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result(s) for
"Cross-breeding"
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The Case for the Entourage Effect and Conventional Breeding of Clinical Cannabis: No “Strain,” No Gain
2019
The topic of Cannabis curries controversy in every sphere of influence, whether politics, pharmacology, applied therapeutics or even botanical taxonomy. Debate as to the speciation of Cannabis, or a lack thereof, has swirled for more than 250 years. Because all Cannabis types are eminently capable of cross-breeding to produce fertile progeny, it is unlikely that any clear winner will emerge between the \"lumpers\" vs. \"splitters\" in this taxonomical debate. This is compounded by the profusion of Cannabis varieties available through the black market and even the developing legal market. While labeled \"strains\" in common parlance, this term is acceptable with respect to bacteria and viruses, but not among Plantae. Given that such factors as plant height and leaflet width do not distinguish one Cannabis plant from another and similar difficulties in defining terms in Cannabis, the only reasonable solution is to characterize them by their biochemical/pharmacological characteristics. Thus, it is best to refer to Cannabis types as chemical varieties, or \"chemovars.\" The current wave of excitement in Cannabis commerce has translated into a flurry of research on alternative sources, particularly yeasts, and complex systems for laboratory production have emerged, but these presuppose that single compounds are a desirable goal. Rather, the case for Cannabis synergy via the \"entourage effect\" is currently sufficiently strong as to suggest that one molecule is unlikely to match the therapeutic and even industrial potential of Cannabis itself as a phytochemical factory. The astounding plasticity of the Cannabis genome additionally obviates the need for genetic modification techniques.
Journal Article
Histone methyltransferase Suv39h1 regulates hepatic stellate cell activation and is targetable in liver fibrosis
2024
ObjectiveLiver fibrosis is a prelude to a host of end-stage liver diseases. Hepatic stellate cells (HSCs), switching from a quiescent state to myofibroblasts, are the major source for excessive production of extracellular matrix proteins. In the present study, we investigated the role of Suv39h1, a lysine methyltransferase, in HSC-myofibroblast transition and the implication in liver fibrosis.DesignHSC-specific or myofibroblast-specific Suv39h1 deletion was achieved by crossbreeding the Suv39h1 f/f mice to the Lrat-Cre mice or the Postn-CreERT2 mice. Liver fibrosis was induced by CCl4 injection or bile duct ligation.ResultsWe report that Suv39h1 expression was universally upregulated during HSC-myofibroblast transition in different cell and animal models of liver fibrosis and in human cirrhotic liver tissues. Consistently, Suv39h1 knockdown blocked HSC-myofibroblast transition in vitro. HSC-specific or myofibroblast-specific deletion of Suv39h1 ameliorated liver fibrosis in mice. More importantly, Suv39h1 inhibition by a small-molecule compound chaetocin dampened HSC-myofibroblast transition in cell culture and mitigated liver fibrosis in mice. Mechanistically, Suv39h1 bound to the promoter of heme oxygenase 1 (HMOX1) and repressed HMOX1 transcription. HMOX1 depletion blunted the effects of Suv39h1 inhibition on HSC-myofibroblast transition in vitro and liver fibrosis in vivo. Transcriptomic analysis revealed that HMOX1 might contribute to HSC-myofibroblast transition by modulating retinol homeostasis. Finally, myofibroblast-specific HMOX1 overexpression attenuated liver fibrosis in both a preventive scheme and a therapeutic scheme.ConclusionsOur data demonstrate a previously unrecognised role for Suv39h1 in liver fibrosis and offer proof-of-concept of its targetability in the intervention of cirrhosis.
Journal Article
Mining, screening, and validation of cold-resistance molecular markers in Vitis vinifera L
2024
To address one of the main challenges restricting the development of global viticulture, it is imperative to breed high-quality and cold-resistant grape varieties. In this study, intraspecific cross-breeding was carried out between two cold resistance and four high-quality varieties for eight populations, including six reciprocal crosses and two crossing combinations. The cold-resistance of six hybrid parents and 481 hybrid F1 progeny was determined by differential thermal analysis, and the cold-resistance grade and frequency distribution were analyzed from the 14 crossing combinations. Bioinformatics and statistical methods were used to mine and design SSR marker primers for 40 cold-resistance related genes. Agarose gel electrophoresis and cold-resistance measurement were used to screen molecular markers of the tested materials. The results showed that varying cold resistance for different populations, with a continuous distribution of cold resistance of intraspecific hybrid progenies of different crossing combinations. The screening and verification of molecular markers revealed that OMT2.1-211, SIRT276, UBC317-800, S238-854, and S241-717 can be used as standard markers to determine cold-resistance of intraspecific hybrid progenies of Ecolly or Meili and Marselan, and P5CS173, P5CS240, and SIRT276 could be used to rapidly screen intraspecific hybrid progenies of Ecolly or Meili and Cabernet Sauvignon. Intraspecific cross-breeding of V. vinifera can be applied to breed suitable intermediate materials or new cold-resistant materials. This work also provides a reference method for the development of SSR molecular markers to target specific genes of interest.
Journal Article
Overexpression of ferroptosis defense enzyme Gpx4 retards motor neuron disease of SOD1G93A mice
by
Danae McLane, Kirsten
,
Na, Ren
,
Gao, Ju
in
631/378/1689
,
631/80/82
,
Amyotrophic lateral sclerosis
2021
Degeneration and death of motor neurons in Amyotrophic Lateral Sclerosis (ALS) are associated with increased lipid peroxidation. Lipid peroxidation is the driver of ferroptosis, an iron-dependent oxidative mode of cell death. However, the importance of ferroptosis in motor neuron degeneration of ALS remains unclear. Glutathione peroxidase 4 (Gpx4) is a key enzyme in suppressing ferroptosis by reducing phospholipid hydroperoxides in membranes. To assess the effect of increased protection against ferroptosis on motor neuron disease, we generated SOD1
G93A
GPX4 double transgenic mice by cross-breeding GPX4 transgenic mice with SOD1
G93A
mice, a widely used ALS mouse model. Compared with control SOD1
G93A
mice, both male and female SOD1
G93A
GPX4 mice had extended lifespans. SOD1
G93A
GPX4 mice also showed delayed disease onset and increased motor function, which were correlated with ameliorated spinal motor neuron degeneration and reduced lipid peroxidation. Moreover, cell toxicity induced by SOD1
G93A
was ameliorated by Gpx4 overexpression and by chemical inhibitors of ferroptosis in vitro. We further found that the anti-ferroptosis defense system in spinal cord tissues of symptomatic SOD1
G93A
mice and sporadic ALS patients might be compromised due to deficiency of Gpx4. Thus, our results suggest that ferroptosis plays a key role in motor neuron degeneration of ALS.
Journal Article
A review on crop improvement strategies and breeding methods in ornamental annuals
by
Rajesh, S
,
Venkatesan, K
,
Beaulah, A
in
Breeding methods
,
breeding strategies
,
Crop improvement
2025
The availability of a broad variety of cultivars in many ornamental species has increased recently, in particular for attractive annuals, which are valued commercially for their use as cut flowers, potted plants, loose flowers, and in landscape gardening. The breeding of ornamental plants in the current scenario is a challenging endeavour with constantly evolving new obstacles. Modern genomic technologies provide prospects for improved precision breeding and selection for characteristics that are more difficult to determine. Traditionally, ornamental breeding has been focused on increasing resistance to biotic or abiotic stress, novelty, yield, and quality. However, accomplishing these objectives necessitates tedious cross-breeding, and exact breeding methods have been noticed to be not applied constantly. Though the purposes of ornamental crop breeding may vary, the process generally does not differ from the breeding of other crops. Furthermore, vegetatively propagated ornamentals constitute most of the crops. The expanding interest in ornamental crops that are produced by modern crop breeding methods such as genome editing, chromosome manipulation, molecular marker-assisted breeding, mutation breeding, and exploiting somaclonal variations, particularly in relation to altering desirable plant features and producing new ornamental traits of the crops which is the main objective of crop improvement practices. Hence, it has become obligatory to evaluate the current state of any technology created following an in-depth study carried out by several research organisations.
Journal Article
Screening diverse soybean genotypes for drought tolerance by membership function value based on multiple traits and drought-tolerant coefficient of yield
2020
Background
Drought is a major limiting factor seriously influencing worldwide soybean production and its impact on yield, morphological and physiological traits depend on the timing it occurs and the intensity of water shortage. Only limited research has however been conducted on identifying the drought-tolerant genotypes at different growth stages (vegetative growth phase, reproductive growth phase and the whole growth phase) as well as evaluate the effectiveness and reliability of multiple phenotypic and yield-related characteristics in soybean.
Results
Two pot experiments and a 2-year field experiment were conducted to evaluate soybean drought tolerance at different growth stages. The membership function value of drought tolerance (MFVD) was used to identify drought-resistant cultivars during vegetative growth phase and reproductive growth stage; the relative drought index (RDI) of yield was used to assess drought-resistant cultivars during the whole growing period. In this study, regression models built based on MFVD indicated that the variation of drought tolerant coefficient (DC) of R/S, TRL, LAI and RSR could explain 73.70% of the total variation at vegetative growth phase. However, higher heritability only found in LAI and RSR, indicating the two traits could serve as reliable criteria for drought evaluation. Similarly, the DC of SPP, YPP, PH, PB, MSNN and STB could explain 94.30% of the total variation in MFVD according to stepwise multiple linear regression analyses at reproductive growth phase. Thus, these six traits were identified as indicators for screening drought resistance genotypes in soybean. In addition, correlation analysis revealed that the MFVD was significantly positively correlated with the DC
RB
, DC
R/S
, DC
RSA
, DC
RSR
and DC
RBR
at vegetative growth phase and DC
YPP
, DC
SPP
, DC
RB,
and DC
PB
at reproductive growth phase. This indicated that these traits were closely related to the drought resistance of plants.
Conclusions
LD24, JD36 and TF31 of vegetative growth phase, and TD37 and LD26 of reproductive growth phase were identified with drought tolerant and highly drought tolerant, respectively. Moreover, 30 accessions with drought tolerance were screened in the field trial and could be applied for the drought resistance of other genotypes by cross-breeding.
Journal Article
Principle and application of plant mutagenesis in crop improvement: a review
2016
The first step in plant breeding is to identify suitable genotypes containing the desired genes among existing varieties, or to create one if it is not found in nature. In nature, variation occurs mainly as a result of mutations and without it, plant breeding would be impossible. In this context, the major aim in mutation-based breeding is to develop and improve well-adapted plant varieties by modifying one or two major traits to increase their productivity or quality. Both physical and chemical mutagenesis is used in inducing mutations in seeds and other planting materials. Then, selection for agronomic traits is done in the first generation, whereby most mutant lines may be discarded. The agronomic traits are confirmed in the second and third generations through evident phenotypic stability, while other evaluations are carried out in the subsequent generations. Finally, only the mutant lines with desirable traits are selected as a new variety or as a parent line for cross breeding. New varieties derived by induced mutatgenesis are used worldwide: rice in Vietnam, Thailand, China and the United States; durum wheat in Italy and Bulgaria; barley in Peru and European nations; soybean in Vietnam and China; wheat in China; as well as leguminous food crops in Pakistan and India. This paper integrates available data about the impact of mutation breeding-derived crop varieties around the world and highlights the potential of mutation breeding as a flexible and practicable approach applicable to any crop provided that appropriate objectives and selection methods are used.
Journal Article
Development of Commercial Thermo-sensitive Genic Male Sterile Rice Accelerates Hybrid Rice Breeding Using the CRISPR/Cas9-mediated TMS5 Editing System
2016
Hybrid rice breeding offers an important strategy to improve rice production, in which the cultivation of a male sterile line is the key to the success of cross-breeding. CRISPR/Cas9 systems have been widely used in target-site genome editing, whereas their application for crop genetic improvement has been rarely reported. Here, using the CRISPR/Cas9 system, we induced specific mutations in
TMS5
, which is the most widely applied thermo-sensitive genic male sterility (TGMS) gene in China, and developed new “transgene clean” TGMS lines. We designed 10 target sites in the coding region of
TMS5
for targeted mutagenesis using the CRISPR/Cas9 system and assessed the potential rates of on- and off-target effects. Finally, we established the most efficient construct, the TMS5ab construct, for breeding potentially applicable “transgene clean” TGMS lines. We also discussed factors that affect the editing efficiency according to the characteristics of different target sequences. Notably, using the TMS5ab construct, we developed 11 new “transgene clean” TGMS lines with potential applications in hybrid breeding within only one year in both rice subspecies. The application of our system not only significantly accelerates the breeding of sterile lines but also facilitates the exploitation of heterosis.
Journal Article
Population structure and phylogeography of three closely related tree peonies
2023
Paeonia decomposita, Paeonia rotundiloba, and Paeonia rockii are three closely related species of Sect. Moutan is distributed in the montane area of the Eastern Hengduan Mountain region. Understanding the population history of these three tree peony species could contribute to unraveling the evolutionary patterns of undergrowth species in this hotspot area. We used one nuclear DNA marker (internal transcribed spacer region, ITS) and two chloroplast DNA markers (matK, ycf1) to reconstruct the phylogeographic pattern of the populations. In total, 228 individuals from 17 populations of the three species were analyzed in this study. Three nuclear clades (Clade I – Clade III) and four maternal clades (Clade A – Clade D) were reconstructed. Molecular dating suggested that young lineages diverged during the late Pliocene and early Pleistocene, younger than the uplift of the Hengduan Mountains but older than the last glacial maximum (LGM). Significant population and phylogeographic structures were detected at both markers. Furthermore, the populations of these tree peonies were overall at equilibrium during the climatic oscillations of the Pleistocene. The simulated palaeoranges of the three species during the LGM period mostly overlapped, which could have led to cross‐breeding events. We propose an evolutionary scenario in which mountain orogenesis around the Hengduan Mountain area triggered parapatric isolation between maternal lineages of tree peonies. Subsequent climatic fluctuations drove migration and range recontact of these populations along the valleys. This detailed evolutionary history provides new insights into the phylogeographic pattern of species from mountain‐valley systems. Location of populations sampled (a); Geographic distribution of the chloroplast (cp) DNA haplotypes (population codes and chlorotype node refer to Table S1), the solid black lines represent three groups according to SAMOVA analysis, and the dotted lines display six groups (b); Maximum parsimony network based on chlorotypes (c). The size of the pie is a positive correlation with the frequency of each haplotype and black dots represent haplotypes that are missing, extinct, or not observed.
Journal Article