyun Wu ◽  
...  
Keyword(s):  
Gene Duplication ◽  
Camellia Sinensis ◽  
Biochemical Characterization ◽  
Specific Activity ◽  
Protein Sequences ◽  
Biochemical Properties ◽  
High Similarity ◽  
New Gene ◽  
Tea Plants

Abstract Background Alanine decarboxylase (AlaDC), specifically present in tea plants, is crucial for theanine biosynthesis. Serine decarboxylase (SDC), found in many plants, is a protein most closely related to AlaDC. To investigate whether the new gene AlaDC originate from gene SDC and to determine the biochemical properties of the two proteins from Camellia sinensis, the sequences of CsAlaDC and CsSDC were analyzed and the two proteins were over-expressed, purified, and characterized. Results The results showed that exon-intron structures of AlaDC and SDC were quite similar and the protein sequences, encoded by the two genes, shared a high similarity of 85.1%, revealing that new gene AlaDC originated from SDC by gene duplication. CsAlaDC and CsSDC catalyzed the decarboxylation of alanine and serine, respectively. CsAlaDC and CsSDC exhibited the optimal activities at 45 °C (pH 8.0) and 40 °C (pH 7.0), respectively. CsAlaDC was stable under 30 °C (pH 7.0) and CsSDC was stable under 40 °C (pH 6.0–8.0). The activities of the two enzymes were greatly enhanced by the presence of pyridoxal-5′-phosphate. The specific activity of CsSDC (30,488 IU/mg) was 8.8-fold higher than that of CsAlaDC (3467 IU/mg). Conclusions Comparing to CsAlaDC, its ancestral enzyme CsSDC exhibited a higher specific activity and a better thermal and pH stability, indicating that CsSDC acquired the optimized function after a longer evolutionary period. The biochemical properties of CsAlaDC might offer reference for theanine industrial production.

scholarly journals Real-Time Challenging of ERα Y537S Mutant Transcriptional Activity in Living Cells

Endocrines ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 54-64
Author(s):  
Manuela Cipolletti ◽  
Sara Pescatori ◽  
Filippo Acconcia
Keyword(s):  
Cell Line ◽  
Transcriptional Activity ◽  
Estrogen Receptor Α ◽  
Living Cells ◽  
Patient Treatment ◽  
Estrogen Responsive Element ◽  
Specific Proteins ◽  
Responsive Element ◽  
Mcf 7

Metastatic estrogen receptor α (ERα)-expressing breast cancer (BC) occurs after prolonged patient treatment with endocrine therapy (ET) (e.g., aromatase inhibitors—AI; 4OH-tamoxifen—4OH-Tam). Often these metastatic BCs express a mutated ERα variant (e.g., Y537S), which is transcriptionally hyperactive, sustains uncontrolled proliferation, and renders tumor cells insensitive to ET drugs. Therefore, new molecules blocking hyperactive Y537S ERα mutation transcriptional activity are requested. Here we generated an MCF-7 cell line expressing the Y537S ERα mutation stably expressing an estrogen-responsive element (ERE) promoter, which activity can be monitored in living cells. Characterization of this cell line shows both hyperactive basal transcriptional activity with respect to normal MCF-7 cells, which stably express the same ERE-based promoter and a decreased effect of selective ER downregulators (SERDs) in reducing Y537S ERα mutant transcriptional activity with respect to wild type ERα transcriptional activity. Kinetic profiles of Y537S ERα mutant-based transcription produced by both drugs inducing receptor degradation and siRNA-mediated depletion of specific proteins (e.g., FOXA1 and caveolin1) reveals biphasic dynamics of the inhibition of the receptor-regulated transcriptional effects. Overall, we report a new model where to study the behavior of the Y537S ERα mutant that can be used for the identification of new targets and pathways regulating the Y537S ERα transcriptional activity.

scholarly journals Quantitative Characterization of Geotrichum candidum Growth in Milk

2021 ◽  
Vol 11 (10) ◽  
pp. 4619
Author(s):  
Petra Šipošová ◽  
Martina Koňuchová ◽  
Ľubomír Valík ◽  
Monika Trebichavská ◽  
Alžbeta Medveďová
Keyword(s):  
Growth Parameters ◽  
Mechanistic Model ◽  
Geotrichum Candidum ◽  
Activity Level ◽  
Effect Of Temperature ◽  
Operational Parameters ◽  
Quantitative Characterization ◽  
Essential Knowledge ◽  
Cardinal Temperatures

The study of microbial growth in relation to food environments provides essential knowledge for food quality control. With respect to its significance in the dairy industry, the growth of Geotrichum candidum isolate J in milk without and with 1% NaCl was investigated under isothermal conditions ranging from 6 to 37 °C. The mechanistic model by Baranyi and Roberts was used to fit the fungal counts over time and to estimate the growth parameters of the isolate. The effect of temperature on the growth of G. candidum in milk was modelled with the cardinal models, and the cardinal temperatures were calculated as Tmin = −3.8–0.0 °C, Topt = 28.0–34.6 °C, and Tmax = 35.2–37.2 °C. The growth of G. candidum J was slightly faster in milk with 1% NaCl and in temperature regions under 21 °C. However, in a temperature range that was close to the optimum, its growth was slightly inhibited by the lowered water activity level. The present study provides useful cultivation data for understanding the behaviour of G. candidum in milk and can serve as an effective tool for assessing the risk of fungal spoilage, predicting the shelf life of dairy products, or assessing the optimal conditions for its growth in relation to the operational parameters in dairy practices.

scholarly journals Postnatal development and testosterone dependence of a rat epididymal protein identified by neonatal tolerization

Reproduction ◽  
2003 ◽  
pp. 495-507 ◽  
Author(s):  
SA Joshi ◽  
S Shaikh ◽  
S Ranpura ◽  
VV Khole
Keyword(s):  
Western Blot ◽  
Postnatal Development ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Polyclonal Antiserum ◽  
Cognate Gene ◽  
Specific Proteins ◽  
Androgen Regulation ◽  
Dose Dependent

A rat epididymal protein of 27 kDa was identified using neonatal tolerization. This study reports the production and characterization of a polyclonal antiserum to this protein. ELISA was used to demonstrate that this antiserum reacts strongly with epididymal sperm proteins, but has little or no reactivity with testicular proteins. Western blot analysis revealed that this polyclonal antiserum recognized a 27 kDa protein extracted from the corpus epididymidis as well as from spermatozoa from the corpus and cauda epididymides, and immunostaining revealed the presence of the protein in the corpus to cauda epididymides. Stronger reactivity was observed in the supranuclear region and stereocilla of principal cells of the corpus epididymidis and in the luminal content of the corpus and cauda epididymides. The testicular section showed no reactivity. Treatment with the antiserum resulted in time- and dose-dependent agglutination of rat spermatozoa. By indirect immunofluorescence, the antiserum localized proteins in the mid-piece region of rat spermatozoa. Studies were carried out to determine the age at which the protein first became apparent during postnatal development. The protein was expressed from day 40 onwards, as demonstrated by western blot analysis. The androgen regulation of this protein was ascertained by castration and supplementation studies. Expression of this protein showed a decline starting at day 14 after castration and by day 21 the protein was absent; however, androgen replacement resulted in the reappearance of the protein. The results of these studies indicate that the protein identified is specific to the epididymis, and is regulated by development and androgens. The importance of epididymis-specific proteins that are regulated by androgens in sperm maturation is discussed, and the need to ascertain the sequence of the protein and clone the cognate gene is indicated.

Cytogenetic analyses of intergeneric hybrids between barley and nine species of Elymus

Genome ◽  
2008 ◽  
Vol 51 (11) ◽  
pp. 897-904 ◽  
Author(s):  
N.-S. Kim ◽  
G. Fedak ◽  
F. Han ◽  
W. Cao
Keyword(s):  
Wild Species ◽  
Meiotic Chromosome ◽  
Abiotic Stress Tolerance ◽  
Chromosome Analysis ◽  
Intergeneric Hybrids ◽  
Biotic And Abiotic Stress ◽  
Crop Species ◽  
Barley Cultivars ◽  
Bivalent Formation ◽  
Gish Analysis

Wild species in the Triticeae tribe are very valuable resources for agronomic improvement in cereal crop species. Intergeneric hybrids were produced between several barley cultivars and perennial species in the genera Elymus , Thinopyrum , and Pseudoroegneria . Caryopsis formation and subsequent plantlet regeneration from embryo culture were variable depending on the hybrid combinations. Chromosome numbers and hybrid identity were confirmed by GISH analysis on the somatic cells of the hybrids. While the hybrids showed very robust vegetative growth and exceeded the parental spikes in size, their floral morphologies resembled that of the wild species. Meiotic chromosome analysis revealed that the bivalent formation frequency per cell ranged from 0.06 in Hordeum vulgare ‘Betzes’ × Elymus curvatus to 3.0 in Elymus humidus  × H. vulgare ‘Manley’. By GISH analysis on the meiocytes of the hybrid E. humidus × ‘Manley’, the frequency of autosyndetic bivalents exceeded the allosyndetic bivalent formation, which gave an insight into the genome constitution of E. humidus as an autoallohexploid species. Regardless of the low allosyndetic chromosome pairing between barley and E. humidus, this combination may be useful for further input, since E. humidus is known to carry many valuable genes for biotic and abiotic stress tolerance.

Systematic discovery and characterization of stress-related microRNA genes in Oryza sativa

Biologia ◽  
2015 ◽  
Vol 70 (1) ◽  
Author(s):  
Kai Bin Xie ◽  
Xue Zhou ◽  
Tian Hai Zhang ◽  
Bao Long Zhang ◽  
Li Ming Chen ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Responses ◽  
Systematic Investigation ◽  
Chemical Toxicity ◽  
Promoter Regions ◽  
Crop Species ◽  
Translation Inhibition ◽  
Microrna Genes ◽  
Insight Into

AbstractAbiotic stresses including drought, salinity, extreme temperatures, chemical toxicity and oxidative are the natural status of the environment to exert serious threats to agriculture. Abiotic stress-related microRNAs (ASmiRNAs) are a group of microRNAs (miRNAs) regulating stress responses in plants. However, the systematic investigation of ASmiRNAs is limited in Rice (O. sativa), a typical abiotic stress-resistant crop species. In the present work, we systematically investigated ASmiRNAs in silico. First, we identified 177 putative ASmiRNAs in O.sativa. Second, we found most ASmiRNAs were driven by TATA-promoter and most stress-related miRNA promoter regions contained the stress-related elements. Third, we found many ASmiRNAs families were species/family specific and a set of miRNAs might derive from genomic repeat-sequences in O. sativa. Finally, we found the ASmiRNAs in O. sativa target 289 genes with 1050 predicted target sites in which 98% sites have cleavage activity and 2% sites have translation inhibition activity. In conclusion, our findings provide an insight into both the function and evolution of ASmiRNAs and improve our understanding on the mechanism of abiotic stress resistance in O. sativa.

Characterization of Spi-B, a transcription factor related to the putative oncoprotein Spi-1/PU.1

1992 ◽  
Vol 12 (10) ◽  
pp. 4297-4304 ◽  
Author(s):  
D Ray ◽  
R Bosselut ◽  
J Ghysdael ◽  
M G Mattei ◽  
A Tavitian ◽  
...  
Keyword(s):  
Dna Binding ◽  
Cell Lines ◽  
Binding Domain ◽  
Dna Binding Domain ◽  
New Gene ◽  
Carboxy Terminal Region ◽  
Carboxy Terminal ◽  
Hematopoietic Cell Lines

We have cloned a human cDNA from a new gene, spi-B, on the basis of its homology with the DNA-binding domain of the Spi-1/PU.1 putative oncogene product. spi-B codes for a protein of 262 amino acids presenting 43% overall identity with Spi-1. Its highly basic carboxy-terminal region exhibits 34% sequence identity with the DNA-binding domain of the Ets-1 protein. We showed that the Spi-B protein is able to bind the purine-rich sequence (PU box) recognized by Spi-1/PU.1 and to activate transcription of a reporter plasmid containing PU boxes. Chromosome in situ hybridization allowed us to map spi-B to the 19q13.3-19q13.4 region of the human genome. spi-B, like spi-1, was found to be expressed in various murine and human hematopoietic cell lines except T lymphoid cell lines.

Biological and Molecular Characterization of a Crucifer Tobamovirus Infecting Oilseed Rape

2009 ◽  
Vol 47 (7-8) ◽  
pp. 451-461 ◽  
Author(s):  
Li Cai ◽  
Kunrong Chen ◽  
Xuejiang Zhang ◽  
Liying Yan ◽  
Mingsheng Hou ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Oilseed Rape

Vernalization response in spring oilseed rape (Brassica napus L.) cultivars

1994 ◽  
Vol 74 (2) ◽  
pp. 275-277 ◽  
Author(s):  
L. A. Murphy ◽  
R. Scarth
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Vernalization Response ◽  
Brassica Napus L ◽  
Early Maturity ◽  
Breeding Programs ◽  
Cumulative Response ◽  
Cold Requirement ◽  
Key Words:Brassica

Early maturity is a major objective of oilseed rape (Brassica napus L.) breeding programs in western Canada. Maturity of crops is influenced by time of initiation and flowering. The presence of a vernalization requirement affects plant development by delaying floral initiation until the cold requirement of the plant has been satisfied. Five spring oilseed rape cultivars were screened for their response to vernalization. Vernalization treatments consisted of exposure of germinated seeds to 0–42 d at 4 °C. Plants were assessed under a 20-h photoperiod. In general, there was a cumulative response to vernalization, with a decrease in days to each developmental stage as exposure to 4 °C was increased. Vernalization treatment of 6 d at 4 °C was sufficient to decrease both the days to first flower and the final leaf number. The characterization of vernalization response is of interest because variation in flowering time in response to year-to-year variations in the environment could result. Key words:Brassica napus, canola, oilseed rape, vernalization

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