eChapters

Abstract

Sequence alignment is the positioning of DNA, RNA, or protein sequences with each other to identify the regions of identity, which may be the result of functional, structural, or evolutionary relationships between the sequences. Therefore, sequence alignment is the process of aligning two sequences to achieve the maximum levels of identity and conservation. This chapter deals with the basic concept of sequence alignment and the tools associated with multiple sequence alignment. Further, it describes various matrices used in sequence alignment.

MENDEL’S RULES OF GENETICS DO NOT ALWAYS WORK

Mendel’s rules:

Segregation of alleles

Independent assortment of genes for different characters

Hold for characters:

Which have dominant & recessive traits

Determined by single genes

Genes are on separate chromosomes

Different types of chromosomes, or

Different homologues of same type of chromosome

These conditions are not always met, so there are many complications

Abstract

Omics arise from ome which means complete or totality. It refers to the collection of technologies used to investigate the roles, relationships, and actions of the various types of molecules that make up an organism’s cells. Omics technologies provide the tools required to investigate differences in DNA, RNA, proteins, and other cellular molecules between species and individuals within a species. These technologies comprise, genomics, transcriptomics, proteomics, metabolomics, ionomics, glycomics, lipomics, cultureomics, pharmacogenomics, metagenomics, foodomics, eigenomics, phenomics, etc. The inclusion of all omics domain is known as multiomics. In this chapter we describe from basic, type structure of omics to all the recent cutting edge technologies in multiomics.

Chromosomes are giant molecules of DNA

Found in nucleus: never leave except in cell division

Carry hereditary units, genes

Two homologous copies in diplod cells

Unwind when replicating or making RNA

Wind up (condense) in cell division

Attach to spindle and separate in meiosis & mitosis

Crossing over in prophase of 1st meiotic division

Chromosomes are equally distributed in mitosis, meiosis

Gametes have half the number of chromosomes as body cells

Sister chromatids are observed to split apart longitudinally in anaphase

UNTIL THE 1940S BIOLOGISTS ARGUED ABOUT WHETHER DNA OR PROTEIN WAS THE MOLECULE OF HEREDITY

Nuclei observed to divide when cells reproduced themselves

Large amounts of both DNA & protein in the nucleus

Many though protein was most likely molecule of heredity

Proteins made of 20 different amino acids- could have more variety than DNA (made of only 4 different bases)

Principle

The principle is to extract plasmid DNA from bacterial cell suspensions and is based on the alkaline lysis procedure developed by Birnboim and Doly (Nucleic Acids Research 7:1513, 1979). It is a known fact that plasmids are much smaller super coiled DNA molecules than the much larger and less super coiled bacterial chromosomal DNA. This difference in topology enables selective precipitation of the chromosomal DNA and cellular proteins and separates them from plasmids and RNA molecules. The cells are lysed under alkaline conditions, which denature both nucleic acids and proteins, and when the solution is neutralized by the addition of Potassium Acetate, chromosomal DNA and proteins precipitate because it is impossible for them to renature correctly (they are so large). Plasmids renature correctly and stay in solution, effectively separating them from chromosomal DNA and proteins.

Partialy Balance Incomplete Block Design (PBIBD)
    
Interblock and Intrablock Information

Abstract

Drug design is a complex computational process that involves studying the structural and physicochemical properties of biological moieties in order to identify new chemical or biochemical substances that can be used as drugs with specific pharmacological properties. The drug discovery pipeline is a crucial aspect of drug design that requires a detailed understanding of the various phases involved. In this chapter, we discuss the fundamental principles and phases of drug design. Additionally, we delve into the concept of docking, a critical step in the drug discovery process that involves predicting the orientation and affinity of a ligand binding to a protein target. The use of computational tools and techniques in drug design has revolutionized the field and is essential for the development of safe and effective drugs.

Quantitative genetics is the study of continuous or quantitative traits and their underlying mechanisms. The main principals of quantitative genetics developed in the 20th century was largely in response to the rediscovery of Mendelian genetics. Mendelian genetics in 1900 centered attention on the inheritance of discrete characters, e.g., smooth vs. wrinkled peas, purple vs. white flowers. This focus was in stark contrast to the branch of genetic analysis by Sir Francis Galton in the 1870’s and 1880’s who focused on characteristics that were continuously variable and thus, not clearly separable into discrete classes. A contentious debate ensued between Mendelians and Biometricians regarding whether discrete characteristics have the same hereditary and evolutionary properties as continuously varying characteristics. I The Mendelians (led by William Bateson) believed that variation in discrete characters drove evolution through mutations with large effects I The Biometricians (led by Karl Pearson and W.F.R. Weldon) viewed evolution to be the result of natural selection acting on continuously distributed characteristics. This eventually led to a fusion of genetics and Charles Darwin’s theory of evolution by natural selection: main principals of quantitative genetics, developed independently by Ronald Fisher (1918) and Sewall Wright (1921), arguable the two most prominent evolutionary biologists.
Interestingly, Galton’s methodological approaches to continuously distributed traits marked the founding of the Biometrical school, which is what many consider to be the birth of modern statistics. Karl Pearson was inspired greatly by Galton, and he went on to develop a number of methods for the analysis of quantitative traits. We will talk more about Galton and Pearson later on in this course. One of the central goals of quantitative genetics is the quantification of the correspondence between phenotypic and genotypic values. It is well accepted that variation in quantitative traits can be attributable to many, possibly interacting, genes whose expression may be sensitive to the environment

Q.1.    What is split plot experiment ?

    Answer
    
    If one has to study two type of factors say A and B in the same experiment where A requires larger plot size and B requires smaller plot size then the structure of the experiment will be that of plots within blocks are known as split plots and blocks within replication are known as main (whole) plots. Such a layout of the experiment is known as split plot experiment.

Q.1.    Define strip plot design ?

    Answer
    
    There is a variant of the split plot design in which both factors A and B will be applied to the larger strips by dividing the experimental field into as many rows as the number of levels of one factor A and into as many columns as the number of levels of second factor B. Then the two factors will be applied at random to the rows and columns. Such a layout is known as strip plot design.

Restriction enzymes cut only at specific sequences of 4 to 8 bases

A long restriction site is rare. Cutting rare sites will produce a few large pieces of DNA.

Restriction enzymes with long sites → small number of large fragments

Restriction enzymes with short sites → large number of small fragments

The amount of variation is measured and expressed as the variance. When values are expressed as deviations from the population mean the variance is simple the mean of the squared values. For example, the genotypic variance is the variance of genotypic values and the environmental variance is the variance of environmental deviations. The total variance is the phenotypic variance of the variance of phenotypic values, and is the sum of the separate components.
Components of Variance
The components of variance and the values whose variance they measure are listed as follows:
The total variance is the phenotypic variance, or the variance of phenotypic values, and is the sum of the separate components. Thus
But if genotypic values and environmental deviations are correlated, VP will be increased by twice the covariance of G with E because if P = G + E, VP = V (G + E) = VG + VE + 2 CovGE. d. The term 2 CovGE is zero when G and E are uncorrelated. Also when there is an interaction between genotypes and environments, there will be an additional component of variance due to the interaction i.e.

The results of Focus Group Discussions and Field Level Workshops (Tables presented at the end of toolkit) conducted with different stakeholders mentioned in the methodology revealed that, communication skills, soft skills, leadership development skills, personal and professional development skills followed by entrepreneurship development skills are more important and needed to perform job effectively at field level extension work (Table 1).

Definition of Animal Breeding
Animal breeding, as the application of science to the genetic improvement of animals, implies a close inter relationship between theory and its application. Genetics has provided the matrix form which logical principles could be developed and tested by experimentation and practice.
During the 20th century, genetics has assumed a broader meaning and numerous subdivisions of the discipline has emerged. Advances in animal breeding also have drawn heavily on contributions from statistics, biochemistry, physiology, economics and other disciplines. Animal breeding and reproductive physiology have been uniquely interwoven.
Animals with superior genotypes cannot contribute to succeeding generations unless their reproductive capacity is maintained at satisfactory levels.
Livestock production is an economic enterprise. Hence, animal breeding recommendations must withstand the scrutiny of economic, as well as genetic considerations, before they are accepted and integrated into enterprises by breeders. As a consequence, a close relationship between the breeder and the science, application and theory has been nurtured.
History of Animal Breeding
• Till 500 A.D. when the fall of Roman Empire began animal breeding was at its esteem. Withthe fall of Roman Empire for about 1000 years called Dark and Middle Ages, animal husbandry was at a still.
• From 1700 A.D., again there was an improvement. The beginning of modern animal breeding is to be found mainly in England and Europe.
• The British Royalty encouraged horse breeding especially for race horses. The Earls and Dukes imported bulls from Holland and bred their native stocks. Dutch cattle were introduced into Hereford shire that laid the foundation of the present Hereford cattle. By crossing the native and Dutch cattle and subsequent inbreeding, the British cattle were improved far beyond the best.

Weaning to 210 days: Weight in kg of feed consumed for producing one kg of live weight for the period from weaning to 210 days of age.
10 Mortality percentages (as percentage)
Pre-weaning mortality: No. of piglets died during the period birth to weaning (28/56 days) the number of piglets born alive.
Post weaning mortality: Number of piglets died during the period from 28/56th to 365 day to the total number of piglets available at weaning.
Adult mortality: Number of adult pigs died to the number started at one year (in percentage).
List of registers to be maintained:
• Birth register
• Youngstock register
• Adult stock register
• Disposal register
• Mortality register
• Weighment register
• Farrowing and growth record
• Service register
• Boar performance register
• Sow performance register
• Veterinary register
• Feed efficiency register
• Account register

Natural Selection
In nature, the main force responsible for selection is of interest because of its apparent effectiveness and because of principles involved. Some of the most interesting cases of natural selection are those involving man himself. All races of man that now exist belong to the same species, because the races are interfile or have been in all instances where mating have been made between them. All races of man now in existence had a common origin and at one time probably all man had the some kind of skim pigmentation – which kind we have no sure way of knowing. As the number of generations of man increased, mutations occurred in the genes affecting pigmentation of the skin causing genetic variations in this trait over a range from light to dark or black.
Natural selection is a very complicated process and many factors determine the proportion of individuals that will reproduce. Among these factors are differences in mortality of the individuals in the population especially early in life, differences in the duration of the period of sexual activity and in the degree of sexual activity itself and the differences in the degree of fertility of individuals in the population. They are also examples of adaptive evolution.

Principle

The rate of joining of DNA fragments is affected by seven parameters:

DNA concentration,

Concentration of compatible ends,

Size of the fragments,

Presence or absence of complementary, single-stranded ends (some nucleases form blunt ends and in these cases special techniques are needed for joining),

G + C content and length of the complementary single strands,

Temperature of the reaction and

Ionic composition of the solution.

Steps for Cloning

Prepare DNA.

Select restriction enzymes for your insert and vector, and determine the appropriate reaction buffers.

Combine the following in a microfuge tube (30 µL total volume):
2 µg DNA
1 µL Each Restriction Enzyme
3 µL 10x Buffer
3 µL 10x BSA
x µL H₂O (to bring total volume to 30 µL)

Tandem Selection
Selection is practiced for one trait at a time until satisfactory improvement has been achieved in this trait. Then, selection efforts for this trait are relaxed and efforts are directed towards the improvement of a second, then for a third and so on, until finally each trait has been improved to the desired level. This method is the least efficient of all the three methods, from the stand point of the amount of genetic progress made for the time and effort by the breeder. Efficiency of tandem selection depends a great deal upon the genetic correlation between the traits selected for. If the genetic correlation is positive and desirable, improvement in one trait by selection would automatically result in improvement in the other trait not selected for, and then the method could be quite efficient. Otherwise, if there were little or no genetic correlation between the traits, which means that they are inherited independently, the efficiency would be less. When the two traits are negatively correlated, improvement in one trait is nullified or neutralized by the regression in the other. For example, in poultry, selection for egg number will result in reduction in egg weight, as they are negatively correlated.
Independent Culling Level (ICL) Method
Method of selecting two or more traits but they both need to meet a minimum standard. It is very strict that if the animal didn’t meet one trait it would be rejected. Independent Culling level (ICL) Method selects several characteristics or traits simultaneously.
Breeders set minimum or maximum culling levels or standards or criteria for each trait of selection objectives. Any animal not meeting all criteria is not selected for use in the breeding program regardless of the level of excellence of other traits. With each successive generation of progeny, the minimum quality of each characteristic is raised thus ensuring improvement of these traits. For example, a breeder has a view of the minimum requirements for milk yield, fat yield, and service period for which cows are breeding. The breeder will determine what the minimum acceptable quality for each of these traits will be for progeny to be folded back into her breeding program. Any animal that fails to meet the quality threshold for any one of these criteria is culled from the breeding program. Thereby, it causes the loss of excellent genes from the population for a particular trait.