Animal Biology - Theses

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    Toxic effects of allethrin on the male reproductive system
    (University of Hyderabad, 2014) Madhu Babu, Golla ; Suresh, Y
    Over the past decades, there has been an increased concern about the impact of environmental contaminants like pesticides on human reproductive system. These pesticides are used for both agricultural and non-agricultural purposes throughout the world. Synthetic pyrethroids persist in the environment and can enter into the geological cycle which can influence reproductive health. Allethrin, the first synthetic pyrethroid, which knock down insects has neurological effects and no reports are available about the impact on male reproductive system. In the present study, we studied the toxic effects of allethrin on male reproductive system using rat as a model system. We identified the molecular mechanism of allethrin cytotoxicity in rat Leydig cell carcinoma cells (LC540). Allethrin shows cytotoxicity in a concentration dependent manner. It increases lipid peroxidation and alters antioxidant enzyme status. Morphological analyses of LC540 cells treated with allethrin revealed the presence of apoptotic bodies. Using flow cytometry, we observed that the number of cells that displayed early apoptotic features and entering into G0 phase of cell cycle increased significantly with loss of mitochondrial membrane potential. The levels of p53 mRNA and cleaved PARP-1 protein were increased, whereas BCL-2, pro-Caspase-3 and PARP- 1 were decreased. Allethrin induced apoptosis was associated with voltage gated calcium channel mediated intracellular calcium release. Besides cytotoxicity, the reduced expression of spermatogenic factors namely Tgf-β1 and Scf suggests the potential of allethrin to affect spermatogenesis
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    Hexamerins expression during larval development of corcyra cephalonica \b regulation by ecdysteroids
    (University of Hyderabad, 2014) Venkata Rao, Vantaku ; Aparna Dutta Gupta
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    Molecular characterization of a diurnal rodent funambulus palmarum ( south indian palm squirrel ) : Cloning and characterization of period 2 from the suprachiasmatic nucleus
    (University of Hyderabad, 2016-07) Varsha S. Prasad ; Anita Jagota
    Biological clocks are time keeping mechanisms that evolved in organisms allowing them to adapt and anticipate the various geophysical variations in their external habitat. The day-night cycle caused by Earth’s rotation on its axis has been the primary selective pressure to impose a rhythmic pattern to physiological and behavioral activities that nearly reflect the length of a day on earth. Such oscillations with a near (circa) 24h periodicity termed as circadian rhythms allows species- specific partitioning of specific activities across different parts of a diel (day) cycle conferring survival advantage to the bearer. Though light act as the major ‘Zeitgeber’ or ‘time giver’ to synchronize or ‘entrain’ the phase of these rhythms to that of the zeitgeber time (ZT), they also persists independent of any photic variable and therefore constitutes the hands of the clock which dictates the ‘circadian or endogenous time’ (CT) of any living entity. The internal ‘period’ varies across individuals of the same species but it is relatively consistent over a range of temperatures (temperature compensation). Apart from circadian rhythms cycles having shorter or longer intrinsic periods are also biologically significant. Ultradian rhythms, have periodicity of less than 20h whereas infradian rhythms are longer than 28h, they can be measured in weeks, months, years (circannual), and longer
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