eChapters

When Gene Expression Appears to Alter Mendelian Ratios Lethal Allele Combinations

Us recessive lethal alleles eliminaters a progeny class. Multiple Alleles

A gene can have more than two alleles, but a diploid individual only has one or two of them.

Different allele combinations can produce different phenotypes and different severities of symptoms.

Different Dominance Relationships

Incomplete dominance of an allele produces a phenotype in the heterozygote that is intermediate between that of either homozygote.

Codominant alleles are both expressed in a heterozygote. Epistasis-When One Gene Affects Expression of Another

In epistasis, one gene masks the effect of another. An example of epistasis in humans is the Bombay phenotype.

The Bombay phenotype results in O type blood for individuals homozygous recessive for the recessive “h” allele.

This group includes a large number of bony fishes in which the primary upper and lower jaws are supplemented by the addition of membrane bones which forms secondary jaws. Hence they are called as teleostomi or perfect mouthed fishes.

All major groups of fresh water fishes lived successfully and flourished during the Devonian period which is also called as the “Age of fishes”. Teleostomii are characterized by a unique mechanism of opening the mouth by lowering the mandible through hyoid apparatus, therefore the skull is hyostylic or the amphistylic. Presence of an ossified operculum, an interhyal bone and the branchiostegal rays are the diagnostic features of this group.

Introduction

On the basis of inputs based ecological principles, the all possible and available resources are allocated to achieve maximum outputs. One of the most promising paradigms of external inputs based agriculture that have emerged for the benefit of small scale resource-poor farmers and that is termed as low external input and sustainable agriculture (LEISA), which can enable such farmers to achieve higher income and attain sustainability by: (i) Optimizing the use of locally available resources, thereby achieving a synergetic effect amongst the various components of the farming system (soil, water, animals, plants, etc.) so that they complement each other in the production of output; and (ii) Minimizing the use of external inputs, except where there is a serious deficiency and where the effect on the system will be to increase recycling of nutrients.

Low External Inputs and Sustainable Agriculture (LEISA): Low external input sustainable agriculture (LEISA) is a way of thinking about farming. It incorporates some ideas found in what people have labelled eco-logical, organic, regenerative, biological, or simply alternative agriculture. Amongst the goals that now drive the interest in low-input sustainable agriculture, two stand out: profitable and productive farming, and protection of resources and environmental quality. Companion objectives include ensuring safe and nutritious food supplies and reducing health risks to farm workers. LEISA involves farmers substituting management, scientific information, and on-farm resources for some of the purchased inputs they currently depend on maintain production sustainability. Sustainability has been defined, for the purpose of including resource-poor as well as resource-rich farmers, as managing agricultural productivity while maintaining or improving the resource base. This means that agriculture must be environmentally solid, economically feasible, socially scrupulous, and flexible (for future needs).

8.1 Life Cycle
As in the case of a typical Lepidopteran insect, the silkworm passes through four distinct stages, i.e., egg, larva, pupa and adult during its life cycle, the duration of which may last for six to eight weeks depending upon racial characteristics and climatic conditions. Multivoltine races found in tropical areas have the shortest life cycle with the egg, larval, pupal and adult stages lasting for 9-12 days, 20-24 days, 10-12 days and 3-6 days respectively. (Fig.8.1)
In uni/bivoltine races, the egg period of the activated egg may last for 11-14 days, the larval period 24-28 days, the pupal period 12-15 days and the adult stage 6-10 days. In nature the univoltine races produce only one generation during the spring, and the second generation egg goes through a period of rest or hibernation till the next spring. In the case of the bivoltine races, however, the second generation egg does not hibernate and hatches within 11-12 days and produces the second generation normally during summer. But it is the third generation egg which undergoes hibernation and hatches only the next spring, thus producing only two generations in a year (bivoltine). In multivoltine races, the life cycle is the shortest because of the warmer ecological conditions where they are reared, and so they may yield as many as seven to eight generations in a year in tropical sericultural areas such as India, Thailand, etc. Silkworm rearing is, therefore, continuous in tropical areas whereas in sub-tropical and temperate zones it is mostly seasonal lasting from spring to early autumn.

Ducks are prone to several external parasites and are also affected by external parasites found in other poultry birds. Birds are plagued by an remarkable range of ectoparasites, ranging from feather-feeding lice, to feather degrading bacteria and many of these ectoparasites have severe harmful effects on host health. External parasites can make ducks very uncomfortable, transmits several diseases and can be fatal in untreated cases. Among the ectoparasites lice is most commonly found in ducks. Ectoparasites infested birds become restless and the feeding and sleeping is disturbed resulting in decreased growth rate and egg production.

Common ectoparasites present on ducks-

In previous section we discussed about the ability of the research design to precisely detect the relationship between cause and effect under controlled conditions. But in social research it becomes difficult to conduct the research under highly controlled conditions and moreover many of the researches in social science aim at prediction rather than understanding.

As we discussed earlier, aim of science is development theory, understanding, prediction and explanation of natural phenomenon. In many of the cases we are more interested in predicting the occurrence of social phenomenon rather than explaining it or understanding its relationship with other phenomenon. Under such conditions internal validity is of less use because a relationship that is established in artificially controlled conditions (with high internal validity) may fail to express itself in natural setup due to effect of extraneous variables. When the relationship between cause and effect is weak enough to be expressed in natural setup then it is of less use in predicting the phenomenon. Under such conditions we require experiments that are conducted in nearly natural setup, so that we can generalize the findings of the research to the wider domain.

Introduction

Milk, which is recognized for its significant nutritional and immunological value to humans as well as animals, is the primary source of vital nutrients and bioactive components that contribute to the newborn’s growth and development. In addition, it includes extracellular vesicles (EVs). EVs are membrane-bound vesicles that are discharged by cells into biofluids like milk. EVs play an important function in intercellular communication and have demonstrated potential in therapeutic applications. This is extremely important since EVs are abundant in milk and carry a wide range of cargo, including proteins, lipids, and nucleic acids, that supports to their classification as bioactive components of milk Milk-derived exosomes have intriguing properties as nanocarriers for theranostic care.

Essential oil is a concentrated hydrophobic oily fragrance liquid extracted from plants, containing easily evapourated chemical compounds at room temperature. Essential oils are extracted from the different plant parts including the flowers, leaves, stem, bark, and roots, and they are extracted from different techniques. The most preferable method of extraction is hydro distillation which is easy to use and cheap. Essential oils are used in every field of life, used in aromatherapy, and act as antifungal, antioxidant, anxiety, pain relievers, and depression.

Introduction
1.1. Definition and Significance of Natural Products
Natural products are chemical compounds or substances derived from living organisms in nature. These diverse sources, including plants, animals, fungi, and microorganisms, produce a wide range of chemical structures and functions. The significance of natural products lies in their diverse biological activities and potential applications in therapeutics, agriculture, and various industries. Natural products have been used for centuries in traditional medicine and continue to serve as the foundation for many modern pharmaceuticals, providing templates for the development of synthetic analogues and novel drugs. Their complexity and unique structural features often translate into high biological activity, making them valuable in the discovery of new therapeutic agents. Furthermore, natural products are generally perceived as safer and more environmentally friendly compared to synthetic chemicals, contributing to their appeal in numerous applications.
1.2. Historical Perspective on the Use of Natural Products
The use of natural substances has a long history, with evidence of their application in ancient civilizations such as Egypt, China, India, and Greece. Traditional medical systems, including Ayurveda, Traditional Chinese Medicine, and Indigenous practices, have utilized plants, animals, and minerals to treat various ailments. These early practices laid the foundation for the systematic investigation of natural products and their medicinal potential. One of the earliest documented uses of natural products in medicine is the Ebers Papyrus, an ancient Egyptian text from around 1550 BCE (Packard, 1931). Similarly, ancient Indian texts, such as the Charaka Samhita and the Sushruta Samhita, describe the use of plant-based medicines in Ayurvedic tradition. The scientific investigation of natural products gained momentum in the 19th century, with the isolation of pure compounds, including morphine, quinine, and penicillin.
1.3. Current Trends and Applications
Natural products are invaluable in various industries, serving as a rich source of bioactive compounds for drug development, sustainable agriculture, and functional food products. Many modern medicines, such as the anticancer drug paclitaxel and the antimalarial artemisinin, are derived from natural sources. These naturally-derived compounds often possess unique structures and mechanisms of action that are difficult to replicate synthetically.

Phenolic compounds constitute a major class of plant secondary metabolites that are widely distributed in the Plant Kingdom. Plant phenolics are biosynthesized through the shikimate/phenylpropanoid pathway leading to different compound classes. They may occur in their natural sources in free forms, as glycosylated or acylated derivatives, and as oligomeric and polymerized structures, such as hydrolyzable and condensed tannins, phlorotannins or lignins. They may also be found linked to plant matrix components such as cell walls, carbohydrates or proteins. It should be indicated that although the terms “plant phenolics” and “polyphenols” are indistinguishably used by some authors, they are not synonymous.

Materials Required

Fruit, pulper, fruit mill, hydraulic press, screw type juice extractor, stainless steel pans, chemical preservatives, glass bottles, closures, crown corks, crown corking machine, plastic barrels.

Procedure

    1.    Select and weigh sound fruits/vegetables for extraction of juice/pulp.    
    2.    Wash and peel the fruits as required.
    3.    Extract the juice by hot or cold process.
    4.    Pasteurize the juice/pulp to inactivate the enzymes and partially kill microorganisms.
    5.    Preserve the juice/pulp by heat processing after hot filling and hermetic sealing or by addition of permissible quantities of suitable preservatives.
    6.    Label the bottles properly and keep them for storage

The decision whether to extract the seed from the fruit at a central seed processing depot or close to the site of, and soon after, collection must be made in the light of local conditions. The reduction in bulk and weight of the collected material greatly facilitates transport and for this reason the extraction of the seed from relatively bulky fruits may be desirable at the site close to the collection area. In some cases it has also been found that early extraction of the seed is essential to maintain maximum viability. The use of the sun drying to speed extraction of the seed is common for many conifers and trees with woody dehiscent fruits. However, too rapid drying of fruits may sometimes cause them to remain closed and prevent later extraction, a condition known as “case-hardening” of cones. This is true for the cones of some pines if they are collected before peak maturity. In such cases it is necessary to keep the fruits under cover, with a good circulation of air, for one or two weeks before more rapid drying is attempted.

The quality of essential oils is very complex. An individual oil may have hundreds of ingredients, the principle components being a group of complex substances known as terpenes and their compounds or derivatives. Due to this reason a single essence has a wide range of therapeutic actions.
The chemical constituents of plants are of two kinds: products of primary metabolism and products of secondary metabolism. The first are mainly carbohydrates, amino acids and fixed oils produced by light-absorbing (photosynthetic) processes. The latter group of chemicals arises from the primary metabolites. They include glycosides, terpenoids, alkaloid and essential oils. Essential oils lack the water soluble constituents such as tannins,
bitter compounds sugar, mucilages and pectins, playing important role in the medical action of the plant.
The essential oils have been credited with possessing almost all therapeutic properties in a concentrated form. The therapeutic properties of the whole oil are that result of synergism: an interaction of all its chemical constituents working harmoniously together so that the whole essential oil becomes more potent than the sum of its individual parts.
The essential oil lacks certain chemical compounds found in the raw plant material. It is still a highly complex substance, that it cannot be replicated in the laboratory. Even though high-tech processes such as gas liquid chromatography (GLC) can separate out main constituents of essential oils. By looking at the chromatogram, it is impossible to isolate the numerous trace elements including number of unidentified compounds which make up
the whole.

Essential, volatile or ethereal oils are mixtures composed of volatile liquid and solid compounds which vary widely in regard to their composition and boiling points. Plants owe their fragrance to presence of traces of essential oils in different parts. Numerous fragrance materials are present in roots, stems, barks, leaves, flowers, fruits and heartwoods.     
Several processes like distillation, enfleurage, maceration, expression, solvent extraction and fluid extraction are available for extraction of aroma principles. Application of these processes, either singly or in combination depends upon nature of material and essential oil or absolute intended to be recovered.

There are many different methods of extracting DNA bands from an agarose gel. Which one you choose will probably depend on the consumables you have available in your lab. Another important consideration is the yield/ purity of the DNA after extraction. Agarose contains various impurities which may inhibit downstream reactions if not efficiently removed from the DNA. We used to give the generic term ‘hoonose’ to the unspecified carbohydrates that co-purified along with the DNA and inhibited enzyme reactions. Modern spin-column kits are very good at removing impurities, old-fashioned ‘kitchen sink’ methods are less good.

Cutting Out the DNA Band

Most of the methods require you to cut out the band. You must visualise the band, in an ethidium bromide stained gel, in a dark-room on a UV light- box (a trans-illuminator). UV is dangerous, wear gloves, long-sleeves and face protection. Never look at UV with unprotected eyes. If possible, set the trans-illuminator to long-wavelegth UV (or low-power) and minimise the amount of time the DNA is exposed. This is because the UV mutagenises the DNA at a measurable rate. Use a scalpel blade to cut around the band of interest. Switch off the transilluminator, switch on the white light and carefully remove the band from the gel and place it on the glass. It is good to trim off as much empty agarose as possible so go back to UV illumination briefly to do this. Place the excised band in a 1.5mL microfuge tube.

DNA can be easily isolated and purified after size selection on an agarose gel. The fragment of interest is simply cut out of the gel with a razor blade and purified by a number of different methods.The easiest is to use a method that involves first dissolving the agarose slice in a solution at 50°C, then binding the DNA from the melted agarose to a silica-gel membrane.

Principle

In this method following gel electrophoresis using low gelling/ melting temperature agarose, the band of interest is removed from the gel. The agarose slice is then melted and subjected to phenol extraction.

here are many methods for extracting DNA from gel apart from using commercial kits, some methods however yield cleaner DNA than others.

1. Freeze squeeze

Excise band and place pieces of it in a home-made spin-column (a piece of filter placed in a PCR 0.5ml eppendorf, pierced the bottom of the PCR tube with a needle). Place the PCR tube at -20 °C for 15-20 mins or freeze in liquid N2. Then place the PCR tube into the 1.5 ml eppendorf and spin at top speed in a microfuge for 15 mins, collect DNA solution which can be EtOH ppt or use directly.

2. Powdered silica

Melt excised bands at 70°C cool and add equal volume of TE-buffered phenol and mix. Spin for 5 min, remove aqueous phase, repeat and EtOh ppt. the DNA.

3. Electroelution

Deoxyribonucleic acid (DNA) carries the genetic instruction for the biological development and functioning of all cellular forms of life. It is the blue print which contains the instructions to construct other cell components. Molecular biology experiments often require isolation of DNA for a variety of purposes like construction of DNA libraries, gene cloning, PCR and other marker technology, etc. The extraction of DNA from actively growing tissue is relatively easier yielding higher quantities of DNA.

Principle

The cell wall is ruptured and the proteins associated with DNA are removed by detergent like SDS or by interaction with phenol. Lipids are extracted with alcohol and DNA is precipitated by isopropanol.

Materials Required

Maize seed samples, Liquid nitrogen, CTAB (Cetyl trimethyl ammonium bromide), Chloroform, isoamyl alcohol, Sodium chloride, Glacial acetic acid, Isopropyl alcohol and 70% ice cold ethanol, TE buffer (5X) (24.2 g of Tris base, 5.71 ml of galcial acetic acid, 10 ml of 0.5M EDTA (pH 8.0) , dissolved in 1000 ml of distilled water). Prepare 1X TE as per the requirement.

Introduction 
The increasing prices of fast-depleting fossil fuels and their environmental impact have driven the quest for alternative fuels for diesel engines. Because of their higher biomass yield, faster growth rates, and superior photosynthetic efficiency when compared to other energy crops like soybean and rapeseed, microalgae are considered as promising candidates for biofuel production (Mubarak et al., 2015). Numerous species of microalgae have been found to have high lipid contents, making them attractive cell platforms for the synthesis of lipids. Their significance as a backup source of bioenergy in the future is indicated by the ease with which their lipids can be transformed into biodiesel (Ren et al., 2021). Tiny photosynthetic organisms known as microalgae are the ancestors of eukaryotic plants on Earth. These organisms range in size from one to hundred microns and are either unicellular or multicellular (Udayan et al., 2022). Due to the genetic and biochemical diversity of their lineages, algae are able to synthesize a wide range of metabolites, including lipids (Manning, 2022). Glycerolipids are the most prevalent and well-known lipid class in microalgae. Glycerolipids are categorized into two classes based on their functions: storage lipids and structural lipids. Membrane lipids, a type of structural lipid, play a crucial role in forming cell and organelle membranes. They typically consist of two fatty acid groups attached to a glycerol backbone, along with a polar group bound to the glycerol structure (Morales et al., 2021). In contrast, polar lipids have a higher oxygen content and possess charged side groups, enabling them to moderately interact with water. Examples include phospholipids and glycolipids (Manning, 2022). Microalgal lipid metabolism predominantly relies on the de novo fatty acid biosynthesis pathway and the triacylglycerol (TAG) synthesis route (Zhu et al., 2022). Therefore, accurately estimating the composition of the lipid fraction is crucial for determining its potential applications, whether as a raw material for biofuel production or for nutraceutical and/or food purposes (Viegas et al., 2020). The production of biodiesel from microalgae presents a novel approach to generating renewable and sustainable energy. Additionally, different techniques, including lipid extraction and transesterification, are utilized to transform lipid-rich microalgae biomass into biodiesel (Gaurav et al., 2024). Microalgae possess thick-walled cell structures, which restrict the release of their bioactive compounds due to the rigidity of the microalgal matrix. Consequently, selecting suitable pre-treatment and extraction methods is essential for effectively obtaining lipids from microalgae while preserving their bioactivity. Traditional methods for lipid extraction, such as Soxhlet extraction, Folch extraction, and Bligh-Dyer extraction, have been used for a considerable time. While these techniques are generally easy to use and cost-effective, which encourages their adoption, they also have drawbacks, including high consumption of organic solvents, environmental pollution, and extended extraction times that can last several hours. Thus, it is essential to investigate suitable techniques that enhance the extraction rate and lower costs while ensuring the bioactive properties of lipids, enabling better industrial applications of microalgae (Zhou et al., 2022). In recent years, the use of nanotechnology and nanoparticles has emerged as a novel approach for extracting valuable metabolites or bioproducts from microalgae. Nanoparticles (NPs) are materials engineered with at least one dimension measuring less than 100 nanometers (nm). Due to their small size and large surface

EXPERIMENT

TECHNOLOGY FOR EXTRACTION OF KERNEL OIL FROM STONE FRUITS

Apricot, peach, plum, cherries, nectarines etc are the important stone fruits belonging to the family Rosaceae. These fruits are known to contain stones/pits i.e., apricot (6.0-11.5%), peach (7.5-11.5%), plum (4.5-7.0%) and these stones are reported to contain kernels (%) apricot (28.0-32.0%), peach (5.7-5.9%), plum (10.0-20.8%), almond (28.0-30.0%). These kernels can yield an oil yield of (42.5-45.5%), (38.5-41.5%), (39.2-40.6%) and (52.0-58.9%), respectively. Thus, these stone fruit kernels can be utilized for extraction of kernel oil by using the improved technology developed for extraction of oil. The developed technology consists of mechanical decortication of stones by the use of mechanical decorticator, kernel separation by using specific gravity separation technique, oil extraction by using table oil expeller and oil filtration through oil filter press followed by packing in PET bottles and PE pouches.

Mechanical decorticator: The mechanical decorticator is a type of roller crusher consisting of two rollers moving in inward opposite directions with the help of 3 HP motor and is provided with a hopper and feeder assembly. The clearance between two rollers is adjusted according to the respective size of stones.

Table oil expeller: Oil expeller is a 24 patti screw type oil expeller driven by 7HP motor, in which the kernels are fed into the moving hopper at pre-determined flow rate, which are pressed in between rollers (worm) and side walls of the expeller. The kernels are then, passed through the expeller 3-4 times until a thin slice of press cake is obtained.