Notification of CSIR JRF NET, Life Science Examination

TMC ACTREC JRF Exam Notification 2016 for Ph.D in Life Sciences


TMC ACTREC JRF for Ph.D in Life Sciences, Notification, 2016

Advanced Centre for Treatment, Research and Education in Cancer (ACTREC)

(A Grant-in-Aid Institution of the Department of Atomic Energy, Government of India)

Applications are invited, in the prescribed format, for the award of JUNIOR RESEARCH FELLOWSHIPS (JRF 2016)  for Ph.D. in Life Sciences at Tata Memorial Centre. The Tata Memorial Centre (TMC) is an autonomous Grant-in-aid Institution of the Department of Atomic Energy. The TMC is comprised of the Advanced Centre for Treatment, Research and Education in Cancer (ACTREC) and the Tata Memorial Hospital (TMH). The TMC conducts Ph.D. program in Life Sciences and is affiliated to the Homi Bhabha National Institute (Deemed University).

On-going research at TMC includes basic and translational research in Cancer Biology. Specific research topics include study of cell proliferation, differentiation, apoptosis, metastasis, tumor immunology, molecular imaging, carcinogenesis, stem cell biology, biophysics, structural biology, bioinformatics, proteomics, genomics, genetics, epigenetics.

Qualifications: M.Sc. (Applied Biology / Biochemistry / Bioinformatics / Biophysics / Biotechnology / Botany / Life Sciences / Microbiology/ Molecular Biology / Zoology or related Biological Sciences) / M.Tech. (Bioinformatics/ Biotechnology); M.V.Sc.; M.Pharm. from a recognized University, with ³ 60% aggregate marks. Those awaiting results may also apply. Candidates having done post-graduation course of only 1 year duration are not eligible.

Stipend: Rs. 25000/-+ 30% HRA (if hostel facility is not allotted) per month as applicable. Limited hostel facility is available on the ACTREC campus on first come, first served basis.

Continue reading

Genetics Online Tutorials and Lectures

Sex Determination in Melandrium album (Silene latifolia)

Sex determination in Silene latifolia

The XX -XY Sex Chromosomal Mechanism of Sex Determination in Plants

Majority of the flowering plants are monoecious with male and female reproductive parts are borne on the same flowers or different flowers of same plant. Only about 6% of Angiosperms are dioecious (male and female flowers on separate plants).  The studies of sex determination mechanisms in plants were done only in very few species, such as Coccinia, Asparagus and Melandrium. Melandrium album or Silene latifolia (synonym) is a dioecious model plant in genetics belongs to the Family Caryophyllaceae. The diploid chromosome number of Melandrium album is 24 (n = 12). This post describes the genetic mechanism of sex determination in Melandrium album or Silene latifolia.

Melandrium album shows sex chromosomal sex determination. They have X and Y sex chromosomal constitution similar to Drosophila and Human. However, the mechanism of sex determination is quite different from the usual XX – XY system. In Melandrium album, the AAXX individuals will be females and AAXY individuals will be males. The Y chromosome plays a crucial role in the sex determination of Melandrium album. The Y chromosome contains male determining genes and female suppressing genes, both are necessary for the development and maturation of fertile anthers in the male plants. Since the female individuals are homogametic, (produce only one type of gametes – XX constitution) the segregation of X and Y chromosomes occurs only in the male individuals during meiosis.

Usually plants with AAXY chromosomal constitution are males. Sometimes AAXY individuals will be hermaphrodite (bisexual) or androhermaphrodites (forming both bisexual and male flowers on the same individuals). The formation of bisexual individuals in AAXY individuals may be due to the mutation or deletion of the female suppressing genes on the Y chromosome or due to the change in DNA methylation pattern.

Mechanism of sex determination in Melandrium album:

Continue reading

Genetics Online Tutorials and Lectures

Genic Balance Theory of Sex Determination in Drosophila melanogaster

Sex determination mechanism


What is sex determination?

Living organisms, with a very few exceptions, are differentiated into male and female individuals based on their morphological, physiological and behavioral characteristics. Even though the mechanism greatly varies, the sexes of the individuals are genetically determined. The biological system that determines the development of sexual characteristics in an organism is called sex-determination. There are two different types of sex determination systems, they are:

(1). Chromosomal sex determination

(2). Non–genetic sex determination

In chromosomal sex determination, the individuals will process specialized chromosomes called sex chromosomes. In this case, the presence or absence of a particular sex chromosome or the relative ratio of these sex chromosomes determines the sex of the individuals.

Similar to human beings, Drosophila melanogaster (fruit flies) shows XX female and XY male sex chromosomal constitution. However, the mechanism of sex determination is quite different in Drosophila from human. In humans, the Y chromosome is the actual sex determining chromosome. Invariable to the number of X chromosomes, the presence of a single Y chromosome initiates the development of male sex in human embryos. Thus, in human XX and XY individuals will be always female and male respectively. In human XXY and XXXY individuals are also males because of the presence of Y chromosome.

What is Genic Balance System of Sex Determination?

Continue reading

Lecture notes in Microbiology

Difference Between Gram Positive and Gram Negative Bacteria

Gram positive and gram negative staining

Gram Positive Bacteria Vs Gram Negative Bacteria
(Similarities and Differences Between Gram Positive and Gram Negative Bacteria)

What is Grams staining?

Christian Gram, a Danish Physician in 1884 developed a staining technique to distinguish two types of bacteria. The two categories of bacteria based on gram staining are Gram positive bacteria and Gram negative bacteria. Bacteria are first stained with crystal violet or gentian violet. All bacterial cells will stain blue or purple colour with crystal violet solution. Then the bacterial cells are treated with iodine solution (Lugol’s iodine) solution and washed with alcohol (de-staining solution).  Those bacteria which retain the blue or purple colour of crystal violet are called Gram positive bacteria and those bacteria which loose the colour of crystal violet after washing with de-staining solution is called Gram Negative bacteria. Gram negative bacteria are later stained with safranin or fuchsin for observation under microscope. Gram negative bacteria after safranin or fuchsin staining will appear red or pink colour. Gram staining differentiates bacteria by the chemical and physical properties of their cell walls by detecting the properties of peptidoglycan. Gram staining method is useful in differentiating majority of bacterial species into two broad categories. Even though all bacterial species cannot be differentiated based on gram staining technique, this method has immense application in clinical diagnostics and biological researches.

Similarities between Gram Positive and Gram Negative Bacteria

Ø  Both are bacterial cells

Ø  Both groups are prokaryotic

Ø  Both lack membrane bounded organelles

Ø  Both groups have covalently closed circular DNA as the genetic material

Ø  Both groups contain extra-chromosomal genetic materials (plasmids)

Continue reading

Lecture notes in Microbiology

Difference Between Prokaryotic and Eukaryotic Translation

Prokaryotic and Eukaryotic Translation

Translation is the process of protein synthesis in the cells. It is the second step in genetic expression in which the ribosomes decodes the information present in mRNA to synthesize proteins according the sequence of codons present in them with different amino acids. Translation is a universal process occurs in both prokaryotes and eukaryotes. The fundamental process of translation is same in prokaryotes and eukaryotes. Members of both groups uses information present in mRNA, which is came from the DNA by transcription, to synthesize proteins with ribosome as the machinery. This post summarized the similarities and differences between prokaryotic and eukaryotic translation process in an EASY but in-depth way.

Similarities of prokaryotic and eukaryotic translation:

@. Both groups uses mRNA template

@. In both groups mRNA is synthesized from the genetic molecule, DNA

@. Ribosome is the protein synthesis machinery in both groups

@. All the 20 amino acids are same in both groups

@. All the 61 codons are similar in both groups

Continue reading