The Drosophila ananassae species complex: Evolutionary relationships among different members

Information about genetic structure and historical demography of natural populations is central to understanding how natural selection changes genomes. Drosophila ananassae is a widespread species occurring in geographically isolated or partially isolated populations and provides a unique opportunity to investigate population structure and molecular variation. D. ananassae and its closely related species serve as a widely used model in population and evolutionary genetics. The ananassae subgroup belongs to the melanogaster species group. This subgroup contains 22 described species distributed mainly throughout Southeast Asia, with some species expanding into northeastern Australia, South Pacific and Indian subcontinent and Africa. Within the ananassae subgroup, three species complexes-ananassae, bipectinata and ercepeae have been recognized based on male genital morphology. D. ananassae and its relatives have many advantages as a model of genetic differentiation and speciation. In this review, distribution, phylogenies, hybridization, sexual isolation among D. ananassae complex have been discussed. The complex of several cryptic island species provides a useful model for evolutionary studies dealing with the mechanisms of speciation

Role of Citrus Concentrate in Extraction and Evaluation of Herbal Polymer

Background: The use of natural polymers as excipients in the pharmaceutical sector is expanding day by day. Low cost, safety issues, availability, and biodegradability are the main causes that make them differ from other sources. Natural sources have a wide range of varieties and characteristics. So, they can be used numerous times in pharmaceutical products as excipients to serve the desired purposes.  Aim:  To extract and evaluate the natural polymeric substances that can be used as excipients in pharmaceuticals from fenugreek seeds by using solvent extraction method. Methods: Trigonella foenum-graceum fenugreek mucilage is drive from the endosperm of the seeds it consists of galactose and mannose of it gives high viscosity in aqueous solution the fenugreek seeds used for thickening, stabilizing and emulsifying food agent. In this procedure we use grapefruit juice to treat with extract mucilage from fenugreek seeds which enhance its stability and bioavailability. Grapefruit juice increases the bioavailability of some orally administered drugs that are metabolized by CYP3A4 and normally undergo extensive presystemic extraction. Results: In addition, grapefruit juice it can decrease the oral absorption of a few drugs that rely on organic anion transporting polypeptide in the gastrointestinal tract for their uptake. The number of drugs shown to interact with grapefruit juice in vitro is far greater than the number of clinically relevant grapefruit juice drug interactions

Genetics of sexual behaviour in <i>Drosophila</i>

575-595The analysis of genetics of behaviour within and between species provides important clues about the forces shaping the evolution of behavioural genes. In Drosophila, a number of key processes such as emergence from the pupal case, locomotor activity, feeding, olfaction and aspects of mating behaviour are under circadian regulation. Genes controlling sexual behaviour are likely to control species specific differences in courtship that are involved in reproductive isolation of closely related species. Courtship in Drosophila is characterized by a series of stereotyped behaviours that lead to copulation and more than 30 genes have been identified through mutations that affect one or more of these elements. Although curiosity about behavioural differences between the sexes undoubtedly predates recorded history, little efforts have been made to uncover the molecular basis of male and female courtship. The brain and nervous system functions that underlie sex-specific behaviour are of obvious importance to all animals including humans. To understand behaviour related to sex it is important to distinguish those aspects that are controlled genetically. The isolation and analysis of Drosophila mutants with altered sexual orientation lead to the identification of novel branches in the sex-determination cascade, which govern the sexually dimorphic development of the nervous system

Experimental evidence for nutrition regulated stress resistance in Drosophila ananassae.

The amount and quality of nutrients consumed by organisms have a strong impact on stress resistance, life-history traits and reproduction. The balance between energy acquisition and expenditure is crucial to the survival and reproductive success of animals. The ability of organisms to adjust their development, physiology or behavior in response to environmental conditions, called phenotypic plasticity, is a defining property of life. One of the most familiar and important examples of phenotypic plasticity is the response of stress tolerance and reproduction to changes in developmental nutrition. Larval nutrition may affect a range of different life-history traits as well as responses to environmental stress in adult.Here we investigate the effect of larval nutrition on desiccation, starvation, chill-coma recovery, heat resistance as well as egg to adult viability, egg production and ovariole number in Drosophila ananassae. We raised larvae on either protein rich diet or carbohydrate rich diet. We found that flies consuming protein rich diet have higher desiccation and heat shock resistance whereas flies developed on carbohydrate rich diet have higher starvation and cold resistance. Egg production was higher in females developed on protein rich diet and we also found trade-off between egg production and Egg to adult viability of the flies. Viability was higher in carbohydrate rich diet. However, sex specific viability was found in different nutritional regimes. Higher Egg production might be due to higher ovariole number in females of protein rich diet.Thus, Drosophila ananassae adapts different stress tolerance and life-history strategies according to the quality of the available diet, which are correlated with phenotypic adjustment at anatomical and physiological levels

Survival curves for chill-coma recovery in males (A) and females (B) derived from either protein (–) or carbohydrate (- - -) enriched medium.

<p>Survival curves for chill-coma recovery in males (A) and females (B) derived from either protein (–) or carbohydrate (- - -) enriched medium.</p

Survival curves for starvation resistance in males (A) and females (B) derived from either protein (–) or carbohydrate (- - -) enriched medium.

<p>Survival curves for starvation resistance in males (A) and females (B) derived from either protein (–) or carbohydrate (- - -) enriched medium.</p

Ovariole number, egg production and egg to adult viability of flies developing on protein rich diet and carbohydrate rich diet. Bar represents Mean ±SE.

<p>Ovariole number, egg production and egg to adult viability of flies developing on protein rich diet and carbohydrate rich diet. Bar represents Mean ±SE.</p

Survival curves for heat – shock in males (A) and females (B) derived from either protein (–) or carbohydrate (- - -) enriched medium.

<p>Survival curves for heat – shock in males (A) and females (B) derived from either protein (–) or carbohydrate (- - -) enriched medium.</p

Survival curves for desiccation resistance in males (A) and females (B) derived from either protein (–) or carbohydrate (- - -) enriched medium.

<p>Survival curves for desiccation resistance in males (A) and females (B) derived from either protein (–) or carbohydrate (- - -) enriched medium.</p