- Backcross breeding is used to transfer one or few genes from a donor plant to an elite cultivar, while recovering the genome of the elite cultivar. It involves repeated crossing of an F1 hybrid to one of the parental lines.
- Six backcrosses are typically required using conventional methods to recover 99.2% of the elite cultivar's genome. Marker assisted selection can reduce the number of backcrosses needed.
- During backcrossing, recombination and crossing over occurs, resulting in gametes with different combinations of parental genomes. Marker assisted selection uses co-dominant markers to identify plants in early backcross generations with higher percentages of the elite cultivar's genome recovered. This allows for more
Marker assisted selection( mas) and its application in plant breedingHemantkumar Sonawane
Marker Types,Prerequisites for efficient marker-assisted breeding programmes,Advantages of MAS,Limitations of MAS ,Marker Assisted Breeding Schemes,• 1. Marker- assisted backcrossing,2. Marker- Assisted evaluation of breeding material,3 Gene pyramiding,4. Early generation selection ,Combined approaches,MAB: I level of Selection – FOREGROUND SELECTION,Second level of selection: Recombinant Selection,MAB: III Level of Selection BACKGROUND SELECTION,
Marker assisted selection( mas) and its application in plant breedingHemantkumar Sonawane
Marker Types,Prerequisites for efficient marker-assisted breeding programmes,Advantages of MAS,Limitations of MAS ,Marker Assisted Breeding Schemes,• 1. Marker- assisted backcrossing,2. Marker- Assisted evaluation of breeding material,3 Gene pyramiding,4. Early generation selection ,Combined approaches,MAB: I level of Selection – FOREGROUND SELECTION,Second level of selection: Recombinant Selection,MAB: III Level of Selection BACKGROUND SELECTION,
Molecular Breeding in Plants is an introduction to the fundamental techniques...UNIVERSITI MALAYSIA SABAH
This slide describe the process of molecular breeding in plants which involves the application of molecular markers for Marker Assisted Selection and Marker Assisted Breeding.
Rice breeding is both challenged and benefited by the fact that a successful varietal improvement program must embrace both the integration single genes that segregate in a simple Mendelian fashion as well as complex traits that are inherited in more quantitative ways. For decades the rice genetics community has produced a wealth of knowledge about these single genes and has developed markers that allow a breeder to track them in a population. However, marker assisted selection (MAS) alone is insufficient to drive the rates of genetic gain for more complex traits that are equally necessary. This presentation will describe the attempts made in the Favorable Environments Breeding program at IRRI to integrate the selection for single genes appropriate for MAS into a more complex population improvement strategy designed to improve quantitatively inherited traits.
Within the last twenty years, molecular biology has revolutionized conventional breeding techniques in all areas. Biochemical and Molecular techniques have shortened the duration of breeding programs from years to months, weeks, or eliminated the need for them all together. The use of molecular markers in conventional breeding techniques has also improved the accuracy of crosses and allowed breeders to produce strains with combined traits that were impossible before the advent of DNA technology
Molecular Breeding in Plants is an introduction to the fundamental techniques...UNIVERSITI MALAYSIA SABAH
This slide describe the process of molecular breeding in plants which involves the application of molecular markers for Marker Assisted Selection and Marker Assisted Breeding.
Rice breeding is both challenged and benefited by the fact that a successful varietal improvement program must embrace both the integration single genes that segregate in a simple Mendelian fashion as well as complex traits that are inherited in more quantitative ways. For decades the rice genetics community has produced a wealth of knowledge about these single genes and has developed markers that allow a breeder to track them in a population. However, marker assisted selection (MAS) alone is insufficient to drive the rates of genetic gain for more complex traits that are equally necessary. This presentation will describe the attempts made in the Favorable Environments Breeding program at IRRI to integrate the selection for single genes appropriate for MAS into a more complex population improvement strategy designed to improve quantitatively inherited traits.
Within the last twenty years, molecular biology has revolutionized conventional breeding techniques in all areas. Biochemical and Molecular techniques have shortened the duration of breeding programs from years to months, weeks, or eliminated the need for them all together. The use of molecular markers in conventional breeding techniques has also improved the accuracy of crosses and allowed breeders to produce strains with combined traits that were impossible before the advent of DNA technology
Introduction
Backcross breeding & its types
Marker assisted breeding
Marker assisted backcross breeding (MABC)
Main strategies
Advantages over conventional breeding
Case studies
Future outlook
Conclusion
Process whereby a marker is used for indirect selection of a genetic determinant or determinants of a trait of interest (i.e. productivity, disease resistance, abiotic stress tolerance, and/or quality).
Trait of interest is selected not based on the trait itself but on a marker linked to it.
The assumption is that linked allele associates with the gene and/or quantitative trait locus (QTL) of interest. MAS can be useful for traits that are difficult to measure, exhibit low heritability, and/or are expressed late in development.
Pre-Requisites: Two pre-requisites for marker assisted selection are: (i) a tight linkage between molecular marker and gene of interest, and (ii) high heritability of the gene of interest.
Markers Used: The most commonly used molecular markers include amplified fragment length polymorphisms (AFLP), restriction fragment length polymorphisms (RFLP), random amplified polymorphic DNA (RAPD), simple sequence repeats (SSR) or micro satellites, single nucleotide polymorphisms (SNP), etc. The use of molecular markers differs from species to species also.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
What is greenhouse gasses and how many gasses are there to affect the Earth.
Basics of marker assisted background selection
1. Backcross Breeding
• Also referred as line conversion or Varietal enhancement
• Repeated crossing of F1 progeny to its one of the parent
• To transfer one or few genes (even OTLs) from a donor to an
elite cultivar (Recurrent parent)
• Repeated backcrossing is done to recover complete genome
of the recurrent parent in addition to the target gene
Example: Introgression of transgenes from a transgenic
plant into elite varieties or Parents of hybrids
Breeder Blogs
2. Breeder Blogs
Markers are used for the
early recovery of the
Recurrent plant genome in
BC1 and BC2 generations
3. Back cross
generations
% of RPG
recovered
after each
backcross
BC1 75.0%
BC2 87.5%
BC3 93.8%
BC4 96.9%
BC5 98.4%
BC6 99.2%
Recovery of the recurrent parent genome (RPG) is important to retain the
originality of the parent in addition to the target trait
Six backcrosses are required to get
99.2% of recurrent parent genome
(RPG) through conventional method
A formula for the calculation of RP genome
recovered after each backcross
Breeder Blogs
4. Marker assisted backcross (MABC) reduces the number of backcrosses
required for the recovery of RP genome. To understand the genetics behind
the early recovery of RPG through MABC, the basics of genes and markers are
important
Genes and markers are segments of DNA on chromosomes. A gene has a known function but unknown
location. A marker has a known location on chromosome, but no apparentfunction. If the location of
the gene is known, that gene can be used as marker
Breeder Blogs
5. Gene 1
Gene 1
Centimorgans(CM)
Kilometers(KM)
Markers and genes on
chromosome are analogue
to road map with cities and
towns. If the genes are
considered as the two major
cities here, the towns in
between them are markers.
The exact distance between
them is known in both maps.
Distance on chromosomes
are measured in Centi
morgans units as like
Kilometres in a road map
Kilomaters(KM)
Analogue of Chromosomes and road map
Breeder Blogs
6. Monomorphic markers.
Present on chromosomes of
both the parents. This
markers cannot be used for
differentiating the parents
Genes shows allelic variations and express different phenotypes. Markers
too has allelic variations, that can be detected using PCR or other methods.
The different types of markers are given below
Polymorphic dominant
markers. Present either one
of the parent. Differentiates
the parents. But cannot be
used for differentiating the
heterozygous state
Polymorphic Co dominant
markers. Present on both
parents but differs in DNA
sequence and size. This class
of markers can differentiate
both the parents and
heterozygous state
Chromosome of Recurrent Chromosome of Donor
Breeder Blogs
7. Marker assisted backcross programme requires large number of Polymorphic co-dominant
markers distributed evenly throughout all the chromosomes.
(If polymorphic dominant markers are used, markers should be selected for both donor and
recurrent parent chromosomes)
Chromosomeof Recurrent Chromosomeof Donor
Polymorphicmarkers
Breeder Blogs
8. The pollination & fertilization process involves fusion of pollen and ovule.
During the gametes formation, two important process takes place
1. Reduction of chromosome number to half in gametes
Each gametes represents only 50% of the parental
genome
2. Recombination and crossing over occurs between
homologous chromosomes of male and female, followed
by independent assortment of chromosome to gametes
In F1 or any segregating population, each gamete
acquires the different combination of parental
chromosomes
Breeder Blogs
9. Now consider what happens during the backcross process at chromosome level, by looking at
one chromosome. This illustrations are applicable to all chromosomes and the genotypic and
phenotypic expression is the collective of all chromosomes
Recurrent parent
100 % RP - TG
Target gene (TG)
Donorparent
0 % RP + TG
50 % RP - TG
Ovule
50 % RP + TG
Pollen
0 % RP + TG
F1 Progenies are Heterozygous and Homogenous
Crossing
Breeder Blogs
10. Recombination takes place in the F1 pollen mother cells (PMC),
generates cross over chromosomes in pollens
Mostly 50 % the chromosomes are
exchanged between homologous
chromosomes and the amount of
chromosomes exchanged also equal
between two chromosomes
Crossing over is not always 50%
between chromosomes. In rare instances
more proportions of chromosomes are
exchanged between homologous
chromosomes
This forms the basic for the
marker assisted selection
Breeder Blogs
11. 1. Pollens with target gene and 50% of each parental chromosomes
2. Pollens without target gene and 50% each parental chromosomes
3. Pollens with target gene and more proportion of either one parental chromosomes
4. Pollens without target gene and more proportion of either one parental chromosomes
F1 produces following kinds of pollens
This two kind of pollens are
predominant in the flowers
These pollens are
Limited in numbers
Breeder Blogs
12. Segregation of F1 gametes and the genotype of BC1F1 populations
Recurrent parent F1
0 % RP + TG
Crossing
25 % RP + TG
Ovule Pollens
100 % RP - TG
50 % RP - TG 25 % RP - TG ~10 % RP - TG ~40 % RP +TG
75 % RP + TG 75 % RP - TG ~60 % RP - TG ~90 % RP + TG
These types of gametes also produced though not
mentioned in pollen genotypes
~60 % RP + TG ~90% RP - TG
Breeder Blogs
BC1F1 generation
13. 75 % RP - TG ~60 % RP - TG ~90 % RP + TG ~60 % RP + TG ~90 % RP - TG
Selection in BC1F1 populations (Foreground selection) for target gene
Foreground selection of target gene (TG) eliminates 50% of the plants without target gene
75 % RP + TG
75 % RP + TG~60 % RP + TG ~90 % RP + TG
Selected BC1F1 plants will be screened for Recurrent plan type characters (Background selection)
Phenotypically
distinguishable
Cannot be differentiated phenotypically.
Breeder Blogs
14. 75 % RP + TG~60 % RP + TG ~90 % RP + TG
Population distribution of BC1F1 population
50% RP 100% RP
The mean of the BC1F1 population is 75% of RPG. Though high RPG plants appears in the
population, selecting high RP plants by phenotypic selection is difficult. This leads to the
selection of 75% RP plants through conventional method, due to the fact that 75% plants
represent the more proportion in the population
No.ofPlants
% of RP Genome
Breeder Blogs
15. Genotyping of the of BC1F1 population with polymorphic Co-dominant markers
Will differentiate plants with different % RPG
The parallel lines indicates the position of the markers on the chromosomes. The co-dominant markers
identifies the male and female portions of chromosomes even at heterozygous state
3 /10 markers
Homozygous for RPG
If 10 Co-Dominant markers/ chromosome were used for genotyping the BC1F1 Population, the
three types of genotypes can be differentiated by the following technique
5 /10 markers
Homozygous for RPG
8 /10 markers
Homozygous for RPG
Number of markers homozygous for RPG was calculated for all chromosomes. The plants with
more number of RPG homozygous markers were selected and advanced to BC2F1.
Breeder Blogs
16. Genotyping will be done at BC2F1 populations with same set of markers. Plants with
more RPG Homozygous markers will be advanced
Comparison of conventional phenotypic selection vs. Marker based genotypic
selection
Breeder Blogs